Suggestions/opinions/advice?

Service manager at our marina recommended a straight 40 weight oil since the 502 tend to burn a little oil. Anyone have any experience with this idea?

Thanks,
Russ

Mobil 1 vtwin 20w50 is excellent doesn't really break down. Or vr1 20w 50 or staight 50 if ur clearences are getting loose and oil pressure a tad low. Both are available at a good parts store.

I built a lab for a company that grades all the oils to the fed Stds. Way cool place if you like blowing **** up..(motors etc) When I asked what was the best oil.. He could'nt answer that.
Legal thing I guess.. But once I re-asked the question. What does he use. He said the only oil he will ever use is Valvolene 20-50 racing oil.. Let it be written let it be done

Mobil 1 15-50 cut my oil consumption in half on my 502mpi's.

My 502mpi used a half a quart of oil everytime I took it out. Switched to 40w Rotella and never added a drop all last season. Jeff Wurl

Good thread. I've always used Mercury 25w40 and mercruiser filters. 500hrs and runs great. Does use a bit of oil though. Always have.

But, was he referring to the off road only VR1 Racing OR the SM (lower ZDDP)rated VR1 Racing oil. Or could it be the Synthetic VR1 Racing oil?

Thanks for the responses!

My 502 was totally rebuilt less than 50 hours ago and i've only owned it since last sept. which means ive only been out with it 5 times so I haven't been able to get a steady read on its oil consumption habits.

These engines can sludge up quickly.

M-1 V-Twin won't break down under extreme heat and won't shear down either. You need both.

Amsoil 20W-50 V-Twin/Redline 20W-50 motorcycle oil/Royal Purple Motorcycle oil...are also very beefy and great choices.

M-1 15W-50 is now an SM oil with too little ZDDP for Offshore Engines.

Never use an SM rated oil.

Oil filter? Merc HP/Wix/Baldwin/K&N/NAPA Gold.

This is for any and all big blocks. Period.

Tried and true.

What is an SM oil?????