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Re: Is my oil pressure too high? [Re: Neil] #2747546
02/28/20 09:10 PM
02/28/20 09:10 PM
Joined: Mar 2010
Posts: 1,060
Atlanta, GA
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mgoblue9798 Offline
super stock
mgoblue9798  Offline
super stock
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Joined: Mar 2010
Posts: 1,060
Atlanta, GA
Originally Posted by Neil
Yes, on the thinner oil and see what you get.

I have been told by a very experienced machinist that synthetics don't cling to parts long term so on a hobby type car that sits a lot you may end up with cam lobes that have less oil film on them. True or not I don't know for sure...… This guy has a 7 second drag car and he uses conventional oil in it.



I take it a step further and run STP oil treatment. Stuff sticks to all internal parts of the engine. Every one I have torn down has a sticky film all over everything. Hell of a lot cheaper than a prelube oiling system and good insurance for the cars that are not used every day in my opinion.

Re: Is my oil pressure too high? [Re: mgoblue9798] #2747600
02/28/20 11:53 PM
02/28/20 11:53 PM
Joined: Aug 2003
Posts: 43,007
Bend,OR USA
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Cab_Burge Offline
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Bend,OR USA
I take it a step further and run STP oil treatment. Stuff sticks to all internal parts of the engine. Every one I have torn down has a sticky film all over everything. Hell of a lot cheaper than a prelube oiling system and good insurance for the cars that are not used every day in my opinion.
[/quote]
I remember hearing adds on TV in 1952 up to 1956 for the new miracle engine oil additive from Germany, STP work shruggy
I started working in service station, not todays gas only stations, in 1961, I started building my own motors shortly after that and started taking customers motor work in around 1974.
I know customers who used and swore by STP, all the STP motors I tore down for inspection had grey gunk deposits in every little low spot in th elifter valleys, I owned a hot tank and the hot tank solution wouldn't touch those deposits after soaking them for several days shock I had to scrape it out with a screw driver or something narrow enough to get in those small recesses wrench
I'm not sure if the STP formula has changed over the years, especially when Andy Granatelli (SP?) owned the company in the early 1960s.
I don't use it now, haven't in over twenty years due to todays oils are way better than they where in 1950s work
Pennzoil use to be crap until Shell oil bought them, they started adding something to the race oil tin the early 2000s hat sticks on anything like crazy, so has Valvoline up scope


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: Is my oil pressure too high? [Re: Cab_Burge] #2747603
02/29/20 12:09 AM
02/29/20 12:09 AM
Joined: Jan 2003
Posts: 3,122
Auburn WA
Dave_J Offline
master
Dave_J  Offline
master

Joined: Jan 2003
Posts: 3,122
Auburn WA
Originally Posted by Cab_Burge
Do you remember how much oil pressure it had with both pumps above 4500 RPM? Is that information on your dyno sheets? scope
I have had to trim a lot o the black high pressure bypass springs to get to have 65 lbs. at 6500 RPM with 5w20 wt. oil in my street motors at or above 130F oil temps.
I think I saw a small HP and torque gain by cutting the pressure back on a high volume oil pump on one of the dyno tests done years ago from 80 lbs. at 5000+ RPM down to 65 lbs. at 6500 RPM with the oil temps above 150 F, maybe 3 HP, maybe less confused
I've never had a bearing problem with 10 lbs. per 1000 RPM rule on any motor with loose bearing clearances, I have seen rod bearings spin in other motors at the drag races that had less than .0020 rod bearing clearances on BB Mopar motors when raced with cool oil temps work


Do not have the Dyno sheets, long gone. 3 military moves and 2 house moves since then. This was when 513's were not common and Fram filters were GREAT. It was an imploded Fram filter that killed that 513. I don't play with big blocks any more.

I am going by memory. All dyno runs were at 180 degrees F water temp. I think with the 20W50 and HV pump it was north of 100PSI at 2500-3000 RPM and 80 PSI with the stock oil pump. With the 5W30 HV pump I think it was like 60 PSI and 50 PSI with standard pump. We did not play with the bypass spring at that time. We did grind it down some later to get closer to the 10 PSI per 1000 RPM.

