Mercruiser 420 Oils - Zinc Additive?
 

Hi,

In the next couple weeks I'll finally be performing the spring maintenance on my new boat I bought in December. Its a 1989 Fountain Lightning 33 swim. Has twin Mercruiser 420's (454 CI) with TRS drives. I cant wait to get it out. The previous owner had a bad lobe on one of the cams, so he had that motor converted to have a roller cam with roller lifters (stock rocker arms).

The other engine still has the flat tappet cam. I was told that I should be using a zinc additive to reduce wear in these older flat tappet engines. Anyone have any experience with this? I have been researching it and found that most oils no longer have zinc in them. I did find a few that do, and am leaning towards Kendall 20W-50 GT1 oil with zinc in it already. I also was told Rotella oil works well. Should I be adding additional zinc? Which one do you guys use? I heard Lucas makes it?

Is the oil capacity 6 quarts?

Also it has BorgWarner Velvet drive transmissions. (I actually work at BorgWarner, lol) Do I use regular ATF? Which brands work well? What about capacity?

I have a good understanding on how to change the drive gear oil. Pretty much identical to an Alpha 1 drive.

That should be it for now. Just gotta change engine oil, transmission oil, drive oil, wash and wax, and I should be good!

I'm sure ill have plenty more posts, since this is my first season with a performance boat.

Anyone boat on Oneida lake near Syracuse NY? I'm new to the area and looking for boating people.

Thanks,

Matt

TYPE F in the transmissions.

As for the oil, yes you want a oil with a good amount of zddp. Heres a good article explaining things about oil

http://www.enginebuildermag.com/Arti..._slippery.aspx

I run the Valvoline VR1 20-50 racing in my flat tappet engine. Has a good amount of zinc in it. As for your drives just FYI they hold 3 quarts in the drive and one in the reservoir built on the transom plate.

B-W trans capacity is 2 quarts.

Here you go. No more cam worries from lack of zinc.

http://www.spectro-oils.com/motor-guard/

Ken