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Lapping oil pump gear ???
https://slantsix.org/forum/viewtopic.php?t=32124
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Author:  Rick Covalt [ Fri Nov 07, 2008 1:21 pm ]
Post subject:  Lapping oil pump gear ???

I just had a used cam core reground by Erson to avoid the wonderful oil pump gear failure. My question is this. I have the matching oil pump gear that was run with this cam for 100,000 miles. I will put this gear on the Dutra reworked oil pump we have, but I do not know if I should lap the gears before installation. I was not planning on it, until I got the reground cam back and it looks like they gave it some kind of treatment. The lobes and the gear have a black or dark gray coating on them. So do I lap them in or not?

Thanks,
Rick

Author:  sandy in BC [ Fri Nov 07, 2008 4:29 pm ]
Post subject: 

Thats a good question.

Author:  Doc [ Fri Nov 07, 2008 4:49 pm ]
Post subject:  Re: Lapping oil pump gear ???

Quote:
... I got the reground cam back and it looks like they gave it some kind of treatment. The lobes and the gear have a black or dark gray coating on them. So do I lap them in or not?
Thanks,
Rick
The cam has been Parkerized.
Quote: Parkerizing (also called phosphating and phosphatizing) is a method of protecting a steel surface from corrosion and increasing its resistance to wear through the application of an electrochemical phosphate conversion coating. Parkerizing is usually considered to be an improved zinc or manganese phosphating process, and not to be an improved iron phosphating process, although some use the term parkerizing as a generic term for applying phosphating (or phosphatizing) coatings that does include the iron phosphating process.

In your case, I would check the mesh of the gears using a small dab of grease. If the contact pattern is well centered and even, apply a generous coating of assembly lube to the gears and go.

If the contact pattern is high / low, reposition the gear on the oil pump shaft. If the contact pattern is un-even, lap it in or try a different gear.
DD

Author:  Dusty Desks [ Fri Nov 07, 2008 4:49 pm ]
Post subject: 

The coating on the cam lobes and gear is to prevent galling on initial startup and aid break-in; I wouldn't lap the gear, since I wouldn't lap the cam lobes & tappets either.

Author:  Rick Covalt [ Sat Nov 08, 2008 5:51 am ]
Post subject:  THanks Guys

Thanks guys.

Rick

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