rwmorrisiii
Member
Hey Guys,
I have been coaching my brother in law thru a rebuild of a GEN-V 454 and we ran into an odd issue using a set of Speed Pro forged pistons. The crank is for sure a 4" stroke GEV-V crank, the rods are rebuilt and are the original 6.135" factory units. The pistons are the correct compression height for the total combo. But... The OD of the crank counterweight is hitting the skirt of those pistons as it nears BDC. #1 installed and worked fine but when he put in #2 it won't make it all the way around. This is tricky for me as I'm not standing there watching this happen but from all the facetime video and photos it looks like the skirts are just a touch too long to clear that crank vs maybe an earlier MARK-IV style BBC.
My question to you all is has anyone heard of this? Experienced this? Or knows how to take the easiest route to correct it? I'm thinking he can just have the crank OD of the counterweights turned down and then the machine shop can re-run the balance job with the existing bob-weights. It does appear that there's different pistons listed for the 1991 and up motors but they are all the factory cast flat top or slight dish units. Hopefully my description can communicate the issue he's seeing and hopefully someone has seen this before! Ah they joys of building motors.... Sometimes the demons pop up when you least expect them.
Cheers,
Robert Morris
I have been coaching my brother in law thru a rebuild of a GEN-V 454 and we ran into an odd issue using a set of Speed Pro forged pistons. The crank is for sure a 4" stroke GEV-V crank, the rods are rebuilt and are the original 6.135" factory units. The pistons are the correct compression height for the total combo. But... The OD of the crank counterweight is hitting the skirt of those pistons as it nears BDC. #1 installed and worked fine but when he put in #2 it won't make it all the way around. This is tricky for me as I'm not standing there watching this happen but from all the facetime video and photos it looks like the skirts are just a touch too long to clear that crank vs maybe an earlier MARK-IV style BBC.
My question to you all is has anyone heard of this? Experienced this? Or knows how to take the easiest route to correct it? I'm thinking he can just have the crank OD of the counterweights turned down and then the machine shop can re-run the balance job with the existing bob-weights. It does appear that there's different pistons listed for the 1991 and up motors but they are all the factory cast flat top or slight dish units. Hopefully my description can communicate the issue he's seeing and hopefully someone has seen this before! Ah they joys of building motors.... Sometimes the demons pop up when you least expect them.
Cheers,
Robert Morris