To be honest Eric, I suspect that Capt. Head "sees" less sheen either because of the conditions present when he saw less sheen or he simply believes there is less sheen because other people said there is and he wants to believe that synthetic oil is "better" than conventional oil.
Nothing against him--- we all "see" or "hear" things we want to see or hear from time to time. Wash and wax your car and it "runs" better, right? At least for awhile.
I'm not going to say he didn't see what he thinks he saw. I wasn't there. But I do think that he saw what he thinks he saw for reasons other than what he believes the reason to be (figure THAT sentence out and you get a prize).
I do not believe there is any connection between the type of lube oil in ones engine, particularly an old, inefficient clunker like an FL120, and the unburned fuel it blows out when it's cold. Now if it was just me believing that, I would take it with a grain of salt. But it isn't just me.
I first became aware of the sheen when my wife called me in a panic when I was doing a job in Germany the first winter we had the boat to tell me that when she'd started it up and gone back to check the exhaust there was this big sheen of "oil" on the water behind the boat. Naturally this got me really worried as well and I spent quite awhile that night trying to figure out how lube oil could go out the exhaust of a perfectly running engine, particularly when there was no smoke at all (my wife confirmed that). It finally dawned on me that it probably wasn't oil, it was probably fuel.
When I got home I immediately called our diesel shop and friends in the engineering department at Alaska Diesel Electric (now Northern Lights/Lugger) as well as a few other people I'd come to know over the years in the diesel engine business. And when I described what we were seeing, I got the exact same response from every one of them. It's unburned fuel from poor combustion in a too-cool combustion chamber. Don't sweat it, it will go away when the chambers get up to temperature. And sure enough, that's exactly what happened and continues to happen today.
And it happens that way every time (when the conditions are such that we can see the sheen). Doesn't matter if it's the first start after an oil change or the last start before an oil change. New oil, dirty oil, same sheen, same amount of time before it dissipates.
So those are the guys I'm going to go with on this. What Capt. Head did or didn't see, or thinks he saw, is irrelevant to me because I'm REAL confident that I got the right explanation the first time around. And, as I said earlier, I don't see the compression ratio being changed by the kind of lube oil that happens to be in the engine. Certainly not enough to change the amount of fuel being burned in the cylinders.
I'm happy to entertain "different" ideas if I think there is some merit to them or they are worth entertaining. This is a case where unless someone really credible in the engine design and manufacturing industry tells me otherwise, the sheen reduction theory being talked about here is not anything I deem wasting any time with. And I'm certainly not going to entertain the idea of changing the type of lube oil I use to pursue some perceived benefit that all the evidence I've come up with to date says does not exist.
What other people chose to do is what other people chose to do, right?
