New to nitro...me too?

[HELINHAWAII]

New to nitro all together. Well, not completely...I had a Cox .049 rc car about 20 years ago! Trying to get a sticky going here where all us nitro virgins can learn a thing or two?

Is there somewhere with reliable nitro information (break in, tuning, maintenance) I can read while I'm waiting for the mailman this week?

Some questions I have: :dontknow

- Ok so, what are these shims I keep hearing about. Do they come with every new engine?

- Clean up tips. I hear a lot of people calling them slimers. What cleans up a heli well? I'm thinking Simple Green. I love that stuff.

- Most folks seem to run an OS#8. Why? What's the difference between it and others?

- Does nitro become nose heavy as it burns fuel?

- Maintenance routine. I know Bob did a video for 450 PMI's and I've got the general heli stuff down pat. I'm more interested in how to maintain my engine.

Thanks in advance freaks!

[george0079]

There are soooooo many variable with nitro fueled helis....... Ambient temp, Altitude,make and model of engine,fuel,glow plugs,gear ratio of heli, muffler.... The best thing to do is find a local heli pilot that has some experience with nitro fueled helis, and ask alot of questions.

A person could get carpul tunnel trying to type all of it out

[Finless]

My shot at it.... YES there is way to much to type on this subject but here is a start.

- Ok so, what are these shims I keep hearing about. Do they come with every new engine?

Don;t mess with the shims right now. Get it running and tuned and down the road you can mess with these. The idea is they change compression ratio a little and sometimes you might change them for lower nitro content etc... FYI the OS has these the YS SR does not.

- Clean up tips. I hear a lot of people calling them slimers. What cleans up a heli well? I'm thinking Simple Green. I love that stuff.

I do not like to use anything with water in it. I use denatured Alcohol. Isopropal will work too but it does have some water in it. Reason I don't like using something with water in it is it promotes rust on parts.

As for cleaning the SLIM off you can be quick about it or very Anal about it (like me). Some guys clean off the canopy, blades, boom and fins and leave it at that. I like to also clean up pretty much everything I can get at. Frames, servos, muffler, in and around the engine, etc....

- Most folks seem to run an OS#8. Why? What's the difference between it and others?

It's the recommended plug BY the manufacturer for 20-30% nitro and it just works!

- Does nitro become nose heavy as it burns fuel

It does change CG as you fly... Heli designers thus try to get the tank as close to the centerline as possible. But for the T700 you start out a tad tail heavy and end a tad nose heavy... I doubt you will notice it much if at all.

- Maintenance routine. I know Bob did a video for 450 PMI's and I've got the general heli stuff down pat. I'm more interested in how to maintain my engine.

Now this could go on for days.... Here are the many choices and what it has to do with is WHAT to do to the engine at the end of the flying day.
1) Just leave it as is...
2) Run the engine dry
3) Use after run oil wither along with run engine dry or not.

I have used all 3 in the past but the thinking is you don't want to leave fuel sitting in the engine for long periods of time. It can attract water and thus rust. As the methane/nitro evaporates the oil can gum up the engine. etc etc...

So some guys feel you should run out the engine dry but others argue this is damaging to your engine as when it is running out so is the oil. Other folks use After Run oil with some of those running the engine dry then using the oil and some just use the oil.
To use after run oil you remove the back plate of the motor and squirt in some oil, Some even go further and put some in the carb and turn over the engine by hand until it loads up so they know the oil got into the cylinder.

OK so my experience over the years. First I started out with just using after run oil. Did that on my planks for years and never had a rust problem so I figured it must work for helis too. Eventually I got rusted bearings. Then I tried running the engine dry AND used after run oil. Lasted longer but eventually I still got rusted bearings. OK so I said the heck with the after run oil and just did the run out thing.. Well got rust? Yep..

In the end it is the 30% fuel and the gasses produced from burning 30% that attracts water and thus rust! Jesse you WILL probably at some point experience a rusted set of crank bearings especially in the high humidity of Hawaii.
WHEN you do, solve the problem buy not getting stock replacement bearings but get a set of stainless bearings! Problem gone....

So with the stock bearings I just run the engine dry and leave it at that knowing eventually I will be replacing them. I have had to replace a set as soon as 1 month when we got a lot of rain and the heli sat for 2 weeks and that was back when I was using after run oil!
Now once I have the stainless bearings in there what I do after flying is NOTHING if I know I will be flying again next weekend. If I know the heli is going to sit for more than a week then I do run the engine out dry... If I am going to be storing the heli for a long period then I run it dry, remove the backplate, use after run oil, and put some down the carb and turn it over by hand a few times.

Also some more tips:
1) At the end of the day use something to plug the exhaust pipe so air cant get in easily.
2) Close your carb all the way
3) Some put the piston at top to close the exhaust port.

If you have a pumped engine then you do not want to leave fuel in the pump. I use my fuel dispenser pump and suck the fuel out of the engine pump.

Hope this helps,
Bob

[HELINHAWAII]

Great tips Bob...exactly what I was after!

[Finless]

Jesse.... funny this SAME topic about rust just came up today...

Check it out

http://www.helifreak.com/showthread.php?t=86870

Bob

[HELINHAWAII]

Good stuff Bob. Glad you're on our side! I'm gonna look right now for some stainless bearings...