5K Piston Sizes

[Zoidburg]

Hi all, hope you had a Happy New Year!

 

The 5K block I inherited has 40 thou oversized pistons and unfortunately has some skirt rattle, which is audible whilst driving at certain RPM's. The rings are new, so I'm thinking either the pistons are old or the block was bored out too far. Since I did'nt do these mods, I don't know for certain what the issue is.

 

I'm thinking that if I replace the pistons with slightly larger ones, then perhaps that will tighten everything up and eliminate the rattle. Does anybody know the max piston size you can squeeze into a 5K block? I'm obviously hoping I can go a little bigger than what's in there!

 

Any advice would help alot, as I don't want to go too big and crack the block etc.

 

Thanks :)

[TRD ke70]

Have heard of them been bored to 82mm, but that was using 4AGE pistons and rods.

 

I think ACL make a set of +60's for them too.

Edited January 1, 2011 by TRD ke70

[Zoidburg]

Okay, 60 thou should tighten things up!

 

If ACL make them then it will be safe for the block, so that sounds like a good option.

 

Cheers

[philbey]

Sounds like it's bored to 60 over with 40 over pistons.... I bought a 5k that had the same thing done.... Dodgy. Yeh ACL make 60 overs.

Edited January 6, 2011 by philbey

[kangaroosa]

I had 83mm Hypereutectic Pistons in my 5K. They were a Gemini part number, but machined to suit.

[Zoidburg]

Yeah I figured someone's had the bore done to suit bigger pistons.

 

I browsed through the MAHLE piston catalogue, they list 50 thou and 100 thou for the 5K. Hmmm, 5K with 100 thou oversized pistons... could be nice?

[philbey]

Mahle are the pistons that ACL supply. I didn't know that they had 100 thou!