Borgie ok maybe a DIS on your part. Here is the link to the thread. you asked and I have a really good memory.

http://www.offshoreonly.com/forums/g...ngine-oil.html

You are correct, however a true marine motor oil will in some cases have more corrosion inhibitors. Main reason why its a marine rated oil. Diesel oils work great in marine apllications, just that a OEM or oil company for warranty reasons and legal ones as well, would likely never endorse the use of a diesel oil in a marine environment. Didn't mean to confuse you with that comment.

BUP- yeah you do have a good memory. So it was a 50% DIS lol! I didn't say it was a bad oil, but I did have maybe some Brand preference interjected there a bit EH! Thanks for the link!

Volvo Penta recommended Mobil 15w-50 on ther DPX 500 and DPX 600 motors.
Page 46 of the manual. Page 53 of the ,pdf file.
http://www.volvopenta.com/volvopenta...on_search.aspx

http://pie.volvopenta.com/ViewFileFr...099&lang=en-GB

SB - U R correct in the past as the DPX in Volvo stables have been long gone now. Really they did not sell that many to begin with. that motor was built by Innovation Marine in Florida for Volvo Penta, I have all the spec on the builds. Actually I have worked on a few in the past and one in California about 4 years ago.

Volvo gas side currently for the past 2 years now recommends 10w -40 for all their engines EXCEPT those DPX. They Volvo Penta sold less than 80 of the DPX 500 & 600 motors if I remember correctly. Too bad the engines were good. the DPX outdrive last time I tried to get a new one was I think 18 to 20 grand and they only had a couple in stock and refered me to Innovation.

Reason for bringing those up is the Pantloads (yes, that's a scientic and quantifiable #) of 500-600hp BBC's with simlar parts on this board.

I know manufacturers can't deny warranty based on brand (Magnuson-Moss), but can manufacturers deny warranty claims if the oil used meets their spec? For instance, a non-OEM straight 30 or 40 that is not marked marine, but is SJ spec'd in a Mercury black motor? (They recommend straight weights as alternatives to their overpriced, relabeled "marine" oil in several manuals). I know I have to run Dexos stuff in late model GMs for warranty, does the oil going into Merc/Volvo have to say "marine" on the bottle during the warranty period?

(Friend bought a new 3.0 Mercruiser, and an extended warranty, I helped winterize it and put my leftover Rotella in when we changed the oil, now I'm a little concerned. In my defense, I advised against it because of the catylyst, but it was Sunday, he was unprepared, marinas were closed, and you don't put babies to bed with dirty diapers, or boats with dirty oil.)

I just wonder way back in the day when we didnt have 10,000 different oils. Synthetic, non-synthetic corrosion resistant, marine, diesel, motorcycle ect ect. You get my point. Why everything didnt blow up? I mean as complicated as this thread is might just scare someone to the point that they might not wanna put oil in the crankcase. The last time I checked not a whole awful lot has changed with the motors we are talking about putting oil in. Only real big difference I see today is better cylinder heads but its still basically the same thing. I think all this fuss back and forth is a complete waiste of time. I've ran all different types of oils in different BBC's applications and have not one time in anything had a bearing issue. When I buy oil I tried to find a decent that I can get a good deal on. My boat runs wide open from the time it gets off the trailor till it gets back on the trailor and I'm not talking about piss farting around on small lakes big water running for miles and miles at a time. I've never had any oil related issues.

As far as Joe's ? About 40 vs 50wt. With Valvoline vr1 40wt temp in the pan was 250 lifters were noisy after WOT runs. 20w50 Bradd Penn 220 pan temp. Gained a little more than 10lbs idle and wide open with the 20w50 with no more lifter noise after WOT. That's 20-30 miles WOT. And the lifters recommend no more than 10w40. Ill stick with the 50wt.

You guys have me have me wondering a bit now. I religiously ran Valvoline VR1 straight 40 in my 420's with Moral lifters. I always had an issue with ticking lifters on that motor when I started it cold for about 5-10 minutes, then it would go away never to be heard for the rest of the day. Bob attributed it to condensation from my cold water lake, but I wonder if the oil wasn't flowing well enough when cold.

Had the same problem you have. Was running straight 40 wt. Bob told me that the oil was too thick when cold. I went to20w-50 and much better. I will most likely go to 10w-40 and see how that does.