Nearly done with the turbo conversion but i also took apart the spare engine to 'have a go' so if the cars engine needs fixing im familular with its build.

I took off the below barrel gasket so i can draw it up and get a 0.8 or 1mm spacer laser cut to lower the compression ratio. But what material should i seek for to make it from?

Is normal aluminium sheet (ah14) going to be ok? or should i hunt for some copper. This isnt a head gasket, but a below piston gasket.

ps the original one iis .3mm thick.

[Edited on 21/10/07 by Moorron]

Would have thought that a barrel base spacer would not be under any pressure like a head gasket so as long as the spacer was flat and even thickness it would be OK . I stand to be corrected though.

I don't know much about bike engines, but does the "barrel" you refer to act as a dry or wet liner in the alloy engine casing?

i.e. does the spacer/hasket your designing have to seal the base of the barrel to prevent engine coolant leaking into the crank case?

there will be some pressure in the crankcase , use a liquid gasket like volvo do for there intermediate section on 5 cyls .

and you should really be considering lower CR pistons so that you keep some squish in that combustion chamber .

Why not post the question on

http://www.technical-forum.com/bike-turbo

There are some issues you need to think about when choosing a material and i am sure you will get the answers you need on there.

I've used aluminium on mine with no problems for years.