Engine rebuild question

[mwmackenzie]

If you were rebuilding your 2.2 turbo and were to be replacing the Cylinder liners Would you use Ali/nicasil liners or the new cars iron ones? what are the benifits or shortcomings of both?? Discuss..... hahaha

Cheers

Mark

Edited by mwmackenzie on Wednesday 6th August 12:28

[anonymous-user]

I thought they wern't interchabgable, I have cast iron linners in a 910 S4 block but they were made for me as a special, from memory the ally linners are 30 thou bigger where they slide into the block.

I race my engine and used cast iron linners to try to add some stiffness

kelvin

[mwmackenzie]

Yeah you can buy them to fit mate from PNM or lotus bits..

I'm going down this route too.

Mark

[Oilchange]

wont they rust in the coolant?

[Esprit2]

No, the iron liners won't rust in proper coolant. Anti-freeze contains anti-corrosion additives, water pump lube... a number of features that make it engine friendly.

Lotus iron and Nikasil coated aluminum liners are not directly interchangeable. The base portions that pilot into the cylinder block are different diameters and the blocks are machined to fit accordingly. In order to fit iron liners to a 1986 onward 910, non-Lotus liners would have to be used.

The major advantages of the Nikasil liners are it's thermal expansion rate and low wear rate.

Iron and aluminum expand at different rates as the engine warms up, so using iron liners in an aluminum block/ head assembly causes several problems. Most importantly, there's a small amount of relative movement between the liner and the head as they grow at different rates. That difference makes it more difficult to get a secure, reliable seal between the liner and the head... ie, it's more prone to blow a head gasket.

With the higher compression ratio and increasingly higher boost levels used from 1986 onward, iron liners would be increasingly problematic.

Secondarily, the Nikasil coating is very wear resistant. Baring direct damage, they rarely show significant wear when the engine is torn down.

The downside... Nikasil coated aluminum liners are more expensive than iron liners.

Regards,
Tim Engel

[mwmackenzie]

Great info tim! I don't know which way to turn although Garry Kemp recomends using the aftermarket Iron liners and some special rings though I never thought about the rest of the engine being alloy and expanding at different rates??? hmmmmm I'll need to see the damage for myself then I'll decide which route to take

Mark

[G_Reaper2]

Iron liners to fit the later HC (red top) engines are readily available from QED and machined to fit correctly. The biggest problem with the old cast liners/pistons when used by Lotus turned out not to be the liners but the extremely inferior Hepolite pistons. The Hepolite pistons in the Esprit Turbo application are at their design/material limit any extra boost or problems causing increased detonation temp simply melt the top of the piston. I have biult up a number of Esprit engines in HC spec with QED cast liners and the later far superior Mahle pistons and these engines are extremely reliable. Most performance engine tuners would go down the cast liner + Mahle Piston route as the alloy Nikasil liners flex too much. This is a problem which caused early HC engines to blow head gaskets hence Lotus had to re-design the head gasket. Garry Kemp (known to a lot of Esprit owners as an Esprit engine expert and tuner) has had great reliability with this spec of engine even tuned for use in a dragster.

N.B the cast liners from QED are approx £60- £70 each so rather cheaper to replace rather than the Ali/ Nikosil which also have other known design problems such as losing their nikosil coating.

Hope this info helps.

[mwmackenzie]

Thanks Reaper, I bought my engine top end off Garry and have spoken yo him about the issues and he also recomended the cast liners so I'm sure thats the route I'll go down this time, my pistons are mahl and have been alluminium carbide coated to protect them and the bottom end from heat (done by poeton)

Thanks for the advice

Mark

[M Blur]

Whatever you do - try and use one guy - bitsy engines often become busty engines because parts aren't married up well..

I'd recommend turfing engine to Garry

JB

[mwmackenzie]

Garry too busy to take it on, I am just going to use one guy, well 2.. one has taken the engine out and will put it back in and the other will build it once he has assessed it and told me, hey it's not so bad, I can sort this no problem mate for minimal cost hahahahaha... I just want it fixed now....

Cheers
Mark

P.S Blurry hows your car coming along??

[mwmackenzie]

Garry too busy to take it on, I am just going to use one guy, well 2.. one has taken the engine out and will put it back in and the other will build it once he has assessed it and told me, hey it's not so bad, I can sort this no problem mate for minimal cost hahahahaha... I just want it fixed now....

Cheers
Mark

P.S Blurry hows your car coming along??