SE liners in LC Turbo

[Simon350S]

Hey all

Know quite a few people have done this but from what Mr Fish has said before I believe there is some work required to the block for them to fit??

Anyone know exactly what it is and got tech info on it or can reccomend someone to carry it out and an approx price??

Cheers

Simon

[Glyn Harper]

I believe the way to go is stick with cast liners. Nikasil/Aluminium ones (from the SE) wear at a greater rate and don't like water in them. In fact, they stopped using nikasil on the V8 and went back to cast liners. They're stronger, last longer and will take more power before distorting under load.

I think nikasil coated aluminium ones are just a bit lighter..

Hope that helps.

Glyn.

[WayneB]

I used the Forged Mahle pistons with the standard iron liners in mine (with no apparent problems).

One of the reasons Lotus went to the aluminium / nickasil set up was to faclilitate greater transfer of heat from the liners to the coolant when the engine is running at high boost for sustained periods.

As my car isnt flying down the autobahn at 150 mph daily, I didnt think it was worth all the extra aggro invoved to go with the aluminium liners.

Edited January 8, 2007 by WayneB

[Simon350S]

Ohh??

Thats confused me a little then as I was told the piston liner setup was a weak point in the older cars and it was a worthy upgrade and something that is saught after when selling the car on...???

Not sure which way to go then.... Anyone else???

Theres nout wrong with the ones i've got at the moment, the cars done about 69 on them but the only smoke is from the knackered turbo when it hits boost, and that only started after it had been sat for ages... guess the seals are shot....

Anyone know how much to recon a turbo?? and any recomendations to who and any upgrades??

Simon

[WayneB]

The Hepolite cast pistons were the major weak link in the pre-HC cars.

I suppose Lotus originally went with them as they are quieter on cold startup (tighter clearances used) and cheaper than forged pistons.

Because they are weaker though, they cant take higher compression ratios or large ammounts of sustained boost.

They also dont like pre-ignition (fron bad low octane fuel/ advanced timing / lean mixture settings.

Edited January 8, 2007 by WayneB

[Malc Holmes]

I agree with the keeping the cast iron liner suggestions. Loads of folks have taken this approach and are still smiling today. I understand that one of the reasons for going to alli liners was to match the expansion rate of the block, so you have less chance of head gasket failure but this just dosn't seem to be a major issue. Lotusbits thrash the living hell out of the enigines in their rally cars and I am pretty sure they are still using iron liners.

The Lotus sale has a discount on the liner/piston combination but they still expensive! QED do new iron liners at a very fair price and espritism.com (thats me that is) can set you up with a new set of HC turbo pistons (the genuine Mahle part) for

[dazmans3]

Ohh??

Thats confused me a little then as I was told the piston liner setup was a weak point in the older cars and it was a worthy upgrade and something that is saught after when selling the car on...???

Not sure which way to go then.... Anyone else???

Simon

From what I understand, following a chat with one of the Lotus engineers during the factiry visit, One of the week points was the cooling flow arround No 4 & no 3 cyls on the LCs. OK for the non turbos, but not enought to coupe with the extra heat produced on the turbos. This was modified on the HC varients with better coolant flow.

It seams the LC turbo engines, as an average, have rebuilds at such low milages. Having said that I do know of a couple that have doen well over 100k on orriginal builds.

Would like to know the comparrisons of head gasket failures & No 3 & 4 cly problems between th LCs & HCs. Though I have heard of more HC engines reahing high milages.

Daz

[Simon350S]

Cheers Daz

Following on from that point, anyone know how they overcame the coolant flow problem on the HC's considering the block is the same?? Or are they different???

Simon

[yeller77]

Just FYI for the thread, the liner bore-in-block size is 1 mm larger for the Nikasil liners, so choice is either do some machine work or use a later block. In addition to improved heat transfer, uniform expansion and sealing is a key with alloy liners as witnessed by the fact that the liner nip is nil to negative with Nikasil and positive nip with cast iron. And the tightest piston to bore clearances are acheived with alloy pistons and liners.

You can bore the cast iron liners quite a bit, I was prepared to go 60 overbore on mine before I happened upon a later block and liner set. There's a guy with a Jensen in the states running 2.4 or 2.6 l on custom iron liners with a to-the-limit overbored block to allow a massive increase in cyl. bore. Nikasil liners don't take to going overbore, but can be readily refinished for around $200 ea. The finish is quite hard and wears quite well, especially with the upgraded processes that Perfect Bore and their stateside affiliates are now using. The processes are well-established and even include liner repair due to the widespread use of treated alloy cylinders and liners in the two-wheeled world.

That's not to say you can't build a fast 907/910 with iron liners. B)

Eric

[AJay]

Cheers Daz

Following on from that point, anyone know how they overcame the coolant flow problem on the HC's considering the block is the same?? Or are they different???

Simon

The main differences are a higher capacity water pump, a different inlet manifold and restricted outlet on the front of the cylinder head. Lotus recommend that i upgraded these components when discussing the Knock problem that i was experiencing with my LC motor running HC piston and liners.

They introduce a modified cooling system for Turbos Technical service Bulletin 1987/26 to provide "increased colling systems safety margin in extreme conditions" this was a factory recall for 85MY on but not for US turbos, and i notice that a full kit is available in the sale for

[Simon350S]

Cheers Andy

Just found it on the list and added it to my wish list for next monday

Simon

[chris24g]

Nikasil liners don't take to going overbore, but can be readily refinished for around $200 ea. The finish is quite hard and wears quite well, especially with the upgraded processes that Perfect Bore and their stateside affiliates are now using.

If anyone is interested, I just listed a set on ebay. They are nikasil liners from my 2.2 turbo. They have been replated and are ready to drop in. They will probably go for the cost of an iron set, since there are not that many turbos in the US.

[lotusmotors]

One last thing; the opening in the front of the engine block (behind the pump) that the water is pumped through is enlarged on the later blocks. It is machined out rather than being left as cast and is maybe 25-30% larger. I usually open it out on the early engines when rebuilding them.

If anyone is interested, I just listed a set on ebay. They are nikasil liners from my 2.2 turbo. They have been replated and are ready to drop in. They will probably go for the cost of an iron set, since there are not that many turbos in the US.