as i dont have the cash to go buying special pistons, to lower the compression on a zetec am i better off fitting a de-compression plate or skimming the pistons a bit?

thanks for any help

Dan

 

To be honest I dont like either method , decompresion plate means 2 head gaskets and therefore more possible failure areas , and machining pistons removes material from a point where turbo engines suffer anyways ...... if I had a choice it would be decompression plate as the possible failure should not be a catastrophic one , where a piston failure could take the whole engine and debris into turbo aswell , just my thoughts

 

thats a good point, if the head gasket blows its not the end of the world i suppose, although ferriday reckon you can use one of thairs with only one gasket and some type of sealing compound

out of interest do you know the std compression of a 2.0 zetec?

 

you can stack the MLS std head gaskets - 2 ST170/cougar gaskets will give you 2mm thickness. Mike @ Ferriday is a very clever bloke, i'd listen to him.

Rick.

 

sorted then, i'll order one of them when i build the zetec, i'm going to turbo my std 3i first then build a zetec when it blows up, may aswell, i'd only bin the engine anyway

cheers mate

 

i bort a 2mm decompression plate from ferriday,use 1 headgasket and compound sealer,but headgasket didnt last long at all.

 

i built a buget one .and put a de comp plate on it .compression ratio was 9;1 as i fitted a 1mm de comp plate .only used 1 head gasket .it made 225bhp at 8psi on the rollers .and still running stong

 

gasket failures on Zetecs are almost always down to the finish not being correct on the mating surfaces, they need to be substantially smoother than composite type gaskets, and a lot of machine shops can't replicate the oe finish.

Rick.

 

thats brill, what spec is the engine? i'm after around that power.