2 stroke ain't dead yet....

[Armadillo]

Found this this evening - very interesting

http://www.nytimes.com/2009/12/20/automobiles/20STROKE.html?_r=1&hpw

[d2dave]

I read somewhere recently that two strokes are starting to make a comeback in trail bike riding.

I have a V6 two stroke hanging off the back of my ski boat and I don't see two stroke outboards disappearing for a long time yet.

Personally I love two stroke engines. Nothing smells better than when the big Merc is fired up and I get a whiff of the exhaust.

Dave.

[Blknight.aus]

now thats clever, very very clever.

I like the electrically assisted turbo....

I can see that developing into a dynamo or generator... spin it up with electricery to start the engine then when its running it charges the battery.

[BlueBandit59]

That is a brilliant concept I hope they can keep it going.
Question?????? Do any of you out there know why the rotory engine from mazda was stopped from being built.??????
It was an almost unbrakable engine and sounded awsome with the right gear on it.
Cheers Nev.

[hoadie72]

That is a brilliant concept I hope they can keep it going.
Question?????? Do any of you out there know why the rotory engine from mazda was stopped from being built.??????
It was an almost unbrakable engine and sounded awsome with the right gear on it.
Cheers Nev.

Mazda still make a rotary; it's in their RX8. I wouldn't go as far as saying it was unbreakable. I did the apex seals in my RX7 at around 150,000km.

[Captain_Rightfoot]

You try and buy a outboard. Sure there are 4 strokes, but the direct injection 2 strokes are really putting up a strong case. They don't use much (if any) more fuel than the big 4 strokes, they are lighter, and have a fraction of the maintenance requirements. Also, they use hardly any oil. In the case of the e-tec - they can actually run without oil for many hours at reduced power settings.

[V8Ian]

now thats clever, very very clever.

I like the electrically assisted turbo....

I can see that developing into a dynamo or generator... spin it up with electricery to start the engine then when its running it charges the battery.One of the early model Hondas (Scamp, Zot??) had a starter/generator as a single unit. Other manufacurers have used the same idea.


That is a brilliant concept I hope they can keep it going.
Question?????? Do any of you out there know why the rotory engine from mazda was stopped from being built.??????
It was an almost unbrakable engine and sounded awsome with the right gear on it.
Cheers Nev.It is still available, not hugely popular due mainly to reliability issues and high fuel consumption.


You try and buy a outboard. Sure there are 4 strokes, but the direct injection 2 strokes are really putting up a strong case. They don't use much (if any) more fuel than the big 4 strokes, they are lighter, and have a fraction of the maintenance requirements. Also, they use hardly any oil. In the case of the e-tec - they can actually run without oil for many hours at reduced power settings.Why not build two strokes with a proper lubrication system, thus eliminating the requirement to add lube oil to the fuel? GM were doing so over fifty years ago. Consider the 53, 71 and 82 Series Detroits.

[vnx205]

One of the early model Hondas (Scamp, Zot??) had a starter/generator as a single unit. Other manufacturers have used the same idea.
.. ... .. ... .. .... .... ... ....

The Haflinger had one.

[2stroke]

Long live the 2 stroke! In a conventional 2 stroke the crankcase is where the induction takes place and a sump therefore isn't possible. Detroits have blowers and intake valves so are a different kettle of fish. No problems with oil delivery on angles offroad in a conventional 2 stroke which makes for a lot of fun. My LJ50 was idling happily in this shot.

[V8Ian]

Long live the 2 stroke! In a conventional 2 stroke the crankcase is where the induction takes place and a sump therefore isn't possible. Detroits have blowers and intake valves so are a different kettle of fish. No problems with oil delivery on angles offroad in a conventional 2 stroke which makes for a lot of fun. My LJ50 was idling happily in this shot.
Which is my point, emission control killed off the old style two stroke. For two stroke to remain a viable alternative, it needs to be modernized. If angle of operation is a concern, dry sump is an option.

[Bigbjorn]

Long live the 2 stroke! In a conventional 2 stroke the crankcase is where the induction takes place and a sump therefore isn't possible. Detroits have blowers and intake valves so are a different kettle of fish. No problems with oil delivery on angles offroad in a conventional 2 stroke which makes for a lot of fun. My LJ50 was idling happily in this shot.

