oil psi?

[inkjunkie]

See oil psi threads pop up every now & then. Pretty much the standard response is 10 psi per 1k rpm. Years ago helped a neighbor with his drag car. Granted it was a SBC but....He did not buy into that 10 per 1k stuff. At full throttle under load he ad less than 10psi. Had a Hamburger pan. Had baffles in it to keep the oil under the pump. There was no pick up, he had an extension on the pump dropping it into the oil pan. Ran 3 quarts of oil. Block had that Glyptal paint http://www.eastwood.com/glyptal-red-brush-on-1-qt.html applied. When he was on the brakes at the top end he needed to kill the motor as what little oil there was in the motor was not in the sump.

He ran like this for years....even when he was spinning 10k+ with a .030 over 283 SBC and a stick shift.

Was he just lucky to get away with it?

 

[straightlinespeed]

I would be scared to run that low of pressure and also the 10 per 1 is low for my car. Of course Im running a new engine so that might make a difference. At 3K Im at about 65psi, idle Im at about 20psi. Been that way for over a thousand miles so far..

I would say he was very lucky IMO.

 

[TrailBeast]

Lucky or really knew what he was doing, one or the other.
I tend to think he knew what he was doing because I don't think you could get that lucky for that long.

Think about it.
There was at that point no drag on the engine from the oil pump, and none on the crank, so he really might have had a little one point trick there.

 

[inkjunkie]

Lucky or really knew what he was doing, one or the other.
I tend to think he knew what he was doing because I don't think you could get that lucky for that long.

Think about it.
There was at that point no drag on the engine from the oil pump, and none on the crank, so he really might have had a little one point trick there.

He had a few tricks that he done, just don't remember them. In the 5-6 years of me helping him never had a bearing failure.

Talked to his machinist about this at great length prior to him building me a motor for a dd. Was told that they had done some dyno testing, pretty much every motor they used during the testing made more power with the low pressure. Motor he built for me went over 400k miles before my Ex sold the truck it was in.

Once up to temperature the motor he built for me never even made 15 psi of oil pressure....on any one of the 5 or so different gauges I put on it...

 

[TrailBeast]

He had a few tricks that he done, just don't remember them. In the 5-6 years of me helping him never had a bearing failure.

Talked to his machinist about this at great length prior to him building me a motor for a dd. Was told that they had done some dyno testing, pretty much every motor they used during the testing made more power with the low pressure. Motor he built for me went over 400k miles before my Ex sold the truck it was in.

Once up to temperature the motor he built for me never even made 15 psi of oil pressure....on any one of the 5 or so different gauges I put on it...

Sometimes flow volume is more important than pressure.
Most people assume the higher the oil pressure the better, when actually the lack of cool oil available to circulate through the bearings is way worse for a motor than low pressure.
Also, loose motors are faster motors overall, so a good hi flow would be a good thing.

Actually planning it all down to the point it ran the sump dry as you were letting off would be an amazing little trick to pull off, but he apparently did it for years at some pretty hi RPM's.
Maybe he figured out 3 quarts at 10 grand was all it really needed so why allow the extra drag.

Na, he just got lucky.

 

[sireland67]

Here is what a professor said to me when I was in college in the mid 80's
"Run the lowest viscosity oil you can with out burning the engine up."
"It is free horse power"
He had a original AC Cobra and raced road courses I think it was SCCA back then.
Is office was covered in pictures with him holding trophies/checkered flag from racing that car.
Often drove it over 20 miles to campus on nice days.
His son still has the car, but he passed on.

 

[Mad Dart]

Yes it works all day long. He did it careful and knew exactly what he was doing.

You guys haven't heard of race teams actually draining ALL the oil out of an engine to win a race at the finals? It happens every day and the engines live. Guys that use LUCAS do it quite a bit to make the win.

 

[greymouser7]

The old timers that dabbled in circle track here in the south east told me that you didn't need 10 PSI per 1K rpm's. They operated as low as near half that-but they made sure and used a good oil. I am not on the Lucas/orAmsoil band wagon-but some of them swear buy it like Mad Dart does.

The things that they told me went directly against the safe mentality that my grandfather was trained-almost brainwashed into believing as he was the head maintenance officer of a Strategic Bomber Command (Pre B-36 Peacekeepers-thru late 60's) at Kelly Air Force Base (piston engines at first w/ lots o pistons).

My beloved grand father wanted me to run 20W-50 in my 4 cylinder subaru loyale (with cheese). It killed the very little performance that motor could squeeze out. My rings were fine and i had to figure out on my own (thought process & asking guys like you guys and rustyratrob) that it was totally un-necessary, kinda like running premium when you don't have any detonation with regular gas.

These guys telling me that I didn't need 10psi per 1K rpm also recommended against a high volume oil pump in my small block builds. Others in the Mopar community have shared the same sentiments.

What makes you bring this up Doug?