Mpls Funk

I have a 1970 with the 350/350 engine. The guy that had the car before me did some mods to it which I know included a bigger carb (double pumper), headers (don't know specifics) and a different cam (don't know specifics). He raced the car.

I have noticed that when I start the car, my oil pressure gague sits somewhere around 10-11 o'clock. When I'm driving down the highway, it is mostly straight up at 12 o'clock. After the car has warmed up, it seems that when I'm idling, the oil pressure gauge drops way down to be slightly past the first line on the gague. Is this normal? Is there something wrong? Could it just be because of the mods the previous owner did?

The car has ~110,000 miles on it...and the previous owner claimed he re-built the engine around 75-80,000 miles. I don't know what all he did to it.

I would appreciate any thoughts!

Peace...b wild!

mrvette

I notice you are in Minn...and for this time of year, those pressures are kinda really LOW, there are all kinds of rebuilds, so that phrase without a machine shop billing of just exactly what was done, means nothing....

I would get some 20w50 oil and new filter and change out, see what happens....if not improved...you may need to get into the pressure relief bypass spring, should be in the block held in place with two bolts just above where filter screws on....replace that assy.....then try it again with same filter in place....if not....welll you could try the oil pump....but that's a messy under the car job....
in all honesty, I think it's worn out and needs a proper rebuild...but what the hell, you can get lucky sometimes....;-)))

GENE

KenSny

Telling us where the gauge pointer sits relative to a clock dial is meaningless. What pressure numbers are on the gauge? For all we know it could be 10psi or 100psi.....and are you talking about the stock gauge or an aftermarket one.


[Modified by KenSny, 3:40 PM 12/28/2001]

Mpls Funk

I'm sorry...I'm at work and don't know the numbers on the gauge right now. It is the stock gague tho. Also, the behavior I'm talking about was happening in the summer/fall...I have not run the car in the last 2 months or so.

Jvette73

I dont know what your actual pressure readings in #'s are, but it is normal for the pressure to drop significantly with a fully warmed engine at idle. Actually, the engine needs very little oil pressure to protect at idle. The important thing is when you speed up the rpm's that the pressure responds by raising accordingly. If you live in Minn. I wouldnt recomend using 20/50 oil in the winter. When it gets cold that stuff gets thick like molassas. I would recomend for cold weather Mobil1 5w30 or 10w30. The syntetic will not thicken up under extreem cold. With Mobil1 your pressure, even on a extreem cold start, will respond much quicker. Youll see it on the gauge.

Techno

I've forgotten the rule of thumb but think its 10lbs. for every thousand rpm.

Eric 96

What I am always told, and read in books, is 10psi for each 1,000prms.

Mark69

Before you do anything else:
Check the gauge! The one I have in my car was dropping to 0 (!) psi when idling warm. When I checked it I found out it was reading about 25 psi too low. These instruments are not really precise, you can see that already in the scale 0-35-70 ;) . After adjusting the oil gauge I found out that my oil pressure is fine. It is about 40 to 50 psi when driving and drops just to about 25 to 30 at idle.