Bearing damage

[Barrie Lever]

Sorry, I fixed the files.
Lohring Miller

Many Thanks

 

[Tom Foley]

So about oil percentages, what do most home brewers use in there different size engines ? I always get 18 % but when I was running Picco Hydro 90 engines would run 20%.

 

[Don Ferrette]

So about oil percentages, what do most home brewers use in there different size engines ? I always get 18 % but when I was running Picco Hydro 90 engines would run 20%.

I ran 15% in .21s when I ran those, 18% in everything else. All synthetic, no castor. I actually found bearings lasted a little longer in the .21s at 15%.

 

[Al Hobbs]

Everyone has their own favorite mixes. Whatever works for you is what you should do.

For 67 size engines and larger, I mix in 5 gallon lots.

2.5 gallons nitro
1.5 gallons methanol
1 gallon Klotz Super Techniplate

That is:
50% Nitro by volume
20% oil by volume

I use more nitro and less oil for 45 and 21 size engines. 60% Nitro and 16% Klotz Super Techniplate.

I like getting castor oil in the mix as it has a higher temperature tolerance. However, some castor will fall out of a high nitro content mixture if you use too much.

If you store fuel over the winter, run it through a fine filter before you use it the next time.

 

[FloridaScaleBoater]

Everyone has their own favorite mixes. Whatever works for you is what you should do.

For 67 size engines and larger, I mix in 5 gallon lots.

2.5 gallons nitro
1.5 gallons methanol
1 gallon Klotz Super Techniplate

That is:
50% Nitro by volume
20% oil by volume

I use more nitro and less oil for 45 and 21 size engines. 60% Nitro and 16% Klotz Super Techniplate.

I like getting castor oil in the mix as it has a higher temperature tolerance. However, some castor will fall out of a high nitro content mixture if you use too much.

If you store fuel over the winter, run it through a fine filter before you use it the next time.

Al, would you mind sharing your recipe for your 45 & 21 fuel

 

[Al Hobbs]

Al, would you mind sharing your recipe for your 45 & 21 fuel

In a 5 gallon jug,
384 ounces Nitro
102 ounces Klotz Super Techniplate
154 ounces Methanol

This is not so easy to measure the components. So, I mix in 5 gallon lots. That means as I switch from one gallon jug to the next, the fuel stays the same.

 

[FloridaScaleBoater]

In a 5 gallon jug,
384 ounces Nitro
102 ounces Klotz Super Techniplate
154 ounces Methanol

This is not so easy to measure the components. So, I mix in 5 gallon lots. That means as I switch from one gallon jug to the next, the fuel stays the same.

Thank you Al.

 

[JoachimRuess]

I don‘t want to hijack this thread (sorry tom), but the articles from lohring are really awesome. Thank you very much for showing here.
Greetings from Germany
Joachim

 

[LohringMiller]

Thanks again. My interest in nitro engines started in high school where I designed and built a 10 cc engine. I was flying control line airplanes at the time. Over the years I've learned from some of the best. I hope my articles will inspire a new generation of engine builders. I'm afraid that the best US young people aren't interested in mechanical things. The ones who are work for companies like Tesla and Space X.

Lohring Miller

 

[WikiWiki1]

So has anyone found that adding a certain type of oil to commercial fuels can extend bearing life? I see torco has 14% synthetic and 2% castor for a total of 16%. So there is some room to add another 2-4% of additional oil to maybe improve or change its properties. I have always added an oz of synthetic oil to every gallon just for good measure but never really took a scientific approach to it.

Brent

 

[Al Hobbs]

So has anyone found that adding a certain type of oil to commercial fuels can extend bearing life? I see torco has 14% synthetic and 2% castor for a total of 16%. So there is some room to add another 2-4% of additional oil to maybe improve or change its properties. I have always added an oz of synthetic oil to every gallon just for good measure but never really took a scientific approach to it.

Brent

You have to be careful as not all lubricants are compatible.

 

[Mark Anderson]

Super Techniplate 20% .45 and up, 50 & 60%, 16.5% in .21 66%

 

[Mike Cathey]

I'm not sure that this is the issue here, but I have found that good bearing life is also related to the technique of pickleing the motor after the race. Starting with disconnecting the fuel line at the carb and hooking up an ignitor up and rolling the motor over (assuming that the boat hadn't gone dead and obviously had water in the motor) with the carb 1/2 open to get all the fuel burnt out of it. I adopted my after run habit after Rod Gerity was walking by as I was pickling the motor using one of these gizmo's that screw into the glow plug hole that have some tubing attached to it to deposit the oil into a pop can or rag. Rod told me that most of my oil was just going up the ports and out of the glow plug hole and very little is actually getting into the bearings. Having enormous respect for Rod I asked him so what I should be doing? He walked over to his pit table and came back with an old dead glow plug with the wire pulled out and said to screw it in but leave it loose like I was starting the motor, except set the starter voltage to 12 volts instead of 24 so I didn't bend the rod or crankpin and not flatten the rod needle bearings. He said to flood the motor with oil while rolling it over until it just starts to hydro lock and then tip the boat on the bunk against the pit table at a steep angle and put more oil down the carb so it would settle in the bearings.

