[DeTomaso] Oil pressure drop
JDeRyke at aol.com
JDeRyke at aol.com
Wed Jul 9 14:29:52 EDT 2008
In a message dated 7/8/08 4:30:18 PM, gaino at earthlink.net writes:
> I added a quart and have not been back out. NO way I'm pumping 5 1/2 quarts
> up and lowering the pan level?
>
Unfortunately, it IS possible to pump the rocker covers full and leave only a
small amount in the pan. Racer Mike Cook stated decades ago that due to the
small drainback holes in the heads and average plugging of these drains, the
rockers can hold over a quart apiece without flooding the PCV. Then if you're
going around a corner, the pump pickup- which is 1/2-3/4 qt ABOVE the pan
bottom, uncovers and the bearings get a taste of fresh air. They won't stand much of
this before there's excess clearance and not enough bearing so the pressure
in that engine is then permanently low and will go lower. 15-20 psi hot at idle
and 60-70 psi hot at 4000 rpms is normal for a corrected gauge. 10W30
detergent oil from a major mfgr should be fine for this time of year; its what I use.
The head drains can be cleared while the engine is on the car; one drain on
each head is straight and will accept a rod or a drill thru it. The other has
two bends, is usually the one(s) plugged and can be cleared with a long 3/8"OD
extension spring twisted thru the hole like a roto-rooter. The crud if any
will fall into the pan, so its advisable to change the oil after doing this.
Second thought: pressures shown on a stock oil pressure gauge are invariably
wrong- usually, lower than whats really there. A mechanical gauge attached on
a tee with the stock sender will tell you how far off the stock gauge is and
you can act accordingly: a corrected gauge reading of 0-10 psi at idle or 30
psi at 2500 rpms means you should be lining up a replacement engine now. Good
luck- J Deryke
**************
Get the scoop on last night's hottest shows and the
live music scene in your area - Check out TourTracker.com!
(http://www.tourtracker.com?NCID=aolmus00050000000112)
More information about the DeTomaso
mailing list