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High Valume oil pump low pressure
Posted: April 19th, 2024, 9:17 am
by len1xj
I put in a high volume oil pump In a new rebuilt 4.6 stroker. I put the oil pump in thinking it would be better on the trails and rocks. I made sure that there was 1/2 clearance between the oil pan and the pickup. the engine still had blue brake in oil in it when I found I could not get any more then 10 pounds of oil pressure at 3000 rpm and almost nothing at idle. I thought that I may have a gasket lick or something was wrong with the rod bearings. I took everything a part and checked the clearness. the clearness on all bearings was .ooo2 I put in a new oil gasket making sure everything was good.
put things back together and I still got only 10 pounds of pressure at 3000 rpm. my question is, is this brake in oil to thin. will going to a 30 - 50 oil help.
thinks for your help
Re: High Valume oil pump low pressure
Posted: April 19th, 2024, 6:42 pm
by Randy Bobandi
len1xj wrote: ↑April 19th, 2024, 9:17 am
I could not get any more then 10 pounds of oil pressure at 3000 rpm and almost nothing at idle.
Sounds like the main oil galley plug was never installed. Or there is an issue with the pressure sensor.
Re: High Valume oil pump low pressure
Posted: April 21st, 2024, 12:59 pm
by len1xj
well, I changed out the oil sensor and I checked with a machinal sensor. only 2 lbs difference. to find the oil galley that is plugged I would have to tear it all apart again. or is there any other way?
Re: High Valume oil pump low pressure
Posted: April 21st, 2024, 1:37 pm
by optmaxx
Did the oil flow to the rockers look good when you primed the oil pump with a drill?
Re: High Valume oil pump low pressure
Posted: April 21st, 2024, 9:25 pm
by Randy Bobandi
len1xj wrote: ↑April 21st, 2024, 12:59 pm
to find the oil galley that is plugged I would have to tear it all apart again. or is there any other way?
You would have to pull the timing cover, which requires removing the crank damper, to check if this plug is in place.
oilplug.jpg
Re: High Valume oil pump low pressure
Posted: April 22nd, 2024, 10:03 am
by len1xj
when I primed the pump there was no flow to the rockers. I thought that the drill was not able to go fast enough to get a good flow. how ever when I saw little or no pressure I took off the valve cover and watched. there was no oil until about 2000, then the oil started flowing starting from the #6 to #1 the higher the RPM with #1 getting less flow. I did get oil all over the engine.
I also broke in the cam with a rpm range from 2 to 3000 with no problem
The oil galley plug; I do not remember weather there was a plug there or not. I will have to go back to some of my pictures and see if I can see anything there.
Re: High Valume oil pump low pressure
Posted: April 22nd, 2024, 3:57 pm
by optmaxx
Oil does come out of the rockers when you prime the system with a drill, that's how you know that the system is primed. I use the regular volume oil pump, and oil squirted out of all the rockers when I primed with the drill.
Oh, you know I also read that the high volume oil pump sometimes has a problem seating fully on the block causing flow problems, and some mod to the pump is needed to seat completely.
Re: High Valume oil pump low pressure
Posted: April 24th, 2024, 2:41 pm
by len1xj
I am going to take the timing cover off this weekend to check that plug. I hope it is as simple as that. Ill let you know what happened.
Thanks
Re: High Valume oil pump low pressure
Posted: June 12th, 2024, 5:37 am
by len1xj
well I took the timing cover off and low and behold the oil gaily plug was gone. I put one in and now I have 50 pounds of pressure when cold and 35 at running temp. all is good now and I am very pleased with it.
Thinks for all your help with this problem.
