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Author Topic:   BBC oil pump in SBC
dirtbuster
Dirt Freak

Total posts: 353
posted December 18, 2002 09:29 AM
I just wanted to see if anyone has used a stock BBC oil pump in their SBC. I know it can be done just looking for experience. I want a little more volume but not necessarily go all the way to a HV pump. I was thinking that the stock SBC had 1.2 gears and HV had 1.5 gears and the stock BBC i think was 1.3?. I thought this would be about right in the middle and provide increased volume without being excessive.
We turn up to 7200 regularly and have used a stock SBC with sythetic oil and had no problems but there are times i wish we had another 10psi oil pressure. At operating temp on the track we usually max out about 55-60psi. I just thought maybe a little bigger pump would help get more oil into the motor.


LAYNE_Trans
Dirt Forum Racer

Total posts: 98
posted December 18, 2002 12:18 PM
OK, I am confused...you want a higher volume but not a high volume pump ?

Two factors are important with oil, volume and pressure but the pump does not alone factor in pressure. To create pressure you have to have tighter clearances, the looser the clearances the more important volume becomes.

Pressure takes horsepower, so most guys try to limit the pressure. So long as you have ample oil (volume) you can run 15-20 pounds of pressure safely. The spring in the pump is a bypass that limits the pressure. If the oil can freely flow back to the pan and pump let the thing pump it's **** off.

dirtbuster
Dirt Freak

Total posts: 353
posted December 18, 2002 12:45 PM
I understand the volume/pressure thing. I know that tighter clearances make for more pressure with the same pump. But if you go real tight then you dont get enough oil flow past the bearings to cool them but you may have a lot of pressure. The thing I was wanting to do is make up for the extra internal leaks created by EDM'd lifters or grooved lifter bores, etc. Trying to get more volume into the engine and maybe make a little more psi with the clearances we have but I dont want to go to a full high volume pump.

[This message has been edited by dirtbuster (edited December 18, 2002).]

rico 08
Dirt Freak

Total posts: 372
posted December 18, 2002 03:00 PM
I have heard bb pumps will really pump the pan dry and send it all up to the valve covers,i'd stick with the stock volume pump,it's the best.

fastrack1
Dirt Full Roller

Total posts: 73
posted December 18, 2002 07:39 PM
FROM EXPERINCE DONT USE THE BIG BLOCK PUMP YES IT WILL PUMP ALL THE OIL OUT USE A M55 A PUMP AND U WILL BE A OK

dirtbuster
Dirt Freak

Total posts: 353
posted December 18, 2002 09:55 PM
fastrack when you say it pumped the pan dry was that with a stock 5 qt pan. The reason i ask is because i have talked to another guy about this swap and he said he does it to every small block he builds and uses a 7 qt pan and never has any problems. He also stated that the reason he does it is because the SBC pump has a 7 lobed rotor and the BBC pump has a 12 lobed rotor (I think those are the numbers he gave me) And that provided a smoother more consisitent oil flow because there was less pulsing of the oil flow from the pump.

racer1030
Dirt Roller

Total posts: 22
posted December 18, 2002 10:10 PM
Std. Volume BB pump will pump the same volume of oil as a HV SB Pump.

racer1030
Dirt Roller

Total posts: 22
posted December 18, 2002 10:12 PM
Std. Volume BB pump will pump the same volume of oil as a HV SB Pump.

LAYNE_Trans
Dirt Forum Racer

Total posts: 98
posted December 19, 2002 05:45 AM
if you are running roller rockers (not just roller tipped rockers), you can use oil restrictors in the block and limit the oil going to the upper end. Stock or stamped rockers require oil, lots of oil so do not use restrictors with them.

Oil in the valve covers is bad, it is possible especially with fords to flil the valve covers with oil and not have any in the pan...ask me how I know.

The SB chevy argugment has gone for years about oil draining from the lifter valley right on the camshaft, windage etc. too deep for this topic but whatever you do insure that the oils return is unobstructed, screens are great but restrict oil return. When you have a bare block openthe drain holes up a bit by removing the rough casting flash around them. The pumps mentioned earlier are great pumps, and not expensive. If it fits use it, don't hassle with adapting something like a BB pump when you do not need to.

dirtbuster
Dirt Freak

Total posts: 353
posted December 19, 2002 09:23 AM
Sounds like ill stick with either a sotck or hv small block pump. For some reason i thought maybe the stock big block pump would fall somewhere in between the 2 and give a middle ground if it was needed.

dode
Dirt Freak

Total posts: 417
posted December 19, 2002 12:40 PM UIN: 13209501
We ran a bb pump last year with an 8 qt pan. Don't ask me...I didn't do it...anyway, it worked fine until one night the pump dropped in the pan because the moron that built the motor used a stock sbc bolt to hold it in, which is too short. At any rate, it should worked fine for us while it was attached.

John

Flanndad
Dirt Full Roller

Total posts: 49
posted December 19, 2002 01:44 PM
In one of my Chevy Books, its says you should use a BBC pump on Race SBC motors, because the pump has more teeth on it. It will provide a more consistent pressure than a SBC pump will. It doesn't mention more pressure or volume just more consistent pressure.
I plan on trying it in my 406.

Racer14K
Dirt Freak

Total posts: 247
posted December 19, 2002 06:32 PM
I've been running the M55A at 7800-8000 rpm, engine builder just pulled it apart and everything looked good, no signs of oil starvation.

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