Inliners International Forums General Discussion Engines High-Volume oil pumps ? 292,

Ok, So my old 292 has a High-Volume oil pump in it for about a year now and no problems I run 20/50 weight oil. Iam now building a new 292. Question which oil pump should I install In new engine? And when would you use a High-Volume oil pump? Thanks for any input

with a new engine with tight /normal clearances, i would not run the HV oil pump. i also would not run 20/50. i do run 15/40 and that gives plenty of oil flow and pressure, even with a turbo robbing some oil.

In different forums I have read that the HV oil pump is hard work on the cam because the springs are so strong. I have no real-world experiences with this... but that is what I have read more than once. Of course... if its on the internet, it has to be true. ha ha

HV pumps simply have longer gears with the same tooth pattern and number of teeth as the stock pump. There are no springs except the pressure relief valve (which is present in the stock pump, and can be compressed between your fingers). The extra volume of oil moved is at the same pressure unless the spring is changed - you can have more volume with less maximum pressure and vice versa.
1. An HV pump provides more pressure than a stock pump at idle and low speed before maximum pressure is reached (regardless of the pressure spring).
2. An HV pump reaches maximum pressure at lower engine speed than a stock pump.
3. Once the bypass pressure has been reached both pumps deliver the same rate, and the extra from the HV goes straight back to the pan.

An HV pump does place extra load on the pump shaft, which is driven off the cam.
If you have high mileage bearing wear and low oil pressure at low speed it helps. About 10 psi per 1,000 RPM is enough. If increasing oil viscosity slightly brings the pressure up, just do that (don't run 70 wt.!).
If not you don't need it.

I would never run a HV pump.
I wore out two brand new camshafts along w/3 -4 distributer gears.

From the engines I have built I never had 10 psi per 1000 RPM ,I think that is a SBC rule anyways.

If you don't need the HV,I would not use it. You lose HP ,creates undue wear on camshaft & distributer gears

I never spun a rod or main bearing running 40-50 PSI oil pressure @ 6500 RPM sometimes up to 7000.

I told Mike Kirby one engine I was running was only getting 45 psi (oil pressure) @ 6500 RPM,he said that was fine,hummm,never spun a bearing.,So I guess??

Next engine I plan on using a standard volume oil pump w/a stiffer reg. spring.


MBHD

Thanks to everyone, So how do I get a stiffer reg spring, and where?

Some guy here had done the swap,I asked for a P.N. but he never posted it.
I'm still waiting.


MBHD

i just take the spring out and shim it with small washers. test the pressure with a air hose.
before taking it apart do some pressure tests on the pump for reference. set the air regulator to zero, apply air hose to bypass passage and crank up the pressure until it bypasses. add washers until you are satified. do not go overboard! tom

One time I did install a Holley carb main jet as a shim under the relief spring,it seemed not to increase the oil pressure that much,maybe 5 psi??

That is what SBC guys have done,but for the SBC it increases pressure by 10 psi IIRC.

Tom,
how think are the shims that you have put in & how much oil pressure have you gotten?

MBHD

Hank and Halfwacked,

I'm the guy who posted that thread about the stiffer oil pressure relief valve spring a few months ago, and I finally found where you can get it and what the part number is. Apparently it's available aftermarket from Mr. Gasket. They call it a High Pressure oil pump spring, and their part number is 26. You can probably look it up on Mr. Gasket website or order one from your friendly local auto parts store. Sorry it took so long to come back with an answer; things have been a little crazy in my personal life lately. Anyway, the advertised specs on this spring say that it will give you 80 psi cold and 45-50 psi hot, which is exactly what happened in my 194 running 20W-50 oil, so I'm reasonably sure that it's the same spring that I got from Chevy years ago. Oh, yeah, it's for the sbc V8, but it fits the 6 cyl oil pumps just fine. And it costs 5 bucks (cost half a buck in 1976, but a lot of things were less expensive then). And I did find a part # for a factory spring (used in the 300 hp 327 sbc motor) which is 14024240 and it costs $5.24 from Chevy dealers and gives the same oil pressure as the Mr. Gasket spring, but has to be ordered; nobody stocks it. Hope this info helps out some.

64NovaWagon,,

Thanks!


MBHD

Thank You, For the Information,

Guys,
High Volume oil pumps do not add wear to anything only HIGH PRESSURE can add more stress on anything, if the HV pump adds to the pressure then and only then can it hurt.

I would always run at least 10# per 1000 RPM on any high power set up to keep an oil wedge formed (6 or V8 no difference).

Most distributer wear is from miss alignment not the oil pressure.

