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  1. #1
    RC poster
    Join Date
    Jun 2019

    What’s Your Nitro After Run Regiment?

    I would like to hear what you guys do for you’re after run regiment after a days running.
    I am new to this site but come to the site with 35 years plus experience in the Nitro world of R/C.

    After reading the posts about after run, I will start with my after run regiment.

    Let’s start with the fuel. Nitro Methane aside from the oil is Methanol (The igniter) and the Nitro (The oxygen atom). Methanol attracts moisture but not enough to do any harm to the engine in 100% of methanol “Residue” left in the engine, it will however harm the engine if not cycled out.

    The nitro on the other hand will damage the engine as the nitro attacks the alloy “namely the top of the piston head”. If left in the engine the nitro will attack the pistons head, this is called “Pitting”, pitting is tiny sharp pointed shards from the pitting left on top of the piston head. These shards break free while the engine runs and under compression break free and score the outer diameter of the pistons head and score the piston wall and sleave resulting in friction and less compression.

    The after run of any nitro engine is one of the best ways to get 10 years out of an engine vs. one or two years.

    The way Traxxas wants you to after run the nitro engine does not really remove all the fuel and with the WD-40 being such a low viscosity it actually drips down off the wrist pin and from the crank pin resulting in a dry start. And also pulls the residual fuel to the bottom of the crank case, pitting the alloy weakening the case over time.

    So here is my after run regiment.

    After a days running my 4tec 3.3 or any nitro engine.

    Removing the nitro from the engine: The most important.
    I start with burning the nitro out of the engine. To do this I use 100% methanol in a separate fuel tank. I unhook the cars fuel tanks fuel line feed tube from the carburetor and plug the methanol tanks fuel line feed tube to the carburetor. With 100% methanol I start the engine with my finger close to the tuned pipes outlet because the engine will run at a higher RPM this way I can bump my finger over the exhaust outlet to limit the RPM without stopping the engine from running, much like a throttle exhaust “if you know what throttle exhaust is”. The engine running on the 100% methanol will burn out all the nitro left in the engine. As the engine runs on 100% methanol the RPM will be very high as the nitro is burning after about half minute to a minute the RPM will fall to a lower RPM, when this RPM drop occurs I know all the residual nitro has been burned out and I can shut the engine down. My engine has no nitro in it to attack the alloy.

    Removing the methanol from the engine: Somewhat important.
    I unhook the methanol fuel tanks fuel feed line from the carburetor, and restart the engine but it won’t start just pop burn out the methanol, only a few blips is needed.
    It is important to start with removing the nitro first and the methanol last because the engine has to run to remove the nitro.

    Now that I have no methanol or nitro in my engine I have to oil it up for my next day of running, the engine will start with a well lubed connecting rod, piston and sleeve.

    Oiling up the engine:
    I use Marvel Mystery Oil for this part of after run. I use Marvel Mystery Oil because it also attracts moisture/water and is a light higher viscosity than water tin WD-40. The Marvel Mystery Oil will adhere to the wrist pin and crank pin so the next engine start will be lubed as marvel mystery Oil has a heavier viscosity and will not drip off the wrist pin and crank pin as much as the WD-40 will.

    I remove the glow plug and look at the bottom of the glow plug making sure the bottom is shinny denoting a perfect fuel mixture (The blacker the bottom of the glow plug the leaner the fuel mixture was), I than can make adjustments the next day to fuel mixture) The cleaner the bottom of the glow plug the richer the fuel mixture was).
    I than put the glow away for a while.

    With the glow plug removed from the engine I pour about a table spoon of the Marvel Mystery Oil into the hole at the head button.

    Now with the starter flip the engine and let the engine cycle to purge the oil out from the hole in the head button. Most use a rag because this step is real messy. But I have a trick for this too.

    Instead of using a rag to cover the head I make a drain tube out of a glow plug and a length of slingshot silicone tubing.

    Drill out the center of the glow plug and slip the slingshot silicone tubing over the glow plug.

    Screw the glow plug into the head of the engine and the oil will flow out of the tube. This way no oil blow by or threw the rag as it is somewhat hard to cover the head.

    With the drain tube screwed into the engines head flip the engine over using the EZ Start to purge out the oil.

    I never had a problem with engine starting as the glow plus is clean.

    Lets hear your regiment.

    Somewhat sad I cant post attachments (Traxxas wont let me) I guess Ill take my experience else ware. But ill leave the links for to go see if you like.
    Last edited by KB21; 07-09-2019 at 11:17 AM.

  2. #2
    RC poster
    Join Date
    Jun 2019
    I guess eventually I will be able to post the pics. Sad.
    Last edited by KB21; 07-09-2019 at 11:06 AM.

  3. #3
    Traxxas Employee TireSlinger's Avatar
    Join Date
    Sep 2010
    I would caution against running 100% methanol in a Traxxas nitro engine. There is no oil in pure methanol, and we only advise using Traxxas Top Fuel for best performance and engine life.

    I've used WD40, Marvel Mystery Oil, machine oil, and a variety of dedicated after run oils over the years with no real difference in engine life. The important thing is to do something to prevent corrosion, any lightweight oil is better than nothing.

    Get the fuel out, clean the engine / air filter, oil it, and put it away. Never needed anything more complex than that.
    Our doubts are traitors, and make us lose the good we oft might win, by fearing to attempt.

  4. #4
    Marshal Double G's Avatar
    Join Date
    May 2008
    Seems like A LOT of work IMHO even if you are going to run it the next day. But if you have the time for it, then go ahead. A good tune, dropping the piston to BDC after running and performing the engine manufacturer's (Traxxas, O.S., etc) after-run procedure seems to work very well for me.
    The Super Derecho

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