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Getting 70psi when priming the oil pump. Normal or to high?

Posted: September 28th, 2014, 9:19 am
by rainman
As it says, it is a new build stroker with a standard vol oil pump.
This pressure was achieved when priming with a cordless drill, not even spinning that fast.
Pressure built real quick to 70psi then stayed at that pressure even while increasing revs on the drill.
Almost like the pressure is riding on a pressure relief valve.
Is this to be expected? / normal.
Was just priming it as I had to go away for work days after getting the engine back.

Re: Getting 70psi when priming the oil pump. Normal or to hi

Posted: September 28th, 2014, 9:43 am
by SilverXJ
Thats a little high. Did you make sure that the plug for the bypass spring was actually sitting against the cotter pin?

Re: Getting 70psi when priming the oil pump. Normal or to hi

Posted: September 28th, 2014, 9:49 am
by rainman
I did not assemble the engine.
It was a brand new meling pump.
When I get home will pull the valve cover see how much oil is getting up there.

Will also query the builder.

Thanks for the prompt reply.

Re: Getting 70psi when priming the oil pump. Normal or to hi

Posted: September 28th, 2014, 10:50 am
by jsawduste
What weight oil ?

70 is a little high but then not if your using a heavy oil.

Re: Getting 70psi when priming the oil pump. Normal or to hi

Posted: September 28th, 2014, 11:34 am
by rainman
15-40w mineral oil.(shell)
As recommend by machinist / engine builder.

Re: Getting 70psi when priming the oil pump. Normal or to hi

Posted: September 28th, 2014, 12:40 pm
by the grey ghost
What rpm does your drill spin at?

Re: Getting 70psi when priming the oil pump. Normal or to hi

Posted: September 29th, 2014, 12:51 am
by rainman
Not to sure,
Was in low gear and not flat out even then.
I'm away at work so cannot check.

Re: Getting 70psi when priming the oil pump. Normal or to hi

Posted: September 29th, 2014, 1:46 am
by Cheromaniac
rainman wrote:15-40w mineral oil.(shell)
As recommend by machinist / engine builder.
Then I wouldn't be concerned about a 70psi oil pressure with that weight of oil in a newly built engine.
Just run the engine as normal for the break-in period and if the oil pressure remains above 60psi when cold, switch to a lighter grade e.g. 10W-30 after 1000 miles.

Re: Getting 70psi when priming the oil pump. Normal or to hi

Posted: September 29th, 2014, 7:37 am
by rainman
Thanks and regards.

Re: Getting 70psi when priming the oil pump. Normal or to hi

Posted: September 29th, 2014, 8:12 am
by SilverXJ
BTW< how are you checking the pressure? Mech gauge on block of via the dash?

Re: Getting 70psi when priming the oil pump. Normal or to hi

Posted: October 1st, 2014, 1:50 pm
by rainman
Mec gauge where the Oem oil sender sits.

Re: Getting 70psi when priming the oil pump. Normal or to hi

Posted: October 3rd, 2014, 10:36 am
by 6TIME
Don't sweat it. You have a tight motor with lots of thick prelube on the bearings. That'll bring the pressure up as it is. Just prime while having someone rotate motor over by hand with sparkplugs out to get oil circulated throughout. Do it until you have oil flow out of every pushrod and you're golden. Good luck.

Re: Getting 70psi when priming the oil pump. Normal or to hi

Posted: October 8th, 2014, 3:07 pm
by woodjeep
Hi Please read this post by me several years ago..... http://www.jeepstrokers.com/forum/viewt ... =15&t=2445 ... I had your same issue-high oil pressure on stand...oil spewing out of the pushrod holes.. cranked the engine a hundred times and pumped oil everywhere or so I thought...I couldn't spin the engine and the drill at the same time but I thought I was golden with all that oil spewing from the lifter pushrods....did the cam break-in and ate all my crank and rod bearings...had to change them out 4 months later...been running good now with 40K on the motor...I do not know how to confirm that you are getting oil out of the crank...you know its pumping out of the lifters but confirming the rest??? I learned the hard way...maybe someone else can offer insight...just a caution

Re: Getting 70psi when priming the oil pump. Normal or to hi

Posted: October 8th, 2014, 3:57 pm
by SilverXJ
woodjeep wrote:.did the cam break-in and ate all my crank and rod bearings...had to change them out 4 months later...
What cause the bearing failure? When you replace the bearings did you change the pump? If not, after replacing the bearings did the pressure come back to normal?

Re: Getting 70psi when priming the oil pump. Normal or to hi

Posted: October 8th, 2014, 4:15 pm
by woodjeep
The oil pressure during the break in was well above 40 to 50 I saw no issues until I drained the oil right after the break in and it was all silvery...I thought ...that's odd ...my oil pressure remained above 40 during the next several weeks then started dropping...then the clunking started..but didn't put it together until I dropped the pan and took a bearing out...then I went ooohhh..that's where the silver came from...luckily it didn't score the crank and its been fantastic since but I still don't know why I didn't feed the mains and rods but everything else got oil...I miked the bearings when I took them out and they lost 0.010 off them...I still don't know why it happened...I prelubed the crap out of them during install and primed that badboy for weeks. I thought I would have no issues