Merlins

[JDNSW]

Seeing the other thread wasn't about aeroplane engines, I thought I would start one on them. I have always had an interest in these engines, because my father spent most of the war building them or tooling for them.

Rolls Royce had reluctantly got into the aeroplane engine business in about 1915, and by the end of the first war had in production the Eagle, a V12 producing 360hp from 20l, and was considered at least the equal of anything else comparable. This had separate cylinders, and was replaced by the similar sized Kestrel with a cast cylinder block in 1927, producing 490hp. For the Schneider Trophy races in 1929, they produced the 37l Rolls Royce R engine. This produced 2500hp (on special racing fuel, with an engine life measured in (single digit) hours, after a major effort to get oil consumption down to 50 gallons an hour.

Using their experience with the 'R', the Kestrel was enlarged in 1934 to produce the Merlin 1, which produced 790hp from 27l. This became one of the most successful aeroplane engines of the period. Power continually increased until by 1946 it was producing up to 2030hp, although the most widely used variants produced around 1700hp.

It powered most of Britain's military aircraft in WW2, including Hurricane, Spitfire, Lancaster and Mosquito, as well as the most successful US fighter of WW2, the P51. It was built by Rolls Royce, plus a number of shadow factories in Britain, Packard in the US, and CAC in Sydney.

Technically, it was a V12 with a single overhead camshaft operating four valves per cylinder via rockers. It had a geared centrifugal supercharger and a geared propeller reduction.

Post war it was used in civilian aircraft to some extent (Avro Lancastrian and Canadair GM-54), but was not really successful. A land version called the Meteor was used in tanks in the postwar period, and it was also used in high speed naval motor boats in a marine version built by Packard. Postwar it was use in air racing and boat racing, in some cases producing power way beyond anything the manufacturers dreamed of.

On a personal note, one of my treasured tools is a screwdriver made from a Merlin head bolt that failed QC. It is about two feet long with a cast alloy handle, and has been in use for over sixty years.

John

[Sleepy]

And don't they just sound great:twisted:

YouTube - Low Spitfire Pass

[one_iota]

and what music it makes: :D

YouTube - Merlin engine Sounds

[JDNSW]

and what music it makes: :D


Helped by the open exhaust!

John

[isuzutoo-eh]

As a youngster familiar with movies of but not the reality of WW2, there is no sound that symbolizes World War 2 quite like a Merlin.


Have SWB 2a, want Merlin. Is there a bellhousing to suit? :D :wasntme:

[isuzurover]

As a youngster familiar with movies of but not the reality of WW2, there is no sound that symbolizes World War 2 quite like a Merlin.


Have SWB 2a, want Merlin. Is there a bellhousing to suit? :D :wasntme:

Funny you should mention that - these guys could sell you one:
V16 Merlin powered Land Rover Custom image gallery and details | The Motor Report Auto News Blog (http://www.themotorreport.com.au/5506/german-nutcases-construct-v16-powered-land-rover-based-behemoth/)


Nice writeup JD. I saw a merlin engine (or what was left of it) near the lincoln bomber wreck in SE QLD. An impressive piece of engineering - though as with all British engineering, the electrics were suspect: Do you believe in Gremlins - Stories of 10 Squadron RAAF in Townsville (http://home.st.net.au/~dunn/gremlins.htm)

The merlin also loved overheating in tropical temperatures too apparently.

[Sleepy]

As a youngster familiar with movies of but not the reality of WW2, there is no sound that symbolizes World War 2 quite like a Merlin.


Have SWB 2a, want Merlin. Is there a bellhousing to suit? :D :wasntme:

Yes:twisted::twisted:

http://img.worldcarfans.com/2008/6/medium/9080627.001.1M.jpg


Bell Aurens Longnose, A Land Rover With Over 1,500 HP - Worldcarfans (http://www.worldcarfans.com/9080627.001/bell-aurens-longnose-a-land-rover-with-over-1500-hp)


I don't think your gearbox would last the weekend though:o

[dmdigital]

You beat me to the Bell Aurens reference Sleepy;) That was my first thought after reading John's post.

[isuzurover]

You beat me to the Bell Aurens reference Sleepy;) That was my first thought after reading John's post.

And I beat sleepy to it ;) :p

Pity it would be the biggest POS in the world to drive though with a Merlin, and impossible to register in Australia I am sure.

What were those guys thinking.....

I believe they also plan to use an R380 with their v16...

[Sleepy]

Yes isuzurover was first with the longnose reference.

I think using the R380 will only delay greabox failure by about 2 days. :lol2:

It's a lovely looking thing but probably just built for show.

(And very gentle acceleration!)

[vnx205]

There is a Merlin engine in the Binalong Motor Museum, along with a lot of other interesting machinery.

My recollection is that even on the outside, it looks incredibly complex, a real plumber's nightmare.

How does the power output John mentioned in the OP compare with similar engines 80 years later?

[clean32]

how do you tell the difrence between a RR built Merlin and a Packard built Merlin
























the packard has the oil on the inside

[Bigbjorn]

how do you tell the difrence between a RR built Merlin and a Packard built Merlin
























the packard has the oil on the inside


Aside from that, some Packard built Merlins had fewer studs holding the primary supercharger halves together on twin stage Merlins. I don't know if there is a register of serial numbers anywhere. That would probably be the only way to determine the builder other than those that had the lesser number of studs. Old WWII RAF fitters told me they preferred the Packard built engines for the simple reason that a high quality US tool kit was supplied with every Packard built engine.
They were built by Rolls Royce at Derby and Glasgow, Ford at Manchester in a purpose built plant, Packard & Continental in the USA, and James Kirby in Australia, or by CAC in the James Kirby plant depending how you look at it. Pugh the RR historian says James Kirby. Kirby's own biography also claims credit for manufacture of Merlins in Oz. In 1963 I obtained Merlin special tools from a storeman at James Kirby, paid for in bottles of Resch's. Nev. Morris at Dalby has a running restored Merlin in his shed, twin stage, probably Mk 63, recovered from a WWII crash site on the Darling Downs.

[clean32]

There were quite a few little differences that the yanks introduced to aid the manufacturing lines. The spur drive for the blowers are a bit simpler, less studs as pointed out, coil packs, rings\pistons, Valve size as is the head porting. UNF @ UNC instead of whit worth etc, hence the tool kit. A bit like DC3 and there stupid star lock screws.

as a rule the RRs had a bit more oumph but the yanks had the life.

As a side note, the poms first asked Mr Ford to build there motors, he declined because he thought that England would fall to the Nazis and that he wouldn’t get paid. Besides he was making more from building trucks for the Nazis.
As for the P51 being American, that’s a joke, the US army having been fleeced of most of there aircraft to be sold to the poms had a bit of a bitch up. So when the pomes wanted to purchase more P40s the army said Nope we want them all. so enters north American with there German Jewish engineers who were up until 18 months before were working for Henkel, ( check out Henkel’s companion to the ME109 elliptical wings and all and that 3 years before the spit). The only motor available was the Allison. From that we got the XP51 GROUND ATTACK. it’s fat laminar flow wings ideal to stand up to the low level buffeting required of close in ground support ( taxi rank, a Kiwi idea) ( aussies were back in the pacific around this time).
Any way the abrasive desert environment wasn’t very nice to the fabric of the hurricanes, no more P40s were showing up but XP51 were, problem no parts supplies for the Allison’s, no problem stuff a Merlin in and that was the unofficial birth of the P51. In reality the P51 only claim to fame is it wide undercarriage and its fuel capacity. they are a bit to stable to be a good fighter.

[hoadie72]

There is a Merlin engine in the Binalong Motor Museum, along with a lot of other interesting machinery.

My recollection is that even on the outside, it looks incredibly complex, a real plumber's nightmare.

How does the power output John mentioned in the OP compare with similar engines 80 years later?

I just finished watching a TV series called "A plane is born", which was made in / around 2000 and from memory the Rotax engine they used was around 1.3L and developed about 100hp. That's a 4 cyl horizontally opposed 4 stroke pushrod engine with carbs.

