How much oil pressure?
#2734557
01/19/20 05:10 PM
01/19/20 05:10 PM
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Joined: Nov 2015
Posts: 884 Missouri
jwb123
OP
super stock
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OP
super stock
Joined: Nov 2015
Posts: 884
Missouri
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Hope I can get some free advice. Finally have my engine back together. It is a 540 CID RB mopar, World product aluminum block, Edelbrock victor Jr. heads. Ohio crankshaft 4.25 stroke crank, and Ohio H-beam rods 7.1 inches long, they are BBC rods. Ross flat top pistons. Before it blew up from a broken rod it ran for ten years as a 512, with aluminum rods. Main and Rod bearings were clearanced at .003 and I ran 20w 50 VR1 racing oil. Stock Hi volume mopar oil pump with external pickup in the side of the pan. With the old engine it held 90 lbs cold and 60 lbs warm, after a 1/4 mile run it would drop to 30 psi at idle, but go up to 60lbs when you touched the gas. I think that is normal for an aluminum block and rods? The new engine has steel rods, I clearanced the mains at .003, and the rods came in at .002, using federal mogul performance mains bearings, mainly because they have a 3/4 groove. and Clevite 77 H series rod bearings. I added an adjustable pressure regulator to my pump long time ago so it's easy to adjust. The old mopar rule was "10psi for every 1000 rpm's" I plan to run the engine 7,000 rpm. The old engine dynoed at 720 HP @ 6,800 rpm. The world products block has priority oiling with a .040 restrictor up to the rocker shafts. I primed it the other day and it held 90 psi with a 1/2 drill. It had lots of oil to the top even with the restrictors. I am thinking about lowering the relief valve down to 60 or 70 psi. I don't think it will lose as much oil pressure when hot with the steel rods, and I wonder if I am moving too much oil with the priority oiling system? I know it takes HP to drive the pump so every little bit helps. Anybody got experience or advice on the World products aluminum blocks?
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Re: How much oil pressure?
[Re: jwb123]
#2734579
01/19/20 06:03 PM
01/19/20 06:03 PM
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Joined: Mar 2006
Posts: 2,675 Mt. Eden Ky.
Hemi Allstate
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master
Joined: Mar 2006
Posts: 2,675
Mt. Eden Ky.
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FWIW I am using the World Aluminum Hemi Block. with .040 " restrictor , Milodon dual swinging pick up High volume Mellings pump . 4.5" stroke X 4.5 " bore. I think mine being a Hemi makes for a bad comparison. I am running more rod bearing clearance than yours too. My oil pressure is more like 75 - 80 lb max. I use 15W40 oil. Some folks like the heavy oil , but I think your pressure would be closer to what you want with a lighter viscosity oil. Mark
1996 Ram 1500 Sport 1968 road runner 1952 Sears Allstate licensed, pump gas, Hemi 5.98 @ 115.73 1.33 60 ft. The best is yet to come. Painless Performance / Street RODDER magazine Top 100 for 2019
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Re: How much oil pressure?
[Re: Hemi Allstate]
#2734598
01/19/20 06:37 PM
01/19/20 06:37 PM
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Joined: Jan 2003
Posts: 14,514 So. Burlington, Vt.
fast68plymouth
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I Live Here
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Posts: 14,514
So. Burlington, Vt.
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I wouldn’t change anything(unless it were like 150psi) til it’s in the car and running, and you’ve made a couple passes on it and can see what the hot pressure is really like.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: How much oil pressure?
[Re: jwb123]
#2734701
01/20/20 12:05 AM
01/20/20 12:05 AM
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Joined: Aug 2003
Posts: 43,315 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,315
Bend,OR USA
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I would much rather see .0022+ on the rod bearings keeping with the .0010 per one inch of crankshaft journal diameter rule in effect I look for .0025 + on steel rod street motors with 5W20Wt oil, I get 80 lbs. at 3000 RPM + with cool oil 18 to 25 lbs.at 800 RPM with 170F + oil temps with Valvoline 5W20WT, 65 lbs. at 170+ F at or above 4000 RPM with a coil and half cut off the old Speed Pro high volume black bypass springs I don't like 3/4 time oil pressure to the rods either I like and use the Federal Mogul, Seal Power # 4095M narrow full groove HD truck main bearings on RB and 426 hemi motors
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: How much oil pressure?
