Piston to Wall clearance

[Brambles]

Just looking at some pistons and I noticed some TRW Forged pistons have a wall clearance of .0015

Pistons like L2316F and L2329F are both that way but the big 12.5:1 340 pistons are .005 clearance.

Does this sound right to you guys? Why can TRW forged pistons run that tight, thats hypereutectic range....

Any other manufacturers able to run forged pistons with that kind of clearance?

 

[340sFastback]

Does not sound right to me. The KB forged ones I am going to use can be run as tight as .0035 but are supposed to be run at .0045 for performance applications.

 

[mopar3762]

the .0015 to .002 sounds right with a stock type engine and probably uses 5/64th rings.only difference is their forged and may require a different hone job, cross hatch or smooth bore.no problems there.the 12.5s are domed and would run a 1 /16th ring and bore to wall clearance would be in the .005 to .008 range. no problems with either pistons, just modern technology and honing techniques.tighter wall to piston clearances give a better ring seal and the 12.5 give a lil more clearance for less drag as they are performance related and require less drag. factory cast pistons used the .0015 to .002 . forged has no bearing on these clearances ,just as long as their within tolerance it doesnt matter.its all in the bore finish. just better tech as the years went by.