Guys,

Can anyone identify these pistons for me? I'd like to know the manufacturer and clearance recommendations if anyone can help. Thanks.

Tom

They look like the old TRW heavy pistons... cant say
about clearance specs

10 to 1 trw slugs. Heavy as heck

Those look like the original 1963 415 low compression pistons like was in my 1963 Belvedere had in it from the factory What actual diameter size are they on the bottom of the skirts compared to how much are the diameters compared to the wrist pin side location under the bottom rings 90 degrees to the wrist pins ? The TP stands for Thompson Product That is one of the comapny that was bought to form TRW in 1961/1963, Thompson Racing Wharehouses, maybe not the proper names for the TRW letters Grumpy Jenkins got NHRA to change thier dome hieght specs. for the 1963 415 HP motors do to the dome being to short to make 11.25 to 1 true compression ratio, they will accept either a .090 or .095 dome hieght now. A lot of NHRA M.W. racers I know would look for a set of 1964 415 HP pistons and mill the .120 domes down to the proper blueprint specs. NHRA would accept them for thier 1963 motors BTW, them babys you have are really heavy, you can do a lot better now by purchasing a new set from one of the piston companys that make the NHRA acceptable pistons, or better yet have a new state of the art set made for your motor

11.1 max pistons like Cab stated, just sold a couple of sets acouple of years ago from Al Corda inventory, run at 7 to 8 thou to be safe.
Russ

Stage III 11-1 and 12.5-1 for comparison.

Those are the same pistons Quick1D100 has a post on and currently on his dyno.

Thompson Ramo Woolridge

http://en.wikipedia.org/wiki/Thompson_Ramo_Woolridge

R.

Thanks for the help guys and I apologize for the large pics - technology challenged at this end. Cab, the skirts go from about 4.242 to 4.247, the diameter at 90 degrees to the wrist pin is about 4.245 with the diameter at the wrist pin being 4.221 to 4.222. The pop up on top of the piston is about .060 high. I was looking for something with a bit more compression than a street wedge.

This what you looking for.








Russ

The deck hieght, combustion chamber size and head gasket thickness will determinge the true mechanical compression ratio The OEM 1963 415 HP pistons had a .063 high dome, not sure of the dome volume, 1964 415 HP pistons had right at .120 dome height, same thing on the dome volume sizes I've never seen a OEM production Mopar V8 motor, regardless of which size or family, have anywhere close to factory deck heights, combustion chamber size or anythig close to the advertised compression ratio My message is, check yours very closely to get exactly what you want

Yeah, brain fart...I corrected it.