[pvirg]

I have a question that I have received several answers to. Racing motor guys say dont worry about it as long as you have 10 lb of pressure per 1000 rpm. others say jank the motor. I have a wild built 351 w. when I start the car the pressure is around 35 lbs at idle. As the car warms up it drops between 10-15 lbs at idle. when the rpms go up so does the pressure. The motor runs like a striped ape with no noise. It only has maybe 1500 to 2000 miles on the motor. Should I pull the motor and replace the bearings in the bottom half? I would like to get threw this summers cruises and rebuild it next winter? Well guys and gals let me know what you think!
Paul

 

[Cruzer]

Might be the cam bearings.

 

[390fastback]

Every car I own does this, even my 5.0 and it only has 110,00 km (68,000 miles).

Someone please buy my Ski Doo!
68 fastback
80 5.0 hatch
91 5.0 coupe

 

[Guest]

I yanked the motor when the oil pressure went below the Min line on the gauge while motoring at freeway speeds. Instead of changing bearing, try changing the oil pump first to a high volume type. It may keep the engine alive until after summer.

Thanks,

Mike
'66 Springtrime Yellow Coupe
289, slightly warmed over
driven daily

 

[camachinist]

What are the rod and crank clearances?

Did you use an oil restrictor kit?

FWIW, my racing W has .0045" on the rods and .0035 on the mains, has a restrictor kit and uses a blueprinted Melling HV pump and 20W/50 Valvoline Racing Oil....

Cold idle psi is around 60; hot is around 30 @ 900 rpm....hot running pressure is around 65...

If you haven't tried a heavier oil, I'd do so...

Your pressure isn't dangerously low but, if you're putting racing loads on the bearings, it's what's keeping metal off of metal...to a certain extent, more is better...

Pat


http://www.jps.net/binay/webdocs/racecar_thm01.JPG