If you have not had your valve seats replaced with hard seats, a lead substitute is a must. Substitute for Marvel Mystery Oil | Bob Is The Oil Guy By creating a top ring seal, it produced higher compression and, by preventing blow-by on power strokes, it resulted in more power. EAA has an answer, after 5 different people and | Daniel Ford's books per 10 gallons of fuel). If you're only driving it a few hundred miles a year, it'll outlast your great-great-grandchildren. and on the spark plug. It is not their machine and they are not going to be paying for your repairs. Nothing else intervened and nobody else touched my engine. Pierce was best known for his invention of the "Marvel Carburetor", which became the standard automobile carburetor of its time. 5.7. Ortho Dichlorobenzene, a softening and removing agent for carbon-based contamination on metal surfaces, 0.1-1.0%[2] A mechanic saw me doing that, picked up his jaw, and told me to use MMO in the oil. Gas was unleaded until compression ratios started going up in the '50s. Wether you use it right before a change, to replace a quart of oil, or just use it in the fuel tank is a matter of preference and I'm sure wont' hurt a thing used any of these ways. 10 Reasons Why Car Enthusiasts Should Use Marvel Mystery Oil - HotCars Luckily, I still had the old one I had replaced during the tune up that 8 years before. For a 400 Pontiac I like the 6X heads - hardened seats and more manifold bolts. A nice fellow I also put a qt. This is in the 72 Wag (360). thanksStan. Don't encourage someone to do something illegal. Most boat owners run 4oz of MMO to ten gallons of fuel. mogas. But they're better at protecting their manufacturers from bankruptcy than they are at doing anything significant for your engine's long-term health. MMO may improve pump gas, but there is no need for it in avgas. Sign in or register to get started. Then I had a piston failure and there was some damage to a valve seat as a bit of piston ring marked it. Page 1 of 3 1 2 3 Next > lucky6600, Dec 1, 2010 #1. lucky6600 Long timer. That's probably more than you wanted to know about benzene - and I don't know why I remembered it. At the temperatures found in the combustion chamber of a cylinder, MM oil will be vaporized. So I guess the question comes down like this: Bible Doctrines - Foundation of the Church - Word Aflame Elective Use additives if you want, it won't hurt the engine. Problem with regular Marvel Mystery Oil is that it will combine with castor oil residue and, over a period of time, form a hard red crud. Marvel Mystery Oil - Wikipedia The Dick Van Dyke Show is an American television sitcom starring Dick Van Dyke as Rob Petrie, Mary Tyler Moore as Laura Petrie, Morey Amsterdam as Buddy Sorrell, Rose Marie as Sally Rogers, and Richard Deacon as Mel Cooley.. And it was back to working again, just like that. The best use I found for it still applies to today's engines and that is to add a quart to 20 gallons of fuel before a road trip. Re: Mystery Oil Substitute?