Oil pressure question. Do I have enough?
Thread Starter
Instructor
Joined: Aug 2005
Posts: 209
Likes: 8
From: Hollywood FL
Oil pressure question. Do I have enough?
I recently built a small block engine, 355, stock bottom end, vortec heads, etc. Somewhere around 360 HP. The oil pressure warmed up is only 20 psi at idle and 45 at cruising speed. To me that seems low for a fresh motor. The clearances are all tight and I used a Z-28 (Melling M55A) pump. This is a street driven car and will rarely see 5000 RPM, so I don't think I'm hurting anything by driving it. I'm just concerned about long term longevity. Am I worrying for no reason or should I be looking for a problem? What do you guys think?
Le Mans Master
Joined: Jan 2006
Posts: 8,319
Likes: 7
From: Wilmington DE, Drive it like you stole it, 68 327 4 speed coupe
its within tolerance
those numbers arent bad, are your sure your gauge is accurate? could just be reading low. my 68 327 idles at 30 psi and runs down the road at 50-55 or so.
also what kind of oil pupm did you put in standard or High volume?
tim
also what kind of oil pupm did you put in standard or High volume?
tim
Thread Starter
Instructor
Joined: Aug 2005
Posts: 209
Likes: 8
From: Hollywood FL
Originally Posted by Garys 68
Sounds OK to me.
What viscosity oil? What's the oil temp?
What viscosity oil? What's the oil temp?
Race Director
Joined: Sep 2002
Posts: 10,362
Likes: 5
From: San Diego - Deep Within The State of CONFUSION!
Originally Posted by MonzaRedConvert
It's Valvoline 10w40. I was thinking of switching to 20w50. I don't have an oil temp gauge, but the engine runs cool (around 160).
Intermediate
Joined: Jan 2006
Posts: 28
Likes: 0
From: Port Washington Wisconsin
yea man those numbers are A-ok i have mine running at about 40 psi idle and 80 psi in high rpm and i run 20w-50 in it, only thing that is bad about the high psi is that when ur really giving it to her at high rpm it will squirt outta the dip stick a bit hehe but its a really fun car 
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Melting Slicks
Joined: Aug 2003
Posts: 2,135
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From: Dayton Oh
Originally Posted by sweethence
those numbers arent bad, are your sure your gauge is accurate? could just be reading low.
tim
tim
My 355 is running a high volume, standard pressure Melling and gets 40psi at idle and 60 crusing. Your numbers don't sound that far off and you should be OK. If you're really concerned, then you could temp attach a good mechanical pressure guage and see how close you really are. I suspect that maybe your sender is just a little off.
