Synthetic Oil Swap?

Bought a a 481 Chevy BB with about 20 dragstrip passes and Royal Purple has been used in the engine. Any problems to now switch to Mobile One Synthetic?

Thanks,
Mike

The engine won't know the difference. But your dipstick won't be as stylish!

Bob,

I was thankful that you might be the one to respond! It has now been recommended that if I switch I stay with a true Racing Synthetic (not Mobile1).

Any recommendations? I was thinking of switching because of the extreem cost of Royal Purple and the availablity. Also other brands (Mobile1) can be purchased by the gallon (nice with a 12 quart oil pan to fill). What's your opinion?

Thanks,
Mike
(Jr's dad!)

You just need to find out which weight the royal purple is. Which number oil was used? Eg. Racing 9, Racing 11, racing 51 etc. If you can tell me which one i can probably find the right Mobil1 equivalent.

Abe

Mike,

If Abe has the line on Mobil 1's nomenclatures that should be helpful.

As for the concepts in general, unless the engine is running "funny fuel" , the most important characteristic of the oil is it's viscosity. Assuming the previous owner is knowledgable of the clearances, and had adequate lubrication protection, that should be what you continue to duplicate. The additives play a smaller roll in racing situations as it's not common to leave the oil in service for comparatively long use. I would expect a significant amount of antiwear additive for camshaft protection, and some detergent/dispersant to keep contaminants ingested and internlly produced, in suspension for filtration purposes. If nitromethane or methanol are the fuels of choice, then the additive chemistry will need to be different than "conventional" oils as there are some chemical reaction considerations. Thus the different numbers Abe was referring to.

Also, the idea of i"it's not broke-dont fix it" applies here. If you are running a engine with high temp chararcterisitics, stick with the thicker fluids. After all, oil pump failure sucks.

OK, maybe I should restate my question. First, cost is not an issue, but I do look for the best bang for the dollar. My point is that Royal Purple will cost me $11 per quart vs. Mobile1 at around $4, obviously that is almost 3 times as much. Is the Royal Purple really that much better? I would rather spend the same amount and change the oil 2 more extra times between normal oil interval changes!

Also I will tell you that the engine builder recommended against Mobile1 suggesting I stay with a racing synthetic. I am not sure what the difference is between a racing synthetic and Mobile1 synthetic?

The engine is running gas (C114) so nothing real fancy or exotic. Normal engine tempretures, filled block with radiator cooling the the heads. Presently the Royal Purple used is Racing 41 (10-40W).

Thanks again,
Mike