I just filled 3 55 gall drums with av gas, while at the airport one of the pilots suggested I add a quart of MMO to each drum. I don't mind the added expence if there was any benifit. After spending 700$ I doubt I would miss it , any pros or cons out there, Still running breakin oil in my IO 540.
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marvel mystery oil
- Thread starter mwood7800
- Start date
swampjet
Well-known member
Mwood,
Don't add anything till after your engine is broke-in. MMO is a top cylinder lubricant and is good but my prefference is 2 stroke SYNTHETIC oil at a ratio of 4 oz. to 10 gals. It burns clean while lubricating the rings and valves without gumming things up. Av gas is extremly dry and has no lead for lubrication. MMO will lube but can gum up and may raise temp.
Don't add anything till after your engine is broke-in. MMO is a top cylinder lubricant and is good but my prefference is 2 stroke SYNTHETIC oil at a ratio of 4 oz. to 10 gals. It burns clean while lubricating the rings and valves without gumming things up. Av gas is extremly dry and has no lead for lubrication. MMO will lube but can gum up and may raise temp.
swampjet, not arguing with you here, just asking a question. it was my understanding that MMO did burn hotter in the cylinders to help remove gum? is this correct or have you found it to be different by your experiences? i did burn MMO in my last tank and fouled a few plugs!!! was it cleaning out the gum already deposited in my cylinders or was it the MMO fouling my plugs?
swampjet
Well-known member
Chances are the MMO fouling the plugs. Run a can of "Sea Foam" thru the fuel and it will clean the fuel system and cylinders out. It's the best stuff I have EVER found. I get it at Discount/Advance Auto parts. It comes in a white and red can. GREAT STUFF!
Thats why I quit running MMO and an aircraft engine guy told me about Synthetic 2 stroke oil. 4oz to 10 gal. of av-gas.
Thats why I quit running MMO and an aircraft engine guy told me about Synthetic 2 stroke oil. 4oz to 10 gal. of av-gas.
Cadillac Performance Pts.
Well-known member
We use MMO when running unleaded fuel in an engine that is known NOT to have hardened valve seats like an old 392 Hemi (unmolested) . Most importantly, keep the drums completely sealed or you will lose "light vapors" which is the easiest part of gasoline to evaporate and also where the octane comes from. That's why all the guys with bass boats who run last years' gas wipe out engines....no octane left in the old fuel. IMO oil in general in fuel is a bad thing. It causes detonation. I'm not sure why, but it does. You'ld think it'd make the fuel burn slower instead of pop ,but under heat and pressure, it won't. It explodes. We do use it or ATF in the oil in hydraulic cammed engines as the detergents keep lifters operating properly, especially on a "less than avg." serviced engine. Again, if the rings aren't very good, it also aids in detonation, since it gets by easier than regular motor oil. I will say too for anyone who runs a flat tappet automotive engine, don't use synthetic anything. May not hurt in the gas, but def. not in the oil, unless you are borderline on detonation anyway. Mineral base only. The reasoning behind this (and it came to me from the owner of Comp Cams) is that synthetic is too slick for flat tappets (regular lifters). The cams are ground so that the lifter rotates in the bore a tad every time you open the valve, giving an even wear pattern. Using syn. makes it so slick, the cam will no longer rotate the lifter and eventually wears a flat spot in it on one side and kills the cam. On a roller cam, by all means use synthetic and that's the only reason not to. It has superior oiling characteristics and on a molecular level, all the molecules are the exact same size, in mineral oil ,there are millions of different sizes, so the ball bearing effect isn't quite as good.
swampjet
Well-known member
Duckluv,
I run a 0520 carbed @ 285 hp. so we are not far off on power. Sea Foam is the best I have found to clean a fuel system including injectors. I have seen it put in a car wth over 200,000 miles with ORIGINAL plugs and it cleaned all the deposits out. It also cleaned all the MMO gunk out of my previous GPU. 2 stroke oil is formulated to mix with fuel but MINERAL type 2 stroke will leave a residue whereas Synthetic will not. That why I said to use Synthetic 2 stroke oil. But remember more is not better. Only 4oz. to 10 gal.
The testing is on hold for now mostly due to time (too dang many things to do!) But some interesting thrust figures. Now we were using a meter between the trailer and truck and this method will show things you don't see or "feel". On my boat a 72" signiture 2 blade pitched to get WOT @2800RPM pushed 825lbs. by changing to a long hub making a 74" and then pitched to 2800 RPM pushed 875lbs and I couldn't tell any more sound level but it was a big difference on the water and on dry ground.
Strange note, we had access to 2 pairs of Cypress blades and several hubs and put a 3 blade setup(70") on my boat but because they were of different tip weights we did not rev to 2800 but settled on pitching to 2600 and got 875 lbs push. so we are trying to get hold of a 3 blade "set" to run up to full RPM to test. Another note, just for fun we put a 4 blade set ( 2 pair) 70" on a 300 hp 0520 and it actually LOST push with only 775 lbs. So more is not always better in a smaller diameter. I will say that the 300 motor did have a shroud which may have had something to do with it due to the small diameter.
Doing calculations on paper may be fun but when you see that meter go up or down is the truth on push- thrust.
