Oil recomendation

[a0k]

Was wondering what oil weight and type oil for my road race 441 ci GM LS series engine you would use? Wet sump with oil cooler, Steel crank shaft with Hp clevite bearings, Steel h beam rods, Rod clearance at .022, mains at .025, high volume oil pump, pressure is at 80 psi now with 0w40 at max rpm 6700. oil temps at 250 max Would mobil1 0w40 be sufficient or go to the mobil1 15w50? Or what else you would recommend? I am looking for longevity not for every ounce of HP.

 

[Bottom_Feeder]

Your engine builder will be able to answer that question a lot better than anyone here can.

 

[19jacobob93]

The 15w50 would definitely be the better more robust option in my opinion.
I'm going to try a 15w50 next oil change instead of my usual 10w30 to minimize wear and hopefully quieten things down a little!

 

[CT8]

I think we left out some zeros in the clearanced .0022? .0025? It seems the pressure you are getting with the oil pump and the 0w-40 is good try the 15w-50 and see what the oil pressure is. 250 f isn't very hot for what the engine is,if the temps are when you track it.I'll bet the car gets up and goes.

 

[19jacobob93]

Originally Posted By: CT8
I think we left out some zeros in the clearanced .0022? .0025?

Knock knock
Who's there?
Excessive bearing clearance.

 

[hansj3]

http://www.hotrod.com/how-to/engine/1310-engine-oil-temperature/

This might be helpful

tl;Dr 250 is fine. There might be a temp increase with heavier oil.

What's your hot idle, what does your oil pump bypass at?

 

[A_Harman]

Your engine is running 80psi oil pressure at 6700 rpm and 250F? That's probably too much oil pressure. I wouldn't be surprised if it's costing you 10HP. Do you have datalogging on the car? Is the oil pressure stable in the turns?

I'm assuming those clearances you quoted are .0022" rods and .0025" main. Those are OK, maybe a little bit on the loose side of nominal.

At only 250F, the 0w40 should be OK.