More from a S2A 4-cylinder?

[Brisso57]

OK. Let's assume we have a S2A 4 cylinder petrol engine in good condition and nominal tune.

What can be done to extract greater power?

* Let's leave aside the "obvious" tricks, such as thinner engine oil.

1. There's balancing and blue-printing;
2. There's porting the head;
3. A more "hairy-chested" cam maybe?
4. An exchange to a better carbie?
5. Dare we suggest turbo-charging or supercharging?

What is the "known art" with this engine?

Doug

[Bigbjorn]

OK. Let's assume we have a S2A 4 cylinder petrol engine in good condition and nominal tune.

What can be done to extract greater power?

* Let's leave aside the "obvious" tricks, such as thinner engine oil.

1. There's balancing and blue-printing;
2. There's porting the head;
3. A more "hairy-chested" cam maybe?
4. An exchange to a better carbie?
5. Dare we suggest turbo-charging or supercharging?

What is the "known art" with this engine?

Doug

Good set of extractors, twin 1 1/2" SU's or one x 1 3/4" SU. Adaptor for this last is easy to make and an SU from an Austin 1800 does not need a needle change. Get a reputable cam grinder to recommend a mild cam that will not greatly affect low speed output. Port match the manifolds. An electronic ignition kit that uses the existing points as a trigger and with the wiring arranged so the electronic kit can be disconnected if it fails and you can hook up to run on points. If you have to fit new valve seat inserts, then you might as well ger bigger valves at the same time.

[olmate]

Rebuilt olmates 4 cyl engine last year. Basically she was machined with heploite (oversized) pistons, rebuilt head including new stems / inserts and oversized valves with a slight shave, has Lukey headers, runs a new stromberg carby with a cleaned up inlet manifold and elect ignition.

She does pull better and runs a lot smoother / quieter but is still just the Landy 4 cyl:). However, I should get a heap more years out of her; thats if fuel prices dont force olmate into the garage for good first.

[akelly]

Street Machine mag did an article a few years ago on getting more HP out of the blue holden 6 - the same things apply to any naturally aspirated carby donk. The first few things they tried got pretty decent results - lose the fan (replace with thermo fan) and ditch the factory air cleaner, there was about 14kw just there... they got a bit carried away towards the end, but the article shows a good range of typical mods and what the effect is on output.

Link to the article Find used cars and new cars online - CarPoint Australia - CarPoint Australia (http://www.carpoint.com.au/Tig/Minisite/Minisite.aspx?alias=carpointau&id=7229)

[JDNSW]

Before starting anything, the thing to do would be to make sure that it is fully up to the original manufactured standard - carburetter in perfect condition, all ignition bits in perfect condition and correctly timed, valves and piston rings sealing properly, no carbon build up, camshaft unworn and chain and sprockets unworn, tensioner working properly, and timing correct, and tappets correctly set. Thermostat correct and it and the rest of the cooling system working to keep the engine at the correct temperature. Fuel pump working properly and no partial fuel line blockages or leaks, manifolds tight, sealed, and matching the ports in the head.
And for the vehicle itself, wheel bearings correctly adjusted, brakes not dragging, gearbox, diff and transfer case bearings correctly adjusted, right size tyres correctly inflated.

The simplest improvement is probably to shave the head. Most four cylinder Landrovers sold here were 7:1, and provided the head is a later one with a square boss next to the carbie, it can be raised to 8:1 or even higher to advantage. This will modestly improve power and economy with virtually no adverse effects.

Beyond that there are a number of things that can be done as suggested, basically all involve improving the breathing (inlet and exhaust), which will increase the maximum power available, but if more than very minor changes are made, particularly to the camshaft, this is likely to be at the expense of driveability at low rpm. One of the attractions of this engine is the way it pulls strongly from idling.

I remember reading many years ago of this engine being supercharged, and this may well be a suitable approach - as it was designed originally as a diesel, it should stand a significant boost, and this may be an easier modification than turbocharging.

On the other hand, I would be very dubious about increasing maximum rpm significantly, as I would expect this to be likely to lead to all sorts of problems - it is already a high revving engine by the standards of its time.

