Mystery Oil

[ELBUFO]

What do you guys recommend in the way of additives for the "M's" engine. I have been using Marvel Mystery Oil in gas, 10W-30 synthetic, and SLICK 50.
I run this in all my rigs...John

[Cal_Gary]

I run Pennzoil 10w30 Synthetic.
Gary

[knattrass]

Being in a cold climate like today - 6 degree - we run 5/40w, 30w in the trans, 90w everywhere else.

[Wayne64]

We all have our opinions and here is mine. John, me thinks you are spending way to much on Motor Doctors in a can. I don't use additives in my fuel, they are already in there for the EFI cars. I might use either Sta-Bil or Seaform if I was putting it away for a couple of months.
Engine oil for my vintage stuff is 15-40W either Delvac or Shell Rotella. The only additive my crank case gets is a can of EOS (GM product no longer available) on a fresh build start up. JMHO

[MSeriesRebuild]

What do you guys recommend in the way of additives for the "M's" engine. I have been using Marvel Mystery Oil in gas, 10W-30 synthetic, and SLICK 50.
I run this in all my rigs...John

Your biggest mistake is the slick 50, one of the worst products ever introduced. When you pull that engine down for a rebuild, you'll see what I mean. No use for me to say more, it's already too late for you, you already fell for that huge lie & poured it in your crankcase. Good synthetic oils are OK, but additives that you pour in can & likely will work against to oils own additive package that is already blended into the oil right out of the bottle making your oils performance not top rate. Some professionals in the field go as far as to say great damage can result. My definition of good synthetics isn't the stuff from the shelves of China Town, I mean Wal-Mart. They have but a couple of good brands on the shelves there, none are synthetic that I know of. Premium quality synthetics are products such as Royal Purple #1 in my opinion, Amsoil, & maybe 1 other. The others are little if any higher quality than the run of the mill stuff. I hope this message doesn't ruffle your feathers, but you did ask.

[greencom]

When my wife and I owned a Cessna 172 all of the old time pilots I talked to used Marvel Mystery Oil in their crankcase, about 4 oz. for ten gallons. They claimed it helped lubricate the top end of the cylinders and kept the rings from sticking in their groves in the pistons. It made sense to me as the avgas would now have some lubricating properties to it. I figured at the very least it would do no harm. When we bought the plane it had just had new pistons and cylinders installed (top overhaul). Over the nine years we owned it we put over nine hundred hours on the engine with no major engine troubles. I did compression leak-down tests on it regularly and after all of those hours the pressure readings did not drop at all! For an aircraft piston engine this was quite remarkable. The FAA certified mechanics at the airport had only one bad thing to say about Marvel, it was not legal to use it in certificated planes. the FAA did not recognize it but most of the mechanics felt it did some good ( they could not of course encourage its use to customers). If it seems to help a highly stressed hot running plane engine running at or near redline most of its life I imagine it would do the same for a much less stressed cooler running truck engine. I use it in all my old vintage vehicles and lawn equipment but not in my more modern car with the catalytic converter, may cause a problem there. I thought I would share my experience with Marvel Oil with all of you. I have to agree with Charles about Slick -50. A similar (and FAA approved!) substance called Microlon was blamed for ruining aircraft engines. I do not see how particles of Teflon in the engine could do anything but harm. Dupont has discontinued selling Teflon particles for aircraft use.

Happy and healthy holidays to all of you,
God bless us all.
Greencom

[greencom]

I need to correct something in my last posting. I meant to say that the old timers used Marvel in their gas tanks not their crankcases. Most added it their gas not their oil. Some did use it in their oil though.
Greencom

[DAP]

I use Marvel mystery oil in all my air tools as an air tool lubricator. Most of my air drills have an oil cavity that weeps thorugh a scinter (*?) busing of some sorts that provides minimal lub. Pouring it in the intake just blows it all over the place and makes a mess.
IU had a fellow student in college that claimed Marv was a great sun tan lotion. HE WAS NUTS IN THE HEAD

[m-37Bruce]

I use Marvel mystery oil in all my air tools as an air tool lubricator. Most of my air drills have an oil cavity that weeps thorugh a scinter (*?) busing of some sorts that provides minimal lub. Pouring it in the intake just blows it all over the place and makes a mess.
IU had a fellow student in college that claimed Marv was a great sun tan lotion. HE WAS NUTS IN THE HEAD

Hey Dan, That was a good one, sun tan lotion!!
I do like the tool lube idea.

