JE Piston Tech
09-19-2008, 12:57 PM
#2
Member
JUNIOR BUILDER
Join Date: Feb 2008
Location: Childers Australia
Posts: 98
piston pin end float
Hi I am in what I see as an unenviable position.I purchased Probe BBChev pistons aws they were the only ones to make a piston of the specification I was seeking & have been trying to get this engine final assembled.When I put the piston pins & spirolocs in I noticed what I considered excessive end float.I contacted Probe & asked what this end float specification should be,& was given piston to bore specs.I again asked for end float specs & was told that "All our pistons are ready to run & the clearances are already setso that the customer does not have to worry about it"A very disturbing statement in itself.To which I said that Iwas not satisfied with that answer & requested the spec,twice more only to have me Emails read & ignored.I have .010" of end float & am wondering what,apart from not ever using Probe anything,to do.Thanks in advance for your time.Mark
09-19-2008, 01:14 PM
#3
Senior Member
MASTER BUILDER
Thread Starter
Join Date: Mar 2008
Posts: 192
With our parts a .010 endfloat is accectalbe but at the end of the tollerence. It would be an expensive fix but if you can find a pin longer, it can be cit down to .005 longer then the ones you have.
09-19-2008, 05:32 PM
#4
Senior Member
RACING JUNKIE
Join Date: Jan 2006
Location: La.
Posts: 2,890
I have to agree with ARUSSEL on this one, and i'm a JE user, but have supplied Probe pistons to a couple of customers. .010 is totally acceptable for end clearance on the pins. There has to be something pretty bad wrong to push a pins past a spiral lock, such as too much piston clearance, bore out of SQ. with main bores, etc. I would assemble it and not worry about it. I've run more side clearance on blown alcohol applications with alum or nylon buttons and no problems.
JMO
Zip.
JMO
Zip.
09-28-2008, 09:56 AM
#5
Member
JUNIOR BUILDER
Join Date: Feb 2008
Location: Childers Australia
Posts: 98
Finally got a reply from probe,the endfloat is supposed to be between .005"& .020" according to the sales manager.That puts what I have in a good position.The clearance specification seems to me at least, to be very large compared to anything I've seen anywhere,which is what I find disturbing.Thanks for the replies I had considered longer pins,but Where to get them?& prehaps some type of shim,or would that cause other problems?On the other hand considering the replies just run them as is,after all they are at the top end of what seems to be considered ok tolerance & as always a little loose is always better than a little tight.