John

[Brisso57]

<Snip> The first few things they tried got pretty decent results - lose the fan (replace with thermo fan) and ditch the factory air cleaner, there was about 14kw just there... they got a bit carried away towards the end, but the article shows a good range of typical mods and what the effect is on output.
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OK. Definitely the fan gets changed for the Thermo jobbie.

The air cleaner is no doubt great for its intended (design) environment, but realistically a lot of 2A's are now hobby vehicles ... that don't run in aggressive environments, so it does make sense to swap the air cleaner for a higher flow conventional type. Does anyone have a suggestion of a widely available replacement, something that could be sourced from a wreckers?
(Holden/Ford/Toyota/ etc) ? It'd be great if the mounting flange was the exact size.

Doug

[isuzurover]

When I built my 2.25P I fitted 0.020" oversized pistons (but you can go up to 0.080"), and shaved the head to about 9:1 compression.

The above combined with extractors and a zenith, and it went like a freight train.

A mate had about 9.5:1 compression, 0.080" OS pistons, slightly strroked, and a bunch of other mods (was an engine builder). His motor had much more power again, but it pinged like a ba$tard on normal fuel, drank like a fish, and broke series 3 gearboxes every other week. He eventually swapped for a Stage 1.

[olmate]

I have gone back to the std aircleaner and have noticed the power drop off from when I had a paper filter fitted. As I have a thermo fan fitted I spose I should just get rid of the std fan and then the ol girl will be as good as she is going to be. :D

Now I have something to do after work tomorrow.;)

[Blknight.aus]

the 2.25 does reveal a smattering of cheap extra power if you do the aircleaner and fan as suggested but also goto the effort of port matching the manifolds and gaskets when you replace the exhaust manifold with extractors.

Thats pretty much the limit without pulling things apart but if your pulling it down Id suggest a bit more muscle on the cam, port n polish the head and up the compression to at least 8.5:1 and nearer to 9 I dont reccomend doing this by head shaving but by hightopp pistons.

There ends the relatively cheap mods and the ones that dont destroy the engine's longevity.

[akelly]

Brisso57 - I replaced my air cleaner with one from a "speed shop" - cost about 40 bucks and has a standard size replacement filter. If I did much dusty work I would have gone with the Finer Filter type with the washable element - but I couldn't really justify the extra dollars. If you measure up the carby throat diameter you should be able to find an aftermarket one to suit.

I'm still running the standard fan, but that's next on the list.

[C H T]

The following mods are simple and not expensive: Fit a 2 1/4 diesel camshaft advanced 3 degrees (with a new timing chain), a set of quality extractors, and a free flowing exhaust system - 2.5 inch would work well, clean up the inlet and exhaust ports, fit either a new Zenith 36 IV or Webber off a late 2.5p. Make sure that Distributor etc are all timed/working correctly.

This should give you a very sharp 2 1/4 petrol motor that will perform very well.

Christopher

[Brisso57]

The following mods are simple and not expensive: Fit a 2 1/4 diesel camshaft advanced 3 degrees (with a new timing chain), a set of quality extractors, and a free flowing exhaust system - 2.5 inch would work well, clean up the inlet and exhaust ports, fit either a new Zenith 36 IV or Webber off a late 2.5p. Make sure that Distributor etc are all timed/working correctly.

This should give you a very sharp 2 1/4 petrol motor that will perform very well.

Christopher

Very interesting Chris.

Can you just clarify the timing? Do you mean set advanced 3 degrees from the normal setting for the standard cam? Or just 3 degrees before TDC?

cheers

Doug

[C H T]

Doug

Diesel cam is advanced 3 degrees from the normal setting. I have had to do with engines set up as mentioned and they have been very sucessfull - and use all standard Landrover parts

Christopher

PS One of my sons has just informed me that the 2.5 petrols use the camshaft that I have suggested

[UncleHo]

G'day Brisso57 :)

