Checking Oil Clearance on new short block

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Jan 20, 2018 | 01:18 PM

warind8191

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From: NW Arkansas

Checking Oil Clearance on new short block

I recently purchased a rebuilt short block here locally, and had asked around here about verifying all the bolts were torqued/tightened correctly. I got the answer I needed there (very much appreciate the help), but now it's got me thinking about clearances. Would it be ok to check each of the clearances for the rods and mains one at a time and just re-torque them as I go, or would that do something weird to the clamping force since they need to be run down in a particular sequence? Planning on using plastigage to check everything before I do a final button up of the motor.

Thanks in advance for an insight.

Jan 20, 2018 | 01:29 PM

RockinWs6

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Plastigauge is about worthless except to tell you there is some clearance. If you are that worried pull it apart and mic everything.

Jan 20, 2018 | 02:04 PM

warind8191

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From: NW Arkansas

Quote:

Originally Posted by RockinWs6

Plastigauge is about worthless except to tell you there is some clearance. If you are that worried pull it apart and mic everything.

While I respect your opinion on plastigage, for every person out there that says it's worthless.. there is another person that says it's just fine as a measurement tool. This is the internet after all. That being said, my question really wasn't meant to get everybody's opinion on the pros/cons of plastigage, I merely mentioned it in passing.

What I really want to know is if checking rods/mains one at a time (assuming that they have been torqued correctly the first time) will somehow jack around with proper clamping force?

Jan 20, 2018 | 05:53 PM

KCS

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Rods would all be ok to do. On the mains, you would have to set the thrust again if you take off the #3 main cap.

Jan 20, 2018 | 07:17 PM

01CamaroSSTx

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Nothing wrong with disassembly and reassembly just be sure and follow the torque specs.

Jan 20, 2018 | 07:21 PM

RockinWs6

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I've found plastigauge is great for final assembly to be sure everything is right but it doesn't replace good machine work. Example I put together a engine with core shift. Plastigauged perfect but you couldn't turn the crank with a bar. I guess it all depends on your point of view and checking what makes you happy. Seeing that the clearance checks out ok with plastigauge confirms you're in the ball park and have clearance,but it really doesn't tell you anything more. The crank could be bent journals out of round, block core shifted, rods need sizing etc. and plastigauge will check fine. I have other problems with it too, how you use it can change the readings.

There is no substitute for micing everything but I realize its a big job that needs proper tools plus a very experienced professional<good luck finding that. A hell of a lot more to setting up internals besides clearances. Everything being SQUARE is just as important.

Last edited by RockinWs6; Jan 20, 2018 at 07:53 PM.