High volume oil pump or not?

[70Chevy4x4Nut]

I have searched all the board for an answer, but still not sure. Should I use a HV oi; pump or will the standard volume be ok? I had the machine shop chamfer the cranks oil ports. I will have the factory oil pan. So does the HV pump suck the pan dry? And now with the modified crank, does a HV pump make sense?

[ryanroo]

if it was me i would stick with the factory volume, if you feel like it you could use a high pressure pump, but a high volume is only needed when running loose bearing clearances. it can suck the pan dry, but that usually only happens at higher RMP i think. depending on how you use the engine then it could pose a problem.
Ryan

[neonlarry]

Most of the more knowledgable engine builders I have talked to say that a properly blueprinted std. pump is more than sufficient. Higher RPM equals more volume. Also with a stock capacity oil pan there might be the possibility of as you say sucking the pan dry. But with a good slick coating in the lifter valley and some work on the drain holes this should not happen.

[swervin ervin]

A high volume pump will not pump the pan dry.

http://www.melling.com/support/bulletins/view.asp?id=12

[67ChevyC10Stepside]

a HV WILL NOT SUCK IT DRY

[70Chevy4x4Nut]

I read the article from melling and I feel I would not have the problem of sucking pan dry. I probably will not be racing the engine to 6500rpm too often for one. And two, the higher oil volumes are good insurance. Thanks for the responses. The article from melling is what I was looking for.

[70Chevy4x4Nut]

Read another article that is swaying me the other way now. Looks like using a HV may not help much on a stock clearanced engine, but may rob a little HP. I may just stick with stock. Don't mind the opinions. I know there are experiences out there that can go both ways. I guess I just need to make my own mind up.

http://www.stockcarracing.com/techar...134_0309_pump/

[sbc350gearhead]

I have used moroso std pumps for years on street engines, with no problems.

[Bowtie67]

I think it's an old myth about sucking an oil pan dry, I have only used hi volume oil pumps whenever I build any of my own engines, for a stock engines I have always used a standard oil pump.

[jamis]

It’s not really a myth it’s more like the right information gone wrong. HV pumps alone wont suck a pan dry. But there is and old trick that sometimes does, plugging the center drain holes on a small block because they say that the oil splashing against the camshaft robs horsepower. Many years ago we had problems with oil pressure being all over the place when sustaining 6,000 to 7,000 RPM for long periods of time such as boat and circle track racing. We found that the pan in fact was being sucked dry. After talking with a Nascar engine builder that had the same problems in the old days when running wet sumps. We where informed that the problem is when you plug those center holes that causes the crankcase pressure to only have two other ways out. That’s at the front and the rear block drain holes. So you can imagine what was happening the oil was trying to work its way down and the crank case pressure was pushing it up or at least slowing down its ability to drain fast enough. Installing screens in the drains also slowed the draining. So you would end up with a large portion of your oil in the lifter valley and not in your pan. So in order to cure this "sucking the oil pan dry syndrome" the plugged holes where replaced with 1/4 X 1 " pipe tubing. The tubes would allow the crankcase to vent and at the same time stop the oil form hitting the cam just like the plugs. We didn’t have any more problems with empty oil pans.

I personally like running the stock volume BB pumps on the SB. I think its a better designed pump and less prone to cavitations at high rpms.

Just my 2 cents.

[NeCrOmAnCeR]

I am currently using a big block H.V. pump in my small block and have no problems. Many times all out race engines have oil restrictors to limit oil flow to the heads. This of course cannot be used with hydraulic lifters, and requires the use of roller rockers. I have always used H.V. pumps and have never had problems.

[67chevss]

I built a 383 stroker and i used a melling high volume oil pump, but when i got the pump it came with to springs. One for high pressure and one for lower pressure. I think the high pressure spring was like 70 psi to 85 psi. the low pressure was like 40 to 65 psi. I used the high volume low pressure set up. You have less chance of leaks.

[72C203503ONTHETREE]

Using a high volume pump will not hurt anything at the engine speeds most people use in their trucks. Actually, the best one to use is the $100 Moroso or Melling blueprinted racing pump which is high volume and has channels in the bottom plate to prevent cavitation. I always used high volume pumps in my engines. Using the big block pump and special sized driveshaft will produce more volume like a high volume SB pump, and it will produce less vibrations as was stated earlier. Supposedly it will use a few more horsepower at higher rpm to run it but its worth it.

[76HighSierra]

In hi-rev applications, when the engine is held at sustained high RPM's for a long period of time, a HV pump can come close to draining the pan. It is usually caused by a combination of using the stock capacity pan and not cleaning up the oil drainback holes. In a hi-po 350 I had, I used to see drops in oil pressure after running it at app. 5K rpm after a mile or so (you do the math and yes, I was a bad boy in my youth ). One really does not need a HV pump, if the oiling system is properly blueprinted. I plan on using an auxiliary camshaft oiler in my 454 build, along with some oiling system mods, so I will need to use one. Most engines don't need them.

[SCOTI]

Bringing this back to the top. I was looking through this thread & was intrigued by the b.blk. oil pump on a sm.blk. engine.

What's the advantage? Better gearing within the pump? Stronger housing-less prone to failures?

Also, what is involved in this swap?

[crazy longhorn]

i dont know that there is an advantage running a BB pump on a sb.....it is said in a few books, that the extra teeth on the gears cause less spark scatter in the distib? Bottom line is that you need about 10psi per 1000 rpms you plan to run. A hy vol/hy press pump will eat a little HP, but IMO...that is cheaper than smoked bearings! i run a Mellings 10555 pump , with an old 1 ton 6 Q pan on my 383. 700 rpms hot @ idle, she holds 35-40 psi @ idle.....the bypass is set @ 70 psi, & that is where the pressure runs @ 3000 rpms hot(enough for a few 7000 rpm passes ). as far as pumping the pan dry, I havent seen that problem.......if you wind it up cold, or run for a few miles @ 6000 +, you might see that problem! My Chev always runs fast idle till the coolant is up to temp, then i drive.....but dont crank her up till the oil has got up to temp. crazyL

[yt500pmd]

A Chevy small-block pump has 7 gear teeth, where the big-block has 12. The additional teeth of the big-block pump smooth out the pumping impulses, which can reduce spark scatter. The stock big-block pump also puts out 10 percent more volume than the small-block, and requires no more power to operate.

[SCOTI]

Anything special required to install the b.blk. pump on a small block?

[crazy longhorn]

A special pickup tube, & a different lenght pump drive shaft....

[NeCrOmAnCeR]

Yes, a special shaft and pick up are needed as cravy longhorn said. Both can be purchased from any supplier. If you do this on a SB 400 you will need to drill out the hole in the block where the drive shaft passes to 9/16. the drive shaft is 1/8" shorter I believe.

[SCOTI]

Well my shortblock is already assembled so I'll just stick w/small block stuff & not risk metal shavings. The short block has a pump but I've been unsuccessful determining the manufacturer & type (hi-press, hi-vol, or both).

I've been trying to decide on a decent oil pan/pump combo. I've narrowed it down to Moroso or Milodon since they seem to offer matched pans w/pumps. I'm looking for a pan w/windage tray that's stock depth.