Forged pistons...

[DanClio]

Hi all,

I'm planning and engine rebuild soon and want to increase the compression ratio. How high can I safely go as BB sell pistons which go to 12.5:1 and K-tec;s one go to 11.2:1. Obviously will be gettin forged con rods as well, just wanted to know what people think are the best pistons and rods to go for, and what compression ratio is most practical.

Cheers
Dan

[Rich]

best ratio for what? std rebuild, charger, turbo, bodies?

[stan]

Is this for road use?

If so, I would think carefully about fitting forged pistons due to the tolerancing variations that arise when an engine isnt permamanently at full load and temp.

As for actaul Cr figure, it depends on the rest of the spec. On a std inlet, with ok-ish cams, I would say maybe 11:1.

I can supply both rods and pistons.

Pistons are £400
Catcams rods £499

both plus VAT.

[DanClio]

It will have cams and throttle bodies and a straight through exhaust system, and will be for road use.

As you were saying stan are forged pistons not recommended for road use? If so what do you think i should do to get the power up a bit more?

Dan

[stan]

Its not that they strictly cant be used on the road, its more a case of it will likely reduce the life of them and so the engines performance. wheather this will happen within a timescale which will detrimental to YOU, I cant say.

You could skim a fair whack off the head to up the Cr a bit.

What spec cams are you thinking of?

[DanClio]

im thinking of catcams 265? duration ones.... how much could you get skimmed off the head?

Dan

[stan]

Catcams 5502225 (these must be the ones u mean?) grind cams are top if you are keeping the std inlet. If you are going for ITB's and aftermakret managment, you can go wilder.

[stan]

They are £450 inc vat btw, £200 for pulleys (or there abouts). I can supply them if needs be.