JMO
Bob
I run a 0520 carbed @ 285 hp. so we are not far off on power. Sea Foam is the best I have found to clean a fuel system including injectors. I have seen it put in a car wth over 200,000 miles with ORIGINAL plugs and it cleaned all the deposits out. It also cleaned all the MMO gunk out of my previous GPU. 2 stroke oil is formulated to mix with fuel but MINERAL type 2 stroke will leave a residue whereas Synthetic will not. That why I said to use Synthetic 2 stroke oil. But remember more is not better. Only 4oz. to 10 gal.
The testing is on hold for now mostly due to time (too dang many things to do!) But some interesting thrust figures. Now we were using a meter between the trailer and truck and this method will show things you don't see or "feel". On my boat a 72" signiture 2 blade pitched to get WOT @2800RPM pushed 825lbs. by changing to a long hub making a 74" and then pitched to 2800 RPM pushed 875lbs and I couldn't tell any more sound level but it was a big difference on the water and on dry ground.
Strange note, we had access to 2 pairs of Cypress blades and several hubs and put a 3 blade setup(70") on my boat but because they were of different tip weights we did not rev to 2800 but settled on pitching to 2600 and got 875 lbs push. so we are trying to get hold of a 3 blade "set" to run up to full RPM to test. Another note, just for fun we put a 4 blade set ( 2 pair) 70" on a 300 hp 0520 and it actually LOST push with only 775 lbs. So more is not always better in a smaller diameter. I will say that the 300 motor did have a shroud which may have had something to do with it due to the small diameter.
Doing calculations on paper may be fun but when you see that meter go up or down is the truth on push- thrust.
JMO
Bob
I agree with Swampjet about that SeaFoam .... I don't know what they put in that stuff but my experience with it is all good.
Adding any oil to fuel will raise cylinder temperature some because oil molecules burn hotter than fuel molecules. This may help to explain Potter's post on detonation. Higher cylinder temperatures are a contributor to detonation, and something you definitely want to avoid with an A/C engine.
A fix for old fuel is to add a little acetone, the same stuff you can get in the paint dept. at Home Depot in the gallon cans. Acetone replaces the vaporizing agents that have perked out from storage. Pure acetone is 150 octane, so again, more is not better. Use 3 oz. per ten gallons.
olf
Adding any oil to fuel will raise cylinder temperature some because oil molecules burn hotter than fuel molecules. This may help to explain Potter's post on detonation. Higher cylinder temperatures are a contributor to detonation, and something you definitely want to avoid with an A/C engine.
A fix for old fuel is to add a little acetone, the same stuff you can get in the paint dept. at Home Depot in the gallon cans. Acetone replaces the vaporizing agents that have perked out from storage. Pure acetone is 150 octane, so again, more is not better. Use 3 oz. per ten gallons.
olf
swampjet
Well-known member
I recommend it. Put one can per full tank of fuel and run it all. Then wait thru several tanks of just fuel before using again. I haven't had high temps while using it. After your fuel system is clean ( you can tell by pulling the spark plugs) then if you want to use an additive such as 2 stroke oil would be the time, not before it is clean.
Bob
Bob
Correction:
In my post above I said "Adding any oil to fuel raises temperature."
What I intended to say was, "adding any mineral based oil to fuel raises temperature".
The synthetics don't have that same effect, and like Swampjet said are safe to add to fuel, and provide upper cylinder lubrication.
olf
In my post above I said "Adding any oil to fuel raises temperature."
What I intended to say was, "adding any mineral based oil to fuel raises temperature".
The synthetics don't have that same effect, and like Swampjet said are safe to add to fuel, and provide upper cylinder lubrication.
olf
hmgm, you'd probably only have high quality 93 octane.
I have a good friend in Australia and he tells me that a lot of the gas they get is skunk ..... that it's been in storage a long time, and that the new blends just don't have any 'shelf life'. This was something (acetone) that they came up with a couple years ago to offset that, and I've tried it. It works.
As far as making 100L from pump 93 ..... I can't go there. You'd probably have to add so much of it that it would start attacking the seals and o-rings in your fuel system.
I used it for a while in my GMC pickup. The truck ran like it had just had a tuneup, but the only problem is that I stopped at Daytona on the way home one afternoon and filled up, and I didn't have any acetone with me. The computer in my truck acted like I'd just given it a load of water! In a computer controlled vehicle, if you start with it, you've got to be able to stay with it. They start quicker, idle smoother, and get better mileage with a little acetone, but if you're computer controlled they get used to it too.
olf
I have a good friend in Australia and he tells me that a lot of the gas they get is skunk ..... that it's been in storage a long time, and that the new blends just don't have any 'shelf life'. This was something (acetone) that they came up with a couple years ago to offset that, and I've tried it. It works.
As far as making 100L from pump 93 ..... I can't go there. You'd probably have to add so much of it that it would start attacking the seals and o-rings in your fuel system.
I used it for a while in my GMC pickup. The truck ran like it had just had a tuneup, but the only problem is that I stopped at Daytona on the way home one afternoon and filled up, and I didn't have any acetone with me. The computer in my truck acted like I'd just given it a load of water! In a computer controlled vehicle, if you start with it, you've got to be able to stay with it. They start quicker, idle smoother, and get better mileage with a little acetone, but if you're computer controlled they get used to it too.
olf