They have exhaust valves. The blower scavenges the burnt gases and charges the cylinders with fresh air through an air box and cylinder ports.

Wonderful engines, Detroit two strokes. Keep good filters on them and they run clean and cool almost forever. I had 6V53N's in a boat and a Bedford KMR-XT5 single drive prime mover and some 8V92TA's in line haul and road train movers. The road train one was tickled up to marine specs, 545 BHP @ 2300 rpm. It could really march.

[twitchy]

2 stoke boat engines will soon cease production, it isn't a fuel efficiency problem it's the oil they put in the water & it is HEAPS.

If you want a 2 stroke then click away.....High Power Density Pivotal Engine by Pivotal Engineering Ltd - Christchurch, New Zealand (http://www.pivotalengine.com/index.html)

[d2dave]

2 stoke boat engines will soon cease production, it isn't a fuel efficiency problem it's the oil they put in the water & it is HEAPS.

If you want a 2 stroke then click away.....High Power Density Pivotal Engine by Pivotal Engineering Ltd - Christchurch, New Zealand (http://www.pivotalengine.com/index.html)

I'm interested to know how a two stroke outboard puts oil in the water when they don't have oil in them.

I can understand a four stroke outboard doing this if the engine developed an oil leak.

Dave.

[d2dave]

You try and buy a outboard. Sure there are 4 strokes, but the direct injection 2 strokes are really putting up a strong case. They don't use much (if any) more fuel than the big 4 strokes, they are lighter, and have a fraction of the maintenance requirements. Also, they use hardly any oil. In the case of the e-tec - they can actually run without oil for many hours at reduced power settings.

I was looking at a new 200hp Merc for my boat a couple of years ago and I toyed with the idea of a four stroke for fuel savings.

I was told by the dealer that the two strokes use considerably less fuel than the four stroke.

This is apparently due to them using the fuel system from Ralph Sarich's orbital engine. Although the orbital engine is dead and buried the fuel system is being used by Mercury outboards.

Dave.

[d2dave]

One of the early model Hondas (Scamp, Zot??) had a starter/generator as a single unit. Other manufacurers have used the same idea..


About 30 years ago I had a customer who had a Honda Scamp with this unit. When it failed to charge I had to remove it to send to the auto sparkie.

What a nightmare it was to remove it from the vehicle.

Dave.

[Captain_Rightfoot]

There is an Aprilia 50cc scooter that was/is available in aus. It had the Sarich DI technology, and it was capable of 110 kph and used less fuel than the normal 50 cc scooters.

It was sold governed, but if you had the appropriate licence you could ask the dealer to remove the restrictions. That is truly impressive, IMHO. :)

[twitchy]

I'm interested to know how a two stroke outboard puts oil in the water when they don't have oil in them.

I can understand a four stroke outboard doing this if the engine developed an oil leak.

Dave.

The exhaust on a boat motor is UNDERWATER, hence the oil smoke you normally see in the air gets pumped into the water instead!!!

[2stroke]

They have exhaust valves. The blower scavenges the burnt gases and charges the cylinders with fresh air through an air box and cylinder ports.

Wonderful engines, Detroit two strokes. Keep good filters on them and they run clean and cool almost forever. I had 6V53N's in a boat and a Bedford KMR-XT5 single drive prime mover and some 8V92TA's in line haul and road train movers. The road train one was tickled up to marine specs, 545 BHP @ 2300 rpm. It could really march.
Sorry Brian you're right...seems I can't think and type at the same time! Yea intake ports around the cylinder and exhaust valves in the head. Don't know why I typed that.

[loanrangie]

The Haflinger had one.

Actually most cars prior to roughly mid 20's had an integral starter/generator - dodge used them up till 1925/26.

[snowbound]

now thats clever, very very clever.

I like the electrically assisted turbo....

I can see that developing into a dynamo or generator... spin it up with electricery to start the engine then when its running it charges the battery.

