jonspeed

Hi all got a 2.5 sti block and was going to run that with my sti version 5 heads . What put me off was the matching of head to block and compression ratios etc . Now thinking more along the route of using the crank and rods from the 2.5 in my 2.0 block . My goal is 400BHP so the 2.5 sti crank and rods should be good for that . My question is what pistons will i need ? Also i assume the same thickness headgasket as currently used will suffice ?

On-the-bog

v5 heads work very well with 2.5 block. For the cost i'd closed deck convert the block and put a decent set of rods in it or you will regret not doing them later.

B9SLJ

iTrader: (1)

I would ring one of the engine builders like Andy Williams , or engine tuner etc an get some advice as they know exactly wats required to suit your build . costs nothing for advice from the professionals

banny sti

iTrader: (68)

Wouldn't you need custom pistons to get the right height with 2.5 rods? In essence you're trying to build a 2.1 stroker engine hence best buying the correct parts off the shelf

On-the-bog

Just need to pick the right ones, off the shelf mahle power pack will do the job

banny sti

iTrader: (68)

excellent, good way to get a cost effective strong engine for 400bhp

On-the-bog

when you go looking at how many different ones are available it will blow your mind, Mahle catalog is huge hahaha

jonspeed

I still have the 2.0 rods as well but the 2.5 sti rods seem to get good reviews .

On-the-bog

http://www.ebay.co.uk/itm/Subaru-2-1...25.m3641.l6368

jonspeed

Cheers for suggestions but I already have the 2.5 crank and sti rods all I want is a definite type of forged pistons that will fit .

merlin24

iTrader: (1)

Mahle do a very good stroker piston in 4032 and 2618 grade with a compression height of 30.30mm to suit the standard length rods.

Mick

jonspeed

Cheers Mick do you mean 2.5 rods or 2.0 rods ? Any idea on part numbers ?

merlin24

iTrader: (1)

the 2.5 and 2.0 turbo rods are the same length @ 130.48mm centre to center.
Bolt type rods are stronger than the earlier nut type rods.
The 4032 grade mahle stroker pistons are SUB193642/16 for 92.50mm
The higher grade 2618 for extreme applications are SUB193642P16 for 92.50mm

jonspeed

Mick you are a great help many thanks