Do any one you use Marvel Mystery oil in your rotaries for any reason at all?

I've used it for premixing instead of 2 stroke oil in the past, it seems to work well. I also use it during engine assembly as the light assembly oil.

I used it to break down carbon in the apex seal slots of my 20B. It seemed to work really well.



It has some sort of solvent in it that ATF doesn't have. That's one of the reasons why it works better. It is also meant to burn where ATF is meant to prevent burning. I know this isn't a MMO vs ATF thread, but it seemed like a good idea to mention it.

yeah, the MMO shouldnt foul your plugs like ATF does.

apex seal lubrication/compression aid and general engine health. i've found that it's great for a lot of things. i never bought into the ATF-thing so i can't speak on it in comparison.

Ya I've used the stuff in the past for various things on my rotaries.

Pretty good ****- no complaints here

PK797 NYC

Thnks alot for every ones feedback very helpful!

I've been using it for quite some time now; about 4 oz per 16 gallons.



I used ATF for the engine soaking thing a couple times; I'm pretty sure thats what eventually clogged my catylitic converters up.

Dito.

Yet another nail in the coffin of the ATF myth.

well, we've always known ATF clogs cats...



it probably works better for dealing with carbon deposits than MMO, but when people use ATF to help build compression on dry or flooded engines which are otherwise fine, it's doing more harm than MMO would.

Every used car I get gets the MMO in the gas tank and in the crankcase for like a few hours. I change the oil and I think the MMO helps break down any old sludge that might be living in my motor. On the rotary its good premix I also add it with a squirt can when I first start a new to me/used car frees sticky stuff. MMO is great stuff!



I think its good for fuel pumps too

It's better to use oil instead of ATF in a dry or flooded engine anyway. Those people still pushing the ATF 'trick' ought to be... ahem. Anyway, MMO sounds like a great lube for fuel pumps (kinda like coolant/antifreeze is a lube for waterpumps). https://www.nopistons.com/forums/pub...IR#>/happy.png



A don't think ATF will work better than MMO for carbon deposits. It has no solvents in it. I'm about to step out and get some cleaning supplies so I can tear down and rebuild an engine soon. I'll try the MMO vs ATF thing on some parts with lots of carbon on them. Probably some apex seals in a bath of each liquid and see if anything develops.

the thing with that is you won't have any compression forces or combustion to burn the ATF off and dislodge the carbon, so I don't see how you can really make a judgement based on parts in a bucket.

Then should I heat them up? Like in a metal container?

i heard it doesn't matter if compression forces are in the mix....jeff- i wanted to do this experiment too. soak the apex and side seals....OH yea, soak some rubber oil seals too!

I'll tear down an overheated engine soon. That'll give me some seals to throw in to some containers.

I just now finally got around to doing this experiment. Each pie plate has three apex seals and either MMO or ATF in it. I'll look around for some oil seals but I doubt I'll find any old used ones around here.

It looks like more carbon fell off of the apex seals in the MMO bath. The ATF bath looks the same as it did two days ago.



ATF is so thick compared to MMO. I doubt ATF can get up into the apex seal slots very well. That's one strike against ATF. It also smells kinda bad compared to the relitavely nice smell of MMO. Another strike (sort of). It also resists burning inside automatic trannies. Yet another strike against it. It also fouls spark plugs when MMO doesn't. It also produces solid compounds when burned which clogs cadilac https://www.nopistons.com/forums/pub...IR#>/smile.png convertors. How many strikes so far?



MMO is great to add to oil and gas, and is thin enough to easily flow up into apex seal slots. It doesn't foul plugs hardly at all (I think). Or it atleast won't foul plugs any worse than pouring oil into the intakes, you know, to unflood an engine or to help start a slow cranking engine. Both of which work fine with no residual plug fouling.



I can't say anything bad about MMO. https://www.nopistons.com/forums/pub...IR#>/bigok.gif



I'm going to try to scrape the carbon off the apex seals with a fingernail to feel how difficult it is, now that they've soaked for 48 hours...

the voice of reason, finally! i'm glad i'm not the only one that sees this because i seemed to have been preaching to the choir on this one.

It seems the ATF and MMO are nearly identical in their carbon softening ability. I was able to chip all the way through the carbon on the spring side of both apex seals with my thumbnail, all the way down to the metal. It took similar amounts of effort on both.



Then again, the carbon could have come off just as easily before the seals were soaked. I'm going to check out the remaining two (unsoaked) 13B seals in a few minutes.



In my opinion, ATF may be substituted for MMO for soaking parts to try to soften carbon, but it may not be necessary at all. I've personally never needed to soak carbonized parts to try to loosen carbon before, and probably never will. I see no need to.

The other 13B apex seals were actually already clean. I must have already ran a razorblade across the spring side. The 12A apex seals had a hefty amount of carbon on them though, and I was still able to cut into it with a fingernail. A razorblade would work ten times better. Besides, dry apex seals let the carbon chip off without sticking to it.



My conclusion is that soaking parts in ATF and MMO is unnecessary. If you need to pour something into your engine to try to unstick an apex or side seal, MMO is best because it is thin enough to get into tight spaces, and has some solvent action. If your engine is carbon locked, MMO will most likely save you from having to tear it down. If your engine doesn't like to start because of a slow starter, Castrol GTX poured into the intake in a small quantity will work wonders. If your engine is flooded, simply pull the plugs, dry them, maybe crank the engine with the fuel pump disconnected to blow all the excess gas out of the plug holes, reinstall the plugs and try again.



No need for ATF at all.



Oh, and another thing. To get carbon off of rotors, I've gotten great results from soaking the rotors in gas to eliminate the oil film. Then I let them fully dry (for obvious reasons). Then I wirewheel all the carbon off of the rotor faces. It works great because the carbon gets whisked away without redepositing itself onto the rotors. The apex and side seal slots, as well as the heat dams, can be cleaned with small scrapers or the seals themselves (the heat dams aren't that hard to clean with a walnut or dental tool).

I've since been adding MMO to my oil and fuel tank ever since this thread started. I've noticed an increase in my gas milage and I swear I have a bit more get up when my ports open up. I hope to get the most out of my orignal engine (137,000) before it is time to rebuilt and have the money to do it.





https://www.nopistons.com/forums/pub...1047683894.gif MMO

Would you have any pictures?

I made both pie plates dirty from scraping the carbon off the seals. They're still cherry-red, for the most part. I guess I could set up the camera and take a two-color shot (red and cyan). It's an experiement with a black and white CCD camera...

Here's one. Not much detail, but at least it's not black and white. https://www.nopistons.com/forums/pub...DIR#>/wink.png

great info! nice job. NOW you should see if the atf eats seals. if you have measuring tools see if there is a difference on the before and after now that they are clean,,,again nice job...

Thanks! I doubt ATF will eat apex seals. I'm more worried about it eating the soft seals. I don't have any handy to test right now.



Here's a closeup.

Now for some greater detail. The convergance is a bit off. See if you can notice it.

You can actually see some of the smaller details now.

rotaries aside.. I've used this in my vehicles since I started to learn to drive and when I got my liscense... Its given all of my daily drivers a better idle and smoother response.. two thumbs up in my book.. though I guess I'm biased..