escort_lx

When fitting these to a standard 2.0 efi pinto, does anyone know what machining is required to the head/block to get the compression back up to a usable figure for turbo use as i believe just banging them in there brings the compression down too low.

pistons are 1mm o/s mahle cosworth yb turbo

cheers

robrs2

Cant remember the exact figures but you get something like 7.2:1 CR with a pinto and yb rods and pistons. You can machine about 1mm off the head and get to about 8.1:1 or you can machine the pistions about 1mm and the block is decked about 1mm to get to 8.5 or more.

Dont forget you need the YB oil spray/pump or the rods need a groove

escort_lx

Thanks mate, what head gasket would i be best to use? I was using grp a cossie b4 when engine was standard. Block is currently in machine shop getting bored for the o/s pistons. Once its back i will cc the pistons and do all the calculations but 1mm was roughly what i had in mind. I measured the head volume to be 50cc.
I also have a 2wd spray bar here ready

do you know if the pistons sit flush in the standard un skimmed pinto block?

robrs2

The outer of the piston is almost level with the block deck.
Not sure about the head gasket as the YB one has different holes in for oil ways.
I’m also going to build a pinto turbo up later this year using YB parts. I already have a standard pinto running a turbo but I’m after a bit more power

escort_lx

They seem to have the same oil ways but slightly different waterways. I have both a reinz grp a and a standard pinto one here. Not sure why they are different

escort_lx

Back up and running, 1mm off the head and yb head gasket setup is giving me about 8.3:1

robrs2

Sounds good. Need to get my spare engine done the same.