The idea being without some restriction that the crankcase wasn't getting pressurized and so the oil wasn't getting forced into the bearings like it is when the motor is running. When I asked Rod about what kind of after run oil he used he said it didn't matter all that much (although he did say he used JB 80, a Justice Brothers product) and the main thing was no matter what kind secret sauce we liked to use, use a LOT of it. He also said that it's easier to just pull the motor after the race was over and then clean up the inside of the boat and then tear down the motor immediately after getting home and hosing it off with Brakeclean, dry it off with air and spray it down with WD and cover with a clean rag until I got around to inspecting and putting it back together again.

Rod also turned me onto another helpful habit of using an aquarium pump (you can get the pump, tubing and Tee's for around $20) that had tubing run into the drain holes on wood boats (which kept them from getting wood rot and also kept the boat lighter throughout the course of a season) and letting it run for a few days. I remember removing the deck of a boat to repair some crash damage that had been run a lot for the 5 years after I had built it, and the inside of the boat looked like it was brand new.

For what it's worth.

 

[Tom Foley]

I'm not sure that this is the issue here, but I have found that good bearing life is also related to the technique of pickleing the motor after the race. Starting with disconnecting the fuel line at the carb and hooking up an ignitor up and rolling the motor over (assuming that the boat hadn't gone dead and obviously had water in the motor) with the carb 1/2 open to get all the fuel burnt out of it. I adopted my after run habit after Rod Gerity was walking by as I was pickling the motor using one of these gizmo's that screw into the glow plug hole that have some tubing attached to it to deposit the oil into a pop can or rag. Rod told me that most of my oil was just going up the ports and out of the glow plug hole and very little is actually getting into the bearings. Having enormous respect for Rod I asked him so what I should be doing? He walked over to his pit table and came back with an old dead glow plug with the wire pulled out and said to screw it in but leave it loose like I was starting the motor, except set the starter voltage to 12 volts instead of 24 so I didn't bend the rod or crankpin and not flatten the rod needle bearings. He said to flood the motor with oil while rolling it over until it just starts to hydro lock and then tip the boat on the bunk against the pit table at a steep angle and put more oil down the carb so it would settle in the bearings.

The idea being without some restriction that the crankcase wasn't getting pressurized and so the oil wasn't getting forced into the bearings like it is when the motor is running. When I asked Rod about what kind of after run oil he used he said it didn't matter all that much (although he did say he used JB 80, a Justice Brothers product) and the main thing was no matter what kind secret sauce we liked to use, use a LOT of it. He also said that it's easier to just pull the motor after the race was over and then clean up the inside of the boat and then tear down the motor immediately after getting home and hosing it off with Brakeclean, dry it off with air and spray it down with WD and cover with a clean rag until I got around to inspecting and putting it back together again.

Rod also turned me onto another helpful habit of using an aquarium pump (you can get the pump, tubing and Tee's for around $20) that had tubing run into the drain holes on wood boats (which kept them from getting wood rot and also kept the boat lighter throughout the course of a season) and letting it run for a few days. I remember removing the deck of a boat to repair some crash damage that had been run a lot for the 5 years after I had built it, and the inside of the boat looked like it was brand new.

For what it's worth.

I feel that the small ID of the hose attached to the blowout fitting in the glow plug hole provides an adequate resistance when flushing . I am guilty of doing a substandard job of blowing out engines at the end of a long day after running 6 classes and running till dark lol . This is the exception not the norm , I usually do a good job on post race maintenance and all engines come out when I get home .

 

[Tom Foley]

I don‘t want to hijack this thread (sorry tom), but the articles from lohring are really awesome. Thank you very much for showing here.
Greetings from Germany
Joachim

No worries some great info here buddy !

 

[RaceMechaniX]

A technique I copied from one of the nitro gurus was to drain the tank of nitro fuel and fill with FAI 0%, so just oil and methanol. I use 20% Tecnhiplate. I will fire the motor with the glow plug for 30seconds so all the nitro is burnt and flushed with the methanol/oil mix. Then do a similar pickle mentioned above. Bearings last a long time and no corrosion inside the motor.

If you don't have easy access to 0%, you can order from John Otto at Technology hobbies or I am sure Jerry and others can do the same.