sortedsaff

im sure this has been asked but just want to be sure .

been offered some 4x4 cossie pistons for my 2wd sapph cos ( 205 block)
there 1mm oversize i know i will have to machine to suit but just wanted to know if there is anything else i should be aware of ?
bloke said something about comp being 7:2:1 ?

be gentle im new to the cossie scene lol

any help much appreciated

Tony

big_wig_074

std 4x4 pistons in a 2wd engine will lower the cr to about 7.8:1 from 8:1 so i would have thought that these would end up being closer to 7:1 in your 2wd engine than 7.2:1.are you going for big power?as these will be low comp of the type usually used in 500bhp engines of old.

costina

iTrader: (1)

Remember to fit them the right way roundarrows facing forward

Unless you want 2wd piston slap and more

Paul

sortedsaff

cheers for the replys guys they wouldnt be going in a massive powerd engine will only be running 350 ish.

so they will be ok if fitted correctly ?

big_wig_074

yeah theyll be fine,get an appropriate chip from stu @ msd on here or similar,tell him the spec and im sure he can do you a chip!

sortedsaff

lovely job cheers bud .

cossieDavedree

isnt your block on standard bore at the moment?

its a big jump to 1mm oversize.

costina

iTrader: (1)

IMO i would consider having valve cut outs machined into them for future power upgrades BD 14 anyone

BTW Stu's chips on greens would be approx 350 with the right turbo etc

Paul

sortedsaff

yes its on std bore but needs a rebore . its a 205 block i plan to run these in the 205 1mm over size. then while thats in the car (as we all know we want more power) so while thats running i will be building up a 200block ready to upgrade for 450+.

COSTINA- they have got valve cut outs already