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How much oil pressure? #2734557
01/19/20 05:10 PM
01/19/20 05:10 PM
Joined: Nov 2015
Posts: 362
Missouri
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jwb123 Offline OP
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Missouri
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?

Re: How much oil pressure? [Re: jwb123] #2734561
01/19/20 05:20 PM
01/19/20 05:20 PM
Joined: Jan 2003
Posts: 26,707
Oregon
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AndyF Offline
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Oregon
Try it and see what you think. I would not lower the pressure with the bypass spring since you are just recirculating the oil when you do that. If the high volume pump is producing more volume than you need then put a standard volume pump on there and see how it does. My guess is that a standard volume pump with the high pressure spring would be perfect for your engine. That is the combination that I've used on similar engines in the past.

Re: How much oil pressure? [Re: jwb123] #2734563
01/19/20 05:21 PM
01/19/20 05:21 PM
Joined: Apr 2003
Posts: 2,702
Tulsa, Oklahoma
340Cuda Offline
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340Cuda  Offline
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Tulsa, Oklahoma
While I have no experience with a aluminum block. I would wait until you have warm engine numbers before I made any changes.

Then first the first change I would make is to go to 10w30 race oil instead of the 50 weight.

Good luck with it!

Re: How much oil pressure? [Re: jwb123] #2734579
01/19/20 06:03 PM
01/19/20 06:03 PM
Joined: Mar 2006
Posts: 2,553
Mt. Eden Ky.
Hemi Allstate Offline
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Mt. Eden Ky.
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.
twocents

Mark


http://marsh-racing.com/Mark%20Mahorney-Allstate.htm
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
Re: How much oil pressure? [Re: Hemi Allstate] #2734598
01/19/20 06:37 PM
01/19/20 06:37 PM
Joined: Jan 2003
Posts: 12,812
So. Burlington, Vt.
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fast68plymouth Offline
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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
Re: How much oil pressure? [Re: fast68plymouth] #2734615
01/19/20 07:21 PM
01/19/20 07:21 PM
Joined: Dec 2012
Posts: 1,381
Wind Gap,Pa.
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Sammy Offline
pro stock
Sammy  Offline
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Wind Gap,Pa.
Start the car and get the engine warmed up to operating temperature.
Water Temperature to 140 degrees and see where your oil pressure is at.

Re: How much oil pressure? [Re: jwb123] #2734701
01/20/20 12:05 AM
01/20/20 12:05 AM
Joined: Aug 2003
Posts: 34,491
Bend,OR USA
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Cab_Burge Offline
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Bend,OR USA
I would much rather see .0022+ on the rod bearings keeping with the .0010 per one inch of crankshaft journal diameter rule in effect up
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 up
I don't like 3/4 time oil pressure to the rods either tsk
I like and use the Federal Mogul, Seal Power # 4095M narrow full groove HD truck main bearings on RB and 426 hemi motors up scope


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: How much oil pressure? [Re: Cab_Burge] #2734766
01/20/20 08:26 AM
01/20/20 08:26 AM
Joined: Mar 2006
Posts: 7,880
MI, usa
dvw Offline
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MI, usa
Currently running a little more rod bearing clearance, .0023-.0024" with steel rods. 65-70 psi hot with 5w30. In the past with aluminum rods at .003" it ran 60-65 psi also with 5w30. 7100-7200 peak engine speed. Single line Melling pump gears with an Indy pump cover. Even with the adjustable pump screw I had to cut 1 1/2 coils off the pressure relief spring to get the pressure down. It has over 630 passes. In that time it's had 2 sets of rod bearings. They always come out looking like new.
Doug

Re: How much oil pressure? [Re: dvw] #2734793
01/20/20 09:58 AM
01/20/20 09:58 AM
Joined: Jul 2008
Posts: 20,598
...in Florida on STAYcation !
Doc Fiberglass Offline
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Isn’t that “rule” ..10 lbs per 1000 ... maybe even a tad less - with the newer quality syn oils ?