What do you intend to do with the vehicle? do you want the extra power for offroad work or for extra speed, as they are two different specs, My 2 1/4 litre 2a has Extractors, a 2" (50mm) exhaust system with a free flow muffler,still runs the military 8 bladed fan and full shrouding & oil bath filter, bellows like a bull and cruises at about 90/95 kph it also has a Webber 34ICH carby, but will be going back to the Zenith 36IV unit, the float bowl of the Webber is a little small and it will vapourise after a short 5/10min stop, and will give fuel starvation problems 100metres after restart, speed will be limited by the gearing, the series Landrover is fitted with 4.7 ratio diffs, so, the engine reaches peak revvs before the vehicle reaches peak speed, 5,300-5,550 rpm is when the engine self-destructs :( this particular motor has done in excess of 100,000 miles the cam is standard, point type dist, light head shave, .040 thou O/size (bore wear) if you are in doubt just ask Numpty's Missus as to how it travels:D

cheers

[Brisso57]

G'day Brisso57 :)

What do you intend to do with the vehicle? do you want the extra power for offroad work or for extra speed, as they are two different specs, My 2 1/4 litre 2a has Extractors, a 2" (50mm) exhaust system with a free flow muffler,still runs the military 8 bladed fan and full shrouding & oil bath filter, bellows like a bull and cruises at about 90/95 kph it also has a Webber 34ICH carby, but will be going back to the Zenith 36IV unit, the float bowl of the Webber is a little small and it will vapourise after a short 5/10min stop, and will give fuel starvation problems 100metres after restart, speed will be limited by the gearing, the series Landrover is fitted with 4.7 ratio diffs, so, the engine reaches peak revvs before the vehicle reaches peak speed, 5,300-5,550 rpm is when the engine self-destructs :( this particular motor has done in excess of 100,000 miles the cam is standard, point type dist, light head shave, .040 thou O/size (bore wear) if you are in doubt just ask Numpty's Missus as to how it travels:D

cheers
Hi Uncle Ho

I'm looking around for a 2A to restore for weekend road use and occasional beach work. (It won't be boulder-jumping or mud-plugging.)
My preference is to get a SWB, but these appear to be much more scarce than LWB's. I'd be happy with either a soft top or a hard top, as I intend to ultimately acquire 2 tops that I can swap as I choose. (I don't want a 5-dr s/wagon.)

If I have to settle for a LWB, then obviously a petrol 4 will be working harder than with a SWB. Hence my interest in this thread. It seems that a 4 in good nick, and with the changes proposed will be quite OK. (From what I've read, it seems that the 4 is more reliable than a retro-fitted S3 petrol 6.)

Further down the track, I want to fit a S3 all-synchro box and also an overdrive, to make it better on the road. It may be a hybrid, but I want a LR hybrid!

Just trying to do a bit of forward planning! :-)

cheers

Doug

[isuzurover]

Hi Uncle Ho

I'm looking around for a 2A to restore for weekend road use and occasional beach work. (It won't be boulder-jumping or mud-plugging.)

Further down the track, I want to fit a S3 all-synchro box and also an overdrive, to make it better on the road. It may be a hybrid, but I want a LR hybrid!

Doug - There are plenty of SWBs around if you look. In fact my father (in Brisbane) has one with all the steel bits galvanised which he may be tempted to part with.

The SIII box is a retrograde step IMHO. Weaker in many places. A IIA box is just as easy/nice to drive once you get some practice at double clutching.

I have heard of the mods CHT mentioned above, apparently works well. In addition, you could fit a diesel flywheel, they are 5-10kg heavier, so would give you more torque, at the expense of a slight decrease in acceleration.

[Brisso57]

<Snip>

In addition, you could fit a diesel flywheel, they are 5-10kg heavier, so would give you more torque, at the expense of a slight decrease in acceleration.

That's interesting. I'm not after acceleration, so that'd be good. (Ta.)


Doug - There are plenty of SWBs around if you look. In fact my father (in Brisbane) has one with all the steel bits galvanised which he may be tempted to part with.

Yes pls. Can you PM me with the contact details.

cheers

Doug

[olmate]

Just taken the fan off olmate and replaced the std air filter with a paper cartridge. Will see how she goes. I do have a thermo fan fitted so I expect all things to be good.;)

Will take her for a drive tomorrow and sus her out.

[akelly]

Olmate - expect more induction noise, that's the downside!