**OIL Pressure PSI ( The mistake behind it)**

[Pontiac1976]

"Oil pressure" Ever one think that high PSI is good or the thing should pump high all the time. Falsies!.  It is good that it be at a good steady psi. But High Volume is a much better thing.
Think of it this way you got a thick shake a small straw you suck on it you will have to try hard to suck on the straw not as hard as a lager straw more air in the straw & the thick shake too.If you take a large straw you will have to be hard psi to make the shake come up more PSI used . Your motor has fixed smaller straw, that it has to pull up the shake if the shake start to melt it will get higher PSI un till a certain point then Psi will start to drop a little.
ie. If you have say 40 PSI high pressure pump but only pumps 2 gal hour, that means it pushing oil like a water or air pipe. ie. a high volume pump @ 40 PSI pumps will pumps 4 gal hour, that means it pushing more oil then the high pressure pump at the same PSI.

brand new oil will pump higher PSI till the oil breaks in then it will ave out un till the motor gets hot the n pressure will drop again and ave out again @ driving ( higher RPM's ) . Now @ lower Idels the not turning fast enough for the hotter oil so oil psi drops in all motors. that just the way it is un less you have a very high pressure pump but it will still have oil pressure drop from a fast Idels to a park Idels it like jumping ( high Idels )you go up but once you energy gone you come down to ground ( park Idels )
So a High Volume pump is better for most motor will pump out all most the same PSI as most med to good high pressure pumps but will all ways pump more oil around then the high pressure pump.
So look for a **HIGH VOLUME PUMP ** I hope this help clear up Oil pressure I will fine tune this a little.

[BowtieGuy]

Very true and for more info, studies have shown that a high PRESSURE oil pump can cause a loss in horsepower. As a general rule a small block Chevy engine needs 10 psi for ever 1k rpm. So 2000 rpm you should have 20 psi oil pressure, 6000 rpm about 60 psi. High volume is much better then stock and way better than high psi. Small block's i know for sure and probably big blocks too, have a bypass when the oil pressure gets too high it will bypass the oil filter so it wont blow it. So if you are running too high of pressure some, maybe all of you oil is not getting filtered.

[jcissell]

I would not recommend a high volume pump in a stock motor. I have built motors for guys with 400hp and using a stock oil pump and turned over 7000 rpm. Seen many stock motors with high volume pumps and stock oil pan when under high rpm the pump will suck the pan dry and cause the motor to lock up/spin a main. If using high volume pump use at leat 8 or 9 quart oil pan. But this is just my opinion. A guy can always shim the stock oil pump spring to achive a higher oil pressure for higher constant rpm's.

[Pontiac1976]

I would not recommend a high volume pump in a stock motor. I have built motors for guys with 400hp and using a stock oil pump and turned over 7000 rpm. Seen many stock motors with high volume pumps and stock oil pan when under high rpm the pump will suck the pan dry and cause the motor to lock up/spin a main. If using high volume pump use at least 8 or 9 quart oil pan. But this is just my opinion. A guy can always shim the stock oil pump spring to achieve a higher oil pressure for higher constant rpm's.

That very true about the RPM oil suction I agree with you on a good part of what you said. But any stock motor in one of the trucks of these years will not be hitting over 7000 RPM to start with for long with out trouble in early time.
They will be floating the valves and be out of the stock cam RPM.
But this was not mean to for other to just go out bye the parts with out doing some reading and getting to know what they want and what parts they should get to WORK as a team in there Motor for there style driving & play.

This was written back some time in a response to a another member question and it seam that about the post.
Most stock blocks are bad for slag and port opening not being the same size or smaller then they are meant to be.
In 93 I got my(car ) 76 350 two bolt block checked and freshened up stock bores .
Then I cleaned out all the oil drains opened then up to let oil get back down to the pump. I also cleaned the intake and exhaust of all slag tried to make everything cleaner or to size that it should be and took all sharp edges off in the block.
I use the oil pump setup I talked about because I run the bigger oil filter, I have Moroso 6 quart oil pan with the longer pick up for the pan, I use a little over 7 liters of oil in my motor. I run 9 to 1 compression on a flat top position with a stock crank stock spec.performer RPM intake, Cam has been bumped up . It make 265 hp
I shift @ 6800 RPM for two shifts in a 4200lbs car with 3.73, 350TH and it's been a good little motor for over 12 yr and still running but very soon it's time to open it change the bearing check the rings. I race it for fun. The 76cc heads Dart2 straight plugs matched with the Lazer cam. Oh use 10w40 in it most of the time or 10w30 now and then.I
change my oil once ever month for 4 months racing or when the oil started to break down when racing.

[njarmentrout1]

Hey guys,
I checked my oil level today, and there is nothing on the stick! WTF! I have a 1980 GMC. Does anyone know if these trucks have an oil pressure light anywhere on it? My gauge looks fine. Good pressure and everything. Anybody have any ideas?

[Pontiac1976]

OK if have now oil showing on the dip stick there could be trouble.
What motor in it the 80 is it stock pan & stock dip stick.
I would check how much oil in it dropping the oil measure 350-305 with stock oil pan going to be 5 to 5 1/2 liters depends on the oil filter.
if you run to long of time with low oil you will wear out the bearing burn the valve guides rings-wear the cam lobes lifter.
there should be oil light on the speedo & the sending unit would be at the back of the motor or above the oil filter that the two spots.

[njarmentrout1]

Well, the good news is, it is still running strong and great. I really don't think I have to much to worry about. I'm not driving it anymore. I'm doing an oil change this weekend and I'm going to look everything over. I also noticed that I have a tranny fluid leak coming from the fluid cooler in front of the radiator. It's coming from the rubber hose connecting to the fitting. So I'm going to replace both the hoses too. Thanks guys!