High oil pressure
#2065162
05/01/16 10:52 AM
05/01/16 10:52 AM
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Joined: May 2016
Posts: 15 Houston, TX
sbklf
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OP
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Joined: May 2016
Posts: 15
Houston, TX
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Hello from Houston. I want to lower the oil pressure on my 71 383 Cuda that pegs the dash gauge when cold and only comes down slightly when hot. I installed a spring gauge and confirmed 80+ cold and around 80 hot. I had a friend rebuild the engine in 95 and he put a high pressure oil pump (M63HP) on it and I run 10-30 oil. I found an old post on this site that discussed oil types and high volume pumps but not high pressure pumps ( https://board.moparts.org/ubbthreads/ubbthreads.php/ubb/showflat/Number/4589685/site_id/1 ). O'Reilly sells three different pumps, standard, high volume and high pressure. Why high pressure over high volume or even a standard pump? The old post mentions adjustable springs for pressure, do they still sell these? What oil type? Can I, should I consider synthetic? In addition to all this the engine has a knock which is another post but I will see if an oil pressure reduction affects it. Thanks, Kevin
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Re: High oil pressure
[Re: sbklf]
#2065188
05/01/16 11:51 AM
05/01/16 11:51 AM
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Joined: Jan 2003
Posts: 21,083 Niles , Ohio
therocks
oh wait.but hey.lets see.oh yeah.
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oh wait.but hey.lets see.oh yeah.
Joined: Jan 2003
Posts: 21,083
Niles , Ohio
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High pressure increases pressure.hi volume increases the amount pumped Ie say 10 GPM vs 20 GPM.There are adjustabe springs avaliable as far as I know.I beliebe Moroso makes one.There are different springs avaliable also.I run 20 50 most time.My 440 runs hi volume hi pressure pump whic were avaliable when it was rebuilt.Runs 80 PSI just about all the time.been like this since at least 2000.Never a problem.I run kendall GT1 when i can get it.Some dont like hi pressure I do.Rocky
Chrysler Firepower
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Re: High oil pressure
[Re: sbklf]
#2065251
05/01/16 01:52 PM
05/01/16 01:52 PM
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Joined: Nov 2003
Posts: 36,041 Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
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O'Reilly sells three different pumps, standard, high volume and high pressure. 80 ain't gonna kill you tho it stresses the intergear more (not a dealbreaker as everything gets stressed) but unless this is a high RPM screamer I'd want less. what I do is (1) get the wt of oil that I am comfortable with (as light as I can safely run & not sure if straight wt is better than multi or not) then (2) go with the pump/spring needed. I'd get the O'reillys std pump (they're cheap), clean it & bolt it on & see what you get for psi. another option would be to cut a coil at a time off of yours
live every 24 hour block of time like it's your last day on earth
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Re: High oil pressure
[Re: sbklf]
#2065351
05/01/16 04:50 PM
05/01/16 04:50 PM
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Joined: Aug 2003
Posts: 43,292 Bend,OR USA
Cab_Burge
I Win
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I Win
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Bend,OR USA
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You can lower the oil pressure several different ways, replace the high pressure spring with a standard pressure spring, trim one to two coils off the high pressure spring or change the pump I use a good set of side cutting wire cutters to trim 1 1/2 coils off most of the high volume pumps I use That normally makes the pressures drop some on most of the motors I've done this to, starts and has 80 lbs cold(below 40F) at idle, 25 to 40 lbs idling when warmed up with 10/30 Wt oil. 65 lbs at 6500 RPM with hot(above 160F) 10/30 wt oil On my old 518 C.I. low deck pump gas stroker motor with real loose oil clearances throughout the motor it would have 18 to 20 lbs at 650 RPM with 180F+ oil temps, 30 lbs at 1200 RPM and 65 lbs at 2000 to 7000 RPM with that oil temp. with 5/20 WT straight petroleum non synthetic Valvoline oil
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: High oil pressure
[Re: Cab_Burge]
#2066301
05/03/16 01:04 AM
05/03/16 01:04 AM
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Joined: Jan 2003
Posts: 5,791 Hamilton, Ontario Canada
Magnum
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Hamilton, Ontario Canada
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On my old 518 C.I. low deck pump gas stroker motor with real loose oil clearances throughout the motor it would have 18 to 20 lbs at 650 RPM with 180F+ oil temps, 30 lbs at 1200 RPM and 65 lbs at 2000 to 7000 RPM with that oil temp. with 5/20 WT straight petroleum non synthetic Valvoline oil This is the combo right here.^ As for spring vs volume. Why correct this problem with a spring. What is the point of having the oiling system constantly running on bypass? It's done because it's easy. Once an engine is clearanced. It should be tuned in with pump volume to achieve the desired numbers. Not too much volume and bypass until you are happy. I've corrected too much pressure many times on fresh motors by switching to an old worn out stock pump.
Last edited by Magnum; 05/03/16 01:05 AM.
