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Old 09-19-2009, 09:24 PM   #1
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Default Should engines be run dry at the end of the day?

Hi guys, does anyone know what's the best practice for finishing off a day's worth of running?

I used to run my engines completely dry but found out that this is not good for them since you are running out of gas and lubricant, causing some additional wear.

What should I be doing instead?
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Old 09-19-2009, 09:29 PM   #2
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i don't leave fuel in my tank, i empty the tank crank up the motor let the rest of fuel run out....but if you not going to race in a period of time i use after-run oil or some people use wd-40
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Old 09-19-2009, 09:41 PM   #3
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i don't leave fuel in my tank, i empty the tank crank up the motor let the rest of fuel run out....but if you not going to race in a period of time i use after-run oil or some people use wd-40
This is exactly what I used to do but was told that it's not good for the engine.
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Old 09-20-2009, 03:19 AM   #4
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I have heard so many different ways of stopping your engine. What I do is just put my shoe on the fly wheel and stop the motor that way. Then make sure the piston is not at TDC. I take the left over fuel in the tank and dump it out. If I am going to use the car within the next hour or so I will keep it in the tank. I have been told told that running the engine dry is bad like you said, but also been told for that two seconds the car runs lean is not going to damage.
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Old 09-20-2009, 05:44 AM   #5
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I agree running the engine completly out of fuel on purpose is not good for the engine. It will create additional wear. I shut the engine down by stopping the flywheel and then use after run oil only if the engine is going to sit for longer than 2 weeks. and dump the fuel in the tank. That fuel will nit be good when you go to use it again. So far this method has worked well for me.
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Old 09-20-2009, 06:09 AM   #6
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When the car is near the bottom of its tank I let it idle until it goes dry.

At idle you don't have any real load to produce wear and you still have some leftover oil on the crank.



Now running out of fuel while screaming down the straight at full throttle is a real bad idea, but sitting on a box at idle is no big deal. I only use aro if the car is going to sit for more than 2 weeks.
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Old 09-20-2009, 06:24 AM   #7
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When the car is near the bottom of its tank I let it idle until it goes dry.

At idle you don't have any real load to produce wear and you still have some leftover oil on the crank.



Now running out of fuel while screaming down the straight at full throttle is a real bad idea, but sitting on a box at idle is no big deal. I only use aro if the car is going to sit for more than 2 weeks.
Agree'd be sure to use after run oil not WD40, it will dry up, if you leave fuel in your motor you'll do more damage to it than idling it empty, have you ever seen methanol when it evaporates? it leaves a chalk like residue that wont just wash away
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Old 09-20-2009, 06:26 AM   #8
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Quote:
Originally Posted by Frank L View Post
I agree running the engine completly out of fuel on purpose is not good for the engine. It will create additional wear. I shut the engine down by stopping the flywheel and then use after run oil only if the engine is going to sit for longer than 2 weeks. and dump the fuel in the tank. That fuel will nit be good when you go to use it again. So far this method has worked well for me.
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Originally Posted by shanty140 View Post
I have heard so many different ways of stopping your engine. What I do is just put my shoe on the fly wheel and stop the motor that way. Then make sure the piston is not at TDC. I take the left over fuel in the tank and dump it out. If I am going to use the car within the next hour or so I will keep it in the tank. I have been told told that running the engine dry is bad like you said, but also been told for that two seconds the car runs lean is not going to damage.
Thanks guys, I have been doing the process outlined above and just took my engine apart today and it is rust free. Looks like a tad bit of fuel being left in the engine doesn't hurt anything.
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Old 09-20-2009, 06:54 AM   #9
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I rarely use ARO because it seems to mess up my glow plugs if any gets up there. It seems to make the engine very hard to start. Alot of ARO oils aren't good for the bearing seals, o-ring, silicone, etc.

Any engine thats going to spend time on my shelf gets completely torn down and I oil its guts by hand after a quick inspection.

No rust problems with Sidewinder fuel so far.
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Old 09-21-2009, 02:03 AM   #10
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I rarely use ARO because it seems to mess up my glow plugs if any gets up there. It seems to make the engine very hard to start.
Interesting! I thought I was the only one to have noticed that evey motor I use ARO on for storage blows its plug with the 5mns after it was started the next time!!! I thought it was me...

My solution: keep a "storage" plug handy...

coming back to the original question: no harm running the motor dry at idle if completely broken in (ie passes TDC).

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Old 09-21-2009, 03:10 AM   #11
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There are absolutely no ill effects that come from running the engine out of fuel. I don't say that to pick on anyone in this thread, so please don't read this the wrong way. Most people who say it's bad for the engine probably just took someone else's word for it who they believed was knowledgable about nitro engines. Those people have never taken the time to observe the effects, or lack there of, of running the engine dry at the end of the day.

I've been running nitro engines for nearly 30 years, and have stored engines without running them out, and others I've taken the time to run them dry. I found there is far more potential harm that can come from storing the engine with residual fuel in the crankcase. The engines stored by just shutting them off suffer more corrosion, even with the use of rust inhibitors. The engines that are run dry have never suffered any extra wear - one of the more rediculous assumptions. there's plenty of residual oil on all the moving parts that for the fraction of a second that the engine remains running after the fuel has run out, it's virtually impossible for any extra wear to take place. Imagine how worn out the engines would be from regular running - You come off the throttle at the end of a long straight and the engine winds down from 40,000 to somewhere in the mid 15,000 rpm range. The whole time, the carb is almost shut and not providing anywhere near the amount of fuel the engine requires at that rpm. If the engines were so fragile as to suffer excess wear from simply running it out of fuel at the end of the day, then normal running on the track would kill it after 10 tanks of fuel.

I run the engine dry all the time, and I even bump the throttle regularly until it runs out to prevent any more fuel from accumulating in the crankcase by just idling. I even pinch the fuel line between runs to run the engine out of fuel. These are the engines that have given me the longest service life and produced excellent power up to and beyond 10 gallons of life.
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Old 09-21-2009, 03:14 AM   #12
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i agree..

i always run it out on the box after im done, keep starting it till it runs out completely
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Old 09-21-2009, 03:32 AM   #13
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This is what i do after every race day.

1) Empty the tank
2) Start it on the starter box to get the rest of the fuel out of the engine and fuel line (I pump the trigger a few times while its kicking over on the box to make sure that there is no fuel in the engine or lines).
3) Take the glow plug out and put 6-8 drops of after-run oil in and then i take the air filter off and put another 5 or 6 drops in the carby and then kick the motor over a couple of times to spread the after-run around (I'll put after-run in even if im going to run it the next week).
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Old 09-21-2009, 07:29 AM   #14
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+1 for running the engine out of fuel. Those concerned about running the engine "dry" are understandably worried that this means that the engine is also running out of oil but this isn't the case. The key is getting as much unburnt ethanol out before putting the engine away because the ethanol promotes rust. If you idle the fuel out of the engine and take it apart afterward you'll still find a pool of oil in the bottom of the crank case.

I also use Penzoil marine fogging oil for ARO. I don't have any engines that have silicone or epoxy plugged cranks and this oil might be bad for those but for "all metal" internals I have had zero problems with fouling plugs after storage. It's key that one doesn't rip the throttle hard for a good 30 seconds after starting a stored engine. All the ARO makes a really lean mixture in the chamber until the ARO clears out. That might be part of the culprit?
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