main bearing check

[usetaboost]

whats the proper way of checking main bearing clearance? Never done it before and all the book says is start with the back one. DO I leave it in place till I finish the rest or do I do them one at a time? While I'm here is there any tricks I should know about the rear main sealing? What vehicle uses the 237 bosch regulator or is it not worth my time? Car is currently stock with slight bigger cam, drop in kn, and flowmaster cat back.

 

[dhjenkins]

A good set of feeler gauges will do the trick!

Just kidding.

Plastigage. It's basically a plastic hair that you place between the surfaces that need checking. As you tighten down on it, it squishes and gets wider (the wider it gets, the less clearance you have). Torque them (all) down in the sequence you would for the 'real' install (without turning the crank), then untorque & read (the piece of paper it comes with has measurements on it to compare it to).

Oh, you can buy it by the piece at most auto parts store for a buck or two - and one should be enough.

As far as sealing, just prepare your surfaces properly and use "the right stuff".

 

[mikestertwo]

A lot of the front wheel drive cars (Mid to late 80's Olds and Buick ) use the 237 regulator. I would eventually go to an adjustable one.

 

[usetaboost]

yes i know how to use the plastigague! I just wanted to know if all the main bearing caps got torque down and then pull them off, or if u do them one at a time, or if u guys got a special sequence. my front main reads 15 and the rest read 20. I know its all in spec but I think its odd that the front is 15 and the rest are 20????? I also noticed my timing cover has some wear from the cam button, is this normal? When would I want to upgrade from the 237 regulator?

 

[bison]

I assume you mean .0015 on the front main and .002 for the others. Sometimes a standard and a .010 under bearing is used to tighten up clearances. I was told that GM techs do this in some engines to eliminate bearing noise on startup. Ive seen it myself on some different engines. More oil pressure will be lost if the front main is too loose rather than the others.

 

[usetaboost]

I planned on using a high pressure pump, wont this cure the "slightly" excessive bearing clearence?

 

[bison]

I wouldnt. I would get the clearances right. If you have to buy a set of oversize inserts and use half of them to get the clearances right then do that instead. Buy a set of .001 over and install only half of them and use half of the old ones. I would plastiguage again for assurance when your done.

 

[bison]

My post no. 7 should have said they use standards and .001 overs to tighten clearances. Want to clear up the confusion there.

 

[usetaboost]

is it possible I did something incorrectly. I put the crank in, started with the rear cap, torqued it to spec, and proceeded forward till all were tightened down. Then I took them all off starting with the front. DId I do this wrong? Need a response quickly, Thanks guys for everything and your suggestions.

 

[usetaboost]

anything?

 

[usetaboost]

Ready to go out to the garage, would like to hear the sound of an lc2 whistling for the first time EVER by the end of the year!

 

[BadAssGN]

Check them one at a time and you really don't want to see any more than .002

did you have this crank machined? or at least polished?



try again, don't leave them torqued down

 

[usetaboost]

Did them one at a time last night. .002 on the nose. So am I good to go?

 

[BadAssGN]

Did them one at a time last night. .002 on the nose. So am I good to go?

You are good to go... have you built engines before or do you need all the info and assembly tips?

 

[usetaboost]

first buick motor, yes tips would be nice, especially for the rear main!

 

[BadAssGN]

first buick motor, yes tips would be nice, especially for the rear main!

REad this thread for some info http://www.turbobuick.com/forums/showthread.php?t=194605

Use a quality assembly lube or straight 30wt oil

Make sure the crank spins freely as you go on the mains.... any sort of binding something is wrong....

make sure you know how to measure and set the thrust

do a search on rear main install.... there are several different methods