[isuzurover]

It is a shame they stuck with carbs...

Bogged from wikipedia:

Carburettor developments

The Merlin's lack of direct fuel injection meant that both Spitfires and Hurricanes were, unlike the contemporary Bf-109E, unable to nose down into a deep dive. Luftwaffe fighters could therefore 'bunt' into a high-power dive to escape attack, leaving the pursuing aircraft spluttering behind as its fuel was forced by negative 'g' out of the carburettor. RAF fighter pilots soon learned to 'half-roll' their aircraft before diving to pursue their opponents. The use of carburettors was calculated to give a higher specific power output, due to the lower temperature, and hence greater density, of the fuel/air mixture, compared to injected systems. "Miss Shilling's orifice" (invented in March 1941 by Beatrice Shilling, an engineer at the Royal Aircraft Establishment, Farnborough), a holed diaphragm fitted across the float chambers, went some way towards curing the fuel starvation in a dive. Further improvements were introduced throughout the Merlins: 1943 saw the introduction of a Bendix-Stromberg pressure carburettor which injected fuel at 5 psi through a nozzle direct into the supercharger and was fitted to the Merlins 66, 70, 76, 77 and 85. The final development was an SU injection carburettor which injected fuel into the supercharger using a fuel pump driven as a function of crankshaft speed and engine pressures, which was fitted to the 100 series Merlins.[8][14] Production of the Griffon-engined Spitfire Mk. XII had begun the year before.

If Dobbo wasn't banned I'm sure he would have fun with "miss shilling's orifice" ;) :wasntme:

[Bigbjorn]

There were quite a few little differences that the yanks introduced to aid the manufacturing lines. The spur drive for the blowers are a bit simpler, less studs as pointed out, coil packs, rings\pistons, Valve size as is the head porting. UNF @ UNC instead of whit worth etc, hence the tool kit. A bit like DC3 and there stupid star lock screws.

as a rule the RRs had a bit more oumph but the yanks had the life.

As a side note, the poms first asked Mr Ford to build there motors, he declined because he thought that England would fall to the Nazis and that he wouldn’t get paid. Besides he was making more from building trucks for the Nazis.
As for the P51 being American, that’s a joke, the US army having been fleeced of most of there aircraft to be sold to the poms had a bit of a bitch up. So when the pomes wanted to purchase more P40s the army said Nope we want them all. so enters north American with there German Jewish engineers who were up until 18 months before were working for Henkel, ( check out Henkel’s companion to the ME109 elliptical wings and all and that 3 years before the spit). The only motor available was the Allison. From that we got the XP51 GROUND ATTACK. it’s fat laminar flow wings ideal to stand up to the low level buffeting required of close in ground support ( taxi rank, a Kiwi idea) ( aussies were back in the pacific around this time).
Any way the abrasive desert environment wasn’t very nice to the fabric of the hurricanes, no more P40s were showing up but XP51 were, problem no parts supplies for the Allison’s, no problem stuff a Merlin in and that was the unofficial birth of the P51. In reality the P51 only claim to fame is it wide undercarriage and its fuel capacity. they are a bit to stable to be a good fighter.

I can assure you that all Merlins used British threads. Personal experience. It was going to be too much trouble to re-draw thousands of engineering drawings to convert, as well as causing untold confusion and maintenance problems as soon there would have been a mix and match situation in the field requiring duplication of spare parts. I still have taps and dies made in the USA in WWII in British systems supplied to the allies for production and maintenance of aero engines. They used seldom encountered items like 5/32, 7/32, 9/32 BSF left and right hand. Left hand BA, and other monstrosities.

Ford told Rolls-Royce that they could not mass produce the engine using RR's tolerances. "Ha", said RR, "you rough motor car types can't work to our high standards". "No", replied Henry's men, "your tolerances are too wide for mass production. We require identical parts that can be assembled by unskilled labour, not selective assembly by skilled fitters matching parts by micrometers." So the tolerances had to be re-jigged and Ford's Manchester plant built by the British government at a cost of millions went into production.

RR had industrial problems in the Glasgow plant. They wanted women and boys to operate automatic machines like turret lathes etc. owing to a shortage of labour, the men having been conscripted into the forces. The Scottish industrial custom was that machines could only be operated by "time served" men, tradesmen, even if the machines were designed to be operated by process workers. The remaining men were reluctant to surrender hard won conditions. Eventually an agreement was reached that women and boys could operate machines for the duration of hostilities or until such times as tradesmen were available again.

Bendix-Stromberg referred to their fueling apparatus as the "anti-gravity carburettor". It was far and away the pick of fuel devices fitted to the Merlins of whatever mark.

[vnx205]

It never ceases to amaze me (even at my age), that things I had just taken for granted turn out to be much more complicated that I realised.

From isuzurover's info:
Luftwaffe fighters could therefore 'bunt' into a high-power dive to escape attack, leaving the pursuing aircraft spluttering behind as its fuel was forced by negative 'g' out of the carburettor. RAF fighter pilots soon learned to 'half-roll' their aircraft before diving to pursue their opponents.

I imagine that most people like me had this idea that fighter pilots just jumped in their planes, opened the throttle and went up and shot down a few enemy aircraft.

It would never have occurred to me that they might have to do some sort of acrobatic manoeuvre at the start of an engagement just to make sure the engine didn't die on them in the middle of a dogfight.

How on earth did they ever concentrate on shooting down the enemy when they had so many other things to think about?

[Sleepy]

Very true.

Add to that, many of these pilots only had minimal experience (measured in tens of hours) and most were in their early 20's.

A lot to learn in a very short time.

It says a lot for "motivation".

[JDNSW]

It never ceases to amaze me (even at my age), that things I had just taken for granted turn out to be much more complicated that I realised.........

How on earth did they ever concentrate on shooting down the enemy when they had so many other things to think about?

Just a few other things they had to think of - how much fuel is left (most fighter aircraft had very limited endurance, especially when the throttle is wide open), how much ammunition is left, where am I and which way is home (for most of WW2 there were no navaids for fighter aircraft). All this after being in many cases in the air or on duty yesterday and for umpteen previous days, and having had little sleep last night because someone was dropping bombs on the airfield.

One of the major reasons for British superiority in the Battle of Britain (apart from radar) was that British pilots shot down had a good chance of landing in friendly territory and in some cases were even back in action the same day. Whereas German pilots shot down were in most cases POWs or drowned in the North Sea. The result was that as the battle continued, Germany ran out of experienced pilots. To a lesser extent, the same applied toaircraft - damaged British aircraft more often made safe landings and were repairable than did German ones, simply because they were operating over home territory.

But the Merlin has to be acknowledged as a major part of the British war effort. At least part of this is because it was so adaptable that it meant fewer different designs had to be manufactured at the same time. The German 'equivalent' engine was the DB600 series - coming in several sizes was far less easy to develop, and in most respects is usually considered to be an inferior engine but did have a couple of notable features including the fuel injection mentioned above, plus a fluid supercharger drive that automatically compensated for altitude.

John

[Sprint]

its a excellent example of natural selection, either you got good at flying and fighting, and learned fast, or you died

[Bigbjorn]

I think that a major reason the Merlin stayed in production so long was that it was engineered into a number of very good airframes. Hurricane, Spitfire, Mustang, Lancaster, Mosquito. The very similar Allison V1710 was just as good a performer when built to similar specification, and a far easier engine to maintain, but development of this type was virtually at a standstill from about 1942 because of the very powerful radial engines coming out of Wright, and Pratt & Whitney, and the development in secrecy of jet engines. The US Navy became very aware of the need to get the pilots back on board. US Industry could build aircraft much, much, faster than carrier pilots could be trained. Pilot survivability became an issue, one of the reasons for the ascendancy of the radial over the liquid cooled in-line engines. The radials didn't have a cooling system to be shot full of holes. The radials were also easier to maintain as one cylinder at a time can be serviced. Particularly important in the cramped accomodation of the carriers of the time. There are plenty of recorded instances of radial engined aircraft getting home with a cylinder or more shot off. Radials are much shorter and the space saved was usually filled with fuel tank, which combined with drop tanks gave the long range required for the Pacific theatre and for escorting the bombers in long penetration of Germany, and later the endurance to hang around the battlefield to give ground forces some aerial artillery when called upon. The Spitfire was pretty much a home defence fighter initially with very short range and time in the air.

