oil pump

[hunt2elk]

Does anybody know if I can use a mp high volume pump on my 69 383 HP Roadrunner without changing the intermediate shaft also. I am replacing most of the gaskets, seals, water pump, oil pump, spark plugs, hoses, belts and repainting the motor while it is in the car to try to stop leaks from a 25 year old rebuild. I dont want to pull the distributer. The only reason I am asking is that in Year One's cat. they recommend changing the shaft-but this is the only place I have seen this stated. I have no idea which shaft is in the motor now.

 

[69 Runner]

No real reason to change the shaft, but I bet they're recommending the one with the "hardened" shaft. The theory is the HV pump is harder to turn, therefore the likelihood of busting the bottom of the shaft is increased. However, I've only used a "hardened" shaft once, and that was in my Six Pack Challenger (which I pounded on) and ran 12's @ 110.6

 

[63RedFury]

I would not use a high volume pump unless you have a deep oil pan.If you put a high volume pump on and use a stock oil pan you will suck the oil dry at high RPM's.You can use a high pressure pump if you have a stock oil pan.
Jim

 

[hunt2elk]

I have the stock 402 pan. My next question is what came on these motors as stock and if they were not high volume then should I put something like a Melling M63 on and not worry about it?

 

[63RedFury]

I would use a stock or a high pressure pump.

 

[69 Runner]

Are you planning on driving or racing this? I ran a HV and a 402 on my 69 Bee (#'s 383) and ran 6 quarts in it to keep from sucking it dry hitting 7000 on the strip. Daily use you'll never run it dry even with 5

 

[hunt2elk]

This is my convertible and only gets 500 pleasure miles a year put on it, so no racing. I am just cleaning up the engine bay and may sell it when the markets come back up. I don't want to let it go but I am looking for another project and would need the cash and floor space for that. Trying to find a solid body 68 Coronet RT or 68 Charger RT. 69 Runner, do you put high volume pumps on all your cars?

 

[69 Runner]

Pretty much. Put one on the 383 in my "As promised" thread, and I doubt it will ever be "mistreated" lol

 

[63RedFury]

I never sucked mine dry until I spun the tires then it would suck it dry right now.That was a 440 with 410 gear.I bought the car with the HV pump and stock pan and it was hell on my bearings.Again I would never run a HV pump with a stock pan.

 

[hunt2elk]

Thanks guys-I went with a standard volume and pressure model. That is what I am replacing. It does make sense to have a higher capacity pan with a higher volume pump, and I don't what to risk damage to the motor.

 

[Meep-Meep]

Good call.

High volume pumps by design move more oil, but where does that oil go? The lower the restriction at the pumps output, the higher the flow rate and the lower the pressure. Loose clearances at the mains, cam, rods, lifter bores and valve train all add up to some number representing a flow rate. Also the pressure relief in the pump (when it's open) adds to the flow equation as well.

I think adding a high volume pump to a normally clearanced engine does nothing but exercise the pressure relief more. Also, I seriously doubt it will suck a pan dry. Off the top of my head the only engine I know of that has oiling issues is the big block Olds - and the reason is the drain back passages are too small to let oil back to the pan and the valve covers fill up with oil.

 

[63RedFury]

390 AMC's had bad oiling issues.

 

[scotts74birds]

I dont mean to hijack the mans thread, but since we are on the subject, and somewhat relevant, can someone clarify the high-volume vs high pressure oil pump subject?

 

[Meep-Meep]

I dont mean to hijack the mans thread, but since we are on the subject, and somewhat relevant, can someone clarify the high-volume vs high pressure oil pump subject?

High pressure pumps have a stiffer pressure relief spring to limit the opening of the valve until a specific pressure is reached. It was the black 70 pound spring that was recommended in the DC book. High volume, as I said above, just moves more oil - but only if the engine clearances allow for it. A good application for a high volume pump would be a turbo installation where you have an extra oil circuit in parallel for the turbos or maybe an external engine oil cooler.

Put your thumb over the end of a garden hose to choke off the water but not shut it off. The pressure in the hose is increased but the flow is decreased. Now release your thumb and the opposite will happen.