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torque question #2

822 views 7 replies 5 participants last post by  CNC BLOCKS NE 
#1 ·
Hey guys, I just went to plastigauge my main bearings and on 4 of the 5 caps the reading is good (0.002-0.003"). On the other cap (which is the 4th cap down the block) I have to torque it about 10 ft. lbs more to achieve the same clearance (0.002"). Do you think I can go ahead and install the crankshaft and just torque this one cap on 10 ft. lbs. more?? This will ensure that all the journals will have the same clearance. Any input appreciated.

Thanks for your help,
Keith
 
#2 ·
Don`t over torque it, I wouldn`t go past the recommended specs. Your in the rule of thumb which is anything under .001 is not enough and anything over .003 is too much. I don`t use plastigauge as it`s not accurate enough, you can measure the same cap twice and get a different reading each time. Even if it`s a little over .003, say .0035, as long as it`s just one cap it`s fine.
 
#5 ·
Yes you can get oversized bearings to make up for the slack, but I`m not sure if you can get them in a single pack, last time I tried I had to buy the whole set, but that was about 4 years ago. Before I would even consider it I would not trust the judgement to plastigage, if the reading is off .001, which is real easy, and you install a oversized bearing, there won`t be enough clearence and it`ll spin the bearing and you`ll be back at square one. Make sure of the journal size first with Micrometers. But as I mentioned, if one has a little more it`s nothing to worry about.
 
#6 ·
Ok I think I'll just leave it at 0.003" then because I can't seem to find just a single bearing either, you have to buy the whole pack :smash: All the others are consistent and the thrust bearing is at 0.003" as well so I think it will be fine.

Thank you guys for your help I really appreciate it.
Keith :welcome:
 
#7 ·
go have the crank cut for all correct....

or you will have a fair chance of lower oil pressure and less oil gpm thru the motor especially at idle.....
and by the time the oil gets to the rockers and exhaust valve stems, there will very little pressure/gpm's left for adaquate flow contact (heads) cooling.....

$$ to cut the crank for correct is always money well spent for longer motor life and so that you don't have to engineer your way around "pia" ping/cooling/etc/etc problems later
 
#8 ·
Which bearings are you using The H- bearings have a thinner shell then the V-series or the P-series bearings and make sure you are using new plastigage as older plastigage will give you a false reading.

We fit up alot rotatores for our circle track customers and some of the performace street engines we build and most of these customers check our work with plastigage and it seems to be right in line to what we measure out so I really think its fairly accrurate for checking clearances with.

Its pretty simple how plastigage works ans if there were problems with using it they would have stopped making it years ago.

Some thing does seem off hear as we use a lot of .001X bearings to get .003 on the mains on the engines we build.

We line hone every block that comes in the shop as it takes a lot of guess work out when they are assembled.

Good luck with your build
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With out factual data your just another guy with an opinion!!!
 
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