[ozzirt]

I haven't read all of the thread and apologise if this has been posted before. If you are interested in Merlins and Spitfires, try to read "Sigh for a Merlin" by Alex Henshaw, Supermarine's head test pilot at their assembly plant in Castle Bromwich during WWII.

Lots of interesting stuff and a few hair raising moments.

[JDNSW]

I think that a major reason the Merlin stayed in production so long was that it was engineered into a number of very good airframes. Hurricane, Spitfire, Mustang, Lancaster, Mosquito. The very similar Allison V1710 was just as good a performer when built to similar specification, and a far easier engine to maintain, but development of this type was virtually at a standstill from about 1942 because of the very powerful radial engines coming out of Wright, and Pratt & Whitney, and the development in secrecy of jet engines. The US Navy became very aware of the need to get the pilots back on board. US Industry could build aircraft much, much, faster than carrier pilots could be trained. Pilot survivability became an issue, one of the reasons for the ascendancy of the radial over the liquid cooled in-line engines. The radials didn't have a cooling system to be shot full of holes. The radials were also easier to maintain as one cylinder at a time can be serviced. Particularly important in the cramped accomodation of the carriers of the time. There are plenty of recorded instances of radial engined aircraft getting home with a cylinder or more shot off. Radials are much shorter and the space saved was usually filled with fuel tank, which combined with drop tanks gave the long range required for the Pacific theatre and for escorting the bombers in long penetration of Germany, and later the endurance to hang around the battlefield to give ground forces some aerial artillery when called upon. The Spitfire was pretty much a home defence fighter initially with very short range and time in the air.

The American navy made the decision to ditch liquid cooled engines in the twenties, nothing to do with WW2. Their decision, however was, as you note a desire to get their pilots home. This was the result, not of enemy action, but of the Liberty engine. This engine, designed by a committee of auto engineers for mass production (allegedly on the back of an envelope in a railway carriage or hotel room) featured separate cylinders with welded on water jackets that regularly cracked. Interestingly, their reliability depended on which car manufacturer built them - and Packard's were reputed to be the worst. Built in very large numbers in 1918, they powered much of US aviation until reliable aircooled radials appeared in 1927.

As these were developed, they became the engine of choice for commercial aircraft in the late twenties and thirties (from the Southern Cross to the DC-2,3,4 etc), with little effort being put into liquid cooled engines, so that both manufacturing capacity and development of US aircooled radials was way ahead of European practice, as their liquid cooled expertise was behind. Add to that the Navy's aversion to liquid cooled engines, and the lack of a separate airforce, and it is little wonder that the best US aircraft had aircooled engines.

John

[Bigbjorn]

The American navy made the decision to ditch liquid cooled engines in the twenties, nothing to do with WW2. Their decision, however was, as you note a desire to get their pilots home. This was the result, not of enemy action, but of the Liberty engine. This engine, designed by a committee of auto engineers for mass production (allegedly on the back of an envelope in a railway carriage or hotel room) featured separate cylinders with welded on water jackets that regularly cracked. Interestingly, their reliability depended on which car manufacturer built them - and Packard's were reputed to be the worst. Built in very large numbers in 1918, they powered much of US aviation until reliable aircooled radials appeared in 1927.

As these were developed, they became the engine of choice for commercial aircraft in the late twenties and thirties (from the Southern Cross to the DC-2,3,4 etc), with little effort being put into liquid cooled engines, so that both manufacturing capacity and development of US aircooled radials was way ahead of European practice, as their liquid cooled expertise was behind. Add to that the Navy's aversion to liquid cooled engines, and the lack of a separate airforce, and it is little wonder that the best US aircraft had aircooled engines.

John

The Liberty was still in production throughout WWII and used in boats and armoured vehicles. Packard were making them, and Hall-Scott, as was Morris Motors (Lord Nuffield) in the UK. Many of the US Navy's torpedo boats had three Liberties. Hall-Scott were also making their own designs used in work boats, and heavy military vehicles. They made an in-line six cylinder single OHC engine of 17.6 litres, an engine of imposing size and magnificent appearance when restored, painted and polished. The torpedo boats also had Merlins as did the RN's MTB's and MGB's. Vosper also made "Fairmiles" using UK produced Isotta-Fraschini engines they acquired the rights to pre-war. RAF air-sea rescue boats also used three Merlins, and later three Griffons. The fuel bill for three Griffons must have contributed greatly to the UK's war debt.

[Grover-98]

I love the spitfire!

It is by far my most favored aircraft of all time and sounds brilliant :), unfortunately all i have is a model :angel:

[JDNSW]

The Liberty was still in production throughout WWII and used in boats and armoured vehicles. Packard were making them, and Hall-Scott, as was Morris Motors (Lord Nuffield) in the UK. Many of the US Navy's torpedo boats had three Liberties. Hall-Scott were also making their own designs used in work boats, and heavy military vehicles. They made an in-line six cylinder single OHC engine of 17.6 litres, an engine of imposing size and magnificent appearance when restored, painted and polished. The torpedo boats also had Merlins as did the RN's MTB's and MGB's. Vosper also made "Fairmiles" using UK produced Isotta-Fraschini engines they acquired the rights to pre-war. RAF air-sea rescue boats also used three Merlins, and later three Griffons. The fuel bill for three Griffons must have contributed greatly to the UK's war debt.

I was nearly going to add the bit about the use of Liberty engines in WW2, particularly as a tank engine. The Hall-Scott engine you mention was probably also derived from one of their WW1 aeroplane engines that was markedly unsuccessful.

I have a fascinating autobiography of one of Vosper's engineers. In it he recounts a visit to Isotta-Fraschini before Italy entered the war. In this visit he was trying to push the production of the engines, and was told the holdup was on the Bosch magnetos. He recounts listening across the desk as the manager phoned Bosch and abused them for late delivery of them. Incidentally he also says that the engines were not made in Britain but were imported, and when Italy entered the war, they were unable to deliver any boats due to a lack of engines, until Packard commenced manufacture of marinised Merlins (production capacity in the UK could not be spared for non-aero uses of the Merlin.

John

[flagg]

The Allison V1710 ran out of puff at higher density altitudes until they packed on the superchargers.. but by that time the Merlin was established.

From vnx205

It would never have occurred to me that they might have to do some sort of acrobatic manoeuvre at the start of an engagement just to make sure the engine didn't die on them in the middle of a dogfight.

Carbies take a lot of management in flight even now (many light A/C still use them). Any 0 or negative G will have you splutter / windmill in no time.. and that takes some getting used too ! Also think about oil and engine lubrication.. Oh and carbie icing kills, too.

The maneuver is called a wing-over.. you can see it in almost all WWII films when the A/C break formation and 'peel off' into a dive. Its spectacular.. and great for the pilot to visually assess the theater as you get views in pretty much every direction.

[Bigbjorn]

The Allison V1710 ran out of puff at higher density altitudes until they packed on the superchargers.. but by that time the Merlin was established.



The Allison in its P38 format had the high altitude capacity and performance that the Merlin never had until the Mark 61 or 63 got the twin stage two speed and intercooled superchargers. The Allisons in the P38's had a turbocharger, intercooler and a centrifugal supercharger. This gave the P38 Lightning its outstanding ceiling and high altitude performance. The Lightnings swept the land based Japanese air force out of the Pacific theatre operating from altitudes that the Japanese aircraft simply could not reach. They had it all, high speed, high ceiling, fast dive, fast climb, stable and heavily armed, not to mention the long range needed for the Pacific theatre. Conversely its specification for the Pacific was a drawback in Europe as they were not built to operate in the severe cold of Europe's high altitudes and engine failures were common at first. All high performance aircraft engines of that era were supercharged or turbocharged or both. It was Stanley Hookers 2 x 2 superchargers that changed the Merlin from a fairly ordinarily performed engine into a good one. They gave it ceiling and high altitude performance by restoring take off horsepower at higher altitudes.

