thelynx

Hey

Im looking to rebuild my cvh for a 220bhp spec, and want it reliable and was wondering what the best options are for this.. Where is the best place to get these items from at a reasonable price.. Also how strong is the standard cvh crank in the s2 engine ?

Any help would be greatly recieved
Cheers

reality

You need to do nothing other than skim the pistons to drop the compression ratio.. the pistons, rods and crank are fine for 220bhp..

Rab

Don't be daft, you can't just skim the pistons and expect it to handle 20psi. If you want 220 bhp mate, I'd suggest a set of steel pistons from the likes of accralite or Ross racing, and have the road shot peened while they're out just to be safe.

Pistons can be had from as little as £90 each. Even if you pay someone else to do the work it'll be about £600 for a bottom end rebuild...

Much safer for piece of mind. I've seen skimmed pistons before, usually after they've melted and your picking them out the sump

turbo.jon

Pistons and crank will be fine its the rods that are the weak point you can get away with skimming pistons but its not best way you might get away with just std pistons on std compression or just go for some forged pistons as above they dont cost loads There are loads of diffrent views you will get but its up to you mate depends how big your wallet is as you could spend thousands

Rick

Steel pistons? PMSL.

Std stuff will be fine @ 220bhp.

Rab

The amount of people that say that and end up with bit of piston in the oil

Maybe up here in scotland people can't set them up or something

thelynx

I shall so some further homework on this.. Seems theres a few mixed opinion here.. I think i would rather spend some cash on quality rods and pistons for the day you get bored and want more power, at least then you know its safe

reality

Maybe that's what it is.. Don't forget, the standard pistons are Mahle, not some other crap.. Taking 40 thou off the pistons for up to about 230bhp is perfectly normal and fine.. if it's set up right, it'll do a lot of miles.. I know of a lot of engines from a very reputable house that are done this way with zero failures.. at 1.5 bar!

So are you saying cossie owners shouldn't machine their stock Mahle pistons on their 500bhp engines? Something people have done for 20 years?

Rick

thelynx

If u have the cash, then by all means get some steel rods and forged pistons.

JimmyBoy

iTrader: (1)

Ideally you would spend that little bit extra to start with and get steel rods and forged pistons rather than doing half a job and having to get the engine out again when something fails cos you skimped on something!

You know it makes sense! Steel rods + forged pistons + ARP bolts.

Out of interest, what cam are you using, and how much boost do you plan on initially using (after its run in) ?

thelynx

Yeh for sure.. Not really sure on cam would prob go for the kent item.. maybe 20psi.. Not really sure at the min just throwing some ideas around now that the zetec build is off..

JimmyBoy

iTrader: (1)

I know people get some stuff cheap from the states for the zetec's but I dont know if this is true for the cvh? Would be interesting to know though.

stuart collins

iTrader: (7)

my crank is takin well over 300bhp . standard rods and pistons will do 220bhp

Rick

Stuart, how's urs coming along now?

Be intersting to see how laggy the GT30 is compared to the 34.

Tim

iTrader: (1)

I know a cvh with skimmed pistons runs 30 psi and nos no problem,s for 10,000 miles steel rods and skimmed mahles mint lad but for what you want shot peened rods would do tbh.

stuart collins

iTrader: (7)

few probs with it, the actuater wasn't strong enough and the waste gate kept openin at 5K and wouldnt run more than 1.5 bar. Think the cossie injectors (400) are maxed out. But the one run we did was comin on boost at 2500-3000

DUDE_SWEET_FRST

so how much are steel rods and low comp pistons then?

and from where?

id love to do them to my engine

reality

Farndon charge about £700 for a set of steel rods.. Custom pistons cost about £150 each from Arias in the UK.. alternatively if you know the measurements of both, you could get someone in the states to make them for you at a cheaper cost (bare in mind import duty and vat)..

Rick

buton do some accralite's off the shelf that u machine to any CR u want.

stuart collins

iTrader: (7)

why low comp??????????

notSteveS2

y do u need low comp for 220bhp???

y do u need steel rods or different pistons for 220bhp???

if ur Standard bottom end is in good condition it will easily handle 220bhp...

if im right Standard pistons (mahle) r forged piston r they not???

as sed the rods r the weakest point but i no several cars includin my own that r runnin between 18-22psi on standard (2nd hand) bottom ends includin my own...

its more a worry bout havin the fuelin to keep up...

concerntrate on that if i was u fella!

stuart collins

iTrader: (7)

i would just put a flowed head with newman cam, grs intercooler hybrid t3 off cossie with down pipe and a managemant system that will make the power u want and if u want silly power later u can change the pistons and rods and get 300+bhp