Hi volume oil pump vs standard volume pump

-
Yes, I have the MP book by Larry Shepard that says the same thing. But it also says to use an HV pump, as do all the books you reference, I bet.
No arguments from me on the high volume. It is all I would use.
Too much is better than not enough after the motor is already done and in the car. But a bigger pickup even on a stock pump is not going to hurt anything either. All kinds of people on the forum lately with low oil pressure after a new build like the op.
 
No arguments from me on the high volume. It is all I would use.
Too much is better than not enough after the motor is already done and in the car. But a bigger pickup even on a stock pump is not going to hurt anything either. All kinds of people on the forum lately with low oil pressure after a new build like the op.

I agree. I think we are on the same page.
 
I go with what Atherton tested and what he says in his books and I'm sticking by it.


Happy New Years to all you guys.
 
The eaby pickup tube measured.
DSC05707.JPG
Looks too thin to drill to 1/2". So if you do the standard oiling mods and drill passages to 1/2" the bottleneck will still be where this tube screws into the pump. About 22% less flow.
 
Last edited:
I had an issue with a high volume oil pump that make me keep a better eye on things. I’m bad at looking at gauges on 8-9 seconds passes down the track. Luckily I have a RacePak in my Duster and while looking at data apparently my bypass spring was sticking and my oil pressure was jumping up to 130 of pressure. Again lucky my Wix oil filter was up to the task of not blowing apart.
Which Wix filter are you running? P/N ?
 
Early this year when I built my daily driven 360 I put a stock oil pump in it thinking everything would be all right.
Well, it wasn't.
Whenever the oil got warms up, the oilpressure at idle drops considerably to well below 20psi.
This was with 10w30 oil, to which I switched to 10w40 oil, which still has this issue.
I'm thinking the hydrualic lifters' oil bands are very close to the top of the lifter bores, causing them to bleed a lot more oil at low rpm and warm/thinner oil.

Short of changing the lifters (to solids) I plan to install a HV pump very soon first to see if this helps the situation.
Are you running hydraulic roller lifters or hyd flat tappet?
 
The eaby pickup tube measured. View attachment 1715273231Looks too thin to drill to 1/2". So if you do the standard oiling mods and drill passages to 1/2" the bottleneck will still be where this tube screws into the pump. About 22% less flow.
.
Agree. Still bigger than the stock pickup tho. That insert is really hard metal to drill. The reading on mine was .444 if I remember correctly on the milodon pickup.

Here a link to it.

Small Block Oil Pick Up Tube Question
 
Are you running hydraulic roller lifters or hyd flat tappet?

Hydraulic flat tappet, converted to solids because of bleed-downs.
But I have a set of solids on order to replace them because I believe the oilband is too high compared to the camfered lifter-bores in my engine.
(Provided the lifterbores themselves are still into spec).
 
Hydraulic flat tappet, converted to solids because of bleed-downs.
But I have a set of solids on order to replace them because I believe the oilband is too high compared to the camfered lifter-bores in my engine.
(Provided the lifterbores themselves are still into spec).
Let me guess they were Comp Cam lifters that bleed off?
I was told by some Cam people not to run solids on a hydraulic grind. Did it work for you performance wise?
Good luck with your bores I know there is a manufacture the moves the oil band down to get away from the chamfer.
 
The lifters were new but I had them for years already. They came in a blank box however so no telling what brand they are.
It's no problem to run solids on a hydraulic cam, but you need to run a very tight lash of around 0.006" and pay attention of hot and cold settings (cast-iron heads & engine).
I've contacted CompCams about this too years ago when they told me to keep the lash tight and make sure the lash is taken up before the actual ramp starts on the lobe. Otherwise you will be hammering the valves and shorten valvetrain-life.

I hope the solid bodied mechanical lifters will take care of the low (warm) oilpressure in my engine.
 
Lifter bore diameter, at least in my '65 book, is .9050-.9058". (Small block and big block). There is just this spec.. not a separate service spec, at least that I can find. Lifter to bore clearance is listed at .0005-.0015"

Interestingly, this vintage of FSM lists oversize lifters being available, in .001", .008", and .030" oversizes. The FSM refers to reaming the bore out and using an oversize lifter if the lifter bore is worn or scored, so this wear matter was set up to be serviced.

Lifters sizes do vary within a range, so you might be able to ask a mfr to sort out a set of lifters sized at the large end of tolerance for you if the bores are just bit oversize. (We did this with a new Crane cam with the opposite problem of some of the larger production lifters not fitting in tight bores; Crane was quite obliging.)
 
The eaby pickup tube measured. View attachment 1715273231Looks too thin to drill to 1/2". So if you do the standard oiling mods and drill passages to 1/2" the bottleneck will still be where this tube screws into the pump. About 22% less flow.
I don,t think you are comparing apples to apples.
The suction side works differently than the output side.
I thought that drilling the passages in the block to half inch was to decrease the pumping losses. It's easier for the pump to push the oil.
It does not mean the leakage rate of the motor will be higher just because we opened the passages up in the block. The bearing clearances would still be the restriction.
The flow rate through the block could still be substantially less than what the passages could free flow.
 
The eaby pickup tube measured. View attachment 1715273231Looks too thin to drill to 1/2". So if you do the standard oiling mods and drill passages to 1/2" the bottleneck will still be where this tube screws into the pump. About 22% less flow.
You could easily cut the threaded end off that pickup, and weld on a larger diameter piece threaded at 1/2 inch pipe.
Would still be a nice looking pickup tube with a larger inlet diameter.
 