As an aside GM's Allison Division made over 70,000 of them, as well as making most of the slipper bearings used buy the other US aero engine makers.

[Bigbjorn]

I was nearly going to add the bit about the use of Liberty engines in WW2, particularly as a tank engine. The Hall-Scott engine you mention was probably also derived from one of their WW1 aeroplane engines that was markedly unsuccessful.

I have a fascinating autobiography of one of Vosper's engineers. In it he recounts a visit to Isotta-Fraschini before Italy entered the war. In this visit he was trying to push the production of the engines, and was told the holdup was on the Bosch magnetos. He recounts listening across the desk as the manager phoned Bosch and abused them for late delivery of them. Incidentally he also says that the engines were not made in Britain but were imported, and when Italy entered the war, they were unable to deliver any boats due to a lack of engines, until Packard commenced manufacture of marinised Merlins (production capacity in the UK could not be spared for non-aero uses of the Merlin.

John

The Hall-Scott big 6 was initially built for truck and bus use by Lou. Fageol in his own brand vehicles for his own fleet which later were commercially available under the name of Fageol. Peterbilt, Kenworth, Freightliner also started this way. The H-S 6 was a big mother of an engine but very attractive with aluminium sump, cam box, side plates, polished copper piping etc. I know of one in a "monster" replica that used to live on the North Shore. Took the owner over twenty years to build. He ended up using modern truck driveline components as there was no vintage stuff that would take even a third of what the H-S could dish out. Frank Boyce in Brisbane had a few, and a few Liberties, he pulled out of boats when converting wartime surplus to pleasure craft. Probably dumped now. Frank died some 5 years ago aged 92.

Vospers own history claims manufacture of the IF's in the UK but neglects to mention by whom.

[flagg]

The Allison in its P38 format had the high altitude capacity and performance that the Merlin never had until the Mark 61 or 63 got the twin stage two speed and intercooled superchargers. The Allisons in the P38's had a turbocharger, intercooler and a centrifugal supercharger. This gave the P38 Lightning its outstanding ceiling and high altitude performance. The Lightnings swept the land based Japanese air force out of the Pacific theatre operating from altitudes that the Japanese aircraft simply could not reach. They had it all, high speed, high ceiling, fast dive, fast climb, stable and heavily armed, not to mention the long range needed for the Pacific theatre. Conversely its specification for the Pacific was a drawback in Europe as they were not built to operate in the severe cold of Europe's high altitudes and engine failures were common at first. All high performance aircraft engines of that era were supercharged or turbocharged or both. It was Stanley Hookers 2 x 2 superchargers that changed the Merlin from a fairly ordinarily performed engine into a good one. They gave it ceiling and high altitude performance by restoring take off horsepower at higher altitudes.

As an aside GM's Allison Division made over 70,000 of them, as well as making most of the slipper bearings used buy the other US aero engine makers.

Interesting.. I never knew that about the P38 variant, having only really followed the P51 which (intially) only had the single stage, single speed supercharger and didn't get the altitude performance until the Merlin variant - as you mention.

[PAT303]

As vnx205 said,it is not until you get past the hype and chest beating that you understand the real reason for alot of what happened and the way it did happen.The second world war was a very closely run thing in the early stages and if it wasn't for a few,and I don't mean the pilots it could of turned out different.If Mitchell had made the plane the RAF asked for instead of what they needed or RR didn't stay with the merlin after all it's trouble and Hooker hadn't made a two stage SC,the list goes on.Germany made alot of very good things,the mauser,FW190.Me262 but what they needed more than anything else was Me 109 drop tanks.There is no one best engine or plane,it's like comparing LR's to tojo's,each has it's fobles. Pat

[JDNSW]

Interesting.. I never knew that about the P38 variant, having only really followed the P51 which (intially) only had the single stage, single speed supercharger and didn't get the altitude performance until the Merlin variant - as you mention.

The P51 with the Allison engine went into service in 1940, from memory, the P38 first saw action in 1942 and the engines Brian refers to were not in service until 1943. There was a lot of engine development in those three years!

The P38, like the Mosquito, and to a lesser extent the Beaufighter, showed that there was a real opportunity for twin engined fighter aircraft, where the higher payload allowed longer range and heavier armament - and nose mounted armament was a lot more accurate and had no convergence problem.

Unfortunately, the P38 (apparently unlike the Mosquito, but like the single engined Tempest at similar speeds) suffered from handling problems related to compressibility effects that killed several test pilots and continued in service with several losses. (The centre of lift moved aft in a high speed dive, steepening the dive, and at the same time the controls locked. The problem was little understood at the time.) Eventually the problem was 'fixed' by fitting dive flaps.

John

[StephenF10]

Here's a photo of a young lad tinkering with his Dad's engine.

The lad is Rob Eastgate, son of Bob who owns Mustang VH-BOB.

[Bigbjorn]

The P51 with the Allison engine went into service in 1940, from memory, the P38 first saw action in 1942 and the engines Brian refers to were not in service until 1943. There was a lot of engine development in those three years!

The P38, like the Mosquito, and to a lesser extent the Beaufighter, showed that there was a real opportunity for twin engined fighter aircraft, where the higher payload allowed longer range and heavier armament - and nose mounted armament was a lot more accurate and had no convergence problem.

Unfortunately, the P38 (apparently unlike the Mosquito, but like the single engined Tempest at similar speeds) suffered from handling problems related to compressibility effects that killed several test pilots and continued in service with several losses. (The centre of lift moved aft in a high speed dive, steepening the dive, and at the same time the controls locked. The problem was little understood at the time.) Eventually the problem was 'fixed' by fitting dive flaps.

John


jd, all the references I can find indicate that all Lightnings were turbocharged and intercooled except the ones ordered by the RAF, only three of which were delivered and the rest taken by the USAAF and converted to their spec. The yanks then regarded their turbocharging work as top secret and wouldn't supply it to the RAF. All Lightnings had handed engines except the ones supplied to the RAF who didn't want to know about this. The difficult handling produced by two engines running the same way caused the RAF to reject the type. Engine ratings were from 1150hp in the first deliveries, July 1941, and steadily increased. The P38H had 1425 take-off hp, and 1600 full military hp. The second most numerous variant, P38J, had the same rated engines but better airscrews and intercoolers giving improved performance. The J was the first with the dive brakes. Later marks had engines up to 1800 take-off hp and 1520 hp @ 30,000 ft with over 35,000ft service ceilings. 3800 P38l's were built. The P38 had numerous variants, almost as many engine ratings, and was produced as a fighter, night fighter, fighter-bomber, bomber, pathfinder, ground attack, photo reconnaisance, trainer aircraft. Almost 10,000 P38 Lightnings were built.

[Sleepy]

This thread is better than the Discovery channel:D.

P38's look evil:twisted: - pity they weren't that widely used in Europe.

https://www.aulro.com/afvb/images/imported/2009/05/820.jpg


I prefer them to the p38a model:p

[JDNSW]

jd, all the references I can find indicate that all Lightnings were turbocharged and intercooled except the ones ordered by the RAF, only three of which were delivered and the rest taken by the USAAF and converted to their spec. The yanks then regarded their turbocharging work as top secret and wouldn't supply it to the RAF. All Lightnings had handed engines except the ones supplied to the RAF who didn't want to know about this. The difficult handling produced by two engines running the same way caused the RAF to reject the type. Engine ratings were from 1150hp in the first deliveries, July 1941, and steadily increased. The P38H had 1425 take-off hp, and 1600 full military hp. The second most numerous variant, P38J, had the same rated engines but better airscrews and intercoolers giving improved performance. The J was the first with the dive brakes. Later marks had engines up to 1800 take-off hp and 1520 hp @ 30,000 ft with over 35,000ft service ceilings. 3800 P38l's were built. The P38 had numerous variants, almost as many engine ratings, and was produced as a fighter, night fighter, fighter-bomber, bomber, pathfinder, ground attack, photo reconnaisance, trainer aircraft. Almost 10,000 P38 Lightnings were built.

