Substituting oils

I have two questions…

I have a gallon of heavy 4 cycle synthetic oil for small engines. my son says that it is an expensive oil used by guys who race 4 wheelers and is often changed after every race. my son left it and has no use for it anymore.

so…, one question is whether or not this would be okay to put in my 1975 ford 360 cu in motor". I m thinking that it is of higher quality than the standard motor oil and would be okay…, but I have never put synthetic in an old v8 before and I don t know if it is a good idea or not. my son isn t so sure that it is okay at all .

question two…

what oils could be interchanged in an emergency?

say there was a zombie apocalypse and I was two quarts low…, could I throw some type f transmission fluid, or some dextron/mercron, in with the oil?

could you run straight transmission fluid for oil?

remember this is an old ford 360. it is tough.

Question 1, probably. You say “heavy” but don’t say what grade it is. 5w50 maybe? I’ll bet it would be fine in the truck. 20w50 may be a bit too heavy if it gets snowy-cold where you live

That synthetic might act like Ex-Lax in the crankcase flushing accumulated crud into the oil very quickly. I switched to synthetic on a 96,000 Suburban I bought used. I have the change the first batch of synthetic at 1500 miles because it looked like tar and it used a quart. Took another batch changed at 3000 miles to look less tar-like and drop the oil use 1 quart in 3000 miles.

Question 2; No, just no. Don’t use ATF as engine oil. It is basically 5w oil designed to allow clutches to grab, not slip, and is not a good shell bearing (rods and mains) lubricant. It is fine on roller bearings but your truck engine doesn’t use roller bearings, so No!

"say there was a zombie apocalypse and I was two quarts low…, could I throw some type f transmission fluid, or some dextron/mercron, in with the oil? "
Yup. It wouldn’t be good for the engine, but you’d have enough problems without worrying about your engine.

"could you run straight transmission fluid for oil?"
Yup. Once. But then your engine will be ruined and you won’t be able to get away from the apocalypse zombies.

Skip your son’s special oil. Use only what your owner’s manual recommends.

Okay, now to get serious. Automatic transmission fluid is not oil, it’s a type of hydraulic fluid.

The most critical job your oil performs is to maintain a proper pressurized fluid barrier between the crankshaft and connecting rods and their respective sleeve bearings. It does this by being pumped through channels in the parts and forced out the spaces between the surfaces and their bearings. It must have sufficient resistance to flow (viscosity) to NOT flow too easily through the spaces and to withstand the compression (squeeze) placed on it by the lateral (sideways) forces transferred to the parts from the combustion of the fuel in the cylinders. Motor oil is designed with this ability. Automatic transmission fluid does not. This resistance to being squeezed is every bit as important as the slipperiness of the oil. Note that what I write applies to the camshafts too, but the crank will seize from lack of lubrication long before the camshafts do, so IMHO it’s moot.

Automatic transmission fluid is designed to quickly and readily move through small orifices in the hydraulic solenoids and to transfer forces… quickly. ATF would easily flow out of the spaces between the crank & rods and their sleeve bearings, allowing loss of pressure and destruction of the surfaces that oil keeps separated.

In summary, motor oil is designed to NOT flow too easily, ATF is designed to flow very easily.

The things they have in common? They both remove heat and they both lubricate. But each in its own way.

Transmission fluid is straight 10 weight oil with the proper detergents, anti-foaming agents, and friction modifiers for the steels and clutches.


I don’t know but where have you been? I noticed your lone comment of dissension over on that other site and have to say I completely agree with you. I thought the place was a little more diverse than it appears is anymore.

hey bing. I ve been arguing over at the Plan B forum. pretty wide range of debate over there. sometimes it s even pleasant…

I ve been piddling around on my truck and listening to cartalk on Saturdays and I missed you guys.

who else could I ask about oil substitution and zombie apocalypses in the same post ?

…and get answers!

Does this gallon of oil have a brand name, a viscosity rating, and an API rating??

Why not just hold onto the stuff and wait for that Zombie apocalypse …if it ever comes.

Then you can pour that stuff on the front stoop. When the Zombies slip and fall on the oil you can use the empty jug to beat the decayed flesh right off them buggers.
Sure beats banana’s!!!

I’ve heard of people adding a quart of Automatic tranny fluid to the engine oil and then driving like that for as day before an oil change. The high detergent additives in the tranny fluid is supposed to keep the engine cleaner.



the jug is labeled Thor Oil-racing lubricant-4cycle heavy-synthetic oil for small engine offroad racing

the label and my eyes have deteriorated to the point where I can t read the fine print…

ok, I had my better half read me the fine print. it says that it has additives and wetting agents to protect engine at high temp yada yada…

…will mix with alchohol but NOT with petroleum products…

so I guess I had better save it for the apocalypse or make a cocktail with it…

thanks guys

I think you’re making a wise decision. Except for the cocktail part… :smile:

Oils are only 75% base stock (the actual oil) . The rest is additives, often not found in racing oils. Regular oils have detergents, emulsifiers, corrosion inhibitors, anti=wear additives, etc, not found in racing oils.

I therefore not recommend that you use this stuff in your truck, even if the “weight” is right.

yeah, I think they run it in alcohol burners…