[ELBUFO]

Mr Rebuild, information please. I have used slick 50 and synthetic oil for years. I had an old 198 Buick v6 that I had to recycle some used pistons in order to put it together after I had done all the machine work, as that was the one part "no longer available". After 10 years of hard abuse (I was dumber way back when) One of the piston tops broke off. If I had wanted to, I could have grabbed another one out of the pile, and made her go, as everything was still within specks. I saw nothing abnormal. You could have eaten off the heads. No gunk, no buildup. My next V6, a 231 has been going for over 20 years. 10 of which was as a daily driver (No, really I have been driving the same M38 since 1974). So what's been your experience with slick 50??
Now back to the mystery oil. I am using it in the gas as a quasi led substitute. What I wanted to know is anybody using something else? I realy want to get as much out of my M37 as I can before I have to rebuild or swap a motor...Thanks..John

[MSeriesRebuild]

Mr Rebuild, information please. I have used slick 50 and synthetic oil for years. I had an old 198 Buick v6 that I had to recycle some used pistons in order to put it together after I had done all the machine work, as that was the one part "no longer available". After 10 years of hard abuse (I was dumber way back when) One of the piston tops broke off. If I had wanted to, I could have grabbed another one out of the pile, and made her go, as everything was still within specks. I saw nothing abnormal. You could have eaten off the heads. No gunk, no buildup. My next V6, a 231 has been going for over 20 years. 10 of which was as a daily driver (No, really I have been driving the same M38 since 1974). So what's been your experience with slick 50??
Now back to the mystery oil. I am using it in the gas as a quasi led substitute. What I wanted to know is anybody using something else? I realy want to get as much out of my M37 as I can before I have to rebuild or swap a motor...Thanks..John

Mr ELBUFO, don't be offended. It's your business what you pour into your engines & of no concern to us. My experience was with a 318 detroit diesel that had it poured into it years ago soon after the product first came out. When it was torn down for a rebuild, it was an awful mess to get that stuff off of everything. The worst thing was the buildup in oil holes, it was bad enough to restrict oil flow in small passages & just impossible to get it out of hard to access passages. The usual vatting process wouldn't touch the stuff. I've forgotten what we finally did to it, but it was the most time consuming & expensive rebuild that we ever did. Slick 50 was 100% the fault of it. I've never tackled another one that had that stuff in it & never intend too. Its terrible on bronze bushings too, coats the bushings making oil impregnation impossible, not a good thing as that's how bronze bushings function so well, it actually stops the flow of oil through the bronze drastically shortening bushing life instead of extending it like Dupont claims. Now if you have torn down an engine this stuff has been used in & have not found serious residue in the bottom end of the engine & oil passages, all I can say is you ain't looking for it.

[ELBUFO]

Charles, not in the least bit offended, exchange of information is what it is all about. I just wanted to pick your brain. As I said the only motor I have rebuilt that went south on me was the 198. When it blew I was new to synthetic oils, and I wanted to see what the results were. Believe me I did a complete tear down. I miked all the parts. I looked for gunk and wear. I did everything short of putting it back together due to the piston availability problem. I was fanatic about oil changes. Needless to say, this has me worried. I have a generator that took a dump after 5 years of 16 hours a week run time (we live off the grid). It was the alternator that went. The engine was still running strong when it quit producing. After the spring thaw I will pull the old unit out of storage and take a look at it. I will let you know what I find. As for the M37, I have only treated it once, and will hold off any further treatments until after I play with the generator. Just so you know I am a retired USAF Vehicle mechanic (one of the lucky ones I can read), so I have a little experience. But I know that I don't know it all. I appreciate the time you have taken. Not just for me but for all us newbies...John

[Cal_Gary]

I worked for Valvoline when the Slick 50 came into being-some of our customers refused to have their oil changed without including a quart of it, so we decided if they wanted it included they had to provide it, and it was noted on their invoice that Slick 50 was added, in order to avoid any legal issues later, since the product was untested. That turned out to be a wise precaution since it does clog the engine arteries in many cases.

As far a synthetics go, some new car warranties actually require the use of synthetic oil or it would void the warranty. I recall to this day a brand-new 94 Corvette in our shop and the driver didn't want to cough up the $39.99 for the synthetic oil change (vs $19.99 for the straight stuff). When I advised we'd have to note it on the invoice that he went with regular oil, he changed his mind. Synthetics are a good investment and tests have proven synthetics are actually "slicker" than the refined fossil fuel oil, and reduce heat and wear. I will confess though that I do not run synthetics in my every-day drivers-just the M, due to financial limitations.
Gary

[steved]

If you use a quality oil, you don't need any additives. The oil has enough additives already in it. By using other stuff in the oil, you can cause dilution and interactions that are not always positive.

As for the slick 50, I ran it a in a 318 Magnum in a 94 Dodge truck I owned when younger...it had over 200k when I totaled it. I have since wised up and don't run any extra BS in my oil. However, IMO, if you add the stuff to to the crankcase of an engine in good condition, it should cause little issue (and no benefit).

I intend to run 5w40 Rotella in mine when that time comes...