You are right about the turbochargers and intercoolers being fitted from the start, but it was not until the P38J that performance of the engines looked better than the Merlin, with better intercoolers (also less vulnerable).

The British ordered P38s with non-handed engines to retain commonality with the P40 engines, rather than rejecting the concept. After the first few were delivered they changed the order for the remaining ones to be delivered with handed engines, but most of that batch were rejected for a variety of reasons, probably mainly because of the dangerous dive characteristics, but also because with the Battle of Britain over, and production of their own aircraft ramping up, the situation was less critical. Another point is that I suspect the conservative RAAF did not like the concept of a fighter with tricycle undercarriage. Lockheed sued the RAAF, but the case was dropped after Pearl Harbour when the USAAF gratefully took the planes.

John

[Bigbjorn]

I have been thinking about how to tell the country of manufacture of Merlins. I am sure that most of the ones I worked on were Packards. If you have the accessory drive housing apart the difference is plain. Packards had a planetary drive of their own design. UK ones had a coupling whose proprietary name escapes me now. US engines had US magnetos, American Bosch and Scintilla, and the UK ones had various British magnetos. USA engines all had Bendix-Stromberg carbs, and UK ones had either SU or Bendix-Stromberg. If the reduction gear and propellor spline are still fitted, this can be another indicator as Packard used two spline patterns, American or British as required. The UK engines had only the British pattern.

R-R historian Pugh records that Packard signed the agreement on 3/9/40 and had two engines running on test beds on 2/8/41 despite delays caused by the decision to continue to use British threads and the time taken to manufacture the necessary tooling in the US. British industry was already over-stretched and could not supply. In 1944 Packard produced just short of 24,000 Merlins and Pugh notes Packard's total production was 55,500.

GM's historians record that the Allison Division was engaged in producing aircraft engines, aircraft engine bearings, and "reaction propulsion power units". Other GM divisions supplying Allison are noted as Cadillac, Chevrolet, Delco-Remy, New Departure, Hyatt Bearing, Delco Products, Packard Electric, AC Spark Plug, Antioch Foundry, Harrison Radiator, & Inland, with numbers of outside firms supplying raw materials, and semi-finished and fully finished parts.

Buick converted to making Pratt & Whitney engines and commenced in early 1942. They achieved the 1942 target in the first 6 months and by the end of 1944 had produced over 62,000 engines.

Chevrolet were making three models of Pratt & Whitney engine involving seventeen of their plants. Their aircraft work also included aluminium forgings for airscrew blades and hubs, pistons, landing gear, crankcase sections. Chev. also made numerous small steel parts for aircraft and converted a large part of their major grey iron foundry to producing magnesium castings.

You really have to visit there to understand the sheer scale and capacity of US industry.

[PAT303]

Keep it up you two. Pat

[JDNSW]

As a followup to Brian's last post - the Auster I used to own had a Gipsy Major III engine that was made by GMH in Adelaide. Another manufacturer of them during the war was, I believe, Tasmanian Railways. About 10,000 of these engines were made in Australia, the most of any aeroplane engine in Australia. Remember that at this time Australia did not have a motor manufacturing industry!

Australia in 1939 had the Wirraway in production, and was starting production of the Beaufort bomber, (including engines). In May 1942, the first Boomerang flew, fourteen weeks after the design was approved. Basically it was a beefed up Wirraway with a Beaufort engine. Although slow by contemporary standards, it was heavily armed and very manoeuvrable. In addition to these types, aircraft produced during the war included the DH82A Tiger Moth, Bristol Beaufighter and DH-98 Mosquito, with, as well as the Merlin and the Gipsy Major, several sizes of the P&W Wasp (Beaufort, Wirraway and Boomerang) and the Bristol Hercules (Beaufighter).

John

[isuzurover]

https://www.aulro.com/afvb/images/imported/2009/05/785.jpg

[Bushie]

VH-AUB = Mustang
+ Spitfire

Bankstown around 1987
(Slide scan but not the best)

https://www.aulro.com/afvb/images/imported/2015/01/215.jpg

Martyn

[clean32]

The Allison V1710 ran out of puff at higher density altitudes until they packed on the superchargers.. but by that time the Merlin was established.

.

Packed on Turbo chargers, they already had a single stage super charger. if you have a look at a lighting. Looking down at one of the fuselages’, 1\2 way down if the outlet exiting from the top, its a round thing, 2inches down is the turbo. The tips would glow red at night. they did try and fit it to the P40 but it took to long.

[clean32]

Interesting.. I never knew that about the P38 variant, having only really followed the P51 which (intially) only had the single stage, single speed supercharger and didn't get the altitude performance until the Merlin variant - as you mention.

The turbo super charged Allison was around for a while but not used because it was not thought at the time that aviation would need to go so high for so long. another limiting factor was the over all length of the dam thing that engineering it into single seat fighters also required every thing else including the pilot to be moved back, a large job in its self as well as limiting the pilots view. None of these problems exists with the Lighting.

[Bigbjorn]

https://www.aulro.com/afvb/images/imported/2009/05/785.jpg

Righto, Ben, what,where, who, when, and where did you find the photo?

[clean32]

As a followup to Brian's last post - the Auster I used to own had a Gipsy Major III engine that was made by GMH in Adelaide. Another manufacturer of them during the war was, I believe, Tasmanian Railways. About 10,000 of these engines were made in Australia, the most of any aeroplane engine in Australia. Remember that at this time Australia did not have a motor manufacturing industry!

Australia in 1939 had the Wirraway in production, and was starting production of the Beaufort bomber, (including engines). In May 1942, the first Boomerang flew, fourteen weeks after the design was approved. Basically it was a beefed up Wirraway with a Beaufort engine. Although slow by contemporary standards, it was heavily armed and very manoeuvrable. In addition to these types, aircraft produced during the war included the DH82A Tiger Moth, Bristol Beaufighter and DH-98 Mosquito, with, as well as the Merlin and the Gipsy Major, several sizes of the P&W Wasp (Beaufort, Wirraway and Boomerang) and the Bristol Hercules (Beaufighter).

John

Cool the DH stuff i know very well. All the DH motors had metric threads with Imperial heads. Rather exspencive with the young air mechanics now days, worse is the 100hour re torqueing of wooden spar caps, you have to be there and watch them every second.

[Bigbjorn]

As a followup to Brian's last post - the Auster I used to own had a Gipsy Major III engine that was made by GMH in Adelaide. Another manufacturer of them during the war was, I believe, Tasmanian Railways. About 10,000 of these engines were made in Australia, the most of any aeroplane engine in Australia. Remember that at this time Australia did not have a motor manufacturing industry!

John

GM-H made all sorts of odd things in WWII. Work boats, field guns, trailers among them.

The parent company's WWII output was prodigious. As well as the aircraft engines and components already mentioned they made complete aircraft, diesel engines, marine engines, locomotives, military vehicles, guns big and small, ammunition, tanks, armoured cars, furniture, civilian goods suitable for the military. Alfred Sloan states that GM then had 10% of the nation's metal manufacturing capacity, and that more than two thirds of their wartime production was products that were entirely new to them.

Chevrolet had not produced any of their own light metal components pre-war and by 1944 was the world's second largest maker of light metal forgings, and had turned part of their huge Detroit grey iron foundry into the world's largest producer of magnesium castings.

