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Oilpump gear failture! Doug!
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Author:  valiantboy_66 [ Mon Feb 23, 2009 1:46 pm ]
Post subject:  Oilpump gear failture! Doug!
It has been a while since I posted last. But a short run down goes like this. I lost oil pressure last fall and decided to put the car in time out. :evil: I finally got the time to pull the engine and see what happened. I pulled the pump and pan, and to my amazement there was no pump gear left. Total disintegration. :shock: The cam is a 546 Engle KV-1. Other than for some small chipping on the edges of the gear the cam looks good. I built every thing for this not to happen. I used a 6 bolt pump I got from Egge, built the pump gear squirter, and cam button. Doug, what more can I do to keep this from happening again? What would it take for you to build me a pump?
Author:  SlantSixDan [ Mon Feb 23, 2009 1:50 pm ]
Post subject: 
Two details I'm curious about:

1. What grade of oil were you using?
2. Street or race usage?
Author:  Joshie225 [ Mon Feb 23, 2009 2:39 pm ]
Post subject: 
Looks like race usage to me.

It's a bit surprising this happened with the small oil pump, but certainly not unheard of. I'm wondering about high RPM with cold oil. That's what killed my first oil pump gear.

On my HP slant that's going together now I'm planning on an extended break-in at limited RPM with light viscosity oil and lower oil pressure. The hope is that the oil pump and cam gears will break in together gently. I may even preheat the oil before the initial start up. After the break-in I'll switch to synthetic oil and bump the oil pressure up a little. I've also drilled out my main bearing feeds, drilled a passage in the oil pump (return from filter) that was smaller than the other passages and radiused the main galley entrances.
Author:  Dart270 [ Mon Feb 23, 2009 4:05 pm ]
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I would find a used pump and put it in. I think this is all about gear properties and not so much about stress and oil wt.

Lou
Author:  terrylittlejohn [ Mon Feb 23, 2009 5:21 pm ]
Post subject: 
I have done some thinking about this and when i first talked to doug all i used were mopar cams, with 3 gear failures i made my own stock belt drive oil pump to get pass that issue, but when doug sent me some hardened gears i tried them in the race car first, with the hard gear and positive gear oiling i hurt the gear with 2 days of racing. when i looked closely at the wear pattern, it was like the trailing edge of the cam gear was cutting the oil pump gear from the valley and tappering off, as it got to the out side edge of the oil pump gear.
All i did was turn the gear around on the oil pump so the opposite side was facing the cam gear, then i got a 220 stone on a diegrinder and rounded the leading and trailing edge of the cam gear. the car was raced the next weekend and when i remove the pump it only had a slight stock appearing wear pattern, so after seeing this improvement i put on a fresh gear, (thanks to doug giving me some spears) now after 3 yrs now racing i have not hurt a gear.
I am running 10-40 castrol with 50lbs at 6500rpms. my conclusion is that the thick outside edge of the cam gear is cutting into the oil pump gear and when you grind it round it is like a ring and pinion contact pattern , only touching on the center of each tooth, i suppose it`s the same as when doug uses lapping compound but allot more aggressive.
Author:  Doc [ Mon Feb 23, 2009 5:21 pm ]
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Did you use one of my case hardened gears?
Send me a PM and we can discuss a 'blueprinted' oil pump that includes a hardened drive gear.
DD
Author:  valiantboy_66 [ Mon Feb 23, 2009 5:58 pm ]
Post subject: 
To answer all questions I run straight 30 wt valvoline VR-1 race oil. and about 55 psi at 2500-6000 rpm. I try to test and tune once during the week and a saturday race. I also drive 20 miles per day to work. It is my favorite mode of transportation. The idea of rounding the leading and trailing edges of the cam gear sounds good to me. The very outer tip of the cam gear got chipped up a little but I don't think it will hurt where the pump gear rides.
Author:  Rug_Trucker [ Tue Feb 24, 2009 5:29 am ]
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popcorn



:shock:
Author:  SlantSixDan [ Tue Feb 24, 2009 7:00 am ]
Post subject: 
Quote:
To answer all questions I run straight 30 wt valvoline VR-1 race oil. and about 55 psi at 2500-6000 rpm.
That's a really heavy oil (why?), and 55 psi @ 6krpm is really going to throw a load on the pump drive gear…seems to me everything would have to be extra-perfect with respect to the gear itself, its mesh with the cam, its attachment to the pump, and the pump itself. I think you're right to "page" Doctor Dodge and look into having him build up a nice pump for you, but you may also want to look at a different, more pumpable oil.
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