I've been talking to the guy that did all of my machine work, and he gave me some really good advise on shimming my distributor. He also said that Crane's Claim that my High Volume Oil Pump killed my gear drive is false. He runs a high volume pump in his Outlaw Sprint Car, and has never had problems.

I am running Dino oil for the next 2,000 miles, then it will be going to Mobil 1.

Before I go through another $40 gear, I'm wondering if I should change this pump. I am already planning on a new oil pan, because somewhere along the line, I got a big dent in the factory one, not to mention that black is the worst looking part of the engine.

Which Oil Pump do you prefer?

Also, Please post any research that you know of.

 

What I've found so far:

Crane

 

This guy wrote a lot of crap about 383's that I didn't agree with, but here is what he has to say about it:

 

Very true. Thats why the stock pump is fine. Thats all I've ever used.

 

Thanks. :) Never had a problem?

I don't know why I got sucked into this high-volume thing. Oh well, it'll give me more things to do while the oil pan is off.

 

Virtually every performance engine book I have ever read says stick with the stock volume pump on the small block. The only upgrade suggested is to use the Z28 oil pressure spring or add shim to the stock one. This includes Lingenfleters book.

 

The stock oil pump (for LT1) is described as "high pressure" in the GM catalog. They also list some high volume pumps as well. I figure the stock oil pump is as good as any.

 

Both high volume and high pressure (beyond stock) oil pumps require more hp to run and they get their power through the distributor gear. Oil is pumped through the engine bearings to keep it cool, NOT to supply pressure to support bearing loads. Bearing rotation generates the pressure to support bearing loads. Experiments have proven that if the bearing journal is highly polished, the bearing life is greatly reduced because the slick bearing surface doesn't "grab" the oil film and generate as much load supporting pressure. If you don't know these facts, then you can come to the wrong conclusion that higher volume or pressure oil pumps are better than stock and also that you should pay the extra money and have your bearing surfaces polished. Caveat Emptor, or.....P T Barnum strikes again. :D

 

Hey noworries,
I will agree with with others that a high volume pump is a no-no.It can also cause spark scatter in the distributor as well.
Thats bad for engine performance and spark in there.
Most street engines do not require a high volume pump unless extremely modifed.I would sugest staying with the stock pump but be sure to have the pick up tack welded on if its only pressed on out of the box.
Most stock pumps have the pickup tube pressed on and its a mod to have it welded permanently.
:)

 

Yep, I toasted my first motor by running a HV pump with a stock pan

 

READ THIS FIRST
http://www.melling.com/highvol.html
http://www.melling.com/engoil.html
http://www.melling.com/miscon.html

I have built and raced over a hundred engines in 35 years and what you should be looking for with a chevy v-8 is 20-25lbs minimum hot (oil at 200F-230F deg )(coolant at 185f-210f deg.) a 750-1000rpm idle and at least 10 lbs per 1000rpm example
1000rpm..20-25psi
2000rpm..30-35 psi
3000rpm..40-55psi
4000rpm..50-65 psi
5000rpm..60-75 psi (the oil pressure bypass return circuit in the oilpump,stops further increases above 75 psi and none are needed)
6000rpm..70->75 psi
7000rpm..70->75 psi
8000rpm..70->75 psi
now if you have just a little less try useing just a little thicker oil (oil should be the thinnest SYNTHETIC that gives these pressure readings)because PRESSURE is the RESISTANCE to oil-flow caused by your bearing clearances and if you have less your clearances are just a little on the large side,BTW (oil should be in the 5w-30w to 15W-40W range) and look here too. http://www.babcox.com/editorial/us/uhs89734.htm http://www.dorianyeager.com/oilfilterstudy1.html</A> http://www.micapeak.com/info/oiled.html <A HREF="http://www.engr.colostate.edu/~allan/heat_trans/page7/page7.html" TARGET="_blank">http://www.engr.colostate.edu/~allan/heat_trans/page7/page7.html
btw this may help you find a good oilpan/pump /pickup, chevy,s can be improved upon! heres a good one for the money; http://cmfilters.com/pr_source/pr_15240.html

and yes you can get away with 15psi at idle, and only 60 psi at 6000rpm for years in a street car but a car engine thats raced needs better pressure/flow to keep the bearings heathy and dont think that just because mr (xyz abc) runs his drag race car with only 10 psi at idle and uses a standard volume and standard pressure pump to not (WASTE HP DRIVEING THE OILPUMP) that you can too. REMEMBER HE ALSO THROWS THOSE ENGINE BEARINGS AWAY AFTER LESS THAN 1000 miles of use! you are most likely going to want them to last just a little longer than that!


ok look at it this way,what your trying to do here is keep an pressureized oil film on the surface of all the bearings to lube and cool them and have enough oil spraying from the rod and main bearing clearances to lube the cam and cylinder walls/rings. now a standard pump does a good job up to 5000rpm and 400 hp but above 6000rpm and 400hp the bearings are under more stress and need more oilflow to cool and because the pressure on the bearings is greater you need higher pressures to maintain that oilfilm.lets look at the flow verus pressure curve. since oil is a liquid its non-compressable and flow will increase with rpm up to the point where the bypass circuit starts to re-route the excess flow at the point were the pressure exceeds the bypass spring pressure. but the voluum will be equal to the pumps sweep voluum times the rpm of the pump, since the high voluum pump has a sweep voluum 1.3-1.5 times the standard pump voluum it will push 1.3-1.5 times the voluum of oil up to the bypass cicuit cut in point, that means that since the engine bearings leakage rate does not increase as fast as the rpms increase because the clearances don,t change that the amount of oil and the pressure that it is under will increase faster and reach the bypass circuit pressure faster with the high voluum pump. the advantage here is that the metal parts MUST be floated on that oil film to keep the metal parts from touching/wearing and the more leakage points the oil flows by the less the voluum of oil thats available for each leakage point beyond it and as the oil heats up it becomes easier to push through the clearences.now as the rpms and cylinder preasures increase in your goal to add power the loads trying to squeeze that oil out of those clearances also increase. ALL mods that increase power either increase rpms,cylinder preasures or reduce friction or mechanical losses. there are many oil leakage points(100) in a standard chevy engine.
16 lifter to push rod points
16 pushrod to rocker arm points
32 lifter bores 16 x 2 ends
10 main bearing edges
9 cam bearing edges
16 rod bearing edges
2 distributor shaft leaks
1 distributor shaft to shim above the cam gear(some engines that have an oil pressure feed distributor shaft bearing.)
so the more oil voluum the better.chevy did an excelent job in the design but as the stresses increase the cooling voluum of the extra oil available from the larger pump helps to prevent lubracation delivery failure, do you need a better pump below 5000rpm or 400hp (no) above that level the extra oil will definitely help possiable deficient oil flow and bearing cooling and a simple increase in pressure does not provide a big increase in voluum that may be necessary to keep that oil film in the correct places at the correct voluum at all times.the stock system was designed for a 265cid engine in a passenger car turning a max of about 6000 rpm but only haveing the stress of under 300hp transmitted to the bearings, Im sure the orriginal designers never thought that the sbc would someday be asked to on occasion hold up to 450-700hp and 6000-8000 rpm.nore did they forsee valvesprings that placed 500lbs and up loads on the lifters and the use of over 9 to 1 compression ratios in the orriginal design so the oil voluums and pressures necessary to cool those valve springs and bearings at those stress levels were never taken into account for that either.




[Modified by grumpyvette, 1:34 AM 5/3/2002]