Replacing oil pump- Standard vs. High Volume?

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panthermike

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Pretty soon here I'm going to replace the oil pan gasket on the F100, which has a 390. While I'm in there, I'm going to swap out the oil pump and screen. AFAIK, the motor is original and the internals are stock for sure.

I noticed at the auto store, they have standard and high volume. Any benefit to HV? I don't mind either way, just don't want a HV if it isn't really "better" to use. The differnce is $10 for what it's worth.

Reasoning for changing oil pump is also because of low oil pressure and it's quite cheap. I believe the low pressure is due to the lifters actually, but because of the price I'll change the pump/screen too. Labor is nil, so that's nice.
 
I would stick with whatever volume displacement is needed stock and not worry about HV unless you are replacing parts to tune towards being a racer and will be at high RPM often for longer periods of time, etc.

Not experienced here, so take it with a grain of salt though I believe that logic is sound, FWIW.
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Also, are you considering one brand over another for the pump? I don't see an issue replacing the original I suppose, though I'm sure some may argue it's best to leave it be if it's doing it's job right and isn't broken so don't fix it.
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i would go for the high volume, as your engine wears it will need more volume to keep oil pressure where it should be. your oil pressure will not get above the stock settings but you will have more volume on demand when you need it! not to mention it will build pressure fast on star up. the only down side is a HV oil pump uses about 1-2 more horsepower to run than a stock pump at 5k rpms.
 
Originally Posted By: 67lemans
If you do go with a HV don't forget the H.D. Shaft


either way get a HD shaft if they have it! they do break sometimes even on bonestock engines
 
Unless you're going with a larger oil pan, go with the standard volume oil pump. If you don't, there's a high risk of oil starvation at higher RPMs.

Reason for this is the pump will have pumped all of the oil to the top of the engine and the pan may be empty because it is not large enough to hold the additional oil necessary to keep a steady oil flow to the entire engine.

A stock oil pump is more than sufficient.

Just my .02
 
Originally Posted By: Chris142
Low oil pressure isn't normally from a worn pump. It's from worn bearings.Whats the actual oil pressure?


Not sure what actual oil pressure is. Those old Ford gauges have L, H and OIL in the middle. Between OIL is normal. The gauge needle is at the middle of the O(low end of normal) at hot idle.

Could a bad lifter cause low oil pressure?
 
High volume pumps put more stress on the parts driving the oil pump, so keep that in mind. Moving more oil than the stock pump the volume/pressure is trying to push more oil harder through the bearings etc.

I would stay stock unless I had good reason to know why I should upgrade. I don't think you really need the high volume pump.
 
I'd go with the stock oil pump. I've SEEN high volume oil pumps cause a sheared pump drive shaft, and I've seen one cause a burst oil filter (granted, it was a Fram). Personally I'd leave well enough alone and go with the stock pump... unless maybe you're just trying to bandaid a worn-out engine long enough to sell it.
 
Originally Posted By: morris
DO pack the new pump with grease, so it will pull oil right away.


Yeah, that's good advice. Or at a minimum you'll at least want to dump some oil into the inlet and spin the pump to get everything lubed up. The important thing is that you don't install the pump dry.
 
please do not pack the pump with grease. You will immediately risk plugging things up until it gets hot enough to melt it.

Simply prime the pump first with oil. Prefill the filter too, you'll get oil pressure very fast.

And worn lifters do not cause low oil pressure, a worn lifter galley could. Cam and lower end bearing wear is the most likely, but sometimes it's as simple as a stuck oil pressure relief valve.

While a new pump is almost always ok it won't fix old problems. And a high volume one frequently breaks the driving parts unless they are upgraded too.
 
Originally Posted By: chubbs1
Qdeezie is absolutely right. You actually risk starvation with the HV pump! Just go with the regular stock pump, it will be more than sufficient. Good Luck!


that is completely wrong! i dont know where you get your info. when a pump by passes oil goes back into the pan. its not going to move more volume than needed to maintain pressure. i have run HV pumps in every SBC i ever built! most were with stock oil pans and i never lost any pressure from oil starvation. aftermarket oil pans are for decreased windage , lower oil temps, and oil control with baffles, so your oil doesnt slosh around in hard cornering or braking

and to who ever said a HV pump blew up an oil filter..well that was mistaken or some kind of malfunction. the filter should by pass and the pump should by pass too way before a filter explodes. cant blame it on the volume

a high volume pump doesnt up pressure its just CAPABLE of more volume to keep stock oil pressure. when stock pressure is reached it by passes and oil goes back to the pan. when pressure is needed it doesnt by pass.

i would not however go with a High Pressure pump or HP/HV design. more pressure isnt needed and wash out is possible
 
btw panther you pressure is low because of bearing wear. theres only two ways to remedy it if not rebuilding the engine. a high volume pump or a heavier oil. dont bother replacing a stock pump with a stock pump, its a waste of time.
the HD shaft is a good idea, i have not had any break but that doesnt mean you wont. i have seen many fords with the hex shaft break with stock pumps. so it really is a good idea.
if you buy the speculation about draining your oil pan and that other hog wash just try a heavier oil and see what happens.

steve is right about the grease thing, and many other things as well. very solid info, as always.
 
The stock gauge is junk. Don't even think for a second that it's reasonably accurate. You need a mechanical gauge and I recommend that you check the actual oil pressure before you go tearing into the thing.

There is a 5v voltage regulator in the dash that goes bad and all the gauges will read low.

6-8 psi @ idle and 35+ @ rpm is ok for that old 390.

Since it has hydraulic lifters if the oil pressure is too low the lifters will get noisey @ idle. If they are not noisey @ idle I wouldn't worry about it.

As for prelubing the pump. The STP in the blue bottle is a great choice. It's sticky and thick enough to stay put but not so thick to prevent it from pumping.
 
Originally Posted By: Chris142
The stock gauge is junk. Don't even think for a second that it's reasonably accurate. You need a mechanical gauge and I recommend that you check the actual oil pressure before you go tearing into the thing.

There is a 5v voltage regulator in the dash that goes bad and all the gauges will read low.

6-8 psi @ idle and 35+ @ rpm is ok for that old 390.

Since it has hydraulic lifters if the oil pressure is too low the lifters will get noisey @ idle. If they are not noisey @ idle I wouldn't worry about it.

As for prelubing the pump. The STP in the blue bottle is a great choice. It's sticky and thick enough to stay put but not so thick to prevent it from pumping.


Thanks for the tips Chris. I believe it's just one lifter making some noise on the passenger side. We ruled out an exhaust leak w/ the "rag in exhaust" test. 6-8psi is ok at idle? Seems low to me, but I am definately a novice.
 
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