[4onthefloor 2]

355 sounds like a diesel
my engine is a fresh 355 with moley rings TRW forged pistons,floating rods, steel crank, cast Dart 2 heads,with 205 intake and 160 exhaust stainless valves . crane energizer cam 480 lift 228 der, , with scorpion 1.5 roller rockers, Elderbrock torker 2 intake, MSD ignition 6A , with a 750 holley carb compression ratio is 10.14 cranking compression is 185 psi per cylinder the motor is in a 1968 Chevelle 2 door sports coupe with a 4 speed saginaw rear end gears are 411 in a 12 bolt posi with ladder bar suspension motor sounded like it was dieseling while running sound came from below intake I ripped the motor down all I found was cranes lifters had 9 parts to them never seen that before but I totally tore motor down to nothing after one and a half hours of running time oil pressure was between 40 psi at idle I'm not sure whether it's piston slap or cranes lifters all bottom end specs are perfect anyone herd of this before

 

[machine shop tom]

Two possibilities come to mind.

Timing WAY advanced.

Too much piston/wall clearance. I'd bet on this one, some guys think that forged pistons need a lot of extra clearance, not realizing the proper clearance is built into the piston. They then bore oversize, thinking they are adding the proper clearance. What part# are the pistons?

tom

 

[LilSmoke]

Yep,p/w clearance. Last time i used trw forged was in 72 and i think they were around .007. Dont know if they have closed em up any or not.

 

[4onthefloor 2]

Two possibilities come to mind.

Timing WAY advanced.

Too much piston/wall clearance. I'd bet on this one, some guys think that forged pistons need a lot of extra clearance, not realizing the proper clearance is built into the piston. They then bore oversize, thinking they are adding the proper clearance. What part# are the pistons?

tom

2L417 clearance is 006 how long will the motor last with these clearances thanks for your reply