iron 370ci main bearing clearances
12-13-2008, 11:30 PM
#1
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?
12-14-2008, 11:07 AM
#2
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".
12-14-2008, 12:46 PM
#3
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?
12-14-2008, 12:54 PM
#4
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.
