New roller cam -> low oil psi?
Thread Starter
Pro
Joined: Feb 2002
Posts: 533
Likes: 0
From: Augusta Ga
New roller cam -> low oil psi?
I installed a solid roller cam and lifters and now my oil pressure is really low. I use to be able to prime the motor by hand and get 40+ psi and at a cold idle I would have over 60. When it warmed up it came down some, but now after installing the cam the oil pressure is lower. The only things I changed while doing this swap is:
Installed new plug behind cam ( the freeze plug looking thing), installed roller cam with lifters and installed a arp oil pump drive rod. Could any of these explain my oil pressure dilema?
Thank you
Installed new plug behind cam ( the freeze plug looking thing), installed roller cam with lifters and installed a arp oil pump drive rod. Could any of these explain my oil pressure dilema?
Thank you
Burning Brakes
Joined: Nov 2001
Posts: 1,241
Likes: 9
From: Houston TX
Re: New roller cam -> low oil psi? (BigC4)
it's usually not a dramatic change, but the solid roller lifters really allow a lot more oil through. the hy-roller lifters are sort of like restrictors. so most of the time someone running a solid roller cam will use restrictors in the block oil passages that feed the lifters.
some roller rockers act as restrictors too, and sometimes just using the right rocker can do the trick. rockers like the comp cams pro magnums, though, are just basically wide open at the pushrod cup.
the crane gold race rockers i've seen for fords have a tiny orifice at the pushrod cup, so they're basically restrictors. i don't know if the SBC ones are like that too, since i've never seen any.
-michael
some roller rockers act as restrictors too, and sometimes just using the right rocker can do the trick. rockers like the comp cams pro magnums, though, are just basically wide open at the pushrod cup.
the crane gold race rockers i've seen for fords have a tiny orifice at the pushrod cup, so they're basically restrictors. i don't know if the SBC ones are like that too, since i've never seen any.
-michael
Thread Starter
Pro
Joined: Feb 2002
Posts: 533
Likes: 0
From: Augusta Ga
Re: New roller cam -> low oil psi? (BigC4)
I had heard of the restrictors and even inquired about them at the machine shop and they said to only use that in race application not for the street, but I do not know. I know I have less oil pressure and it bothers me. I had a sensor of security seeing that pressure up above 40 at idle. What about the direction of the lifters, should that matter?
Thank you
Thank you
Burning Brakes
Joined: Nov 2001
Posts: 1,241
Likes: 9
From: Houston TX
Re: New roller cam -> low oil psi? (BigC4)
i should have asked, what's the pressure now? over 40 at idle is a very generous amount for these engines, so you might be expecting too much.
the orientation of the lifters does not matter, no, that only matters in terms of clearance issues. on some engines, for instance, the link bars have to be on the inside instead of the outside. but you might even have lifters with the centered spring-loaded link bars, so then it's the same no matter how you install them.
personally, i'd be worried if idle pressure were below 25psi or so, and i'd want to see over 60psi up top. but that's subjective, i honestly don't know what is acceptable to the engine for long-term durability. i bet it could have less than i stated and still live a long time.
since you had over 40psi at idle before, i take it you're using a HV oil pump?
-michael
the orientation of the lifters does not matter, no, that only matters in terms of clearance issues. on some engines, for instance, the link bars have to be on the inside instead of the outside. but you might even have lifters with the centered spring-loaded link bars, so then it's the same no matter how you install them.
personally, i'd be worried if idle pressure were below 25psi or so, and i'd want to see over 60psi up top. but that's subjective, i honestly don't know what is acceptable to the engine for long-term durability. i bet it could have less than i stated and still live a long time.
since you had over 40psi at idle before, i take it you're using a HV oil pump?
-michael
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Re: New roller cam -> low oil psi? (MSR)
I suspect your lifter to lifter bore clearance may be slightly greater resulting in the lower pressure.
You can always drop the pan and shim the spring to increase the max pressure if it's not as high as you like, but this won't help idle pressure.
I'd first switch to a heavier oil, Valvoline Racing VR1 20W50 would be my choice. This may help at both ends, especially if you're running 10W30 or lighter weight oil.
Jake
You can always drop the pan and shim the spring to increase the max pressure if it's not as high as you like, but this won't help idle pressure.
I'd first switch to a heavier oil, Valvoline Racing VR1 20W50 would be my choice. This may help at both ends, especially if you're running 10W30 or lighter weight oil.
Jake
Melting Slicks
Joined: Sep 2003
Posts: 2,775
Likes: 0
From: 1,000,000,001 Posts
Re: New roller cam -> low oil psi? (JAKE)
Mine dropped also, after I installed the ZZ4 cam...
I was running 10W40 royal purple with the stock cam
I run 10W30 royal purple with the new cam
I was running 10W40 royal purple with the stock cam
I run 10W30 royal purple with the new cam
Pro
Joined: Jul 2001
Posts: 557
Likes: 0
From: Taxahoma
Re: New roller cam -> low oil psi? (JAKE)
20W50 would be like running syrup through it, hope it never starts in the cold then. The safe level is 10psi/1K rpm altho 10psi at idle would scare me some even if it's safe (out of lingenfelter book i believe). Mine always was 20-30 at hot idle.
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Re: New roller cam -> low oil psi? (Black87c4)
20W50 would be like running syrup through it, hope it never starts in the cold then. The safe level is 10psi/1K rpm altho 10psi at idle would scare me some even if it's safe (out of lingenfelter book i believe). Mine always was 20-30 at hot idle.
Then when you bring the car out and the ambient temps climb, switch to whatever will keep your idle pressure up.
The only other option is see is an engine rebuild to tighten up the clearances; but that's an over the top solution.
I run 20W50 year round in Texas; he's in Georgia which is about the same.
Jake
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