Dynostart! used on the old bubble cars (Izetta?) My brother had one back in the 60s

[rick130]

<snip>
Why not build two strokes with a proper lubrication system, thus eliminating the requirement to add lube oil to the fuel? GM were doing so over fifty years ago. Consider the 53, 71 and 82 Series Detroits.

Why ?

All you are doing is taking away all the advantages of a two stroke, namely simplicity and lack of weight and complexity.

Stratified air injection is being used in two strokes to clean up emission's, as are catalytic converters.

Strato engines generally use an extra butterfly and 'transfer' ports to inject fresh air ahead of the incoming transfer charge, this sweeps the exhaust out of the cylinder rather than the incoming charge, significantly reducing the amount of mix lost out the exhaust and significantly reducing emissions.

[p38arover]

Found this this evening - very interesting

http://www.nytimes.com/2009/12/20/automobiles/20STROKE.html?_r=1&hpw

It reminded me of the old Commer Knocker TS3 engine.

Hillman Car Club of South Australia – Commer TS3 Two Stroke Diesel Engine (http://www.sa.hillman.org.au/TS3.htm)

[Bigbjorn]

It reminded me of the old Commer Knocker TS3 engine.

Hillman Car Club of South Australia – Commer TS3 Two Stroke Diesel Engine (http://www.sa.hillman.org.au/TS3.htm)

A great little engine and there is the nub of the matter, little. Far too little displacement to make real horsepower. I was once quite familiar with them. Wall and Co. in Winton had eight of them at one time. Commer Knockers were a great eight ton body truck but not a great prime mover, not enough power, even though many of them were used as prime movers. You did not want to be in a hurry if you had a bogie trailer and 17 tons of freight on one. Likewise with sheep crates and often a dog trailer with sheep crates. The wind resistance of these things is horrific and plugging across the plains into a strong headwind imbued drivers with a modicum of patience. Add a pair of cylinders, more bore and stroke and the knocker may have survived twenty years or more longer.

[p38arover]

I agree about them being slow as a prime mover/trailer. Going up Razorback behind one was simply awful!

[incisor]

love the sound of the things....

YouTube- Driving a Commer 2 Stroke Knocker TS3

[Bigbjorn]

love the sound of the things....

YouTube- Driving a Commer 2 Stroke Knocker TS3 (http://www.youtube.com/watch?v=e0sLp7wvq60&feature=related)

They had a distinctive snort-snort-snort sound. One wheat season in the ealry sixties we and others had been carting into the Allora depot and were all gathered in the Commercial after a days work when the sound of a knocker hard at it was heard when the truck came over the crest at Glengallan some miles away. The exhaust system came adrift in front of the first muffler, too hot to fix so he just kept coming in to beer time. Deafened him for quite some time after he shut down. Bloddy loud without mufflers.

I much preferred the sound of Detroit 6V71N or 12V71N. They had a real crackle.

[Bigbjorn]

I agree about them being slow as a prime mover/trailer. Going up Razorback behind one was simply awful!

Try sitting in one on a hot day somewhere like the old Burringbar pull in the North of NSW. You nursed every rev to hit the bottom flat out to get a good go at the climb and by Murphy's Law, it seemed every time there was some ****** caravanner dawdling along admiring the view and forcing you down into the bottom of the box for a long hot drag up the hill at not much more than walking pace.

[incisor]

I much preferred the sound of Detroit 6V71N or 12V71N. They had a real crackle.

YouTube- Detroit Diesel 6V71N (2/2)

nice but not quite the character imho ...

[Bigbjorn]

YouTube- Detroit Diesel 6V71N (2/2) (http://www.youtube.com/watch?v=eDkA_4ALzUw)

nice but not quite the character imho ...

That is a poor recording. It gets blower and fan noise but not the exhaust note. Looks like the engine is on a dyno. and the exhausts are probably 4 metres away up in the air. Odd looking engine variant, has the later model cast rocker covers but the tag on the engine says it is a two valve which is an old, old, engine.

[d2dave]

The exhaust on a boat motor is UNDERWATER, hence the oil smoke you normally see in the air gets pumped into the water instead!!!

What harm is done by putting smoke into the water?

Dave.

[clean32]

What harm is done by putting smoke into the water?

Dave.

