I'm intrigued by your test , Jon. If the multi-weight holds up it should start better in the cold and cool better in the heat. It seems to me that if you monitor the oil pressure you could notice if the oil molecules shear because I would think it would lose viscosity. Are you planning to do a viscosity test periodically?
Yes, I'm monitoring oil pressure and will be sending oil samples in for full scale testing including viscosity. I think it is important to independently verify what is happening to the oil and also to check the piston ring grooves. The ring groove ash buildup is one of the reported problems with standard multigrade oils in our engines. I'm confident the results will be positive or I would not have started this, however the evidence is all that countes.
Jon did I send you the oil analyses that I had?
Forest, indeed you did and that will be great for comparison. thanks much
Thanks for the video link, it expands on my thinking. It's interesting that the shop that overhauled the 6v92t in my 77 coach recommended using straight 30wt oil year around. They did a lot of work on oilfield 2-stroke engines and claimed to have never seen a problem with the lower viscosity oil. The pressure was a tad lower but that was all. This is getting exciting.
High shear strength and low ash are the primary issues when dealing with the two stroke Detroits. My '92 Newell has the original metal plate in the engine compartment showing Newell recommended Mobil One. I believe they put Mobile One in the new engines when they were delivered. I have always used Delo 100 40 weight as that is the recommendation of the old 2 stroke Detroit mechanics.
I applaud anyone willing to do some serious testing of theories.
My lube service got in a 55 gal drum of Mobil 40w ( it is the oil recommended by DD service center in El Paso) just for my coach. We usually do 3-4 changes a year. Running Shell Rotella 15w40 in Yanmar generator engine.
Interesting discussion so far but I will keep using Delo 100 40W as long as it is available.If it ain't broke...........................especially if it is working.
(05-25-2014, 10:52 AM)prairieschooner Wrote: [ -> ]Interesting discussion so far but I will keep using Delo 100 40W as long as it is available.If it ain't broke...........................especially if it is working.
Yup.....my theory, too.