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Cylinder wall to piston clearance with Nitrous.

Posted By: 70satelliteguy

Cylinder wall to piston clearance with Nitrous. - 10/30/13 07:08 PM

Ross recommends .006 clearance with bore size of 4.50 and above. They also recommend an additional .002 with Nitrous use over 250 hp.That comes to 008 total. That seems like A lot of clearance!
What are you guys with Nitrous assisted motors 4.5 or larger running?
Thanks Mike
Posted By: Biginchmopar

Re: Cylinder wall to piston clearance with Nitrous. - 10/30/13 07:10 PM

That's not alot. Put it where they want it. Good Luck!
Posted By: Nitrojunkee

Re: Cylinder wall to piston clearance with Nitrous. - 10/30/13 07:16 PM

Quote:

That's not alot. Put it where they want it. Good Luck!




x2 I Assume they are Ross forged pieces? You may get a little slap when It's cold, but that's not a lot of clearance.

Run it how they are saying, and you'll be golden.
Posted By: 70satelliteguy

Re: Cylinder wall to piston clearance with Nitrous. - 10/30/13 07:40 PM

Yes they are Ross forged pistons. I just did not want to put it back together at 008 if there would be a problem!

"You may get a little slap when It's cold"

I will never be able to hear it anyway

Thanks MIke
Posted By: cudaman1969

Re: Cylinder wall to piston clearance with Nitrous. - 10/30/13 07:41 PM

Fast Hemi's run .012 .A secret they don't tell.
Posted By: 70satelliteguy

Re: Cylinder wall to piston clearance with Nitrous. - 10/30/13 07:46 PM


"Fast Hemi's run .012 .A secret they don't tell."
Really Is there a performance advantage to that?

Mike
Posted By: moparniac

Re: Cylinder wall to piston clearance with Nitrous. - 10/30/13 07:48 PM

On my diamond pistons at 4.505 the piston called for .0065 clearance.
Posted By: Nitrojunkee

Re: Cylinder wall to piston clearance with Nitrous. - 10/30/13 08:06 PM

Quote:

Yes they are Ross forged pistons. I just did not want to put it back together at 008 if there would be a problem!

"You may get a little slap when It's cold"

I will never be able to hear it anyway

Thanks MIke



Exactly!

FYI, Diamond recommended .0075 on my custom blower pistons... Minus .002 for hard anodized coating. So I think you're right on!
Posted By: Crizila

Re: Cylinder wall to piston clearance with Nitrous. - 10/31/13 12:25 AM

A lot depends on the length of the skirt. I run a pretty short skirt on my forged Icons and their blower application recommended .008 to .010". I set them at .008". When I pulled it down recently, there was some skirt scuffing going on. New build will get .007".
Posted By: cudaman1969

Re: Cylinder wall to piston clearance with Nitrous. - 10/31/13 03:28 AM

Quote:


"Fast Hemi's run .012 .A secret they don't tell."
Really Is there a performance advantage to that?

Mike


my older (90s) had .012 much newer (big name) had .011
whatever works,has to be a reason, they don't make make mistakes like that. Personally i don't know but what i measured. Pay them 250 grand and they will tell. Ask something on SSAH and hear the quiet.
Posted By: 572charger

Re: Cylinder wall to piston clearance with Nitrous. - 10/31/13 11:01 AM

my 4.50 bore are at 9 thou so i can run my fogger at 300 hp
Posted By: 70satelliteguy

Re: Cylinder wall to piston clearance with Nitrous. - 10/31/13 07:41 PM



"my 4.50 bore are at 9 thou so i can run my fogger at 300 hp "

572 are those Ross pistons? Do you have any noticeable blowby?
Thanks Mike
Posted By: Cab_Burge

Re: Cylinder wall to piston clearance with Nitrous. - 11/01/13 01:56 AM

I have use Ross pistons on many builds, I always specify the close tolerance alloy so the rings will stay sealed better when running I add .0005 additional piston the cylinder wall to what they specify on thier literature. That alloy seems to be delicate so more clearances help keep the piston skirts from rubbing on the cylinder walls To tight, even .0001 to tght, will fail Looser is better on race motors, don't let them rub the cylinder walls
Posted By: 572charger

Re: Cylinder wall to piston clearance with Nitrous. - 11/03/13 12:01 PM

they are diamond pistons no blow by ring end gap is 28 on the top and 30 on the second . most of the time i put about 6.5 thou on a piston to wall on a street motor
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