ITS smoke on the water, you must have had a hair cut or gone bald

[d2dave]

ITS smoke on the water, you must have had a hair cut or gone bald

Great song, Deep Purple from the album Machine Head.

But we are talking about smoke in the water.

Dave.

[clean32]

Great song, Deep Purple from the album Machine Head.

But we are talking about smoke in the water.

Dave.

ohhh OK BONG

[twitchy]

What harm is done by putting smoke into the water?

Dave.


The Blue smoke is UNBURNT OIL!!!!!!!!!!!!!!!!!!;)
Have you never seen the end of a 2 stroke bike exhaust, lots of oil in there.

[d2dave]

Smoke is the result of burning. If something is not burnt it won't smoke.

This is why we get the smoke, because the oil is burnt. The exhaust on my out board does not have oil residue in it and neither does my chainsaw.

My outboard is old and I'm sure modern ones put out a lot less smoke than mine and with modern technology could easily solve any pollution problems.

I am sure outboards will still be around long after I have departed this planet.

Dave.

[twitchy]

you think so????????????

Two and Four Stroke Outboard Engines (http://ezinearticles.com/?Two-and-Four-Stroke-Outboard-Engines&id=1015583)

http://www.kimointernational.org/Portals/0/Files/RESL102D.pdf


That took ten seconds to find............. 2 strokes pollute the water......... Don't get me wrong there is nothing better than a 2 smoke at full noise but.

[d2dave]

So what this is saying is that smoke is unburnt oil. So if the oil is burnt there will be no smoke.

Does this then mean at the camp fire if I burn all the wood I will have a smoke free fire.

Dave.

[Rosscoe68]

Smoke is the result of burning. If something is not burnt it won't smoke.

This is why we get the smoke, because the oil is burnt. The exhaust on my out board does not have oil residue in it and neither does my chainsaw.

My outboard is old and I'm sure modern ones put out a lot less smoke than mine and with modern technology could easily solve any pollution problems.

I am sure outboards will still be around long after I have departed this planet.

Dave.
Smoke = " A suspension of fine solid or liquid particles in a gaseous medium ".
could be due to burnt or unburnt oil. i suggest you clean a 2 stroke motor in a drum of water one day and then take a look at the scum on the surface of the water after it settles to get an idea of the amount of scum they pump into the water. The big problem with most 2 strokes is each time a new charge of air/fuel is loaded into the combustion chamber, part of it leaks out through the exhaust port. That's why you see a sheen of oil around any two-stroke boat motor. The leaking hydrocarbons from the fresh fuel combined with the leaking oil is a real mess for the environment.
this appears to being addressed in this new engine.

[Captain_Rightfoot]

you think so????????????

Two and Four Stroke Outboard Engines (http://ezinearticles.com/?Two-and-Four-Stroke-Outboard-Engines&id=1015583)

http://www.kimointernational.org/Portals/0/Files/RESL102D.pdf


That took ten seconds to find............. 2 strokes pollute the water......... Don't get me wrong there is nothing better than a 2 smoke at full noise but.
The first article makes no reference to direct injection 2 strokes so I would imagine it's old or just useless.

I'm not sure how much you've been following the outboard market of late, but if all 2 strokes are to be banned then you better tell all the major manufacturers about it because their primary development and marketing focus is on direct injection 2 strokes.

These motors use almost no oil, and less fuel than 4 strokes. As ever they are still lighter and cheaper than 4 strokes.

You should look into them... they really use virtually no oil, and definitely less than a 4 stroke does if you include their oil change. As I said earlier, the e-tec range (and probably others) can operate indefinitely at reduced power settings with no oil.

[harlie]

Important distinction to make here is the difference between Fuel Injected 2 stokes and the more traditional types. The older 2 strokes still have the exhaust port open when the inlet port is opened (position of piston). This little point allows up to 30% of the fuel/oil mix to exit directly out the exhaust - UNBURNT and into the water. Fuel injected engines like e-tec, Optimax and the one mentioned at the top of this thread don’t have this issue. Go across any well used bay and you can see the oil slick that hangs on the surface for ages marking the path of a carby two stroke outboard.


