Hi, bronze dizzy gear has falied in my Hemi after 2000 road miles, what is the best brand gear to buy to replace it. Also a friend pointed out I may have to much oil presure which is componding the wear problem. The motor has 65psi hot idle and 90psi when the revs are up, it has a meling H/V pump.
Does anyone offer a softer bypass spring for these pumps, would this help?
Thanks Tim

Swap out that HV pump for a standard one, pressure is a function of volume.

Don't run too thick of oil, cut the relief spring down a bit, and be sure to run the collars on the distributor shaft. It helps keep the wear pattern more consistent.

The problem with just cutting the spring is that the pump will still have to move the same volume - but push it through the bypass. So power is wasted driving the pump and the oil is heated needlessly going though the bypass - not to mention the strain on that drive gear! With the kind of pressure the OP has he does not need the hv pump.

Thanks for the replies,current oil is ULX 20w50 what would you recomend and is there any preferances for bronze gear manufactures?
I will also drop back to a std pump. Tim

It's the thick oil you're running. Try a max of 10-30wt. You may need the extra volume with the thinner oil.

When mine wears out, I'm going to have my next bronze gear cryogenically treated.

Also, I switched to the new Milodon pump body and am using the stock cover on it. It reportedly takes significantly less power to drive it due to a more pointed shape of the gerator lobes.

Although your posted oil pressure is a bit high, Im going against the grain here and saying its not the oil.....

Ive run 20W 50VR1 in my own driver Challenger and the gear lasted years, I inspected it regularly, but there wasnt any appreciable wear. How many miles?? WAY more than 2000 and 10+ years. And I live in an area where I did start it on some pretty cold days.

You live in Australia, so I assume you arent staring the car in zero degree temps..

I notice you are running a chrome sheetmetal timing cover. How are you controlling cam end play. If you think that cover wont deflect, you are wrong. Ill bet that cam is walking like crazy if you dont have something in front of that cover to limit endplay..

Edit: My apologies, I thought the pic another memnber posted was the OP's. Anyway, how are you(OP) controlling end play? What type of timing cover are you running?

Look into that.

MB

My first thought was cam walk, also loose bushing, or bushing not seated all the way down, or shaft to long for the pump.

With that kind of pressure I'd scrap the HV pump and go to a standard volume. It's obvious that the motor can't handle the volume being pumped and the excess volume is causing the high pressure.

A softer spring probably won't help because the relief valve, even wide open, can only handle so much volume.

To reply to some of the answers.
The bush in the block is now worn but I beleive this is a result of debris from the bronze gear getting in between the drive and the bush as the drive is marked up in that area.
I have one of those Diamond roller thrusts on the front of the cam and a factory timming cover.
The motor is a 557ci using a World block.

factory cover and roller do not mix without support

Bronze gear against bronze bushing = wear. Same reason you don't use a steel gear with a steel roller cam ... similar metals !!

You want one of these cast covers - available from Promax in Indianapolis for $100. They fit under a stock pump and are thick enough to drill and tap for a plug so you can accurately measure cam endplay.

Bronze gear against bronze bushing = wear. Same reason you don't use a steel gear with a steel roller cam ... similar metals !!

The bush in the block is not worn on the top where the bronze drive runs on it is worn inside where the oil pump drive runs, that is why I suspect dedris from the bronze drive failure got between the drive and the bush. The drive is marked up where it runs in the bush.

Correct me if I am wrong but dosnt the turning of the dizzy/oil pump drive force the cam to the back of the block, I thought this is what the torrington on the back of the timmig gear set was for?

The bushing is worn inside from the cam walking forward and trying to put pressure on the drive shaft. The roller button mounts on the front and is stopped by the timing cover. A factory cover will flex and allow the cam to move forward, even with the roller button

The end play is set at .015thou. I understand the timming cover may flex a little if the button runs against it.
Correct me if I am wrong but dosnt the turning of the dizzy/oil pump drive force the cam to the back of the block, I thought this is what the torrington on the back of the timmig gear set was for?

Tim