what engine oil should I run in my new motor

[mxcobra]

its a gm goodwrench base 190hp mated up to mercruiser modded with volvo parts, and 4 brrl carb.... GM says 5sae30 mercruiser says 30sa i heard guys here using 20 40 or something why not use Honda 10 40 sj like I put in the smaller four stroke outboard and motorcycle engines?

 

[Bondo]

Ayuh,.... Is this motor a flat tappet motor, or roller tappets,..??

I run Shell Rotella T, 15W-40 in our entire fleet,...

 

[R055]

Question has been asked a million times. You can use any oil you want to basically. It's just a car block. I use Mobil one full synthetic 5w30 or 10w30 in my 2003 mercruiser 4.3.

 

[Rick Stephens]

OH NO - an oil thread!

 

[mxcobra]

Ayuh,.... Is this motor a flat tappet motor, or roller tappets,..??

I run Shell Rotella T, 15W-40 in our entire fleet,...

its not a roller motor so flats it is..

 

[TyeeMan]

OH NO - an oil thread!

Ha!! Too funny! You should see the oil threads on snowmobile websites, , they almost get violent. :yell:

By the way, I run Amsoil Synthetic Marine Oil and Amsoil filter.

Sorry, just had too.:joyous:

 

[jimmbo]

Ha!! Too funny! You should see the oil threads on snowmobile websites, , they almost get violent. :yell:

Some get that way here too

 

[HT32BSX115]

Did I smell an oil thread?

I am not letting on what I use!!

 

[Scott Danforth]

With a flat tappet cam, you need zinc. And for break in, you need lots of zinc. Bondo has you covered

 

[JASinIL2006]

No Title

Not an oil thread... aaaaaarrrrgggghhhh.....

 

[QBhoy]

As mentioned, it's a bit of a preference, but depending on use and climate, marine oil can have its advantages and would be recommended.
Main thing with your situation is that you remember and change the oil a few times in the next wee while, whilst you break her in

 

[Grub54891]

Use drain oil! Think about it, it already has some grit in it for wearing in the new parts faster. Cut's down the break in period at least 1/2........

 

[jimmbo]

You should consider a roller cam, that way you don't have to worry about the lack of EP additives. I know someone is going say that the oils marketed by Volvo and Mercury are just rebottled auto oils. Maybe, maybe not. They generally are top quality oils, and maybe they do have an additive package more suitable for the marine engine operating parameters. At least they know to market the viscosities their engines should use.

 

[Lou C]

We all have opinions but the best way to back that up is to do an oil analysis every so often. I've only done 2, one when I used Chevron Delo 400 straight 40 and the second was when I used Merc/Quicksilver 25/40. Both held up well, but the Merc oil did a bit better, stayed in grade better surprisingly.
I'd like to see a test of Rotella or Delo 15w/40 against the Merc/Quicksilver 25/40. While the oils speced for both gas and diesel like Rotella and Delo used to have more zinc than straight gas engine oils, I'm not sure that's actually true any longer.