Thrust Bearing

[juan89]

Hello, how come the oiling hole on the mains thrust bearing
is smaller than the rest?

Juan

 

[A2000RICH]

Hello, how come the oiling hole on the mains thrust bearing
is smaller than the rest?

Juan

if i was forced to come up with an explanation i would say possibly because its got a higher resistance leakage path compared to the non thrust bearings-------would seem logical to me........RC

 

[boosted nova]

scribe

 

[charlief1]

It's an oil pressure thing from engineers. The further from the origial source of the pressure, if you reduce the size of plumbing, it will increase pressure. It works in hydrology theory but in function it sucks.

 

[Steve V]

I open the hole up to the same size of the other mains. I have not had an issue and I have good oil psi on all engines like this. I also blueprint the oil pump,redrill the cam bearings. I use 10w-30 oil.

 

[boosted nova]

When you re drill the cam bearings are you drilling the block or opening up the bearings. Need more info on these types of mods get ready to put in all new bearings in my motor now. Do this stuff all the time to small block Chevy's, but I don't know about Buick motors yet. Lots to learn. Thanks for all the help. Sorry not trying to high jack the tread .

 

[Steve V]

When you re drill the cam bearings are you drilling the block or opening up the bearings. Need more info on these types of mods get ready to put in all new bearings in my motor now. Do this stuff all the time to small block Chevy's, but I don't know about Buick motors yet. Lots to learn. Thanks for all the help. Sorry not trying to high jack the tread .

I am not messing with the block. The holes are too big so I redrill with smaller holes only one that's tricky is #1 as it has 2 oil holes. Do a search and the sizes should come up.

 

[juan89]

I checked the original GM bearings and they all have the smaller
main bearing oil holes, just like the thust bearing.

Then, I checked Clevite , King and Federal Mogul main bearings.
The aftermarket bearings have the larger holes on all the bearings
except, the thrust one.The larger holes match the hole size inthe block.

So, I wonder if there is any benefit or drawback in enlarging the thrust
bearing oil hole to match the size of the block.

Thanks,
Juan

 

[KL Mallender]

I believe that both center mains need to be larger in size due to they're feeding two sets of rods each compared to single rods from #1 &4 mains, and should be sized according to rpm demand, the higher the rpms, the bigger the rod feeds need to be.
Buick built it to shut off by 5750 max and clearanced it accordingly, the instant you open up journal clearance's from stock spec's, oiling supply becomes the sore spot in pump capacity and pan volume.
4 qts in the pan doesnt stick around too long at high rpm's, build accordingly.

Kevin.