Harry

My 292 has a stock pump, small cam, 4 bbl and headers, so it is not a high performance and doesn't need the oil pressure you guys are running.
I used dino oil for the break in four years ago, but have used 5-30 mobil 1 since then. The truck oil pressure gauge has no numbers, just hash marks. The needle is above the middle mark when going down the road and below middle at idle.

I only ran 10-40 in it before the rebuild and it had 200,000 miles on it then.
I for one don't see the need for big pumps or 20-50 oil on an engine that is expected to last.

I read something from a guy that sells lubricants for a living. He ran a test on his own cars. He measured the time it takes for a cold engine to build oil pressure. He determined that it took 60% longer to build full pressure with 20-50 than it did with the 15-40 he had been running.
An engine experiences more wear at cold start up than the next hundred miles down the road.

Hey Guys (No Hot Rod) I run 20/50 oil because some times I run my Toyota Rock Crawler on it side and the engine runs out of oil, and no oil pressure only runs at idle (runs on propane) for a short time and it seams to be ok, What do you think?

An engine experiences more wear at cold start up than the next hundred miles down the road

Yup - and the car manufacturers are quite happy not to have it discussed.

no oil pressure only runs at idle (runs on propane) for a short time and it seams to be ok, What do you think?

1. get a tilt switch and hook it to your ignition
2. get an Accusump

Ok Thanks, So what usually breaks when you run a (HV pump)? How about a Poll, What broke because of a HV pump?

Worn out camshafts (drive for distributer) & distributer gears,,,,,meaning many.

Switch back to a stock volume pump,,,same engine,same block ,same distributer,,,no problems.

Like I stated before,I ran 6500 RPM & saw 40-45 PSI oil pressure tops,never blew up or sun bearings,& Mike Kirby said that pressure was fine.

Personaaly I would like more pressure,but as long as things are getting all lubricated,any extra pressure is just causing drag on your engine.

I have built a few SBC's & a few inline Chevy 250 engines,I will say I would never get the oil pressure as a SBC would.

Maybe if you modify the inlines oil pump you could get higher pressures., but w/a SBC,it is really easy to get high oil pressure.


MBHD

It's probably only a small contributor, but the loading of the cam and drive is cyclical as a lobe sees spring pressure, and the loading of a gear oil pump is also cyclical (gerotor pumps have much lower cycling amplitude), but with a different frequency. Increasing the instant load by raising oil pressure raises the amplitude of the "spike" when the 2 frequencies coincide.

I have seen distributor drive and cam gears destroyed and an oil pump tang broken off with hv pump on a 292. (separate events)

Just a guess: factory SBC pumps have relief valve capacity well below the volume that needs to be bypassed under high load conditions (oil temperature 0° F, 60 wt. oil, instantly revving the engine to warm it up).
The result is that the pump tries to produce 200 psi (which has almost the same effect as sticking a broom handle between the gear teeth), the valve only dumps 30, and something breaks... if the filter doesn't explode first.
On a dedicated race engine that needs more volume for an external cooler it might help - but then you will be heating the oil before the engine is run, won't you?
Gee, when did they learn to do that?
1st time that I know of: heating castor oil beforehand made it easier to start and increased engine life. The engine was a Liberty V12 - you guess the year.

Hmm, Liberty V-12, oil pre heat for ease of cold start and extended engine life.

Ummm, winter of 1916-1917?

Hank, has anyone drilled the drain back hole that provides lubication to the dist gear from the front lifter gallery to a larger size???....could it be tapped for a tubing "nozzle" that would direct the oil to the gear???.......Fats

Ummm, winter of 1916-1917?

Ding ding ding!!!

drilled the drain back hole that provides lubication to the dist gear from the front lifter gallery to a larger size???....could it be tapped for a tubing "nozzle" that would direct the oil to the gear

Haven't seen it, but both sound good. Since the drain hole size doesn't lower system pressure it has to help, especially since the load cycling is worse at low speed when the oil flow is lowest. There may be a way to use bypass oil to run a squirter?

I think you are more than 1/2 wacked!

Not on the current engine in my Camaro,but my new engine I did some modfications so the gear will get more oil to it.

MBHD

Here,s another Question. The engines that had problems with HV pumps where they High-performance,{race engine,s} or mild engine,s [street use]. I have a new Melling M-62-HV Extra Volume Racing Pump Provides 20% additional Volume. Thats what it says on the box. Should I just Ebay it and go with stock pump with a new spring. Thank Guys for all your input after all HalfWacked

My engine is a mild street engine.

Personnaly, I would not use the extra volume racing pump.

My two cents & personal experience thrown.

Not saying it will happen to you or anyone else.

MBHD