427 CBB oil pressure

[james schaechter]

Originally Posted by 70RS/SS396

The motor is modified like this, I know that the oilpump is modified to give this pressure. And they rew this motor 7400 rpm when it was raced in the 80s. But I dont want to risk anything now, ......so there isnt any problem with the pump or oilfilter but is it safe to run a cbb with this oil pressure?
But What oil should I run 40 or 50 ?

Thanks

If this hasn't seen daylight since the 80's it sure would be a good idea to pull the pan and look it over if you can. Much cheaper to do that than to wait for trouble.

[70RS/SS396]

Have done that, and it looks great. And it has new head gaskets ect. The motor is in perfect condition.

But maybe I need to change the oilpump go get more oil pressure.

Originally Posted by james schaechter

If this hasn't seen daylight since the 80's it sure would be a good idea to pull the pan and look it over if you can. Much cheaper to do that than to wait for trouble.

[Mike Taylor 3601]

If you dont know what bearing clearances you have I would check them most likely they are a loose, you can test oil pump by taking old main cap and tap it to accept gauge where oil come from pump,stick in bucket oil spin it w/drill and can see what pressure pump is bypassing at,have someone help hold it or mount to bucket it's hard to hold by yourself.
Mike Taylor 3601

[70RS/SS396]

If I going buy a new oilpump, what should I buy?

Melling has one Anti-cavatation design pump.
"Approximately 25 percent over stock volume. Anti-cavatation design. Reduces cavitation effects in high RPM applications. Using this oil pump will reduce pressure at idle. Chromoly steel drive shaft included. Standard pressure spring is included."

http://www.summitracing.com/parts/MEL-10778C/

Is this a good choice? Or can you recommend something else?

Or maybe a GM pump?

http://www.summitracing.com/parts/NAL-3969870/

Or a standard Melling?

http://www.summitracing.com/parts/MEL-M77HV/

Going to rew this engine about 7-7200 RPM

[Alan Roehrich]

The Schumann pump is probably the best off the shelf pump for under $200.

[Mike Taylor 3601]

70SS/RS396
Evidently this is less oil pressure than this engine had when ran before or you probaly would'nt be concerned about it? I ran and seen lots of engines live long lifes with that pressure.
If this is lower than engine had before,does it have main studs or have you changed to a stud set? The reason I'm asking this is because BBC main studs alot of them have a 12 point nut that goes next to oil pump,because the hex nut alot of times won't clear the oil pump and will hold pump off main cap.
If nothing else is wrong and you have HV pump w/hi press.spring that comes in them you probaly have about .004-.0045 bearing clearance
std. vol std.press pump you probaly have about .003-.0035 bearing clearance,that is if you don't have leak somewhere.
I would test pump before I bought another one installed it and had same results,if pump puts out around 60 lbs then you know it's not the problem.
Mike Taylor 3601

[70RS/SS396]

Originally Posted by Mike Taylor 3601

70SS/RS396
Evidently this is less oil pressure than this engine had when ran before or you probaly would'nt be concerned about it? I ran and seen lots of engines live long lifes with that pressure.
If this is lower than engine had before,does it have main studs or have you changed to a stud set? The reason I'm asking this is because BBC main studs alot of them have a 12 point nut that goes next to oil pump,because the hex nut alot of times won't clear the oil pump and will hold pump off main cap.
If nothing else is wrong and you have HV pump w/hi press.spring that comes in them you probaly have about .004-.0045 bearing clearance
std. vol std.press pump you probaly have about .003-.0035 bearing clearance,that is if you don't have leak somewhere.
I would test pump before I bought another one installed it and had same results,if pump puts out around 60 lbs then you know it's not the problem.
Mike Taylor 3601

Hi

No the engine has the same oil pressure as before (in the 80s, when it was raced in stock eliminator).
I know the engine has ALOT of 1/4mile runs with this oil pump and pressure. So it sould be fine. Talked to the builder of the engine and he modified the pump to have this low oil pressure. He drove QS w40 oil, he tried thinner oil, but he had some problem with the puchrods went thrue rockers when he rew 7400+ rpm. But with the w40 oil it was OK.

But when I talk to people now all say, change the pump....you need more pressure....7-10 psi / 1000rpm.

So I dont know what to do