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Just a random question but im a bracket racer and i have a nothing special engine.My engine hot holds between 12-15lb ideling and 25-30lb going down track.Is that enough i mean the motor runs great all i did was switch from penzoil 10w-30 to Royal purple 10w-30.Anyone have any thoughts it still runs great and it actually speeded up .04.Thanks
 

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^^x-2^^
 

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It may live just fine like that, but.... it's risky. I'd want more pressure, and furthermore If it were mine I'd want to know why it's so low....
 

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I like IceCream
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Idles with 12-15lbs here.............48-50 down track to 8300rpm. Seems fine.
 

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I'm at about 50-75 psi at idle, depending on temp. Usually right at about 50 hot. Down track at 7500 rpm, just a tic under 85.
 

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pig hunter
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like chris said above... fwiw i set all my bbc up to have 60-65psi spinning up to 8000rpms.. using 10-30 oil..
 

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If its under 25PSI @ 1250RPM (idle) hot I worry. If this is just a bracket engine I would run 20W-50 conventional oil and save the money over the Synthetic.
 

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Butch
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I have never been over 50-55psi in the lights. Nate went 55psi in the lights and 20psi hot at idle, a few people were taking bets on when a bearing would go. Bearings look like new when they were inspected at 350 runs

If you have much more pressure than this, your getting the pressure from most likely a restriction or creating the pressure using a high volume pump that is not needed
 

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Butch
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If its under 25PSI @ 1250RPM (idle) hot I worry. If this is just a bracket engine I would run 20W-50 conventional oil and save the money over the Synthetic.
Why? Your getting more flow @ idle with lower pressure, as long as you know all your clearances are DEAD ON
 

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Why? Your getting more flow @ idle with lower pressure, as long as you know all your clearances are DEAD ON
Try telling this to a customer that has no idea what's in an engine but wants to have fun every weekend. More is better at idle to me. I want as much oil splash going on parts as possible for a long happy life.
 

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I run a Titan pump, wouldn't run any other. I'll take my high volume/high pressure over the lower stuff any day. Long, heavy rods, long stroke, somewhat high rpms, that's alot of weight moving around that needs an oil cushion. I know I won't be starving for oil.
 

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Butch
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I run a Titan pump, wouldn't run any other. I'll take my high volume/high pressure over the lower stuff any day. Long, heavy rods, long stroke, somewhat high rpms, that's alot of weight moving around that needs an oil cushion. I know I won't be starving for oil.
What about restriction? You can only push X Volume through X Restriction. If the restriction stays the same, which is everything in the engine, and you go to a given pump and have more oil pressure, that is due to a restriction OR the pump creating a restriction trying to push more oil through X Restriction that didn't get larger with more volume, thus more pressure

Take an engine that runs at 70psi, take one that runs at 20psi hot/50psi in the lights, the second one will have less wear, as its FLOWING the oil, not allowing it to be forced through a restriction that pushes the pressure up, making it flow less volume

Another way of looking at it, a Holley Black Pump flows 140gph at 4psi outlet pressure, but at 9psi, it flows 90gph
 

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What about restriction? You can only push X Volume through X Restriction. If the restriction stays the same, which is everything in the engine, and you go to a given pump and have more oil pressure, that is due to a restriction OR the pump creating a restriction trying to push more oil through X Restriction that didn't get larger with more volume, thus more pressure

Take an engine that runs at 70psi, take one that runs at 20psi hot/50psi in the lights, the second one will have less wear, as its FLOWING the oil, not allowing it to be forced through a restriction that pushes the pressure up, making it flow less volume

Another way of looking at it, a Holley Black Pump flows 140gph at 4psi outlet pressure, but at 9psi, it flows 90gph
Your kidding right? :rolleyes:
 

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I personally run a double gererator Titan pump, I had Bob build it for me and it is far overkill, but, I also had him get the pressure as low as he could get it, in my case it is 50 @ idle and 60 @ WOT. I have never had a issue with a pump or pressure for that matter, only clearance. Now it is possible for you to have too much volume and pressure for that matter. Too much volume could cause problems, but someone with more technical savy could chime in and further that statement.....
 

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An engine does not need a lot of oil pressure to survive, especially at high RPM. As long as there is enough pressure to circulate the oil, especially to the valve train, the engine will be OK. The most critical element in the oil system is maintaining a "wedge" of oil between bearing shells and crankshaft and camshaft journals. This wedge will be maintained as long as sufficient volume oil is getting to the crank and cam and is not influenced by higher pressures. For race-only applications I like to see around 20 lbs at idle and no more that 50 to 60 lbs at the top end (8000+ RPM). Any more pressure than this just adds to the internal friction related to oil pump drag.
 

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Just a random question but im a bracket racer and i have a nothing special engine.My engine hot holds between 12-15lb ideling and 25-30lb going down track.Is that enough i mean the motor runs great all i did was switch from penzoil 10w-30 to Royal purple 10w-30.Anyone have any thoughts it still runs great and it actually speeded up .04.Thanks

If it's a nothing special engine with a stock oiling system with that oil pressure, I would find the problem. JMO.
 

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I like enough pressure to wash the hot oil from the bearing surfaces and replace it with cooler oil. Oil film strength is what withstands the high dynamic loads. It's a timing thing.
 

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Butch
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Your kidding right? :rolleyes:
About what?

I have never had an engine over 60psi, and NEVER SHOW WEAR. People have took my bearings that look NEW out of engines and run them in their engines

Remember BRACKET ENGINES, NOT MILLION DOLLAR R&D AND CUP ENGINES WITH DRY SUMP OILING
 
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