The Frigidaire Division was making civilian appliances for both the civilian market and the military, and making, lockers, cabinets, tables, chairs and so on from sheet metal for the military. They had unused capacity and asked the Procurements Board if there was anything in need that they could make. They ended up redesigning the Browning .50 machine gun so they could make it on their sheet metal machinery and by June 1945 had produced 328,000 of the short barrel version, in the process getting the cost down from $690 to $169 over three years. Other GM divisions were making the .30 machine gun and the M1 rifle.

[JDNSW]

Cool the DH stuff i know very well. All the DH motors had metric threads with Imperial heads. Rather exspencive with the young air mechanics now days, worse is the 100hour re torqueing of wooden spar caps, you have to be there and watch them every second.

That is something I did not know about them (the threads I mean). I wonder if that is part of the heritage of those engines? As you may know, the first DH Moth used an Airdisco engine, which was made by mating four cylinders from a Renault V8 to a new crankcase. The Gipsy 1 engine was designed as a successor to this when the supply of disposal Renault engines ran out, so it is likely to have used metric threads as well, seeing the conversion and the Gipsy had the same designer, Major Frank Halford.

Of course you realise that small fasteners on the engines are certain to be BA - which has Whitworth heads but metric dimensions and threads (but a different thread form)?

John

[clean32]

Quick history, air motors

In the beginning there was every thing chain driven rubber bands but basically a pile of rubbish

Then some frog made it across the channel with out getting his feet wet.

Roll out the rotary mono valves, light easy to build Balanced
Then can the 6s and V12s both air and liquid cooled, 6 cylinder being the smoothest of all layouts but they all suffered with heavy flywheels in an effort to dampen down there vibrations. Damiler Benz, liberty etc

Next the radial came into favour, the 4 stroke giving now good power and didn’t suffer from the vibration problems of the inline motors. But they did have the problem of frontal area, in short more power = bigger motor= more drag

Next the V12s become popular again as they sorted out the vibrations and were able to produce more power with out melting things, but the down side was the same to much drag, they needed big radiators

Then came Glycol, effectively reducing the sixe of radiators to 1\3 of before. This gave the in lines a big boost, upping there power and size etc super chargers turbo chargers water and NOS injection etc.

Next came sodium filled valves and this got the radials back into the game and they started to play with super charges turbo chargers and water and NOS injection again.

Next came onboard radiators and the invention of the bleeding edge ( as can be seen on hurricanes and spits.) the first of the was the XP51, ( engineering wise it is this aircrafts only real claim to fame) this pushed the inline back in front of the radials.

There it about stops as in came the turbine

[strangy]

Thanks for this thread .
it reminded me of a genius/ lunatic who loitered around Central West NSW.
He had cut down a damaged Merlin for his motorbike.!!!

V twin like nothing else! I am trying to find a picture of it. But after so many moves some things get archived in a safe place.

It set a number of speed records and upset a lot of the constabulary on its unofficial outings!!

[mike 90 RR]

Thanks for this thread .
it reminded me of a genius/ lunatic who loitered around Central West NSW.
He had cut down a damaged Merlin for his motorbike.!!!

V twin like nothing else! I am trying to find a picture of it. But after so many moves some things get archived in a safe place.

It set a number of speed records and upset a lot of the constabulary on its unofficial outings!!

.... I remember this story .... Always thought it was a "tall tale" :eek:


TOP STORY you have hear folks ... My eyes are glued reading it all :)

Mike
:)

[clean32]

I can assure you that all Merlins used British threads. Personal experience. It was going to be too much trouble to re-draw thousands of engineering drawings to convert.

Mate, sorry but there was a bit of a mix up. initially the yanks build motors with fittings supplied by the poms, then the poms couldn’t keep up so they stated to make there own imperial stuff. once the US army got involved they wanted all there stuff. NB UNC and UNF are American threads not English


, as well as causing untold confusion and maintenance problems as soon there would have been a mix and match situation in the field requiring duplication of spare parts. I still have taps and dies made in the USA in WWII in British systems supplied to the allies for production and maintenance of aero engines. They used seldom encountered items like 5/32, 7/32, 9/32 BSF left and right hand. Left hand BA, and other monstrosities..

As squadrons were formed and equipped or taken of the line and re equipped with aircraft that came sequentially off the line. this was a deliberate move as different motors and air frames from different factories did differ quite a bit.
replacement aircraft came from where ever.

,
Ford told Rolls-Royce that they could not mass produce the engine using RR's tolerances. "Ha", said RR, "you rough motor car types can't work to our high standards". "No", replied Henry's men, "your tolerances are too wide for mass production. We require identical parts that can be assembled by unskilled labour, not selective assembly by skilled fitters matching parts by micrometers." So the tolerances had to be re-jigged and Ford's Manchester plant built by the British government at a cost of millions went into production. ..

a nice bit of 1952 American propaganda, Fords Manchester plant was nationalised in 1940 after Mr ford made his Pro Nazi comments ( as polished in October 1939) ford didn’t get ownership of there plant back until 51,
Millions of pounds, yes that what it costs to convert a car factory to an aircraft factory.

[isuzurover]

Righto, Ben, what,where, who, when, and where did you find the photo?

Gar Wood (http://www.speedboatclassics.com/gar_wood.htm)

Also interesting:
channel4.com - science - speed machines (http://www.channel4.com/science/microsites/S/speedmachines/speedboats_technology.html)


Perhaps Wood's greatest design was the Miss America X, called a "madman's dream" Powered by four 1800-horsepower, 12-cylinder Packard engines.

The boat smashed the world record, the first to do over 2 miles a minute: at 124.915 mph. It's a speed that, 64 years later, remains a respectable time for the Gold Cup race on the Detroit River.

[Bigbjorn]

Mate, sorry but there was a bit of a mix up. initially the yanks build motors with fittings supplied by the poms, then the poms couldn’t keep up so they stated to make there own imperial stuff. once the US army got involved they wanted all there stuff. NB UNC and UNF are American threads not English



As squadrons were formed and equipped or taken of the line and re equipped with aircraft that came sequentially off the line. this was a deliberate move as different motors and air frames from different factories did differ quite a bit.
replacement aircraft came from where ever.


a nice bit of 1952 American propaganda, Fords Manchester plant was nationalised in 1940 after Mr ford made his Pro Nazi comments ( as polished in October 1939) ford didn’t get ownership of there plant back until 51,
Millions of pounds, yes that what it costs to convert a car factory to an aircraft factory.

You need to read "The Magic of a Name, The Rolls- Royce Story The first 40 Years" by Peter Pugh; "Not much of an Engineer" by Stanley Hooker; "British Aviation - The Ominous Skies 1935-39" by Harald Penrose.

A.R.Smith, the managing director of Ford, received the necessary authority from the Treasury and decided to build an entirely new factory at Trafford Park, Manchester. Penrose wrote "The result was a shop with tools tailored to the Merlin's design, though less capable of being switched to different engines, fundamentally more productive of Merlins than the Rolls-Royce line in Derby, and making a cheaper engine of no less quality."

Hooker stated "Ford would have to redraw all of the Merlin drawings to their own standards, and this they did, It took a year or so, but was an enormous success, because, once the great Ford factory at Manchester started production, Merlins came out like shelling peas at the rate of 400 a week. And very good engines they were too, yet never have I seen mention of this massive contribution which the British Ford company made to the build-up of our air forces."

Pugh records Merlin production as:- Derby 32,377. Crewe 26,065. Glasgow 23,647. Ford Manchester 30,428. Packard and Continental 55,523. In 1944 Packard had reached a peak production level of 2,000 a month. So Rolls-Royce made half the Merlins, and Ford, Packard, and Continental made the other half. Lord Hives conceded that Rolls-Royce never had a hope of meeting the demand with their production facilities and methods.

[clean32]

That is something I did not know about them (the threads I mean). I wonder if that is part of the heritage of those engines? As you may know, the first DH Moth used an Airdisco engine, which was made by mating four cylinders from a Renault V8 to a new crankcase. The Gipsy 1 engine was designed as a successor to this when the supply of disposal Renault engines ran out, so it is likely to have used metric threads as well, seeing the conversion and the Gipsy had the same designer, Major Frank Halford.