I don,t think you are comparing apples to apples.
The suction side works differently than the output side.
I thought that drilling the passages in the block to half inch was to decrease the pumping losses. It's easier for the pump to push the oil.
It does not mean the leakage rate of the motor will be higher just because we opened the passages up in the block. The bearing clearances would still be the restriction.
The flow rate through the block could still be substantially less than what the passages could free flow.
I agree with this thinking in general but don't know the ultimate answer.

The real problem (that I don't think is well understood) becomes what does the flow into the engine rise to at higher and higher RPM's?

(Not to mention what odd things happen then... like the issue of oil bypassing the passage to main #4 or the oil starvation to the valvetrain.)
 
I agree with this thinking in general but don't know the ultimate answer.

The real problem (that I don't think is well understood) becomes what does the flow into the engine rise to at higher and higher RPM's?

(Not to mention what odd things happen then... like the issue of oil bypassing the passage to main #4 or the oil starvation to the valvetrain.)
Yes that would be a variable. But as I posted earlier about using a high volume pump, unless you are after every last horse power from your build, extra volume and pressure is not going to hurt you.
Having not enough will.
Same with drilling the block passages larger. It ain't gonna hurt, and as you have said, at high rpm you may need it.
But the suction side is different. If the pump is into bypass and recirculating oil inside the pump, there would not even be any flow inside the pickup tube until the bypass closes again. I am thinking
That the eBay pickup and the milodon, even though they still only use the stock size thread, but with a larger diameter tube there would be a Venturi effect that would still offer better suction.
Now if you want an interesting read, Ryer Morrison says pickups don,t suck at all. He claims the oil is displaced into the pickup by the oil level in the pan. It is forced in or something to that effect. Lol
 
Those both look nice and smooth. Took me while to read the letters on Kroosers'... Champ Pans... of course LOL
Now if you want an interesting read, Ryer Morrison says pickups don,t suck at all. He claims the oil is displaced into the pickup by the oil level in the pan. It is forced in or something to that effect. Lol
I would guess he is saying it is caused by the pressure differential from the pan to the inlet side of gears..... pressure differential is the cause of all flow. Which kinda points how you could test all of these pickups against each other: Have a 'standard' pump working into a fixed flow at a fixed RPM, and measure the pressure drop right at the inlet of the pump.
 
Now if you want an interesting read, Ryer Morrison says pickups don,t suck at all.

Suction is just a way to describe "low pressure".

It is forced in or something to that effect.

At sea level atmospheric pressure us about 14.7 PSI. It's less at higher elevations. That's what is pushing the oil up the pickup tube to the oil pump. Thus, the larger the pickup tube the less restriction to flow and therefore more potential flow. The larger size sounds obvious, but at only 14 PSI any increase is size is going to help. The pressure differential, as mentioned by nm9stheham, is what makes it work. The pump creates the low pressure area.
 
Suction is just a way to describe "low pressure".



At sea level atmospheric pressure us about 14.7 PSI. It's less at higher elevations. That's what is pushing the oil up the pickup tube to the oil pump. Thus, the larger the pickup tube the less restriction to flow and therefore more potential flow. The larger size sounds obvious, but at only 14 PSI any increase is size is going to help. The pressure differential, as mentioned by nm9stheham, is what makes it work. The pump creates the low pressure area.

No argument here, but, liquid seeks its own level, if no air can escape the oil pump on a setting engine, the oil could not drain or come up the tube . Such is the reason my single line pick up, that has an upward loop down ( because of header clearance) , to the pan fitting doesn`t drain out ----I`m thinking. The oil pressure comes up almost instantly when I start it. ?????????????????
 
No argument here, but, liquid seeks its own level, if no air can escape the oil pump on a setting engine, the oil could not drain or come up the tube . Such is the reason my single line pick up, that has an upward loop down ( because of header clearance) , to the pan fitting doesn`t drain out ----I`m thinking. The oil pressure comes up almost instantly when I start it. ?????????????????
The other example I can think of is the typical auto cooling system.
 
No argument here, but, liquid seeks its own level, if no air can escape the oil pump on a setting engine, the oil could not drain or come up the tube . Such is the reason my single line pick up, that has an upward loop down ( because of header clearance) , to the pan fitting doesn`t drain out ----I`m thinking. The oil pressure comes up almost instantly when I start it. ?????????????????
'I can't visualize that but I'll take your word for the loop. As an explanation, if you use a standard filter and the plug up in the block above the pump is in place, that will help keep oil in the system below the pressure sensing point, for at least overnight and maybe for some days, depending on how well the 'flapper' anti-drain back valve in the filter seals. That is the main system design feature to keep things primed. You can't prevent the oil draining out of the system much beyond that point, once it starts 'downhill' to the mains.
 
'I can't visualize that but I'll take your word for the loop. As an explanation, if you use a standard filter and the plug up in the block above the pump is in place, that will help keep oil in the system below the pressure sensing point, for at least overnight and maybe for some days, depending on how well the 'flapper' anti-drain back valve in the filter seals. That is the main system design feature to keep things primed. You can't prevent the oil draining out of the system much beyond that point, once it starts 'downhill' to the mains.
Please
Which filters offer the best anti-drain system.
I have been using WIX standard filters
 
-
Back
Top