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-   -   how much oil press is too much (https://www.offshoreonly.com/forums/general-boating-discussion/134806-how-much-oil-press-too-much.html)

troc 07-10-2006 12:12 PM

how much oil press is too much
 
Anybody have any experience with the Maximum psi a BBC can run? Thanks

Papache 07-10-2006 09:03 PM

Re: how much oil press is too much
 
over 100psi is to much

troc 07-11-2006 07:31 AM

Re: how much oil press is too much
 
Thanks, I am running 90 psi when cold @wot then drops to about 75#s I guess I'm good. Thanks for the info.

nocigarette 07-11-2006 08:47 AM

Re: how much oil press is too much
 
I Think To Much Pressure Is Horsesheet,under A 100 Is Fine I Run 80-85 Cold And 60 -65 At Wot.........and Most Of The Time It Is Wot............

Strip Poker 388 07-11-2006 12:52 PM

Re: how much oil press is too much
 
If its a non modified melling pump the bypass spring in them is set at 75PSI, maybe the gage is off?

Could Your bearing clearances be tight? :eek:

mascarab 07-11-2006 05:47 PM

Re: how much oil press is too much
 
I have the blue spring in the pump. Main and rod clearances are at mercury recomended minimum,new cam bearings. I guess the gauge could be off, can check with mechanical. Would you see pressure surging as relief spring
popped off and on?
Thanks

Strip Poker 388 07-11-2006 06:01 PM

Re: how much oil press is too much
 
Heres a little info on pumps in this thread
http://www.offshoreonly.com/forums/s...t=500efi+build..

All my electric sending unit gages I have cked are off. Even after sending my Livorsi fuel pressure gages and senders back to Livorsi to get calibrated to the senders $$$$$. One is off 14PSI :mad: the other one is 6 psi off. I just use them as a reference to see if there is a prob now.

blue thunder 07-11-2006 07:33 PM

Re: how much oil press is too much
 
That's right strip poker. Excess pressure is dumped out the pressure relief. The more over the pressure limit the more oil dumped. The problem in my limited opinion is that this dumped oil drops directly out of the pump and back down to the pickup area. This oil goes around and around getting hotter and hotter thereby possibly cause oil temp issues. That is my take on too much oil pressure. Ideal is probably a little over pressure relief cold to help build temp, then a little under that value hot. Over the pressure relief value hot would be a problem.

BT :cool:

Strip Poker 388 07-11-2006 10:44 PM

Re: how much oil press is too much
 

Originally Posted by blue thunder
That's right strip poker. Excess pressure is dumped out the pressure relief. The more over the pressure limit the more oil dumped. The problem in my limited opinion is that this dumped oil drops directly out of the pump and back down to the pickup area. This oil goes around and around getting hotter and hotter thereby possibly cause oil temp issues. That is my take on too much oil pressure. Ideal is probably a little over pressure relief cold to help build temp, then a little under that value hot. Over the pressure relief value hot would be a problem.

BT :cool:


another thing I tought about the more oil being bypassed is getting aerated and slung around ,so double the HP lost,

Also the way mine is set if real loose on bearing clearance its slinging more oil around,low oil pressure but Ive got that cushion, also a good oil pan. I guess there's always a trade off.Like some professional engine builders told me I am over thinking the oil system on a BBC, They said they work fine asis,but it cant hurt :rolleyes: :D

I had a SBC drag motor with high oil press once 90 cold:eek: it broke a Moroso Dist hold down clamp stud, the resistance just pushed the dist out :eek: Maybe that's why the make better oil pump drive shafts :rolleyes:

Rob


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