That smilie guy is good .. but he’s on the border of 5 per ! tsk grin

Re: How much oil pressure? [Re: Cab_Burge] #2735003
01/20/20 05:25 PM
01/20/20 05:25 PM
Joined: Nov 2015
Posts: 362
Missouri
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jwb123 Offline OP
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jwb123  Offline OP
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Joined: Nov 2015
Posts: 362
Missouri
Originally Posted by Cab_Burge
I would much rather see .0022+ on the rod bearings keeping with the .0010 per one inch of crankshaft journal diameter rule in effect up
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 up
I don't like 3/4 time oil pressure to the rods either tsk
I like and use the Federal Mogul, Seal Power # 4095M narrow full groove HD truck main bearings on RB and 426 hemi motors up scope


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.

Re: How much oil pressure? [Re: jwb123] #2735037
01/20/20 07:22 PM
01/20/20 07:22 PM
Joined: Aug 2003
Posts: 34,491
Bend,OR USA
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Cab_Burge Offline
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Bend,OR USA
I only use full groove main bearings on all Mopar V8 now, not half or 3/4 grooves tsk
The Chrysler 331 up to the 392 C.I. hemi motors used full groove stock on those large barge motors, that convince me to use them all the time up


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: How much oil pressure? [Re: Doc Fiberglass] #2735078
01/20/20 09:55 PM
01/20/20 09:55 PM
Joined: Jul 2004
Posts: 19,099
State of confusion
Thumperdart Offline
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State of confusion
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.....
Re: How much oil pressure? [Re: Thumperdart] #2735081
01/20/20 10:13 PM
01/20/20 10:13 PM
Joined: Sep 2014
Posts: 2,942
Washington
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madscientist Offline
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Washington
Originally Posted by Thumperdart
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
Re: How much oil pressure? [Re: Thumperdart] #2735109
01/20/20 11:42 PM
01/20/20 11:42 PM
Joined: Aug 2003
Posts: 34,491
Bend,OR USA
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Cab_Burge Offline
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Bend,OR USA
The 10 lbs. per 1000 RPM applies to Mopar V8 only,IMO,mainly BB with super loose lifter to lifter bore clearances up
A all out drag race motor with a dry sump oiling system is in another world from us ,Dom whiney


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: How much oil pressure? [Re: Cab_Burge] #2735119
01/21/20 12:08 AM
01/21/20 12:08 AM
Joined: Aug 2014
Posts: 559
Ohio
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lockjaw-express Offline
mopar
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Posts: 559
Ohio
On my 440 with Crane Ductile Iron Rockers. my oil pressure was 50 PSI cold, and 15 PSI Hot at Idle...20/50 VR1 oil.

After buying a new set of New Comp Steel & Bushed roller rockers and shafts, I went from 80 PSI cold to 25 PSI hot at idle.

Almost all of my loss was due to loose fitting rockers.

Just another are to check.

Mark

Re: How much oil pressure? [Re: Cab_Burge] #2735141
01/21/20 01:12 AM
01/21/20 01:12 AM
Joined: Jul 2004
Posts: 19,099
State of confusion
Thumperdart Offline
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State of confusion
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.....
Re: How much oil pressure? [Re: Thumperdart] #2735151
01/21/20 02:47 AM
01/21/20 02:47 AM
Joined: Sep 2014
Posts: 2,942
Washington
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madscientist Offline
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Washington
Originally Posted by Thumperdart
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
Re: How much oil pressure? [Re: madscientist] #2735201
01/21/20 09:58 AM
01/21/20 09:58 AM
Joined: Jan 2005
Posts: 171
Sterling Heights, MI
John_T_Brown Offline
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John_T_Brown  Offline
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Sterling Heights, MI
I look at oil pressure from a different perspective... as long as the engine has 15 to 20 psi after the trip down the quarter mile I don't care what the max pressure is. I just look at the data after the run to see if the pressure matched the rpm going down the track to make sure there was no fall off. grin


If it ain't broke fix it anyway!

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