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Oil pump gear shearing/ hardened replacement
https://www.slantsix.org/forum/viewtopic.php?t=66176
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Author:  Budget mopar guy [ Thu Sep 09, 2021 6:43 pm ]
Post subject:  Oil pump gear shearing/ hardened replacement

I've searched the forum and I was wondering if a hardened oil pump gear has solved the oil pump gear shearing on the cam. I bought a .440 lift comp cam and the entire engine is together now. Now I'm worried about the oil pump gear shearing off. Have we found a reliable remedy for this?

Should I replace it with a hardened one??? And if so where do I get it

Author:  Jase [ Fri Sep 10, 2021 8:18 am ]
Post subject:  Re: Oil pump gear shearing/ hardened replacement

I do not know if hardened gears are still available. I am unsure if even that was a reliable solution, or if the problem was more a result of the new camshaft gear tearing everything up, due to some issue with the gear pattern on the cam.

The generally expressed path seems to be to re use the old oil pump, and original cam, and have then cam reground... so that the original gears and wear pattern remain.

Do you still have the old oil pump and old camshaft on hand? If so, keep them just in case.

Author:  slantzilla [ Fri Sep 10, 2021 9:36 am ]
Post subject:  Re: Oil pump gear shearing/ hardened replacement

Doug Dutra was doing the hardened gears, no idea if he still is.

I had one in my motor that ate the cam gear.

A little added insurance is installing a cam stop in the front cover. It's pretty simple to do. You should be able to find the directions on here.

Author:  DadTruck [ Fri Sep 10, 2021 10:55 am ]
Post subject:  Re: Oil pump gear shearing/ hardened replacement

You are probably worrying over something that will never happen.
Especially if you don’t plan to run high RPM’s. I would make sure the
oil pump gear is centered to the cam splines and call it a day. You could always
take a few photos of the oil pump gear when new, then pull the pump at 5000 mile
intervals and photograph it each time documenting any progressive wear or lack of wear.
My thoughts are, if the cam splines to drive gear mesh is going to have issues, it will
show prior to failure. You can then do something about it when you have evidence that it
is worth worrying over.

Author:  Old6rodder [ Fri Sep 10, 2021 11:13 am ]
Post subject:  Re: Oil pump gear shearing/ hardened replacement

Some Comp cams got out awhile back with the pump & dist teeth hobbed, but not finished. I got one of'em, and just hand polished the teeth after it ate a dist gear. No more issues from it.

Other, pump only, problems've resulted from exceeding the factory pump Pressure/Flow Rate enough to increase the loading on the teeth to a level that makes it hard to keep the small tooth contact lubed properly even on smooth teeth. Bettering the lubing seems to be the answer there.

Author:  Greg Ondayko [ Fri Sep 10, 2021 11:36 am ]
Post subject:  Re: Oil pump gear shearing/ hardened replacement

For Most Stock / Hot rod Street vehicles all of the above suggestions are good.

If you are going all out crazy say over 5800 RPM all of the time, then an external belt driven pump along with appropriate plumbing is the answer.

Greg

Author:  SpaceFrank [ Fri Sep 10, 2021 1:24 pm ]
Post subject:  Re: Oil pump gear shearing/ hardened replacement

I never had an issue with cam or pump gears on my road racing Slant, running either stock cams or an Isky cam that I bought new in 2004. Always used an aftermarket Melling M66C pump (7/8" rotor). To be fair, we never spun higher than 5000 RPM and weren't making monster power.

I finally experienced the dreaded gear tooth failure after I swapped on a higher-volume M66HV pump (1" rotor) with a hardened gear from Doug. (What's that thing you're not supposed to do when it ain't broke?) The engine only survived because I felt it stumble while powering out of a corner, and I looked down at the gauges to see oil pressure at zero. I assume the stumble was from all the gear teeth shearing off.

I doubt the extra loading from an additional 1/8" inch of pump lobe thickness (compared to the M66C pump) was the critical factor in causing a failure. To the extent that the gear problem still exists with properly finished cam gears from a reliable cam vendor, I don't think hardening the oil pump gear is the solution.

Author:  Greg Ondayko [ Fri Sep 10, 2021 3:00 pm ]
Post subject:  Re: Oil pump gear shearing/ hardened replacement

You prolly felt the stumble due to inadequate interfacing the the distributor .. they are driven off the same gear.

Same thing happened to mine in the ruster at clay city. Wild dist. timing events then no oil pressure.


Greg

Author:  emsvitil [ Fri Sep 10, 2021 10:07 pm ]
Post subject:  Re: Oil pump gear shearing/ hardened replacement

Any update on the redesigned gear with different tooth count?

Author:  Rick Covalt [ Sat Sep 11, 2021 2:54 pm ]
Post subject:  Re: Oil pump gear shearing/ hardened replacement

I tested the 14T one for Doug in my truck on a new cam and it ate the pump gear pretty bad in a short time.I will have to find the post on here.

https://www.slantsix.org/forum/viewtopi ... r&start=15

Author:  slantzilla [ Mon Sep 13, 2021 5:37 pm ]
Post subject:  Re: Oil pump gear shearing/ hardened replacement

I run a lot of rpm, but only for a short time. I cut the filter open every oil change, so far no junk in it.

Parts store stock oil pump on an unknown camshaft.

Author:  DadTruck [ Mon Sep 13, 2021 6:02 pm ]
Post subject:  Re: Oil pump gear shearing/ hardened replacement

Dennis, have you ever pulled the pump just to take a look at the drive gear and does it have any auxiliary oil spray?
And just curious, how often do you change the engine oil - filter in your race car?

Author:  slantzilla [ Mon Sep 13, 2021 6:51 pm ]
Post subject:  Re: Oil pump gear shearing/ hardened replacement

Once a year. Have not pulled the pump. No oil spray. Planning on pulling the motor this fall, it's got to be a time bomb by now. :mrgreen:

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