installing engine bearings

grumpyvette

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http://www.engineparts.com/it_bearinginstall.asp

http://www.hotrod.com/articles/crankshaft-rod-bearing-install/

http://www.tpub.com/content/constructio ... 24_423.htm

http://www.gmhightechperformance.com/te ... to_03.html

http://engineparts.com/it_crankinstall.asp

http://engineparts.com/it_bearinginstall.asp

https://mobiloil.com/en/article/car...w-to-assemble-an-engine-part-2-the-bottom-end
notice the open slot between the rear main cap supporting the oil pump and bearing shell support and the area supporting the rear main seal, this prevents PRESSURIZED oil from the bearings reaching the rear main seal.
oilcappass3.jpg

the as cast recess in the rear main cap where the oil pump mounts can be rather restrictive and shallow, so a bit of careful mill or grinding work to open up and add some depth certainly helps oil flow if its done carefully
oilcappass4.jpg


failure to use the correct oil pump,mounting stud, bolt or nut or carefully check clearances when mounting an oil pump can cause problems
pumpss1.jpg

pumpss2.jpg

ONE RATHER COMMON MISTAKE IS USING THE WRONG OIL PUMP STUD OR BOLT TO MOUNT THE OIL PUMP AS IF EITHER EXTENDS THRU THE REAR MAIN CAP IT CAN AND WILL BIND ON THE BEARING AND LOCK OR RESTRICT, SMOOTH ROTATION
oil%20pump%20stud.jpg


http://garage.grumpysperformance.co...-bearing-trashed-in-1-2-hour.5141/#post-71921

A simple modification to the upper thrust bearing may be beneficial in some engines. Install the upper thrust bearing in the block to determine which thrust face is toward the rear of the engine. Using a small, fine tooth, flat file, increase the amount of chamfer to approximately .040" (1 mm) on the inside diameter edge of the bearing parting line. Carefully file at the centrally located oil groove and stroke the file at an angle toward the rear thrust face only, as shown in the illustration below. It is very important not to contact the bearing surface with the end of the file. The resulting enlarged ID chamfer will allow pressurized engine oil from the pre-existing groove to reach the loaded thrust face. This additional source of oiling will reach the loaded thrust face without passing through the bearing clearance first (direct oiling). Since there may be a load against the rear thrust face, oil flow should be restricted by that load and there should not be a noticeable loss of oil pressure. This modification is not a guaranteed "cure-all". However, the modification should help if all other conditions, such as surface finish, alignment, cleanliness and loading are within required limits.
bearing41.jpg

ThrustBearingModParallel01a.jpg

trustbca.png

bearing41.jpg

bbctqsp.png

http://www.handymanlyness.com/archi...h/rebuild_01/05_crankshaft_install_GM_V6.html

http://engineparts.com/techbulletins/CL77-1-205R.pdf


Installing Main Bearings:
emcrra83a_engine_rebuild_99_Jimmy.jpg



I inserted the new main bearings in the engine block, after I wiped the bearing pocket with a paper towel sprayed with brake cleaner.

The main bearings were marked "upper" and "lower". The upper bearing shells go in the block, the lower bearing shells go in the caps.




Note how the tang on the bearing shell aligns with the groove in the casting (arrow).

emcrra84aro_engine_rebuild_99_Jimmy.jpg




emcrra85a_engine_rebuild_99_Jimmy.jpg

After all 4 upper bearing shells were installed, I carefully set the new crankshaft in place.





I pushed the lower bearing shells into place in the main bearing caps.

emcrra87a_engine_rebuild_99_Jimmy.jpg




emcrra88aro_engine_rebuild_99_Jimmy.jpg

Checking The Bearing Clearances:
I placed a small piece of Plastigage (red arrow) on each main bearing journal before installing the cap.
plastig1.JPG

https://www.carshopinc.com/product_info.php/products_id/49347/SPG1-12

71DiMRV8kgL._SX522_.jpg


plastig2.png

yes I use both micrometers and snap gauges and cross check with plasti-gauge
and yes when you compare the crushed width of the plasti-gauge youll find it rarely falls as an exact match to the bar chart tape that is packaged with it so you can judge clearance based on crush width
http://garage.grumpysperformance.com/index.php?threads/bearing-clearances.2726/
plas1v.jpg

plas2v.jpg

BEARv13.jpg






I installed the main bearing cap and tightened the bolts to 77 foot-pounds.

emcrra89a_engine_rebuild_99_Jimmy.jpg




emcrra91aro_engine_rebuild_99_Jimmy.jpg

Then I removed the bearing cap and compared the width of the squashed Plastigage to the scale on the package.

