Marvel Mystery Oil

[af3683]

Does anyone put Marvel Mystery Oil in their gas tank when they fill up? Thanks.

Art

 

[DougF]

I used to put a small amount in at each fill up. Haven't since the new engine was installed.

 

[TR3driver]

I've been using synthetic "TC-W3" 2-cycle oil instead. Cheaper, use less, works better.

 

[JerryVV]

What does this do for an engine?

 

[poolboy]

Good question, Jerry. I'd really like to know more about the "works better" part, too.

 

[sail]

Sea Foam with winter any day now.

 

[af3683]

MMO is supposed to lube the upper cylinder walls.

 

[JerryVV]

I never understood the phrase "Upper cylinder lubrication" besides I think my valve guides probably do a pretty good job of that currently. Not that they should but that head has not been touched in years other than a mild valve lapping job 20 years ago.

 

[DNK]

I think Paul was a past or present user of said product

 

[Brosky]

Marvel Mystery Oil has been used for years (by us old guys) for fogging engines before storage. That means pouring it in the carburetor while the engine idles until it stalls the engine out and then it remains shut down for the storage time. I used it a lot on boat engines and cars that would not be run for months over the winter. That would be a case of lubricating the upper cylinder walls.

After doing this, the engines always started right up in the spring and after about 5-10 seconds of a little smoke, the engines ran fine.

I still use their gas treatment in my TR6 every year and have never had a problem with the same fuel sitting in the tank for the entire winter.

 

[DrEntropy]

Beats th' punai outta all else on the market.

 

[3798j]

I'm a long time user in both the crankcase and gas tank (and will no doubt continue). Somehow just feel better adding it even if it is snake oil (plus, one must admit, great name, great bottle).

 

[PeterK]

I use it for all of the above plus I also use it after I drain fluids to clean out any sludge or crud, especially good on lawn equipment.

Pay $16 per gallon at the auto parts store.

 

[TFB]

I used MMO for years on antique motorcycles.Air cooled flatheads,prone to poor lubrication to valve guides and cylinders with 350-450 deg. f normal operating temps.An upper end lubricant helps greatly ,but like RandallI now use 2-cycle oil,@100:1 mix,mostly because I always seem to have some around for the outboard,chain saw etc.
Tom

 

[Don Elliott]

In 2007, I experienced a lot of stalling and other gas starvation related problems. I had just refinished an engine re-build with new rings and honed bores. It was during my 1,550 mile trip to Valley Forge for VTR that the stalling etc, would occur. I felt it was caused by the ethanol that the US had mandated. In Canada, I could still get ethanol-free gasoline and there were none of these problems. I had always used the top grade of gasoline.

Once at VTR, Charles Runyun suggested that I add 4 oz. of Marvel Mystery Oil to each fill-up. So I started to use it and even had to drive down to Vermont for 6 quart bottles because it's not available in Canada.

At the same time, following one of Randall's excellent suggestions, I changed the fuel lines from the front of the water pump to both the carbs. My 1958 TR3A had the original 49 year old (at that time) hoses with the banjo fittings - so I replaced these two upper hoses with new ones with the outer stainless steel braiding and used the same banjos. Since 2008, driving about 13,000 miles, I have never suffered the stalling and gas starvation issues with the new hoses and the MMO which I am still using.

BTW, with 17,000 miles on the engine since I re-built it, I have never had to add any top-up oil between oil changes (3,000 miles) and that's with Castrol 10W30 oil and a small bottle of ZDDP plus additive when I change the oil.

 

[TR3driver]

I got interested in upper cylinder lubricants when one of our local club members had severe ring wear in his rebuilt TR4 motor after only a few thousand miles. Steve Hedke at British Pacific said he had seen the same thing on other old but rebuilt engines, including a flat-head Ford V8, and a "series" Land Rover. The theory is that the E10 is more likely to wash off the lubrication film, if you use a bit too much choke on a cold start (getting liquid fuel into the chamber). Well, my tail pipe is as black as the next one, so I went on-line to see if others had reported similar problems. Doesn't really prove anything, but I found a lot of believers on the "Bob is the oil guy" web site.

Personally, all I can report is that the idle rpm went up, and the engine does seem to run marginally smoother.

The TC-W3 standard is for water-cooled outboard motors and such; supposedly somewhat different than oil designed for use in air-cooled 2-strokes (which run much higher cylinder wall temperatures). I bought a gallon at Wally-mart, which I decant 4 oz at a time into some old pill bottles to carry in the car. When I fill up, I dump one of the bottles in first. At that ratio (around 300:1, depending on how empty the tank is), there is no smoke or smell. And I didn't notice any effect on octane.

Worth noting, perhaps, that Triumph recommended using an upper cylinder lubricant as well.

<span style="font-family: 'Comic Sans MS'">An upper cylinder lubricant may be used to advantage, during the running in
period of a new engine. The lubricant should be mixed with the fuel in the
proportions given on the container. Such lubricants may be used with
advantage throughout the life of the vehicle, particularly during wintry
weather,</span>

 

[Brosky]

A lot of guys want the cylinder walls to have some lube on them over a long period of sitting, which is why we did the MMO that way. When you flood the engine with oil, that takes care of lubing them.

 

[Geo Hahn]

I use MMO but only in my other vehicle which is notorious for having one hydraulic lifter that's slow to pump up. With MMO in there (the theory goes) it pumps up faster and you lose most of the tick-tick-tick that old VWs are known for.

Those air filter covers look so much like mine that I wonder if we're getting them from the same source. Mine are sliced from foam Shop-Vac filters.

 

[vettedog72]

Among other applications I use Marvel Mystery Oil in the dashpots of the carburetors.

 

[Don Elliott]

You're correct Geo. I bought an open-foam filter from Sears for their Wet/Dry vacuums for about $20.00 and cut it into 4 rings. I have been using these two foam filters on my carbs for 5 years now and still have the other two pieces on a shelf somewhere in my garage.

I also use "AMS filter oil for foam filters" that I pour onto the foam - then I put them onto the original filters as shown. I feel they keep the dust out the carbs and the engine.