To say 2-strokes in their traditional form will be around for ever is a poor comment – why do you think that they have all had a star rating on them for some years now. In EU and US there are no bans on their sales but most areas now have bans on their use. Wide Bay Water (water supply for Hervey Bay / Maryborough) are the first authority in Australia to implement such bans – you have to have 2 Star or higher to be allowed on their dams. All new Carby 2 strokes outboards sold in Aus are 0 star. More bans like this will follow; it’s why the industry was forced into these ratings.


The only reason they outsell the injected 2s and 4 strokes is price – some sizes it’s double… I personally think that someone who buys a carby two stroke outboard in today’s climate is a bit of a hypocrite. They go out to enjoy a pristine water-way and leave 1/3 of their oil in the water…..

[harlie]

The first article makes no reference to direct injection 2 strokes so I would imagine it's old or just useless.

I'm not sure how much you've been following the outboard market of late, but if all 2 strokes are to be banned then you better tell all the major manufacturers about it because their primary development and marketing focus is on direct injection 2 strokes.

These motors use almost no oil, and less fuel than 4 strokes. As ever they are still lighter and cheaper than 4 strokes.

You should look into them... they really use virtually no oil, and definitely less than a 4 stroke does if you include their oil change. As I said earlier, the e-tec range (and probably others) can operate indefinitely at reduced power settings with no oil.


Real world figures from our club (owners not agents) show that one brand of the new injected two strokes matches the 4s for fuel usage but the others are still behind. You also have to use the synthetic oils to get the emissions levels they advertise, and if the user decides to change to a cheap oil, the computer has a setting which effectively doubles it's oil ratio, making the expensive oil not so expensive…. They all are however miles better than carby 2s.


The 4s do suffer from high servicing cost and weight– I have 3 of them. The 4s are also more sensitive to prop selection and boat trim - it's got to be right to get the most out of them.
For my tinnie (currently Honda) - I wish the little e-tecs were out when I set it up…

[Rosscoe68]

I personally think that someone who buys a carby two stroke outboard in today’s climate is a bit of a hypocrite. They go out to enjoy a pristine water-way and leave 1/3 of their oil in the water…..

well said !
well said indeed :)

[twitchy]

The first article makes no reference to direct injection 2 strokes so I would imagine it's old or just useless..

Was using it to make the point that 2 strokes leave oil in the water!!!!!!! There fore it wasn't useless

As for following boating, ummm not in this lifetime. If my fourby or bike breaks down I can walk home, if I crash it doesn't sink & the likely hood of getting eaten going home is next to nil......:D

[Captain_Rightfoot]

Real world figures from our club (owners not agents) show that one brand of the new injected two strokes matches the 4s for fuel usage but the others are still behind. You also have to use the synthetic oils to get the emissions levels they advertise, and if the user decides to change to a cheap oil, the computer has a setting which effectively doubles it's oil ratio, making the expensive oil not so expensive…. They all are however miles better than carby 2s.


The 4s do suffer from high servicing cost and weight– I have 3 of them. The 4s are also more sensitive to prop selection and boat trim - it's got to be right to get the most out of them.
For my tinnie (currently Honda) - I wish the little e-tecs were out when I set it up…


Mercury now claim their engines use 25% less fuel than e-tecs!

[Captain_Rightfoot]

Was using it to make the point that 2 strokes leave oil in the water!!!!!!! There fore it wasn't useless

As for following boating, ummm not in this lifetime. If my fourby or bike breaks down I can walk home, if I crash it doesn't sink & the likely hood of getting eaten going home is next to nil......:D

From what I've seen people are almost exclusively buying injected two strokes or four strokes. So, it's largely irrelevant. :)

[twitchy]

From what I've seen people are almost exclusively buying injected two strokes or four strokes. So, it's largely irrelevant. :)


See this little dot-> . That's the point, I think you missed it....;)

[harlie]

Mercury now claim their engines use 25% less fuel than e-tecs!

Mercury have claimed that for several years now, they claim that the Opti uses less fuel than all the 4s as well... Our member's numbers tell a different story. Mercury is also the only manufacturer that will not allow the connection of fuel monitoring devices (voids warranty) other than their own - and will not allow sea-media to use their super accurate fuel meter during a test... There are also official emission figures for all outboards sold in aus and they also don't paint a good picture for Mercury. So if they use 25% less than e-tec why is their emissions nearly always double. I have them in hard copy, see if I can find them on the net and post.

