Liners, Pistons and rods

[Fordy]

Quick spec - MS2, carb, 285,T28 24psi

So I've managed to crack 3 inlet valve collets and valve grooves and bend a rod and naff a piston/gudgeon pin, my fault for having a high rev limiter but it has been a fun 4 years on this engine.

I've got a big valve head being made atm with new guides not shortened and 36~ inlet and 32mm~ exhaust valves.

So I'm looking for some help from wiser members.

Steel liners or ductile liners.
Wossner pistons and pec rods.

What piston rings and gaps did people find sealed and worked well on the steel liners?

Might aswell go 77mm pistons, so where to get a headgasket that size? and are my only options mls? as i'm trying to avoid getting the block skimmed.

I'm looking for answers which will give me another 4 years of abusive driving and pod runs :smokin:

[Trevhib]

Not in my knowledge zone this really but I do know that in the past people have said if you have steel liners then you need forged pistons. :agree:

[Matt Cole]

I wouldn't use steel liners in an iron block. In fact I'm not aware of any modern manufacturers using steel liners anymore. Differential expansion causes them to sink in the block. They can also twist in the block, cause leaking gaskets and excessive crank pressure due to the silly ring clearances. Total seal gapless rings can help with the latter, but the cost is reasonably prohibitive when only tuning a 1950's push rod engine!:crap:
Wossner and pec are decent enough companies and produce reliable components. Go for the best cast liners you can get, maybe not perfect circle as some had issues a few years back. If your set on 77mm bore pistons JE used to do some pretty good quality units coupled with 128mm long and 77mm stroke rods.

Yes avoid skimming the block unless you are going to match the liners with an appropriate gasket. Some carefull calculations will be needed to make sure you get a decent seal.

You can get a pro-seal 1.8mm 77mm bore gasket as an alternative to the mls. Cambridge motorsport are dealers.:agree:

[Fordy]

I'll be going with ductile liners from Westwood due to cost and less arsing about with rings, but ATM unsure if I stay 76mm for headgasket ease reasons or go 77mm

I believe the wossner rings and ductile liners should suit better than steels.

I've also emailed pec to see if they oil groove the sides of the R5 forged rods to aid oil flow to under the piston/skirt or if they can make the grooves for me

Fingers crossed, ductile liners and conrod mods to aid oil flow upwards will reduce any liner wear but also drop piston temps

[Matt Cole]

I think it was BB tuning a few years ago that fitted f7p/r (I forget) piston oil spray jets. Seemed to work ok although clearance was an issue. There's a thread some where I'm sure.

[Fordy]

Matt if you see this picture you'll see what I mean regards the oil grooves.

Oil that usually just comes out anywhere gets channelled upwards, I was going to get a set of stock rods modified before I found that I've damaged a piston pin.


I'm also searching for uprated bearings, as mine after 4 years are toast, I only know of 1 oil pressure loss experience on this engine which could be the cause, but while I'm in here be silly not to try source better bearings for it.

So far i've found the following still supply bearings

Mahle
King race
Glyco

Think I've got Glyco in already which I wont use again, Maybe King can supply something uprated but their catalogue doesn't list any other than standard Alu on steel material.

I've found a supplier of 77mm gaskets which aren't mls for around £30-40, but i've got a sneaky suspicion that the uprated blue seals have 77mm fire rings so i need to measure a old crushed one to check

[Danny]

He up , how did you. Go on here buddy with diffrent bearings ?

[Fordy]

Used Mahle bearings :agree:

[Danny]

do you have supplier details for those bud? what is the material on those ?

[Fordy]

Same aluminium bearing