Rage

I guess this is a little less than the ringing endorsement that I was looking for. Given that the engine oil change history for my stock 496 was 1.) repalced the orginal factory oil and filter at about 10 hours with engine hot (boat delivered in Fall), 2.) replaced the oil and filter again at 90 hours after relatively mild usage with hot engine I have trouble imagining a huge reservoir of engine wear debris left over from an engine total of 90 hours of use with Merc 25W40 still waiting to contaminate future oil changes of Mobil 1 20W50. But maybe I am truely that ignorant.

Is there any true A vs B comparison engine wear debris test data that compares Mobil 1 20W50 versus Merc 25W40 engine oil?

Hydrocruiser

[QUOTE=Rage]I guess this is a little less than the ringing endorsement that I was looking for. Given that the engine oil change history for my stock 496 was 1.) replaced the original factory oil and filter at about 10 hours with engine hot (boat delivered in Fall), 2.) replaced the oil and filter again at 90 hours after relatively mild usage with hot engine I have trouble imagining a huge reservoir of engine wear debris left over from an engine total of 90 hours of use with Merc 25W40 still waiting to contaminate future oil changes of Mobil 1 20W50. But maybe I am truly that ignorant.

Is there any true A vs B comparison engine wear debris test data that compares Mobil 1 20W50 versus Merc 25W40 engine oil?[/QUOTE]

I understand what you are asking for and the reason I can not give you a definitive answer is because this is specific to your engine I believe.

Nobody has been able to help me despite several calls to better understand and help answer your questions better. You have a very good question and I hope we can find an answer.

I am being told you should repeat an oil sample to get additional data because one sample does not constitute a study. One needs several samples to see a trend.

Hope that helps.

Jamie Bowman

NEED YOUR HELP FAST!! it is 67 degrees outside and just put M1 V-twin in a 2003 chevy truck w/ the 496 motor. I am not an experienced valve guy, but it sounds like the valves are floating and rattling at start up, after it is warm and you give it gas, sounds like floating, after floating goes away, let off gas and sounds like floating again on idiling down. this happens with or without a load. AM i ABOUT TO DESTROY THE TOP END OR DAMAGE IT? SHOULD I DRAIN THAT OIL AND GO BACK TO M-1 EP 5W-30 AS PER MANUFACTURE?

Hydrocruiser

Going from 5w-30 to 20w-50 is a steep climb.

More than I would be comfortable doing.

Jamie Bowman

drained it moments later! can I mix M1 5W 30 EP w/ any of the 20W 50 V twin I drained? & if so what ratio in st pete area for winter & summer? in winter we are rarely below 40 degrees & can wait until it is 50 or above. summer high 95 low 80. earlier posts may have answer but appreciate new info for myself & others I have reading this thank you

Rage

[QUOTE=Hydrocruiser]Thank you for your conscientious effort and comment. Much appreciated.

I must say you are starting to make me a little nervious with your " this is specific to your engine I believe " comment. Would your expand further on this?

Re the suggestion to repeat an oil sample for additional data, when is that additional oil sample to be taken? Now? After another season? Other?

Finally the most important question, is there any possible secenario where the Mobil 1 20W50 V Twin oil could be the cause of actual increased engine wear in a 496 engine versus the Merc 25W40 oil for which the engine is designed?

Thanks

Hydrocruiser

Going from a 25W-40 to a 20W-50 is not a big climb.


Many race teams use 20W-50 synthetics in their 496/502 engines. It sets a prescient.

berns29scarab

dont mean to hijack your thread but quick question...have you ever used engine restore in a marine application ? have used it in a few high mileage cars with good results ?

Rage

Re the suggestion to repeat an oil sample for additional data, when is that additional oil sample to be taken? Now? After another season? Other?

minxguy

Rage, we are talking base oils here ...not finished lubes, which have the additions of various additives. A Group III base stock is a highly refined petroleum stock. The refiners just remove more of the impurities from the petroleum basestock. This extra refining brings the Group III base stock closer to synththetics in some ways, but not the way the base stock was created.

Yes it is very difficult how you define a synthetic, Mobile took Castrol to court and lost. The definition has seemed to morphed into more of a performance level than a quality level of base stock. A Group III "synthetic" can no way hold a candle to a Group IV synthetic from a performance venue. As I have stated both of these base stock types receive additives to make a "finished" lubricant. The whole is equal to the sum of its parts
A synthetic basestock is one that is created chemically, NOT one that is highly refined petroleum.

Ken