Called the Shell/Rotella hot line
 

Rotella T 15W-40 is not working for me. It is puking out the breather
hose. I called the Shell hot line and was told the 15W-40 is a bit thin
for my 502 and that I should use Pennzoil straight 40W. I asked about
Rotella 40W and was told not to use it in a gasoline engine. Period.
I bought the Pennzoil 40W oil and will do some testing soon.
I will post my results. In the mean time I installed a valve cover K&N
breather filter. It seems to help.

I am using straight 40 Rotella. I didn't even know it was a truck oil and it does carry automotive certification but there seems to be enough doubt that I may get it out of there before running really hard. It was recommended by a local high performance shop to use in a performance gasoline engine. I don't think they know what they are talking about!

If you want to run a conventional oil, it is hard to beat Kendall 20W50. Merc even recommends it in their 600's. Plenty of ZDDP. Autozone carries it. If you don't see 20W50 on their shelves, they will get it in within a day or two.

My friends that are cummins freaks will not even run rotella in their trucks. I run the kendall in my 496 mag ho's. I was told that kendalls original formula is still produced by another company and is the bomb. I have been using mobil 15w-50 synthetic in my turbo cars forever. I swear by it in that application.

I know. This is what the hot line guy told me. I did not want to argue
all points with him but I read out loud my owner's manual verbiage
which states "API classification of SH, CF/CF-2". I told him his oil
Rotella 40W carries this classification. He reiterated Pennzoil 40W not
Rotella 40W. He said the Rotella should not be used with a higher
revving gasoline engine. I guess the "frothing/foaming" issue is real.
That is what I am getting. Froth out the breather hose. When I run
3000 RPM's or lower - NO trouble. If I get oil temps over 180
degrees then run full throttle - NO trouble. I get the froth when the
oil is warm, under 135 degrees, and I run WFO.

I also asked about Castrol 40W instead of his Pennzoil 40W, since
Shell owns Pennzoil I did not want him hawking his brand only, and
he said it was a good choice also. Pennzoil and Castrol can be found
at the major auto parts stores on sale now. I went to Advance Auto.
Ask about the "oil change specials".

I love Penzoil 20 50 . I love rotella too....for my Loader that is. I have use the rot in the boat but only to clean out the engine after a water prob. Someone may correct me but my experience has been that most oils for autos now is void of zinc which can still be found in rotella.
Quite a few years ago I was having problems wiping out lifters and cams in my 500's we( me and my engine guy) tried using cam break in lube for the zinc . No more problems.
I'm curious, anyone else have a similer outcome?

i dont hink 40 is the right weight for merc marine engines,i use brad penn 20-50,it has the zink&phos that really helps lubrication.in my opinion,40 is a little thick when it is cold,just my opinion.

Someone please correct me if I am wrong, but I am pretty sure that the original Kendall formula is being produced by Brad Penn.

My engine builder swears by it and we used the Brad Penn break in oil for the first 10 hours and then Brad Penn straight 50W. He told me if I decide to run my boat late into the season I can switch to the Brad Penn 20W-50, but I doubt I will run my boat when the temps get below about 60.

Plenty of zinc in the green oil.

That's what I thought too. My first boat dealer told me SAE 30W at
all times. When I did my first oil change I of course read the owner's
manual which stated air temperature:
under 32 degrees F SAE 20W
33 degrees F - 50 degrees F SAE 30W
over 50 degrees F SAE 40W

The dealer said he did not care what the manual said. Run SAE 30W.
This was in a Merc 7.4L engine. No trouble ever. Now with the 502
I think I will try the SAE 40W. Maybe in the Spring I will run the
SAE 30W. :eek:

I've heard enough to get the Rotella out of there. I'm not going to change the filter until I winterize though. I guess one qt. of Rotella mixed with better oil won't hurt for awhile. As far as other oils, I have my favorites but that topic has been beaten to death so that's all I'll say! No more Rotella though. Idiot at the store should have known it was a truck oil but seemed to think that it was for performance gas engines.:angry-smiley-038: