1973 25' Seacraft Seafari

[DonV]

Hummm....good point Sandy, I don't think BRP has their own refinery! Someone has to make it for them to their specs. See below link, lots of mumbo jumbo for XD-100 and Amsoil HP, for folks like Denny

http://www.amsoil.com/performancetests/g2968.pdf

[Bushwacker]

Fairly well controlled test they ran by using twins on the same boat, and very thorough evaluation they conducted! It's good to see it was based on ASTM standards! I used to do similar distress trending work on jet engine hot sections after endurance tests, but nobody had done that before, so there were no standards . . . we had to just make up our own as we went along! We got good results but it was harder to convince our USN and USAF customers that the tests were valid since both the tests and evaluation procedures were all new! They finally agreed with us, but it took awhile!

The reported distress differences are so small that they're probably due to minor within-tolerance differences between engines. Interesting that it did confirm that XD-100 burns so clean that a decarb process is not needed to prevent ring sticking! I tend to agree that it's probably the same oil, although E-TECs have been run for thousands of hours in commercial applications like Sea-TOW, so a longer test might have been more definitive. Don, do you know if Amsoil has their own refinery?

Building and operating a refinery is an enormous capital-intensive operation that's way beyond what the engine builders could afford, so their oils are simply made to their specifications by one of the major oil companies. Don't know if that logic also applies to Amsoil or not. Although the Amsoil stuff is probably close enough to safely use in an E-TEC that's off warranty, BRP has a good record of often covering parts costs of some failures well beyond the warranty period, so I think I'll keep using XD-100 since I really don't use that much anyway and it's cheap insurance as Don says. However the Amsoil stuff appears to work great, so using it in any oil-injected motor seems to be a good idea!

[DonV]

Now that we've really got this thread off on it's own tangent.....I don't think there's a refinery involved. From the Amsoil web site.


What's the difference between conventional and synthetic motor oils?

Answer: Motor oil, whether synthetic or petroleum-based, consists of molecular chains of hydrogen and carbon atoms, referred to as hydrocarbons. Petroleum crude oil is a thick, highly flammable dark-brown or greenish liquid with high energy density. Many contaminating elements exist in this complex mixture of hydrocarbons, including sulfur, nitrogen, oxygen and metal components such as nickel or vanadium. Petroleum crude oil is the raw material used for a wide variety of petrochemicals, including solvents, fertilizers, plastics and lubricants.

The oil refining process separates the various types of molecules in the oil by weight, resulting in a concentrated batch suitable for manufacturing products such as gasoline, LPG, kerosene or lubricant base oils. The chemical composition of conventional motor oil can vary substantially depending on the raw crude oil refining process.

While petroleum base oils are refined, synthetic base oils are manufactured and can achieve a higher performance level. Synthetic oil is chemically engineered for a certain molecular composition with a tailored and uniform structure. Such fine-tuned control over the final molecular composition of synthetic oils is the key to their superior performance properties. Designing molecular structures in a planned and orderly fashion results in molecules, and end-products, that are far more stable than their refined petroleum counterparts.

[Capt.Nate]

So, we took the boat out yesterday. Everything ran great, except the oil reserve pump which I knew was out, so had to manually add oil to motor reservoir. No biggie. After we got back I noticed a lot of water running from under the bracket. I pulled the plug on the bracket pontoon and it ran for about 10 minutes. Looking back at this picture I can tell the boat is sitting stern heavy. I tested it again by putting water into the pontoon through the maintenance hatch and found its slowly leaking between the bracket pontoon and the boat itself, not through the plug. I need to seal the pontoon properly and hopefully prevent it from taking in water, perhaps seal bracket bolts again? This was supposed to be done by the service in SC, but seems it wasn't done properly. Any suggestions on product? There is bottom paint around the bottom portion of the pontoon, the bracket is a Stainless.