In this case, the Plastigage had flattened out a bit wider than the scale for .002 inches, but narrower than the scale for .0015 inches. That meant the clearance on that bearing was a bit less than .002", perhaps .0017 inches or so. All four of the main bearings had very similar clearances.


The Haynes book says that the GM 4.3 liter V6 engine, for model years 1996 to 2000, should have main bearing clearance between .0011" and .0023". Except for the number 1 main bearing, which should have clearance between .0008" and .0020", which is three ten-thousandths of an inch tighter.

I checked all four main bearings in this manner, doing just one at a time.





Installing A New Rear Oil Seal:
Ideally, the rear oil seal would be installed when the new crankshaft is set in place, but I didn't do it that way, as explained below.

emcrrb01a_engine_rebuild_99_Jimmy.jpg

To remove the old rear oil seal, I placed the metal housing on two blocks of wood to support the edges, and I used a small pin punch and a hammer to pound the seal out.




I cleaned up the oil seal housing with mineral spirits.

I used carb cleaner for the stubborn oil stains, then I rinsed it with brake cleaner, which leaves no residue.

emcrrb02a_engine_rebuild_99_Jimmy.jpg




emcrrb03a_engine_rebuild_99_Jimmy.jpg

I installed the new rear oil seal by tapping on the edge of the seal with a block of wood and a hammer.

I tapped all around the perimeter to make sure the seal went in straight, not crooked.




I removed the crank and scraped off this old gasket that goes behind the oil seal housing.

I cleaned up the mating surface on the engine block.

This gasket removal should've been done earlier, but I missed it.

emcrrb04a_engine_rebuild_99_Jimmy.jpg




emcrrb05a_engine_rebuild_99_Jimmy.jpg

This plastic ring came with the gasket set.

This ring is folded into a "C" shape and inserted inside the rear oil seal to keep the seal lips spread apart during assembly...




... Like this.

But installing the oil seal at this point didn't work for me... I could not keep the seal on the end of the crankshaft and get the seal housing over the stud on the back of the engine block.

I had to wait and install the rear oil seal when I could get the engine off the stand, which meant when I was ready to install the engine and had rented a hoist.

emcrrb06a_engine_rebuild_99_Jimmy.jpg




My Mistake:
GM uses three bolts and a stud to fasten the rear seal block to the engine. I failed to realize that this stud could probably be removed without much trouble, if an impact wrench is used.

With the stud removed, it should be possible to set the crankshaft in place with the oil seal dangling from the end, and then push the oil seal block into the gasket on the engine block.

http://www.enginebuildermag.com/2014/06/replacing-crankshafts-connecting-rods-bearings/

Installing The Crankshaft, For Real:


emcrrb07a_engine_rebuild_99_Jimmy.jpg

I applied a bit of assembly lube to each main bearing.

Then I set the crankshaft in place.


I applied more assembly lube to the crank main journals, and installed the bearing caps, starting at the rear.

I tightened the bolts snug with a large ratchet, then I torqued each main cap bolt to 77 foot-pounds.

After installing each main cap, I turned the crankshaft back-and-forth a bit, to make sure the crank was not binding.

emcrrb08a_engine_rebuild_99_Jimmy.jpg




emcrrb09a_engine_rebuild_99_Jimmy.jpg

The crankshaft after installation.

If there is a lot of assembly lube oozing out, that's okay.

The crankshaft should turn freely at this point, although the highly viscous assembly lube gives the shaft a "sticky" feel as it's turned.

the web sites designed to teach and answer questions
youll notice most threads have
numerous links,
and theres a search feature,

using that will help answer questions,
if you need more info please ask detailed questions


http://garage.grumpysperformance.com/index.php?threads/another-496bbc.5123/

http://garage.grumpysperformance.co...-about-your-potential-dream-bbc-combos.14607/

http://garage.grumpysperformance.com/index.php?threads/427-tall-deck-bbc.14451/

http://garage.grumpysperformance.com/index.php?threads/427-tall-deck.15267/

http://garage.grumpysperformance.com/index.php?threads/types-of-crankshaft-steel.204/

http://garage.grumpysperformance.com/index.php?threads/matching-parts-and-a-logical-plan.7722/

http://garage.grumpysperformance.com/index.php?threads/496ci-revamped.14642/

http://garage.grumpysperformance.co...ng-to-take-awhile-but-theres-good-tips.15295/

http://garage.grumpysperformance.com/index.php?threads/a-mid-range-454-bbc-build.8215/
 
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