Clearance problem, whats the best solution

[foR.]

Ok..

I have a vr4 block, crank and rods.

Oversized gudgen to 22mm I believe to fit E8 pistons.

Thats all well and good.

I just bought some BC 272's and got a call from the rebuilder and he said there "might" not be enough clearance (which he is triple checking now)


If worst comes to worst whats the best way to solve this?

I guess there is not allot you can do bar change the pistons, which would also involve me changing rods too..

Would cutting deeper releaf's in the pistons for the valves be best? Would that affect the strength of the piston?

any help appreciated..

Jacob

 

[DOUGMO]

i would be suprised if they would hit mate.

has it had heaps of meat taken off the head and block?

 

[foR.]

Thats my initial thought, I don't know the history of the block nor head.. So I can't say unless I had the mechanic measure both and compare with standard specs.

He should be giving me a ring shortly with the verdict but I've had a chat with Paul Olsen (Mitsi tuner here in NZ) so there is some assurance that cutting the reliefs is fine.

Just means dis assembly and more time and a little more money spent..

Sure beats new rods and pistons though.

*FACK* and it was supposed to be home this week =/

 

[bazeng]

What do you have exactly mate?

evo8 pistons with what rods exactly?

Anyway, 272's shouldn't have any issues with stock pistons / rods.. Is he used to building these motors? or is this the first one for him?

What comp ratio are you running?
What gasket?

If worse comes to worse, get a thicker head gasket... Tomei do a 1.8mm gasket.`..

 

[JAP63]

The evo 8 pistons are factory forged from memory, sound correct?
Are you saying that with the rod at full upward stroke, the lift of the cam is enough to plunge a valve into contact with the piston crown?

 

[foR.]

Bazeng, this is his first E8/vr4 combo but has build 4g63's before.

It was a false alarm thank god, I didn't think there would be contact but it was the hydro lifters were acting up and had over extended when he measured.. And obviously you can't see that when the head is on.. But shining a torch down it made it obvious.

All is well now, just a late afternoon heart attack for me haha..

Just to answer your question anyway I'm running vr4 rods, E8 pistons 8.5:1 comp and a ralliart triple layer headgasket

Cheers

The evo 8 pistons are factory forged from memory, sound correct?
Are you saying that with the rod at full upward stroke, the lift of the cam is enough to plunge a valve into contact with the piston crown?

That's what I had feared, but upon 2nd measure and the lifters in the correct place everything was within tolerance.