Outboard manufacturers can claim nearly anything. Bolt two different engines on the back of any hull, correct fit and prop on the black one and over prop, mount the white one low and yes - the black will win. I've never seen test result where the manufacturers engine who is hosting the test does not win, and win by an absurd difference. sorry marketing vs real numbers.... And they are all doing it. Evenrude claim the e-tec uses heaps less than the Merc... So does Yamaha. So does Suzuki And they all claim to be better than each other...

On the other side Mercury win hands down for dealer support, I've had two, I wouldn't give them top marks for refinement though

[DeeJay]

Was using it to make the point that 2 strokes leave oil in the water!!!!!!! There fore it wasn't useless

As for following boating, ummm not in this lifetime. If my fourby or bike breaks down I can walk home, if I crash it doesn't sink & the likely hood of getting eaten going home is next to nil......:D

Rule number 1- don't generalise. As stated by others 2 stroke fuel injection is very clean burning- its approved for use in the antarctic due to its negligable pollution.

[V8Ian]

Try sitting in one on a hot day somewhere like the old Burringbar pull in the North of NSW. You nursed every rev to hit the bottom flat out to get a good go at the climb and by Murphy's Law, it seemed every time there was some ****** caravanner dawdling along admiring the view and forcing you down into the bottom of the box for a long hot drag up the hill at not much more than walking pace.
I wish I had a dollar for every time I fell over the top of old Burringbar, northbound in a sub 200 hp banger. The right hander at the bottom used to kill the run up, particularly if there was southbound traffic, but you could get air under the bogie of a strap trailer on the decent.

[twitchy]

Rule number 1- don't generalise. As stated by others 2 stroke fuel injection is very clean burning- its approved for use in the antarctic due to its negligable pollution.

Clean but I bet it still leaves some even if if its a tiny bit, which means what???????

Thalidomide was approved at one point ;)

[Captain_Rightfoot]

Clean but I bet it still leaves some even if if its a tiny bit, which means what???????

Thalidomide was approved at one point ;)

Did you consider that a four stroke may be passing a quantity of oil into the exhaust too? That would be fairly common. If there is absolutely no tolerance then you better just ban all engines on boats and get used to fish and chips hold the fish.

[DeeJay]

Clean but I bet it still leaves some even if if its a tiny bit, which means what???????

Thalidomide was approved at one point ;)


I think the Western world has learnt from Thalidomide & no longer has the "who gives a stuff what we put into the atmosphere attitude"..we are moving on.

We are all polluters, every one of us, its a case of making an effort, which is why I spent $14,000 on a high tech outboard motor, instead of persisting with the "old" 2 stroke.

[Bigbjorn]

but you could get air under the bogie of a strap trailer on the decent.

Of course, you were not floating, were you?

Knockers as a prime mover were a real pain on those steep climbs on the main highways of 40-50 years ago. Pretty Sally, Moonbi, Liverpool Range, Toll Bar, Bulahdelah Hill with the hairpin bend to slow you down to a walk, et al.

A Qld. Main Roads engineer tells me that the standard for Main Roads Dept. works now is maximum 10% grade.He says in Qld, Cunningham's Gap, Toowoomba Range, and a section of the Gillies are all on the 10% limit for short sections with around 100 metres of the Gillies still at 12%, it being deemed not of economic benefit to reduce this. I read this as being "will cost too much".

[twitchy]

Did you consider that a four stroke may be passing a quantity of oil into the exhaust too? That would be fairly common. If there is absolutely no tolerance then you better just ban all engines on boats and get used to fish and chips hold the fish.


It had jack to do with tolerance towards boat engines.
Lets make it simple..... go back & read the two strokes pollute water bit with my first post. I dont give a **** about boat engines be they 2 or 4 stroke, the comment was made that "2 strokes pollute the water" Mr. Whippy didn't understand how they could pollute & I explained. As you stated, yes the injected 2 stroke is WAY better & yes the 4 stroke could be dumping a bit of oil as well but that isn't what it was about.