Of course you realise that small fasteners on the engines are certain to be BA - which has Whitworth heads but metric dimensions and threads (but a different thread form)?

John

you got it, frogy metric motor, pommy spanners. Airframes were all imperial. The motors didn’t change until the Queen 6. You will notice on the up right motors the angular sump plate, this became level just before they flipped it over.
BA came from DH just like the “font times new roman” I think ??

I have the R series cam profile some where but I don’t have the piston dimensions

[JDNSW]

you got it, frogy metric motor, pommy spanners. Airframes were all imperial. The motors didn’t change until the Queen 6. You will notice on the up right motors the angular sump plate, this became level just before they flipped it over.
BA came from DH just like the “font times new roman” I think ??

I have the R series cam profile some where but I don’t have the piston dimensions

BA was pretty much the standard for small diameters for anything with any pretence of precision in the British Empire from about 1900 up to about 1950, when it started to be replaced by UNF. BSF was occasionally used for small fasteners, and of course for rough work Whitworth. But my 1970 2A still has a lot of BA in the small fasteners!

(My experience of DH engines is limited to the Gipsy Major, and then only from the throttle end, not the spanner end)

John

[Bigbjorn]

BA was adopted by the British Association for the Advancement of Science about 1900, to be used for electrical, instrument, and clock work. It was adapted from a Swiss thread, the Thoury thread, and the Association started considering it about 1884. It is of 47 1/2 degree form and uses metric dimensions and a 0.9 factor in progression down from 0BA, pitch = 0.9 designating number. 0BA is identical to M6 x 1.0 and will interchange with 1/4" BSF or 1/4" BSB (which two are identical). The British Standard of 1951 only covers 0BA to 16BA although sizes down to 26BA are listed in some publications. BA was declared obsolescent after the metric system was officially adopted as the primary system of weights and measure in the UK.

Its use today is pretty well restricted to repairers, restorers, and model engineers. Suttons still list a range of BA taps and dies in their catalogue but whether they still make them, or are selling old stock is a moot point. Bruce Gardner, B.S.F. Bolts, in Melbourne has a great stock of BA taps and dies.

[vnx205]

BA was adopted by the British Association for the Advancement of Science about 1900, to be used for electrical, instrument, and clock work. .. .. .. .. ... ...
When I was a kid, dad had a jar of assorted small nuts and bolts. They never seemed to fit any other bolts or nuts. They may have been WWII RAAF as he was an armourer during the war.

Maybe they were BA threads from radios and such things.

That would explain why they never matched anything else wouldn't it?

[Bigbjorn]

When I was a kid, dad had a jar of assorted small nuts and bolts. They never seemed to fit any other bolts or nuts. They may have been WWII RAAF as he was an armourer during the war.

Maybe they were BA threads from radios and such things.

That would explain why they never matched anything else wouldn't it?

If of that vintage and under 1/4", it is most likely they were BA. 3/16" was the smallest BSF size, and BSW went down to 3/32" which was in use until quite recently in Yale type tumbler locks made in Australia.

[rick130]

IIRC (and the ol brain is a bit hazy ATM, life's been a touch hectic over the last few months. Thank my deity for the AULRO relief :D) the adoption of the Merlin over the Allison engine in the P51 totally changed the CofG and therefore the balance of the aircraft.

The Allison engined aircraft was apparently quite a nice thing to fly, with the Merlin being bigger and heavier and it really upset things in a steep dive and to a lesser extent general handling.
There was a fusealge fuel tank behind the R/T (which was a huge thing behind the pilot) that needed to be kept at least 1/2 to 2/3rds full or you may not pull out of a dive.

Col Pay (now deceased) had a P40, Mx IX Spit (David Lowy now owns it) and P51 (CAC-18 ??) and he preffered flying the P40 out of the three.
We'd sometimes be shopping in Scone and Col would be doing circuits over the town. Nothing sounds quite like a Merlin. :D

[Bigbjorn]

IIRC (and the ol brain is a bit hazy ATM, life's been a touch hectic over the last few months. Thank my deity for the AULRO relief :D) the adoption of the Merlin over the Allison engine in the P51 totally changed the CofG and therefore the balance of the aircraft.

The Allison engined aircraft was apparently quite a nice thing to fly, with the Merlin being bigger and heavier and it really upset things in a steep dive and to a lesser extent general handling.
There was a fusealge fuel tank behind the R/T (which was a huge thing behind the pilot) that needed to be kept at least 1/2 to 2/3rds full or you may not pull out of a dive.

Col Pay (now deceased) had a P40, Mx IX Spit (David Lowy now owns it) and P51 (CAC-18 ??) and he preffered flying the P40 out of the three.
We'd sometimes be shopping in Scone and Col would be doing circuits over the town. Nothing sounds quite like a Merlin. :D

Alan Hewson from Mt. Cotton had a Mustang. Jack McDonald of Gumdale had a Mustang and a Kittyhawk. Jack still has a Hawker Hart under restoration. The late Guido Zuccoli from Toowoomba had a collection of at least a Spitfire, a Sea Fury, and a WWII Fiat fighter which had been repowered with a Merlin. Very expensive toys!

Stanley Hooker recorded that the Mustang could exceed the performance of the Spitfire at 25,000 feet using 296 less horsepower, and the Mustang could carry three times the fuel.

[rick130]

<snip>

Stanley Hooker recorded that the Mustang could exceed the performance of the Spitfire at 25,000 feet using 296 less horsepower, and the Mustang could carry three times the fuel.

Just what that famous laminar flow wing was designed for.

Col had a huge range of warbirds, not sure what's happened to them since his death, but I'm pretty sure his company is still going.
IIRC they had been pulling things like Trojans out of Vietnam and restoring them for a number of years too.

Used to love the Sea Fury of Guido's.

[JDNSW]

Now isn't this thread more interesting than one on a TV programme?

John

[vnx205]

Now isn't this thread more interesting than one on a TV programme?

John


Yes.

[JohnF]

Ezekiel 27:28

[JDNSW]

Ezekiel 27:28

I think he may have been talking about sea pilots!

John

[isuzurover]

Ezekiel 27:28


28 The shorelands will quake
when your seamen cry out.

And the relevance to this thread is???


Oh God, Christians...
(As usual, there is a Simpsons quote for all occasions.)

[Bigbjorn]

Used to love the Sea Fury of Guido's.

About 1992 he told me it then cost about $150 of Avgas to warm up and taxi around Toowoomba airport, take of and do a circuit, land and taxi back to the shed.

[JDNSW]

About 1992 he told me it then cost about $150 of Avgas to warm up and taxi around Toowoomba airport, take of and do a circuit, land and taxi back to the shed.

Which raises the interesting point that none of the engines we have been discussing can be operated at their rated output today, because the fuel is not available. The Sea Fury, like the later Merlins and Allisons, were designed to run on 115/145 octane - best available today is 100LL. You would have to run at less than maximum designed boost unless running with extra octane enhancers!

John

[isuzurover]

Which raises the interesting point that none of the engines we have been discussing can be operated at their rated output today, because the fuel is not available. The Sea Fury, like the later Merlins and Allisons, were designed to run on 115/145 octane - best available today is 100LL. You would have to run at less than maximum designed boost unless running with extra octane enhancers!

John

You sure? Wikipedia disagrees:

100/130

Avgas 100/130 had a higher octane grade aviation gasoline, containing a maximum of 4 grams of lead per US gallon, maximum 1.12 grams/litre. 100LL "low lead" has replaced avgas 100/130 in most places, but Avgas 100/130 is still sold in Australia and New Zealand as one of the two manufacturers in Australia is unable to make Avgas 100LL.[citation needed]

[isuzurover]

Leaded racing fuels or Avgas (http://www.environment.gov.au/atmosphere/fuelquality/emerging/avgas.html)

[Bigbjorn]

I used to run my Dodge Challenger with 426 Hemi on 115/145 Avgas. The guy who owns it now complains about not being able to buy adequate fuel. He told me the airport fuel dealers will only sell it into an aircraft. He uses 98 unleaded and mixes benzol or toluene or some such one to four. He says he will get lower compression pistons when he has to overhaul. It currently has 12.5:1 compression ratio. It is on restricted registration and gets occasional use on a Sunday.

