Redline 10-40 in my 308. too thin, or ok?

Really. So I guess you must have pistons made of unobtanium. Pistons that are constant size and that never contract when at room temperture.

All the pistons I know of are cast iron or aluminum alloy based, and contracted to quite a dramatic undersize (in a 308 for example about .125")in the crown area when cold, and wobble like the dickens until they expand out to full bore size at operating temperture (600F). By keeping power and engine speed low until temps are up in the operating range, you put a great deal less stress on the engine.

I also question these oil analysis data. Once an engine is run in, regardless of what oil you run in it, or how abusive you are to it, the motor is not going to wear considerably for a long time. What good oils and good driving patterns do for us, is extend that "no wear" period out much further. So instead of having an engine thats getting tired at 50 or 60K miles, you have an engine that is still in its prime at 180K miles. So just because I see no significant material in the oil of a rather young engine, its not anything I am going to get excited about. I wouldnt expect to see any.

The point is, no one ever got a car engine or any other engine to reach high mileages or high hourly time by pounding on them cold. And to try and pass it off as okay to do it because your confident the oil is flowing is very ignorant IMHO. There is a hell of a lot more going on inside a cold engine than just how well the oil is flowing. Not only are the pistons shrunk in thier bores, the valve clearances are wider, if you have a timing chain the chain and sprockets are cold, the chain guides are cold, I just cant see any reason under the sun to floor a cold engine. None.

 

So true, Artvonne.

And then we have the equally cold transmission to consider. Same thing.

 

I've got to go with you on that one! Aluminum blocks and heads grow in ways that are difficlt to predict and I want them all grown up before the coals are thrown at them. That said it is a good feeling knowing the oil gets up top real quickly with the thin synthetics regardless of the supplier.

Dave

 

Aluminum has one of the highest coefficients of thermal expansion of any metal. That means it expands more per degree than other metals do. Furthermore, you can crack your oil cooler by revving a cold engine or crush the internals of your oil filter by high rpms in a cold engine. High rpms in a cold engine is asking for trouble.

 

water temp- 165-170 when car running; in traffic, easily goes up to 195 (and the aux fan kicks in)- never had overheating problems.
oil temp - 175, never went beyond the 210 mark
oil pressure- almost always just under 85

All numbers observed with past and present oil. In a nutshell, there isn't much difference, but I still scratch my head why they don't stick to one kind of oil.

Ron

 

Carreaper, have you thought about buying ZDDP and adding it to you oil? I purchase it from Eastwood and add it to all of my 1986 and older cars. Anyone else doing that?

 

Lawrence, you are closer to the truth. But a delightful pain.

It is more like 1 bar = 14.503773801 pounds/square inch

Nothing like accuracy huh?

Scuba diving in Bars and Meters is SO much easier ........ when working DECO tables (and when NOT) .....................

What do you do?