Roush 402R oil pressure & temp

[CHP2RA]

Thanks for the specs, DW and MAXX.

The previous owner used Mobile 1 10W-30 in this engine, which is still in it. From a cold start, the water temperature takes 7 to 10 minutes idling to reach 80 C (177F), so it doesn't seem that this radiator has a high-performance thermostat. The oil temperature lags the water temperature during warm-up, but after reaching operating temperature, the oil temperature stays 7 to 15C above water temperature. Driving around town, the water temperature stays in the 80 – 90C (177 - 194F) range, and oil temperature 92 – 97C (198 - 207F).

The oil pressure is 60 PSI at a cold start, and gradually moves down to 42 psi when fully warm. Driving around town, it stays around 47 psi.

On a spring day last week (May, 83F, sunny,) I drove about 15 minutes on the freeway, (72 mph, 2200 RPM, fifth gear) and then hit a Texas sized traffic jam, and spent 10 minutes in stop and go traffic. After a few minutes of S & G, I glanced at the oil temp, and saw 104C (219F). Yikes! The water temp was 95C (203F), so the radiator fan has not yet switched on. I threw the manual switch, (which the previous owner had labeled 'kenlowe') and the oil temperature dropped to 100C in a few minutes.

This roadster Superformance does not have an oil cooler, and I'm wondering if I might need one? In this part of Texas, we get many summerdays above 100F. A plexiglass cover for the oil radiator does seem a good idea. The previous (original) owner lived in cool Connecticut, and I'd hate to damage this sweet sounding motor with boiling oil.

Bonus question: In what country did the previous owner grow up?

[jhirasak]

CHP2RA,

Oil temperature above 100 C (212 F) and less than 110 C (230 F) when fully hot is preferable to sustained oil temps below 100 C to eliminate any moisture that might be acquired due to the combustion process. Also, modern synthetic oils are more resistant to viscosity deterioration and oxidation than conventional petroleum based oils.

I used to live in Texas and added an oil cooler after one summer when sustained ambient air temperatures exceeded 100F for several days. Under those conditions, my water temperature rose above 212 F and a noticeable drop in oil pressure was experienced in stop and go traffic. Now that I live in SoCal, I doubt that I will experience those conditions again.

John