I'm involved in an argument right now, and am going on experience rather than documented facts, which bothers me because I can't proove what I remember versus what I can document. Anyway, does anyone know, or have an educated guess, at how much oil pressure a stock small block Ford oil pump could generate, say if the bypass was welded shut?

Thanks for any input.

Take care,
-Chris

 

I think it would depend on the oil returns in the engine, more than the pump. I have seen people modify oil pumps, by playing around with one of the springs inside, they caused the engine to run close to 80 PSI.

-Jon

 

Ok I think this might help but I may be a wee bit off, I remember reading that an engine needs 10 psi of oil for every 1000 rpm and I believe ford oil pumps are capable of creating that kind of pressure. If your redline is 6000rpm your pump is capable of pumping 60lbs and the engineers have added the bypass to stop parasitic HP loss. I would think that above 3000 RPM the design emphasis shifts to abundant lubrication without the unnecessary aforementioned parasitic HP loss that 65 PSI at 6500 would require.

Does this help or should I crawl back under my rock?

 

This may help

http://melling.com/techbul1.html

I was looking around for an answer for you and came across it

 

Cheeb-
You are the best! That site answered my question (150 psi). I don't know why I didn't think to look there myself. Bad me! Great you, though! Thanks again!!

Take care,
-Chris

 

Just a question, isn't that spring also vented to the top part of the pump? I believe the bypass portion of the pump is used to over oil the pump when spinning at high RPM....or is that SB chev??

Can't really remember, depending on what your up to it might be something to look at........I would hate to hear the RRRRRRRR BANG!!! story from anyone around the board.

 

It was a stupid arguement. I have seen oil filters get blown apart due to a bypass valve getting stuck shut, usually thanks to other debris in the oil. That's what I was taught in my engines class at the local cc 15 years ago, and it's been my experience as well. Well, this know-it-all yahoo tells me I'm crazy, and that a stock pump could never do that. I needed proof from a reliable source. Here is all I needed. The paragragh at the bottom says it like it is.

Again, thanks a million!

Take care,
-Chris

 

Oh you were dealing with a blah blah... blah blah's are very dangerous and cause untold amounts of stress.

my Yugo has a cam and turns 400 hp and will run the quarter in blah blah blah.....

I had a buddy build a big block about 3 years back and he put those plastic rocker covers on it "to save weight" hee hee. Anyway he must have been building the motor without his helmet on because he didn't cut any breathers into them at all (yes, I know he's a tool.) So anyway, he fires the thing up and sets the high idle to set the cam and what not and then it happened, the positive crank case pressure got so high it blew his billet dip stick across his garage and pumped out about 4 litres of oil before he got it shut down.

He calls me and when I looked at the mess I almost wet myself..

150lbs? no problem