Oil pump gaskets

Snakeoil · Post by **Snakeoil** » Sat Oct 23, 2010 9:10 pm

When I pulled the oil pump from my engine, I noticed that both gaskets on the sump screen appeared to be the same. They are both a black paper type gasket. Yet, the parts book specifically shows that they are two different gaskets and the old pricing indicates that the B gasket is roughly 3 times the price of the A gasket. I did a search and found a pump that failed because somebody had removed the screen assembly and omitted the second gasket.

So, my question is, does anyone know the proper thickness of the B gasket? I will buy an OEM gasket if they are available. But I noticed that at least one of the engine kits I've seen for sale does not have those gaskets. I realize that the B gasket and the strainer establish the proper spacing for the drive and driven gears on this pump.

Any input on this would be appreciated.

Thanks,
Rob

48lesco · Post by **48lesco** » Sun Oct 24, 2010 8:45 am

Yes they are different gaskets, and they are the same thickness. I don't have one to measure, but they're probably about .020." There's also a thinner one between the two halves of the pump.

Snakeoil · Post by **Snakeoil** » Sun Oct 24, 2010 9:29 am

Common gasket material is 1/32" or 0.031". Cannot see, once assembled if that thickness gasket will cause too much lash in the gears.

I have some scraps from the non-compressed area of the gasket I can probably measure for thickness.

It never occured to me this could be a critical item until I noticed two different gaskets in the parts manual and found the post where the pump gear failed because the strainer and one gasket had been left out at reassmbly.

I was hoping one of the experienced engine builders here could advise if I can get away with self-cut gaskets from 1/32 gasket material.

Thanks,
Rob

davomoto · Post by **davomoto** » Sun Oct 24, 2010 11:30 am

Rob, I have made my own oil pump gasket before with good results. I now avoid the kit that doesn't include them! Why they aren't included is beyond me!

jerry · Post by **jerry** » Sun Oct 24, 2010 2:32 pm

Oil pump gasket thickness should be about.020" compressed (used). When oil pump is assembled in lower crankcase and crank dropped in the oilpump gear backlash should be approx. 004" to .006". I have had to go through this exercise as I run 40% bigger capacity pumps which have then been slowed down 20% entailing an extra spacer between the pump and crank case. All the best Jerry.

LOUD MOUSE · Post by **LOUD MOUSE** » Sun Oct 24, 2010 5:46 pm

Hello there Jerry.
If anyone wanted to know the thickness of the gaskets all they need to know is that all of the exterior (LS/RS head, Oil Pump, Cam chain tensioner gaskets are cut from the same material. .............lm

jerry wrote:Oil pump gasket thickness should be about.020" compressed (used). When oil pump is assembled in lower crankcase and crank dropped in the oilpump gear backlash should be approx. 004" to .006". I have had to go through this exercise as I run 40% bigger capacity pumps which have then been slowed down 20% entailing an extra spacer between the pump and crank case. All the best Jerry.

jerry · Post by **jerry** » Sun Oct 24, 2010 9:47 pm

I agree wholeheartedly LM. All the best Jerry