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.

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

Hypertectonic! lol :D

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

I knew youd like that..... lol O0

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

i am about to do the same. chiming in to hear the answer

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

Found some pretty good info here

http://www.turbod16.com/viewtopic.ph...st=0&sk=t&sd=a

I'll probably go .002-003. I'm only shooting for 300 whp

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

Couldn't let me show you up could you jon?
i got my block checked and im gonna have about .005 piston to wall.
Im not worried about it. ;)

Stock rods?
Bearing?

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

I'm running with .005 on all piston-cylinder clearances, absolotely no slap at all, .005 is still almolst twice the service limit according to honda's spec's. You can have the pistons knurled, which expands points of the skirt to close this gap down, I was going to have mine knurled but the machine shop didnt have a knurling tool small enough at the time so I said ---- it. she purrs like a kitten even upon a cold start up.

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

TunerToys rods and haven't decided on bearings yet.

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

Yea .005 is 2.5 times the Honda service limit.

'99 vitara 1.6

http://users.adelphia.net/~digitalco....clearance.gif

'95 z6

http://users.adelphia.net/~digitalco...clearance2.gif

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

My machine shop hooked me up on oem honda main bearings, I think I paid like $75 for all 10 pieces. For the rods I went ACL

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

I think im going all acl race.
http://cgi.ebay.com/ebaymotors/ACL-R...spagenameZWDVW
WHAT
Block?
Head?
turbo?

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

Z6 block, Y5 head, .48/.60 T3 at first

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

.0035 is the perfect gap for vitaras. i ran .004 on mine and was perfect. jfk78 runs the MOST out of any vitara setup ive ever seen, and his is .008....he lays down 450whp and runs 10's so i guess it isnt that bad :S

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

Thanks for the input. I was leaning towards .003"

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

Good tech info. HMTECH ;D

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

i had the machine shop do mine to factory honda specs only a bit on the loose side so we'll see once i start her up.