69 Super Bee, 93 Mustang LX, 04 Allure Super
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Re: High oil pressure
[Re: Magnum]
#2066325
05/03/16 01:41 AM
05/03/16 01:41 AM
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Joined: Nov 2003
Posts: 36,041 Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
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As for spring vs volume. Why correct this problem with a spring. What is the point of having the oiling system constantly running on bypass? It's done because it's easy.
Once an engine is clearanced. It should be tuned in with pump volume to achieve the desired numbers. Not too much volume and bypass until you are happy. the above makes VG sense (I learned something today). My thoughts: (1) get the clearances where you want em when you build (2) pick reasonably light wt of oil (3) start with std vol pump & go from there
live every 24 hour block of time like it's your last day on earth
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Re: High oil pressure
[Re: Sinitro]
#2066755
05/03/16 09:45 PM
05/03/16 09:45 PM
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Joined: Mar 2006
Posts: 9,871 MI, usa
dvw
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MI, usa
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Mine has one. PSI still to high. The first thing I would do is try thinner oil. My race motor has been running 5w/30 for 300 passes at 65 psi@7100. Rod bearings looked perfect mains not bad considering the power is (close to 900). The adjustable regulator which is turned down all the way. It does have the tall rotors (high volume). Idle psi is 55, 75 at speed after cutting the spring by one coil. It still has 10w/40 oil fo break-in . My bet is that with the 5w/30 it'll be real close. If not I'll lop off one more coil. Doug
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Re: High oil pressure
[Re: sbklf]
#2066767
05/03/16 09:56 PM
05/03/16 09:56 PM
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Joined: Nov 2011
Posts: 2,154 Its a TRAP!
DARTH V8Я
Oh No!! I just had a moron attack!
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Oh No!! I just had a moron attack!
Joined: Nov 2011
Posts: 2,154
Its a TRAP!
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For me around 20psi at idle is what i shoot for. 60psi on the intermediate shaft during idle is never good. Lots of strain. The old rule of thumb 10 psi for ever 1000rpm is more than enough.
When it takes more than a sweet mullet to prove you rule at the trailer park..
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Re: High oil pressure
[Re: sbklf]
#2067975
05/05/16 09:37 PM
05/05/16 09:37 PM
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Joined: Sep 2014
Posts: 4,457 Washington
madscientist
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master
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Washington
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Your oil pressure is fine. Leave the fly poop in the pepper and move on. I'd rather have 80 at idle than 20. Unless it is DEAD stock.
Just because you think it won't make it true. Horsepower is KING. To dispute this is stupid. C. Alston
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Re: High oil pressure
[Re: sbklf]
#2068004
05/05/16 10:26 PM
05/05/16 10:26 PM
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Joined: Mar 2003
Posts: 4,848 Memphis
HemiRick
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Your hope that reducing pressure will cure a knock, is nothing but wishful thinking IMHO
Take care, Rick 68 Coronet R/T 440 & 68 Charger 528 Hemi,and 5 Challengers! 6 cyl, 318, 360, 383, 451
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Re: High oil pressure
[Re: sbklf]
#2068023
05/05/16 11:05 PM
05/05/16 11:05 PM
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Joined: May 2016
Posts: 15 Houston, TX
sbklf
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OP
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Houston, TX
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I want to reduce the pressure because I don't think it needs to be that high. I don't have any hope of a pressure change curing my knock, but am interested to see if a change affects it.
Last edited by sbklf; 05/05/16 11:06 PM.
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Re: High oil pressure
[Re: sbklf]
#2068049
05/05/16 11:53 PM
05/05/16 11:53 PM
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Joined: Jan 2003
Posts: 5,791 Hamilton, Ontario Canada
Magnum
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master
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Hamilton, Ontario Canada
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I want to reduce the pressure because I don't think it needs to be that high. I don't have any hope of a pressure change curing my knock, but am interested to see if a change affects it. You want to reduce the pressure for the same reason EVERY car manufacturer has reduced the pressure. It wastes fuel and robs power. There is a pressure that is too low and pressure that is too high and there is a super wide margin in between. The smarter of us run near the low side without going under.
69 Super Bee, 93 Mustang LX, 04 Allure Super
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Re: High oil pressure
[Re: sbklf]
#2068084
05/06/16 01:09 AM
05/06/16 01:09 AM
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Joined: Aug 2003
Posts: 43,292 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,292
Bend,OR USA
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Are you using a electric or mechanical gauge? I wouldn't worry about the cold oil ressure at all, never If it has reasonable oil pressure, at least 10 lbs per thousand RPM, with hot oil running down the road your golden
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: High oil pressure
[Re: Cab_Burge]
#2068137
05/06/16 09:04 AM
05/06/16 09:04 AM
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Joined: May 2016
Posts: 15 Houston, TX
sbklf
OP
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OP
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Joined: May 2016
Posts: 15
Houston, TX
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Are you using a electric or mechanical gauge? Original elec in dash and a mechanical mounted on the engine to confirm that it is actually running high as the dash gauge shows.
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