iron 370ci main bearing clearances
iron 370ci main bearing clearances #1: .0015-.0018"
#2: .0015-.0018"
#3: .0012-.0015"
#4: .0015-.0018"
#5: .0015-.0018"
Measurements were taken w/plastigauge, hence no dead nuts number. The motor is a iron 370ci with coated bearings, it'll be street/strip, shifted at 7000rpm and a 150 shot a few times a year. Probably ~475-500rwhp on motor. Are these clearances too tight? I wouldn't bat an eye if it was an aluminum block, but not sure w/iron. If they're too tight, what's the best way to fix?
#2: .0015-.0018"
#3: .0012-.0015"
#4: .0015-.0018"
#5: .0015-.0018"
Measurements were taken w/plastigauge, hence no dead nuts number. The motor is a iron 370ci with coated bearings, it'll be street/strip, shifted at 7000rpm and a 150 shot a few times a year. Probably ~475-500rwhp on motor. Are these clearances too tight? I wouldn't bat an eye if it was an aluminum block, but not sure w/iron. If they're too tight, what's the best way to fix?
What crank? Stock caps, I assume? What bearing and who coated them?
Usually, I like to see a little higher like .0022-.0030" depending on the application. You can take the crank to a crank grinder and have him turn the crank down to get the clearance you want. With .0015" of clearance, I'd have the crank turned .001" for .0025".
Usually, I like to see a little higher like .0022-.0030" depending on the application. You can take the crank to a crank grinder and have him turn the crank down to get the clearance you want. With .0015" of clearance, I'd have the crank turned .001" for .0025".
Crank is stock LS6, caps are stock 6.0 with factory bolts, bearings are Engine Pro Race Series coated bearings supplied by my machine shop. I assume turning the crank down to the desired clearance is a more sound solution than mixing bearing sizes?
Well, you could use a larger id bearing. You should be able to get a X bearing for more clearance, but it's gonna end up being about the same price as turning the crank. Having the crank turned would help/eliminate any bend/taper/out-of-round in the journals.
Appreciate the input! Would turning the crank a half thou to attain .002-.0022 be sufficient clearance for my app? Main concern being losing oil pressure with larger clearances.
