oil in a GT-40?

[Joesboatn]

I have an 01 SAN with the GT-40. A lot of people recommend valvoline VR-1 40w oil but my local auto stores carry the VR-1 50w. Will this suffice? Im in So. Cal. my lake gets close if not 80 degrees and the outside weather gets 100 degress plus. Thanks

[bwana50]

RE: oil in a GT-40?

IMO, any 40W oil would be fine in the GT-40. Much ado is made about zinc additives (which VR-1 has), but that mainly applies to engines with "flat" lifters. The GT-40 has roller lifters, so no problem.

[bchesley]

RE: oil in a GT-40?

GT-40 is a flat tappet motor. No rollers in a Gt-40 so I needs the zinc. I looked at the inside of one just yesterday.

[bwana50]

RE: oil in a GT-40?

Interesting. I asked PCM and they said roller lifters. Perhaps they changed midway through the production?

[bchesley]

RE: oil in a GT-40?

Never changed. The GT-40 ended in 02 to be replaced with a roller motor. PCM guy must have been confused.