Thread: 2 Litre Mods

"Head work and bigger valves - convert to ULP"

I don't think you will need to modify the seats or valves for ULP. The original seats are very hard apparently and were made in the days when petrol was very poor quality.

In fact I don't know of any car that hasn't had hardened seats fitted that needed them after the withdrawal of leaded petrol,

Cheers Charlie

I run ULP in my 53 no problems at all. Which has a 2L.

It loves British Petroleum 95.....

Tho today it got 91 as it was 93.3 c per L Yepeee!!!! I wonder if we will see 89.9 again!

Originally Posted by garrycol

Hi Everyone,

I have bought a late 2 litre engine to go into my station wagon - for starters will need a new carby, dizzy.

I am assuming the engine will need as a minimum, valve grind, bearings and rings - most likely more.

So - given I am going to have to do major reconditioning I am looking for suggestions to improve overall performance.

First up some givens - I want to use an original carby - maybe jetted for more oompf, I will use an original dissy and will use an original exhaust manifold.

Aim - more power and torque but not at the expense of a peakier torque curve - ideally more torque but still coming in at low revs.

Performance mods for consideration:
1. Head work and bigger valves - convert to ULP

I doubt there is room for larger valves. If there is might be worth doing.

2. Better cam grind.

Needs an expert, which I am not

3. Boring the engine - take out to max oversize or actually overbore?

I don't think you can safely go more than the max oversize. What you can do will also be limited by available pistons.

4. Increase compression ratio from the 6.?? to 8.?? - shave head or different pistons?? Would the conrods - bottom end take it?

It would have to be new pistons - there is no combustion chamber in the head - the bottom of it is flat. Bottom end should take it as long as you don't increase maximum revs.

5. Bottom end - would another landie crank fit - to stoke it out a bit?

Can't think of anything that would fit.

6. Given the contraints of a standard bigger jetted carb and standard exhaust manifold - could consider extractors if they could be easily made - would fuelling be an issue with a modded engine.

This engine is limited primarily by breathing - but you want to keep the manifolds! Larger diameter exhaust is likely to help, but remember that freeing up breathing, while it is likely to increase maximum power, would also make the engine less flexible and less driveable.

Any other suggestions - everyone has ideas on how to mod engines - and thoughts accepted - but would like to hear from people who have actually modded the 2 litre petrol engine and what they did and how did it go.

Thanks

Garry

This engine has been out of production for fifty years, so most of the people who would have known how to modify it are dead. The similar six stayed in production for another twenty years, so perhaps you might find more useful information on it. I suspect that the biggest improvements you could make to power would be to increase the compression ratio, and to fit twin carburetters. But the second would be quite a job, and is likely to reduce flexibility.

John

If breathing is a problem, why not go for a turbo? I suspect that this is all a bit mute as most doing up series ones are trying to restore back to original as possible. If you want to get more power and are prepared to make mods why keep the same engine? Just drop a modern 4 cylinder into it! Turbo diesel. Some bloke near Ballarat stuck a 200 Tdi into his 86" I think he is pretty happy that it has more power that he needs to use.

Garry

You might consider a contemporary Rover 6 cyl saloon motor ..I've seen at least two LWB series 1's with them fitted ...the drawback is the fitting.. from memory , they cut a section of the bulkhead out or some radical thing .

I don't think you can do much with the original motor ... If it was a easy option to make it produce more bhp or torque.. then plenty of people in the UK would be 'hotting up' motors, but you never hear of it . You can use the Series 3 F head pistons . Apparently, the Rover 6 cyl pistons will increase the compression slightly, by about 5% or something like that. You could also polish the inlet and exhaust ports in the head/block ..would it make much difference ?

Mike

Getting off track a little with talk of turbos and 6 cylinders etc.

I have to rebuild a 2 litre (this is a given) and I am just after advice as to what mods I might be able to do while the engine is pulled down to improve perfromance.

Certainly on outwards appearance I want the engine to appear standard - hence the original carby and dixxy requirement and no other add ons.

Seems to go is to bore to max oversize and clean up the head.

Cheers

Garry

Originally Posted by garrycol

Getting off track a little with talk of turbos and 6 cylinders etc.

I have to rebuild a 2 litre (this is a given) and I am just after advice as to what mods I might be able to do while the engine is pulled down to improve perfromance.

Certainly on outwards appearance I want the engine to appear standard - hence the original carby and dixxy requirement and no other add ons.

Seems to go is to bore to max oversize and clean up the head.

Cheers

Garry

If you can locate high compression pistons, it would help. Series1buff suggested that six cylinder Series 3 pistons will fit and increase the compression a little.

John

The 2 litre engine responds surprisingly well to power modifications, it is a crossflow design which has been strangled in order to achieve low speed torque.
You can replace the inlet manifold and carb with a 4 branch design manifold fed by a 2 barrel progressive Weber carburettor, and replace the exhaust manifold with a similar 4 branch 2 into 1 header, and the result is amazing. Even with the standard camshaft.
It will spin easily to 5000 rpm and is a delight to drive.
I drove my little '56 in this condition for 15 years and loved it.

There is a downside though, sustained engine speeds over 4000 rpm will cost you a camshaft and followers. The chrome facing on the followers quickly comes off, and that is the end of the camshaft.

It is also very noisy above 3500 rpm. even though I balanced the engine.


If you want to retain the original look of the engine, you can polish the roughnes out of the inlet ports, and make sure the ports line up smoothly.

The same with the exhaust manifold, although that is not as important as the inlet, a free flowing muffler will help.

Increasing the compression ratio will definately help, there is enough metal on the top of the block above the piston top savailable to machine, I think there is about 1 mm available to remove, and you can use a steel shim gasket instead of the copper composite one.

Experimenting with carb jetting and venturi size can give benefits too, remember the engine was designed to run most of the time at 2000 rpm and full throttle, although you may lose some low speed torque.

Good luck,
Terry