We install a bright red light high up on the dash in the driver's line
>> of sight that turns on anytime the oil pressure in the main oil galley
>> drops below 25 or 30 psi. The pressure switch should not be mounted
>> directly on the engine where heat and vibration can cause them to fail,
>> but should be on the firewall bulkhead where the flex hose joins the
>> solid metal pipe that goes to the oil pressure gauge.
>> We set the oil pressure as per the factory manual to 70 psi at 2000
>> rpm with the engine oil at least 160 degree F. With a good oil pump and
>> the clearances mentioned above, you should see 90 psi at 6,000 rpm with
>> oil up to 200 - 210 degrees with 20w/50 oil. If the oil temp gets to 230
>> it might drop to 80 psi but should never be any less it over 4,000 rpm.
>> With all of these mods, there are some corners on some tracks where we
>> have seen the low oil pressure light come on for a second or so. These
>> have always been high "g" left hand corners that come after hard braking
>> zones, ie turn 5 at Laguna Seca, turn 5 at Thunderhill Raceway where you
>> brake very hard from about 70 mph while going up a steep hill ,down to
>> about 25 mph, then turn left over a severe crest &then go steeply
>> downhill while accelerating and turning to the right. The light comes on
>> just at the as the car crests the hill. So there is something going on
>> in the pan when performing this maneuver with a left turn that does not
>> happen then you brake and then turn right! I have yet to understand
>> exactly what is going on but the condition certainly exists. With good
>> Penn Grade 1 race oil, I have left my foot in it while the red light has
>> been on for the second or so and no seen any signs of failure on the
>> bearings afterwards. There is still probably 20 psi of oil pressure in
>> the main galley and the high quality oil is still able to maintain film
>> strength. I have not used an acusump or any other form of supplemental
>> oil supply.
>> In four or five race weekends with lots of track time and engine RPM
>> from ,4,000 to 7,000 , the bearings should NO WEAR that you can measure.
>> The surface of the bearing turns darker in color than they were when new,
>> but we generally see NO surface "pulling" or damage to the bearing
>> surface.
>>
>> Greg Solow
>
The Engine Room
Morgan & Sports Car Specialists
Santa Cruz, Calif. 95060
831 429-1800
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