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Re: do mopars just get low oil psi or is it just mine?
[Re: 5spdcuda]
#671479
04/17/10 03:06 AM
04/17/10 03:06 AM
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Joined: Feb 2003
Posts: 21,318
Manitoba, Canada
DaytonaTurbo
Too Many Posts
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Too Many Posts
Joined: Feb 2003
Posts: 21,318
Manitoba, Canada
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Quote:
Clearances are probably on the loose side. Also high volume isn't the same as high pressure. I use a high pressure spring in any modified engine. With 20-50 weight oil my cold pressure is 75-80 psi. Hot idle is 40 psi, 30 psi if it's been run hard. Hot pressure at 2000 rpm is 60-65 psi. Pressure is 5 psi lower when using thinner oils. Most stock Mopars run 45-50 psi at 2000 rpm hot and anything from 15-30 psi at hot idle.
My tired stock bearing/crank 440 ran 75-80psi cold with 15 or so at a 700rpm idle in gear. Any amount of throttle and the oil pressure would shoot right up, and that's with an original pump/spring pushing 10w-30 oil. Your HP spring and thicker oil doesn't seem to develop any more pressure than my tired stocker did. I later tried putting in a HV pump, and saw a small increase in pressure at idle, 5psi or so, with the biggest difference being it built a lot more pressure quickly with any amount of throttle.
You can't have pressure without volume. A high pressure relief spring will do nothing for the OP. All a high pressure spring does is raise the upper limit of oil pressure you will develop before the relief pops, and trust me, the relief is a hell of a lot higher than 8psi. What you need is more volume, and if you're already running the HV pump, about the only thing you can try is a thicker oil.
You can try the stiffer spring if you want, however I would bet it will gain you nothing.
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Re: do mopars just get low oil psi or is it just mine?
[Re: Supercuda]
#671483
04/17/10 11:33 AM
04/17/10 11:33 AM
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Joined: Nov 2007
Posts: 21,822
Kirkland, Washington
Pacnorthcuda
Too Many Posts
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Too Many Posts
Joined: Nov 2007
Posts: 21,822
Kirkland, Washington
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Quote:
Quote:
where can i get a high pressure spring?
Won't help you.
The high pressure spring sets the MAXIMUM oil pressure. It will not raise you lower oil pressure at idle.
The only caveat is if the pressure relief valve is sticky, taking it apart to install a new spring might loosen it up and get it working. But it won't be the spring that fixed it. There was a batch of oil pumps a few years back that had this problem and I think it was Melling pumps too.
Exactly. A High pressure spring aint gonna help one iota. Its only goning to keep the relief valve from opening until a higher pressure is reached at speed. At lower pressures the regular spring is keep the valve closed just fine.
The pump itself could have excessive clearannce between the rotor and the case. Considering the low cost and ease of replacement on a BB you might want to try a different HV pump, or machine down the case clearance on this one.
But in all probability it is a loose motor. You could drop the pan and plastigage the bearing clearances...
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