Buick rear main seal in a Stage II????

[Lee Thompson]

Has anyone run into or heard of a problem keeping a Buick seal in a Stage motor from leaking? I have an older Stage block that takes a Buick seal. I have put 2 in in less than 100 miles. The crank is the correct dia. for a Buick seal. Both seals were new (Felpro) neophrene. It is coming from around the seal and not the side seals. Also what is the purpose of the flange on the crank between the bearing and seal? The eng. is going to have to come back out, so if someone can shed some light on this, I will be forever indebted to you.

 

[norbs]

Take a pop can and cut a 1/8th strip off it, place it under the seal on both ends. This acts as a shim, been doing it on 3 engines now, works well, no leaks!

 

[EightSecV6]

Check to make sure the drain in the cap is cut properly and not blocked by the pan gasket.....
The ring is a deflector, obviously in your case, it isnt working!

 

[Eticket]

Lee,

I believe I'm having the exact same problem!

Please let us know what you find..

I wonder if a standard rope seal would do better.

John Nguyen

 

[Lee Thompson]

seal

My thoughts were to go to a rope seal if upon closer inspection nothing could be found. After talking to Whitey @ Moldex, he informed me that a rope seal can only be used on a crank that has the knurling on it. The Moldex cranks do not have the knurling, factory cranks do. He said the knurling is to lube the seal. Without knurling the seal will burn. In the next few days I hope to find time to pull eng. and look again. Hoping Bill/s suggestion is right. (Rear cap not letting oil return to pan)

 

[Jay Wicks]

Hi Lee, Whitey is quite correct, the helix on the crank is used for seal lubrication/oil confiscation for the rope seal. It will not cause a problem if it is or is not present with a neoprene rear seal,---unless a reverse rotation helix is cut on the crank. Example: a boat motor set for reverse rotation. Check the seal I.D. of the cap to ensure there is proper seal preload. Also, recheck the crank surface seal O.D. and ensure it is ROUND with a dial indicator. Many times I have seen near perfect crank journals with bent flywheel flanges causing the rear seal area to be out of round. This will allow oil migration past the seal on the low side of the surface. The cause of this was the use of a heavy flywheel and "dropping the hammer" on 4 speed cars {NHRA Super Stockers}. When everything is correct, there should be no seepage.

 

[norbs]

If you use the shim idea i stated you will never have a leak again. Buy a can of coke and try it.

 

[chevyII]

Ill second the pop beer can idea. I have only tried this with a rope seal on pontiac engines and worked good.

 

[Lee Thompson]

update

Finally got around to pulling eng. Sat. morning. Pulled pan and rear cap. There is a thin line of ( BURNT ) seal on the crank. Can remove with finger nail. One of my bestest friends came by and we spent about 3 hours looking and measuring. I put a stock block and crank on the bench next to the stage eng. Cranks are the same dia. Flanges (or slingers) are identical Slots where the seal sits are the same dia. and width. Everything measured out the same. The only difference we could find is the slot in the cap ( for oil to return) is about twice as big in the stage eng. My thinking is that all the oil is dropping into pan and none is reaching the seal. Probably take another week to get reassembled and running again. We/ll see.

 

[quickt]

If the seal is burned on to the crank it must be too tight. I have used cranks either way BBC or stock with no problems. When you install the seal in the block and sit the crank in place try looking to see if there is some air space between the lip on the seal and the main body of the seal. If there is no air space then the seal tension on the crank will be too much. If there is plenty of room try the coke can idea. Where is the seal worn? Is the lip worn off all the way around or just top and bottom?

 

[Lee Thompson]

seal

Lonnie, I understand what you are saying, but I have checked all this. Looking @ the seals very outer edge ( where it come to a point, the very first part of the seal to touch the crank) it shows wear( or burnt) from the outer edge back somewhere around .020-.030. This is uniform all the way on both pieces Also, there is an air gap between the base and angled lip. Looks to be the same amount of gap as my stock eng. sitting beside it. This tells me that the bore the seal sits in is TRUE all the way around. At least it measures the same as a production block.

 

[EightSecV6]

never heard of that happening before......If it is leaking it is getting enough oil to lube it. Did you install the seal and install the rear cap with no crank to see what it looks like? If the cap has been cut and cut and cut in order to re align bore the block, the seal may actually be oval when in place and making contact on the top and bottom too tightly causing it to burn.If that is the case, you will be married to the rope seal. Can you get an inside mic in the seal groove to measure it at a bunch of different places with the seal and crank removed and the cap torqued down?

 

[Eticket]

Bill,

How would a guy use a rope in this case... As in the posts above.. the crank has to be cut for the rope seal?

Lee,

i'm counting on you to solve our problem before I pull the oil pan off again!

Thanks guys,
John Nguyen

 

[Lee Thompson]

Phone

ETicket - I believe you have my #. Call me.