with Paul. Sending unit. Did you reuse your old one by chance? You could hook up a manual gauge to verify the numbers.
Proper/Correct Oil Pressure
Thread Starter
Melting Slicks
Joined: Jan 2003
Posts: 2,714
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From: Shreveport LA
LA Events Coordinator
Proper/Correct Oil Pressure
What is the proper/correct oil pressure? I have a GMPP 350 (290hp) and when it's idling, the pressure is 40-45 psi. But when I'm going down the interstate at 70mph (engine turning 3200 rpms), the oil pressure gauge pegs all the way to the right (80 psi). Everything on the engine performs perfectly....no oil seepage, stains or anything.
Pulled the plugs....all perfect. When I do a search of the forum for "oil pressure", I get every thread with the word "oil" in it OR the word "pressure" in it. It even picks up "fuel pressure"
....why can't it be simple?
Anyway, why is the gauge reading 80 psi at high rpms? Is this normal?
Pulled the plugs....all perfect. When I do a search of the forum for "oil pressure", I get every thread with the word "oil" in it OR the word "pressure" in it. It even picks up "fuel pressure"....why can't it be simple?Anyway, why is the gauge reading 80 psi at high rpms? Is this normal?
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
What is the proper/correct oil pressure? I have a GMPP 350 (290hp) and when it's idling, the pressure is 40-45 psi. But when I'm going down the interstate at 70mph (engine turning 3200 rpms), the oil pressure gauge pegs all the way to the right (80 psi). Everything on the engine performs perfectly....no oil seepage, stains or anything. Pulled the plugs....all perfect. When I do a search of the forum for "oil pressure", I get every thread with the word "oil" in it OR the word "pressure" in it. It even picks up "fuel pressure"....why can't it be simple?
Anyway, why is the gauge reading 80 psi at high rpms? Is this normal?
Pulled the plugs....all perfect. When I do a search of the forum for "oil pressure", I get every thread with the word "oil" in it OR the word "pressure" in it. It even picks up "fuel pressure"....why can't it be simple?Anyway, why is the gauge reading 80 psi at high rpms? Is this normal?
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
https://www.amsoil.com/storefront/hdd.aspx?zo=1489781
Burning Brakes
Joined: May 2009
Posts: 1,232
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From: Tucson AZ
St. Jude Donor '12
why can't it be simple?
advanced search, select "Search titles only", then put plus signs in front of your keywords: +oil +pressure
Try that and see if you like the results better
Thread Starter
Melting Slicks
Joined: Jan 2003
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From: Shreveport LA
LA Events Coordinator
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Thread Starter
Melting Slicks
Joined: Jan 2003
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From: Shreveport LA
LA Events Coordinator
Pro
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From: Millersville, MD
Drifting
Joined: Feb 2005
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From: San diego ca
What is the proper/correct oil pressure? I have a GMPP 350 (290hp) and when it's idling, the pressure is 40-45 psi. But when I'm going down the interstate at 70mph (engine turning 3200 rpms), the oil pressure gauge pegs all the way to the right (80 psi). Everything on the engine performs perfectly....no oil seepage, stains or anything. Pulled the plugs....all perfect. When I do a search of the forum for "oil pressure", I get every thread with the word "oil" in it OR the word "pressure" in it. It even picks up "fuel pressure"....why can't it be simple?
Anyway, why is the gauge reading 80 psi at high rpms? Is this normal?
Pulled the plugs....all perfect. When I do a search of the forum for "oil pressure", I get every thread with the word "oil" in it OR the word "pressure" in it. It even picks up "fuel pressure"....why can't it be simple?Anyway, why is the gauge reading 80 psi at high rpms? Is this normal?
Given all that, plus a new motor with the tight clearances of a new motor, your pressure doesnt seem out of the ordinary to me
Last edited by fauxrs2; Jun 2, 2009 at 09:50 AM.
Race Director
Joined: Mar 2006
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From: Florida
Almost all oil pumps, even oem are made by Melling.
The relief valve is set at 70 psi for all their HV pumps, and it can vary a few psi, high or low. Your gauge is approx off by 10 psi.
Ir you want lower oil pressure, either change to a lighter weight oil, (common with new cars these days 0w30), or change the relief spring in the oil pump to a lighter one.
BTW, mine is the same and I like it.
The relief valve is set at 70 psi for all their HV pumps, and it can vary a few psi, high or low. Your gauge is approx off by 10 psi.
Ir you want lower oil pressure, either change to a lighter weight oil, (common with new cars these days 0w30), or change the relief spring in the oil pump to a lighter one.
BTW, mine is the same and I like it.
Cruising
Joined: Oct 2005
Posts: 14
Likes: 0
I have the same scenerio with my '69 300/350. If I'm idling it's around 35-40 and once I get the rpm going it seems to get up to 75 and even the guage limit 80. I talked to someone at my local garage that seemed to have some knowledge (although I wouldn't bet my life on it) and he said he wouldn't be worried unless it was bouncing all around especially bottoming out, which it isn't.
I guess I wonder now if I should try using a lower viscosity oil or change out the oil pressure sending unit.????
I guess I wonder now if I should try using a lower viscosity oil or change out the oil pressure sending unit.????
Burning Brakes
Joined: Aug 2005
Posts: 1,164
Likes: 1
From: Europe, France
I have the same pressures with my new melling performance oil pump :
60 PSI cold at idle
40-45 PSI hot at idle
80-90 PSI hot at high RPM
But if you get these pressures with the stock oil pump and 10W30, something is wrong. My original oil pump never reached more than 55-60 PSI and this was with cold oil
With my new oil pump, I bought a new mechanical AutoMeter oil pressure gauge to withstand the higher pressures :
60 PSI cold at idle
40-45 PSI hot at idle
80-90 PSI hot at high RPM
But if you get these pressures with the stock oil pump and 10W30, something is wrong. My original oil pump never reached more than 55-60 PSI and this was with cold oil
With my new oil pump, I bought a new mechanical AutoMeter oil pressure gauge to withstand the higher pressures :
Last edited by 73StreetRace; Jun 2, 2009 at 12:14 PM.
7th Gear
Joined: Aug 2015
Posts: 7
Likes: 0
proper correct oil
Good choice! Bet your guage is off. Here is something a little lighter with plenty of Zinc and phosphorous.
https://www.amsoil.com/storefront/hdd.aspx?zo=1489781
https://www.amsoil.com/storefront/hdd.aspx?zo=1489781
Melting Slicks
Joined: Apr 2009
Posts: 2,632
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From: Great Plains Iowa