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Author Topic:   how much oil pressure?
One87Racing
Member
posted February 26, 2003 10:52 PM
Stock SBC. new cam, main and rod bearings. Oil clearances range from .002 to .0028 on the crank. Stock volume pump (clevite brand) and pickup mounted 3/8 from bottom of stock oil pan. I had the oil bypass plugged and made 35 psi at 5000 rpm. I put an unplugged bypass in and picked up 5 psi. 40 psi isn't enough for me to feel comfortable running the engine to 6000. all the ford engines I ever built made 62 psi at 2500 up to 6500 (bypass spring in the ford pumps is about 62). Is that all the pressure a stock pump makes on an sbc? should I put in a high pressure spring? or am i missing something here? Please help!


armintroutracing
Member
posted February 27, 2003 01:21 AM
thats all you will get from a stock pump.you can buy a high volume pump. or shim the spring to get more pressure. i run around 60 psi. hot.


mudcat #34
Member
posted February 27, 2003 02:24 AM
same here about 60


dirtbuster
Member
posted February 27, 2003 08:34 AM
If you keep your clearances on the tighter side like.002-.0025 you should be able to get more than 40 pounds. As long as you dont have a big leak somewhere else. I have seen stock pumps make 60+ pounds in a fresh engine. We run a stock pump in our mod and at speed it makes 60 hot. We have another engine with around .0026-.0028 clearances and HV pump and it makes about 65-70 hot.

Also you can check the endplay on your oil pump gears and make sure it is around .002 sometimes they can be off a ways and not be as effecient in pumping oil.

jnewman44
Member
posted February 27, 2003 08:48 AM
There is a plug under the rear main cap, If you dont put it in you will have an internal oil leak, and poor pressure.


66jj
Member
posted February 27, 2003 09:31 AM
youd have no pressure without that plug.



dirtbuster
Member
posted February 27, 2003 10:24 AM
What oil filter are you using?
What kind/weight of oil?


Pickel
Member
posted February 27, 2003 12:15 PM
40 psi is about all you will get out of a stock pump.. I run a covett HV pump and 60psi idling about 80 racing... I straight kendel 50 with fram filter( I know most people dont like fram but it has never let me down)lol..


One87Racing
Member
posted February 27, 2003 01:15 PM
at this point i'm running 20/50, but it will have 50 for track time. I'll check to make sure all the plugs are in, I don't remember putting one in under the rear main cap.


dirtbuster
Member
posted February 27, 2003 06:01 PM
Unless it is a new block I doubt the plug is missing under the rear main. If it was you would have trouble getting any pressure.

If you have a Fram filter on you might change it out with something else and see if that helps. There is another post on here where a guy was having pressure problems and changed to a different filter and pressure was back.
Check out this thread: http://www.thedirtforum.com/cgi-bin/postdisplay.cgi?forum=Forum20&topic=001115

[This message has been edited by dirtbuster (edited February 27, 2003).]

Racer14K
Member
posted February 27, 2003 06:06 PM
CHANGE THE FILTER !!!!!


One87Racing
Member
posted February 28, 2003 06:03 PM
i've used 2 different brands of filters. I'm pulling the pan and putting in a high pressures spring into the pump this weekend. I'll keep you posted on what happens. Thanks for all the input.


rdwind
Member
posted February 28, 2003 07:24 PM
Have you tried changing the filter. You may have a restriction in that filter. That would explain why when you went to the unplugged bypass adapter your pressure went up a little because you were allowing more oil to flow into the engine without getting backed up in the filter. To me this would be the easiest place to start is with a different filter, maybe even a different brand.

I dont think changing the spring will do anything unless it is a faulty spring or the bypass valve is stuck open. The only way it would raise your pressure is if your bypass was opening and you were bypassing oil in the pump and you shouldnt be with only 35 psi. If the bypass spring is supposed to open at 60psi and you only have 35psi the bypass is not opening so going to a stiffer (70+psi)spring will not change anything. That means you are leaking too much oil in the engine to reach the bypass pressure with the spring you have so a stiffer spring wont do anything. A high volume pump may help you out because it will pump more oil into the engine and make up for the amount of oil lost due to leakage and thus raise your pressure.

One last thing. Have you tried another pressure guage? Maybe your guage is not working properly.

[This message has been edited by dirtbuster (edited March 01, 2003).]

iowa_dirt_track_girl
Member
posted March 02, 2003 12:33 PM
becareful running a high volume oil pump withouy restrictors and a good oil pan because yo will lose oil pressure before you get to the corner you schould have 10 pounds per thousand rpm

[This message has been edited by iowa_dirt_track_girl (edited March 02, 2003).]

One87Racing
Member
posted March 02, 2003 02:33 PM
I figured out my problem.....I'VE HAD TOO MANY FORDS, and not enough chevys. I plumbed a mechanical guage into the port above the filter and came up with 72 psi at 3500 ish rpm and 40 at idle. (the other guage was in the port at the back of the intake). I then plumbed in the old guage into the port above the filter and only had 55 psi at 3500 ish rpm. Time to buy another guage! I thank you all for your input on the point of my stupidity. I should have checked with a second guage before I freaked out. thanks!


Alltel
Member
posted March 02, 2003 10:26 PM
I was going to say that I have never ran anything but the stock oil pumps, and I always get good oil pressure. I haven't done anything to the oil journals, and with a stock pump, I can get at least 60lbs.


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