Originally Posted By: stangyellow
Originally Posted By: OVERK1LL
5w40 should be fine. What's it making for power?
With the stock 8lb pulley setup it put down 448rwhp and 426rwtq a few months after break-in. It has ported gt-40 heads, 42lb injectors, MSD distributor, 6AL box, Ford B cam, list goes on.... Its a 90lx notchback, original v8, automatic. Since swapped over to a "World Class" T5 thats still holding together with a Centerforce dual friction.
The engine builder suggested that 20w50 be used because of higher engine temps, and thats what he used on all his Mustang builds. I figuerd he knows more about it than I do, so i stayed with it. I'll look into 5w50 Pennzoil.....
*edit GT40X heads
Why a "B" cam? that's a pretty antique grind
Regardless, that's not too bad. Most of the guys I know run 40 and 50 weights. I personally use 40's in my 302's.
The oil temperature CAN be an issue if the oil is shared with the blower. Is that the case with yours? I know vortec offers both styles; shared and self-contained.
You should get yourself oil temp and oil pressure gauges. That will tell you what you need to know. I'm betting something like Delvac 1 5w40 will be MORE than enough for this application, particularly at that power level and will work a lot better at start-up temps than the 20w50.
Who did your tune? I'd be more concerned about block failure and detonation than oil choice, 302's don't seem to die lube-related deaths in my experience.
I've got two buddies with S-Trimmed H/C/I cars, one makes 534 to the tires, the other 525. Both have never had lube issues, 40 or 50's used, typically 5w40 or 5w50. I think Mobil 1 15w50 has been used as well.