I'm going to build up a new bottom end as mine currently has I need to fit mine with steel rods and has a little piston slap, it's irritating me sounding like a deisel. But what pistons shall I use?

My current bottom end has Accrilite Forged pistons, but I found a set of early Mahle Forged C20XE pistons (very very cheap) so bought them. Which would be better? I know the XE pistons will give me comp ratio of 7.8:1 with a CVH head and Focus RS headgasket IIRC but not sure what the Accrilites have been machined to?

Also the Accrilites have been machined with flat crowns and I have been told that at higher boost they will possibly damage?

 

mahle dude

 

how do you know xe pistons will give you 7.4? Thy're for i highish power normally aspirated engine which usually means high compression. Whats the difference between the xe pistons and the let pistons that are normally used?

 

Let have bigger dish for lower comp but both have the same forge markings. + XE pistons dont go to the top of the bore there is about a 2mm gap.

 

mahle all the way

 

It's something to do with the cvh head having a bigger combustion area than the zetec head. CVH being 55mm to the zetecs 48mm? IIRC. Because of this the LET pistons will give a comp ratio too low for ZVH so higher comp XE's are used.

 

Mahle pistons and rings will do the job matey

 

Right then. Sell the accrilites and use the XE's. Next question is what steel rods shall I use? I know the little ends Need opening up from 20.83 (?) to 21mm for the vaux wrist pin but would Eagle rods be ok to use? I heard something about them being the wrong length so messes up the comp ratio?

 

why not try wossner or CP

 

for the piston question id use mahle,rods there are plenty out there to choose from, one thing muz is why zvh?if you run a management system why not full zetec?

 

Mainly due to the fact I have a very well specc'd CVH head modified to use a Zetec headgasket which has a brand new Newman cam and solid lifters which I would loose alot of money on if I went Zetec and had to sell it. Plus I do like the way the Ford motorsport rocker cover and custom XR3 inlet look in the bay.
With a forged bottom end and the rest of my set up I should be able to see 300 bhp with a turbo swap which is plenty through the front wheels.

 

thats fair play dude,but it would of been a cheaper alternative to use full zetec the head will see in excess of 300hp with virtually no mods, were as cvh you need big cash to see anything near that, on a more plus side anyway you should see more torque with the 8v head