[clean32]

[QUOTE=rick130;977201]Just what that famous laminar flow wing was designed for.
[QUOTE]

not quite correct, the laminar flow wing was a hang over from the XP51, this being designed as a ground attack aircraft needed a thick wing to be able to sustain the buffeting and some battle damage, this was also the reason for moving the glycol and oil coolers onboard rather than have them hanging of the wings ( spitfire) or under the chin P40) in trials the XP51 was some 22'mph faster than the P40 ( Allison powered)

If we are to compare a spit to a P51 i would sagest that the MK9 ( interim) and the P51 B ( razorback) rate of clime to the spit strait and level to the p51 until 18 000 feet when the spit pulled ahead. The higher the altitude the more Attitude the P51 needed ( hanging off the prop) in a dive the p51 was ahead with cooler flap closed, spit ahead with cooler flap open.
The P51 was a dog with full tanks, tail heavy and quite unstable, this alone killed many green and over confidant pilots. In short you could not clime fully fuled, put the nose up and she kept going up.

to compare civil military aircraft today is a bit off, lacking amour and armaments and in the case of the P51 all its fuel tanks.

the P51 had some other draw backs, the .5 browning would Jam at any negative G or over +3 G, stability problems after the razorback was dropped hence the little sharks fin. And optical problems. its no surprise that the OLD hands kept there older P51s. the only example of this with the spits was DB and then he didn’t want the 20mm cannons so they built him a 8 X 303 ship. But the spit never had the problems that the P51 had. But neither was it as great an aircraft as most believe. Most pretty sure but not the best.
Nor has the spit the real battle scars to mark its reputation.
If we were to look at the P40 ( of Australian interest) this is the only aircraft to fight though the war. Starting with a radial then supercharged V12. But there are many more examples that should be held in higher esteem than the spit.

oh the spit has a veering angle of attack along its wing length, the advantage of that was the wing root would stall before the tip

[JDNSW]

You sure? Wikipedia disagrees:

I have not seen 100/130 for years - but I'm quite prepared to believe it is around in some areas. I remember there was a lot of angst when 100/130 was replaced by 100LL, not because of the octane rating - they are in fact the same - but because the low lead causes exhaust valve seat recession in some engines, particularly older engines that were designed to run on high lead 80/87.

But not really relevant to my point - 115/145, which the engines were designed for, has not been available for years (Actually some marks of Merlin were intended to run on 100/150, which allwed even higher boost and producing even more power).

John

[rick130]

About 1992 he told me it then cost about $150 of Avgas to warm up and taxi around Toowoomba airport, take of and do a circuit, land and taxi back to the shed.

Back in the late eighties the rule of thumb used to be $1500/hr to keep in the air for the high performance warbirds.
God only knows what it would cost now :eek:

[isuzurover]

Back in the late eighties the rule of thumb used to be $1500/hr to keep in the air for the high performance warbirds.
God only knows what it would cost now :eek:

How the hell can anyone afford to own one???

As an aside, someone once told me that their were experiments using pure o2 in WWII to give aero engines a power boost - anyone know anything about that.

[mudmouse]

One of the wifes rello's owns a P-40 (Allison) and runs a restoration workshop in NZ. He's an old drag racing lunatic....anyway, the hourly operating cost of the Kittyhawk is around $5500. The bulk of that is insurance, fuel is the last consideration.

I can't imaging the cost of something with a 'real' engine, like a P-47 or Neptune. A plug change alone would be around 4 grand :o.

Makes running old Land Rovers look like a doddle.


Matt.

PS. No, I'm not in the will.........yet:twisted:

[clean32]

How the hell can anyone afford to own one???

As an aside, someone once told me that their were experiments using pure o2 in WWII to give aero engines a power boost - anyone know anything about that.


There were plenty, mainly the big radials played around with it.
Aircraft like the Corsair had water injection for high altitude cruse, I think they got an extra 50hp but at that altitude it had already dropped to 1980hp
Nos was a new thing as well, Allison played around with this a lot and was used extensively in boat racing post war.

[Bigbjorn]

There were plenty, mainly the big radials played around with it.
Aircraft like the Corsair had water injection for high altitude cruse, I think they got an extra 50hp but at that altitude it had already dropped to 1980hp
Nos was a new thing as well, Allison played around with this a lot and was used extensively in boat racing post war.

Water-methanol injection is/was used in highly pressurised engines as an additional inter-cooler and for its properties in reducing detonation. Those WWII aero engines used it most commonly when "emergency military power" was used. The pilots called this putting the throttle "through the gate". Extra boost and extra charge cooling requires extra fuel to be supplied to the mixture, and further retardation of ignition timing. A big increase in output resulted. Detonation is always a major problem with pressurised engines once boost gets much above 8 psi over atmospheric at sea level. USAAF aircraft with this facility had a "tell-tale" that had to be reset externally after emergency power was used. The ground crew were thus aware of the pilot's indiscretion even if he was not forthcoming. USAAF policy was that all engines thus used had to be removed and dismantled for inspection and overhaul. EMP was only supposed to be used for short periods, 15 seconds typically. Corsairs and Thunderbolts had water-methanol injection, not sure of others. Some carried up to 50 US gallons of the mixture. I know nothing at all about the usage rate.

[JohnF]

I saw the Ezekiel 27:28 reference in a British aeroplane magazine in the Library, and threw it in after looking at the King James Version, forgetting most will look it up in modern versions. It is pilots in the KJV. It was meant to be in jest.

[Bigbjorn]

I think he may have been talking about sea pilots!

John

Maybe it was Gilbert and Sullivan?

[Landy110]

and what music it makes: :D

YouTube - Merlin engine Sounds (http://www.youtube.com/watch?v=9Vy7UgCwEkk)
I've seen a lot of war movies and footage of air shows but this clip captures the "spiritual" sound of a roaring merlin better than I've ever heard before.

I pity the poor soul that has never had his knees turned to jelly by that incredible noise.

[JDNSW]

This thread has set me to rereading L.J.K. Setright's "The Power to Fly (ISBN 0 04 338041, London, 1971) and Herschel Smith's "A history of Aircraft Piston Engines" (Kansas, ND, no ISBN, about 1990).

The first of these is particularly recommended, but both are quite rare. (A quick search found just one copy for sale of Setright - US$559, Smith, still in print plenty for US$29.99)

John

[Bigbjorn]

Found the following reference. Stanley Hooker wrote in "Not much of an Engineer", "a number of Ford engineers came to Derby to familiarise themselves with the drawings and methods of manufacture. One day their Chief Engineer appeared in Lovesey's office, which I was then sharing,and said 'you know we can't make the Merlin to these drawings'. I replied loftily 'I suppose the drawing tolerances are too difficult for you and you can't achieve the accuracy?' 'On the contrary,' he replied, the tolerances are far too wide for us. We make motor cars far more accurately than this. Every part on our car engines has to be interchangeable wqith the same part on any other engine, and hence all parts have to be made with extreme accuracy, far closer than you use. That is the only way we can achieve mass production.'

Lovesy joined in "Well, what do you propose now?" The reply was that Ford would have to redraw all the Merlin drawings to their own standards, and this they did."

A. Cyril Lovesey was Flight Development Engineer and in charge of Merlin development. Eventually he became Chief Engineer (Aero Engines), Deputy Director of Engineering, and a board member.

[incisor]

look what i came across today, a merlin in bits

[Bigbjorn]

Did you find some photos or actually see that one in bits somewhere? Caboolture Airport? Brings back memories, not necessarily good ones. If you took the photos, is it possible for me to go and have a look?

[incisor]

saw in real life at the beaufort bomber restoration groups hanger at caboolture airport.

well worth a visit...