Over the years I have always blueprinted and ported all oil pumps. Most oil pumps have too tight rotors, small passages and lots of bugers in the ports.


Retired, US ARMY 1973-1994
ASE mechanic, Electrical 1994-1997
Retired GTE/VERIZON/FRONTIER 1997-2015


Posting cheap tech help (CRAP) here since Nov 97, 1000's of posts, some may be good.

03 Suzuki Burgman 650(Burger King) Scooter
65 Formula S Cuda
78 Little Red Express Truck
98 Buick Regal (wifes car)
Re: Is my oil pressure too high? [Re: Dave_J] #2747914
02/29/20 11:48 PM
02/29/20 11:48 PM
Joined: Feb 2010
Posts: 1,645
Phila. Pa.
Mattax Offline
top fuel
Mattax  Offline
top fuel

Joined: Feb 2010
Posts: 1,645
Phila. Pa.
Guys Thanks for sharing what you found on the dyno!
Originally Posted by Cab_Burge

I've done a lot of engine dyno testing and found out that the oil temps can have a direct affect on HP, 30 W oil at 130F would not have as much power as it would at 170+ F oil temps, 8 HP gain with hotter oil up I then tried 10W30 wt and saw 5 HP differences between 130 F and 160F, the next test was with straight 20W and I saw no HP gain from 70F up to 210F shruggy work
That is why I use that weight oil now in all my street motors and low (below 750HP) HP bracket motors up


Thank you both for sharing!
The termperature relationship makes sense.

Viscosity for a straight 30 at
130 F is around 45 cSt
175 F is around 20 cSt
8 Hp

For a 10W-30
130 F is around 35 cSt
160 F is around 25 cSt
5 Hp

I don;'t have info from straight 20 plotted.
But to your findings on that engine it seems that viscosity above 20 or 25 cSt was costing power.

Originally Posted by Dave_J
we did a Dyno run on a 513 BBM years ago using 20W50 racing oil. All tests were at 180 degrees F. We then replaced the HV oil pump with a standard one and gained 10 HP. Then we dumped the 20W50 and ran 5W30 and gained 15 Horsepower. So a gain of 25 Horses. .


@ 180 F
20W-50 has viscosity around 34 cSt
_5W-30 has viscosity around 18 cSt.
15 Hp




Last edited by Mattax; 02/29/20 11:51 PM.
Re: Is my oil pressure too high? [Re: Mattax] #2747934
03/01/20 03:18 AM
03/01/20 03:18 AM
Joined: Aug 2003
Posts: 43,007
Bend,OR USA
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Cab_Burge Offline
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Joined: Aug 2003
Posts: 43,007
Bend,OR USA
One of the first tests I did on straight 20Wt Valvoline non synthetic which showed that oil made the same power at 80 F oil temps as it did at 220 F shruggy
That was on a pump gas iron headed motor that barely made 500 HP and it took a long time to get the oil temps up to 220F running it at 2500 RPM with small dyno load on it. We had to turned the fans off to the dyno room, both inlet and outlets to get the oil that hot shruggy I would shoot for between 160 F and 180 F water temps on the dyno pulls.
I was concentrating on making the same power as much as possible for bracket cars back then wrench
IHTHS thumbs

Last edited by Cab_Burge; 03/01/20 03:19 AM.

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: Is my oil pressure too high? [Re: Cab_Burge] #2748058
03/01/20 04:38 PM
03/01/20 04:38 PM
Joined: Jul 2008
Posts: 30,252
Florida STAYcation
dIc dOc Deity ! Online penguin-006
The village idiot's idiot
dIc dOc Deity !  Online Penguin-006
The village idiot's idiot

Joined: Jul 2008
Posts: 30,252
Florida STAYcation
IIRC .. An older article in National Dragster about oiling systems written by WJ .... he was using 0 weight oil with a max pressure of 60 psi.. !

GOOD to see here that the usage of smilies HERE ... is not TOO HIGH too ! laugh2

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