Marvel Mystery Oil

Has anyone had any experience or opinions concerning this product. Adding this to the fuel sounds like a good idea,based on what the manufacturer says. I'm sure they are totally objective and unbiased, but I'd like some other opinions anyway.
Thanks

I have a really good mechanic friend, and over the years whenever he or I bought a used car, the first thing he did was to buy a bottle of MMO. He would take off the air cleaner pour some down the throat of the running engine, The rest would go into the gas tank. Every car! Under his care my big ford motors were the smoothest running engines around, and he was a dedicated Bow-Tie guy. We would put some into the oil on every change also.The 429 in my Mercury needed just a "bump" of the key to start. The first winter my GT6 sat (in a damp shed) the motor locked up. MMO in each cylinder, and a flywheel turning wrench (with a bar) he broke it free, all of the rings intact.

Arch 93 said:

Has anyone had any experience or opinions concerning this product. Adding this to the fuel sounds like a good idea,based on what the manufacturer says. I'm sure they are totally objective and unbiased, but I'd like some other opinions anyway.
Thanks

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This is probably the best stuff you can put in your car and also great for upper cylinder lubrication. I put in the carb dampers too. The name sounds funky but don't let that stop you.

I used to watch my Grandad use it on his old McCormick Farmall tractors back in the 60s ( which seemed like yest. btw). I've used it since to free rusted nuts, mechanisms etc. and to squirt in stuck or sitting cylinders, add to gas for top end lube while running, and use a cologne when in a pinch.

I use MMO in the tri-carb dampers in my '57 100-6 MM racer and I use it to lubricate the cylinder walls of all my Healeys when I put them up for the winter.
Good stuff.....lame name.

When I put MMO in the dampers, it disappeared in 6 weeks. (maybe that's the mystery) I did like the faster damper action on acceleration but went back the the stuff Moss sells. It stays put.

I put the Moss stuff in my dampers and it disappears in a day.

John Turney said:

I put the Moss stuff in my dampers and it disappears in a day.

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What is the Moss stuff? I have always been told to use Dextron.

Moss sells dash pot oil especially for that purpose. Cost a bit ($8.00 for 125ml) but seems to last. I think it is 20wt non detergent. MMO is thinner and suppose to allow the piston to move faster for faster acceleration. I found little (if any) improvement when I first started using it but when it disappeared I got erratic carbonation. Prior to the MMO I used regular motor oil 20/50wt. All kinds of theory about the use of that. I was told the detergent wasn't food on the brass parts of the damper and that multy grade would give different damping as the temperature increased. I found no real difference in any of the oils. I like the Moss stuff cause it comes in a handy, small dispenser that I can carry in the boot although I've yet to need topping up in two seasons.

Ive used transmission fluid and power steering fluid as well. for me,the tranny fluid worked better.
dougie, your engine bay is full of win!

For more years than I care to remember in my carb dampers I use a 50% MMO and 50% ATF mix. If the SU damper oil disappears you may need to replace the neoprene pin washer. Stromberg’s use neoprene “o” rings on the needle.

Thanks for your help. Time to order some MMO.

You can probably find MMO at your local Walmart super center. Ours also carries the blue container STP oil treatment that contains ZDDP.

tahoe healey said:

I like the Moss stuff cause it comes in a handy, small dispenser that I can carry in the boot although I've yet to need topping up in two seasons.

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Rich, next time I see you at one of the car shows, I'm gonna bring a suit case and ask you to pack it for me. You could build a Healey with the parts you've got in the boot. More often then not, you've mentioned, I carry (insert part here) as a spare in the boot.

Just joking, but good to know you're at one of the shows. You know, in case I need a part

tri_carb_healey said:

dougie, your engine bay is full of win!

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And you race that car?!
That's a double win!
Beautiful.

Roger, all kinds of space in the boot. Tons of room under the battery (I carry spare water pump, fuel pump and solenoid in there) and behind the facade hiding the fuel filler tube (like spare radiator hose and inner tube). Got a cut down 5 gal bucket with lid under the spare that hold an awful lot like clutch and brake rebuilding kits, wiper blades, 14 gauge wire and tune up kit with spark plugs. More stuff to the left of the spare and and below. More stuff in the well aft of the fuel tank. Got things (soft) over the battery. Lots of tools including timing light and tach. If you move the battery forward, you can carry two qts of oil on the battery shelf locked in place by the battery restraints. Mostly, I help others with this stuff. You think I got a lot, you know Len with the trailer he tows. Only thing I've ever had to use is the fuel pump. Lots of assorted tools. Now, you should see my clever wife pack for a weeks trip including the lap top! When we put a suitcase on the luggage rack, it only has cleaning supplies (very light weight). Still get over 20 mpg and boy does the rear track well.

big6 said:

For more years than I care to remember in my carb dampers I use a 50% MMO and 50% ATF mix. If the SU damper oil disappears you may need to replace the neoprene pin washer. Stromberg’s use neoprene “o” rings on the needle.

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Are you talking about a washer as part of #3 on this diagram?

Dougie,

You engine / carb setup is superb !

It looks like you have a 2nd crankcase vent that runs to a 2nd
valve cover vent then both vent hoses go over to / under the drivers side wing ?
Why two crank case vent tubes ?
Where does the 2nd one originate from ? I cannot tell from the
picture.
How and where did you terminate the ends of those two hoses ?

I also don't have stock air cleaners and have my one vent hose
running to the bottom of the car on the passenger side of the engine bay. That is why I am interested where your two vent hoses end.

Ed

Ed -

My '57 100-6 MM is period prepared and I actively vintage race road race it. The 2nd vent which originates as the stock one, helps to remove some of the internal pressures under race conditions. The twin vent hoses exit into a "catch tank" mounted in the fender-well, per vintage race requirements.....no spills on the track.