[Re: Cab_Burge]
#2735003
01/20/20 05:25 PM
01/20/20 05:25 PM
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Joined: Nov 2015
Posts: 884 Missouri
jwb123
OP
super stock
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OP
super stock
Joined: Nov 2015
Posts: 884
Missouri
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I would much rather see .0022+ on the rod bearings keeping with the .0010 per one inch of crankshaft journal diameter rule in effect I look for .0025 + on steel rod street motors with 5W20Wt oil, I get 80 lbs. at 3000 RPM + with cool oil 18 to 25 lbs.at 800 RPM with 170F + oil temps with Valvoline 5W20WT, 65 lbs. at 170+ F at or above 4000 RPM with a coil and half cut off the old Speed Pro high volume black bypass springs I don't like 3/4 time oil pressure to the rods either I like and use the Federal Mogul, Seal Power # 4095M narrow full groove HD truck main bearings on RB and 426 hemi motors There was just a long thread on speed talk about 3/4 and fully grooved main bearings as well as oil timing where the main oiling hole lined up with the rod journal, and the degrees of the crank and when the cylinder fires loading the crank. I have always liked the 3/4 groove on mopars. If I can ask why do you not like the 3/4 groove bearings? I always went with the longer the groove the more oil to the rod.
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Re: How much oil pressure?
[Re: dOc …]
#2735078
01/20/20 09:55 PM
01/20/20 09:55 PM
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Joined: Jul 2004
Posts: 19,318 State of confusion
Thumperdart
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I Live Here
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State of confusion
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I think this is an old wives tale being I know of 9000+ rpm motors having around 55-60 lbs and no issues. I even noticed Erica Enders had 18-22 lbs at idle when I freeze framed a cockpit view a while back and HEARD they too do not run 10 lbs. per 1000 rpm's.....
72 Dart 470 n/a BB stroker street car `THUMPER`...Check me out on FB Dominic Thumper for videos and lots of carb pics......760-900-3895.....
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Re: How much oil pressure?
[Re: Thumperdart]
#2735081
01/20/20 10:13 PM
01/20/20 10:13 PM
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Joined: Sep 2014
Posts: 4,457 Washington
madscientist
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master
Joined: Sep 2014
Posts: 4,457
Washington
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I think this is an old wives tale being I know of 9000+ rpm motors having around 55-60 lbs and no issues. I even noticed Erica Enders had 18-22 lbs at idle when I freeze framed a cockpit view a while back and HEARD they too do not run 10 lbs. per 1000 rpm's..... Much different than a screwed up Chrysler oiling system. You can run that low with roller cam bearings and things like that, and correct oil to the rods. But our stuff doesn't oil like that.
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: How much oil pressure?
[Re: Cab_Burge]
#2735141
01/21/20 01:12 AM
01/21/20 01:12 AM
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Joined: Jul 2004
Posts: 19,318 State of confusion
Thumperdart
I Live Here
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I Live Here
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Posts: 19,318
State of confusion
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I figured Pro-Stock could get away with it being a dry sump but it does make ya wonder and fwiw at 7000r's on my junk I have about 58-60 lbs last time I checked....
72 Dart 470 n/a BB stroker street car `THUMPER`...Check me out on FB Dominic Thumper for videos and lots of carb pics......760-900-3895.....
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Re: How much oil pressure?
[Re: Thumperdart]
#2735151
01/21/20 02:47 AM
01/21/20 02:47 AM
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Joined: Sep 2014
Posts: 4,457 Washington
madscientist
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master
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Posts: 4,457
Washington
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I figured Pro-Stock could get away with it being a dry sump but it does make ya wonder and fwiw at 7000r's on my junk I have about 58-60 lbs last time I checked.... Your not that far off. The good news is it living. And obviously there is some wiggle room in there, especially since most guys no longer use a 50 grade oil any more. You have less pressure but you are still getting flow. You may be able to back it down a bit more. The question then becomes how much power are you saving to drop another 5 pounds? When I was testing some of my junk we started back the oil pressure down and lost power. At 8500 I was at 100 PSI. At 80 we lost a pretty big amount of power. I forget the number but 45-50 HP is what I remember. We finally traced it to bushed rockers and the rockers were grabbing the shafts.
Just because you think it won't make it true. Horsepower is KING. To dispute this is stupid. C. Alston
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