75.5 mm Vitaras, what piston to wall clearance?
 

I'm going to pick up a used Z6 block and run some 75.5mm Vitaras after the block is properly bored. After a lot of reading I see that the guys who run a STD bore Vitara in a STD bore Z6 have up to .030" piston to wall clearance which is way out of Honda specs, and slaps like ---- when cold, but seems to work ok when warmed up.

I want to have the correct clearance which is under .020" by Honda standards, but what should it be? I don't want the piston to seize up from expansion after it's warmed up, but I also don't want to run the same shitty clearance that most other people do with STD bore Vitaras. Anybody know what the ideal clearance would be with 75.5mm Vitaras in a Z6?

Re: 75.5 mm Vitaras, what piston to wall clearance?
 

Ask Endyne :1

Re: 75.5 mm Vitaras, what piston to wall clearance?
 

I just drop the pistons, rings, and the block off at the machine shop and let them do the math.

Re: 75.5 mm Vitaras, what piston to wall clearance?
 

honda cast needs under .001"
Check out the vitara specs and use those

I know for forged
low silicone = .004+
high silicone = .003+

Re: 75.5 mm Vitaras, what piston to wall clearance?
 

Mine are .015 on vitara 75mm. no problem meng. Might not apply but I wanted to throw it out there for reference.

Re: 75.5 mm Vitaras, what piston to wall clearance?
 

I'm will be running three thou shortly, I know one person on H-T is running the same already, no issues.

Re: 75.5 mm Vitaras, what piston to wall clearance?
 

I said 30 thou...

Re: 75.5 mm Vitaras, what piston to wall clearance?
 

No one has run with that much clearance that I have read about. I think the current H-T record is running 0.016 and he's got the most clearance out of everyone. If I had pulled out my stock pistons and dropped in 75.5mm Vitara's, I still would have had 0.006 piston to wall clearance, which is excessive.

Re: 75.5 mm Vitaras, what piston to wall clearance?
 

So you're saying that your gap now is at .026"? and when you say excessive, do you mean just the opposite?

There's a thread on here about someone running 0.030, can't find it.

Re: 75.5 mm Vitaras, what piston to wall clearance?
 

I know that when you do small block fords you want about.007 it would expand more than a honda due to the fact that they are larger. I have no Idea what to run the vitaras at since they are hypertectonic.