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View Full Version : Oil pressure guage on Chevy 350's


MATTHEW
01-25-2002, 06:52 PM
I have a '98 Chevy 4x4 3/4 ton with 34,000 miles. I have the typical oil pressure guage. 0-1/4mark(20 lbs)-40 lbs-3/4mark(60lbs)-and 80 lbs.
When I am idling , it sits at just above the 1/4 mark. I guess that means it is at 22lbs. Then it goes to just above 40lbs when I am moving. That seems rather low, doesn't it?
My Grand Cherokee sits at 40, then goes to 60 when moving-and it has 94,000 miles.
My question is this- is this normal? I don't have much time to get it pressure tested at the garage.

75
01-25-2002, 07:43 PM
40 psi of hot oil pressure on a Chevy 350 with the (presumably) stock oil pump actually sounds about right.

Remember that the oiling system on those small-block Chevy engines is different from the one used on your Cherokee - the basic design of the small-block family dates back to 1955, and the 350-inch engine has been around since '67 - a year longer than I've been around!

odin
01-25-2002, 08:47 PM
75
Your right even the vortec is basicly the same engine as a 55 all high teched over
But yet gm always manages to get more torq and power than fords overhead cam gas engines

OBRYANMAINT
01-26-2002, 10:37 PM
an engine builder once told me that to be sufficient all you need is 10 lbs of oil presssure per 1000 rpm

i know this is a generality but i have always used it

75
01-26-2002, 11:19 PM
Just so there's no confusion, when I mentioned the basic design of the small-block Chevy going back to 1955 that was meant as a good thing - HAD to be a good design to still be competitive over 45 years later! :)

Obryan - I have heard the same "rule of thumb" myself from a couple mechanics I know, again I think it tends to apply more to the older engines than some of these modern, nervous, high-revving, high-strung engine designs................................

MATTHEW
01-27-2002, 01:38 PM
That is like the straight 6 engines. That's all I ever had. Great power. This is the first 350 I have ever owned, so its all new to me. I had experience with the mid 80's Ford v-8's. Once they hit 80,000 miles, they would leak and burn oil. I hope mine will be still going strong at 80,000.
I had always been told that 20 lbs is barely adequate. Does anyone recommend using synthetics like amsoil?

odin
01-27-2002, 04:39 PM
Mathew

I use the amsoil in all the trucks and lawmowers to
I also rigged a amsoil oil duel bypass on the 97 one ton dump its relpaces the regular oil filter with a duel remote that has a be90 bypass and a sdf full flow oil filter on it
Their air filter's are great to
Havent rigged the bypass on the duramax yet but probaley will later on.
These gm pushrod engines have been high teched a lot since 1955 but they still get more power and torq than the competition's gas engines
The guiding hand behind the devolopment of these engines was a man named harvey earle who started stuff like the early fuel injected engines.They called em these motors the mighty mouse back then in 55.Earle designed three great american classics the 1955-56-57 chevrolets.