I am doing my Canton oil pan here in the next few weeks and I have some questions to ask..I have been having cavatation problems with my current oil pump/stock oil pan combination with my oil psi dropping 10psi around 4k rpms..I have noticed babbit in my oil and I have found 1 flake about the size of 1-2cms..I am worried my main bearings may alrdy have alot of wear on them due to the poor oiling..Motor has 2.5k very easy miles on it(no track time at all) When I do my oil pan should I pull the #1 main and inspect the bearing or just leave it alone..
My oil psi is great at idle(70 when cold,40when warmed up)
Driving around it sits at 65ish and holds there unless I go up to 4krpm..

Any suggestions?

Anyone ever checked/changed their main bearings while motor was still in car w/ the k-member dropped?

Cody

 

I've never even heard of this being attempted. I cam imagine it would not be too difficult to drop one of the caps and inspect the bearing, but to replace all of them with motor in car is just ludacris I think. You'll hafta unbolt all the rod caps and remove the crank from the motor while in the car. And who knows how hard it will be to get back together while still in the car. I say pull the sucker. You'll probably end up spending less time pulling the motor to replace the bearings than if you were to attempt it on your back. Go ahead and do the rod bearings while you're at it. You'll hafta crack the rod caps open anyways to get the crank out. Good luck.

 

i know someone who did it.
ask in the michigan forum
i think his name rob williams
99% sure thats his name

 

Did he say how big of a PITA it was?

 

With my oil psi the way it is right now I dont think my bearings are bad at all since it holds great psi..

Codyh

 

I think I'd rather have a root canal than to change the main bearings with the motor still in the car. Almost hard to believe someone pulled it off.

 

How would you get the block side bearing in past the crank and keep it clean on the back side to prevent a spun bearing. Can't take the crank out without removing all the rods and they are at different positions in the cylinders. Not to mention the timing chain has to be removed. and the one piece rear seal has to be taken out so the trans has to go.

 

I agree seems like a lot of work to do might as well pull the motor.
They might get away with just changing one side of the bearing but not the other side.

 

Guys,

I'm the guy who changed mains & rods with the engine
in the car. I did it on my '94 Z28. The hardest part of the
whole job was getting the oil pan off. There is a tool you
insert into the oil hole to get the top (block) bearing out.
You insert the tool, then rotate the crank and it forces the
bearing around. You roll the new one in and tap it into
position with a punch. The lock notch stops the bearing from
spinning.

If you are dropping oil pressure at 4,000 rpm it could be
oil filter restriction, low oil level, plugged oil returns or a
bunch of other things.

I think pulling a cap to inspect might not be a bad idea.

GOOD LUCK!

 

can you tell me a little more about this special tool? i am about to try the same thing because pulling the motor is impossible for me.

 

The tool looks like a "T". The post of the T goes into the crankshaft oil hole.
As you spin the crank the cross bar of the T contacts the edge of the bearing and rolls it around the crank. You have to rotate the crank so the tab on the bearing comes out first, otherwise the tab will get jambed between the block and the crank. The worst part of the whole job was getting the oil pan off. It is a PITA, but I took my time and everything worked out.

 

I've done in the car as well. Without a doubt, the biggest PITA is getting the pan off and out.

That tool specified above is really the best way but it's not the only way. I didn't have the tool but I did have some 1/8" plastic lying around. I cut a piece about the width of the journal and about 6 inches long. I pushed it up next to the crank adn it pushed the bearing around. Once it was out to the oil hole I hooked it with a hook tool and pulled it out.

Replace the rod and mains while you're in their and have the pickup welded onto the pump. Also replace that small collar that holds the pump driveshaft in the pump.

Good luck!

 

Yep.

Rolling in new bearings as it's called is not a big deal if you have access, heavy duty engine mechanics do it all the time. Yes, you cannot get the block side saddle oil free, but that has no effect on bearing retention, the crush due to the OD of the two bearing shells being slightly larger than the housing bore is what keeps the bearings in place, the tangs are just there for location and ease of assembly, they also do nothing to keep the bearings from spinning.

My only concern is that you may be seeing babbitt from the cam bearings, which cannot be changed without the motor being pulled. Generally though, worn cam bearings cause low oil pressure at idle, so if yours is ok as you state you may be ok.

 

Wow! Quick reply to a 9-year-dead thread!

Any links or pics of this tool? I'm assuming this tool is not application specific for SBCs, but rather for industrial/commercial diesels where this practice is more-common?

Your reply has renewed my curiosity!

 

The tool is commonly known as a "Sneaky Pete".