hooking up a engine with CDI Ignition
 

Ok I am still working on putting my 1st engine with cdi Ignition in my plane.. I have a 3w and the book said that I should use a solid metal rod for the throttle. I have read that you should not do that with CDI ignition engines. It can give you interferrence to your radio.. I would just like to ask what are other people doing for a throttle.

I got this engine without a switch for it. What is a good switch that I can put on the modual and the battery for the CDI ignition.. Will a switch like the one on the RX work as well or do I need to get a special one.

I also need to know where to put the modual. That is going to be the hard part. the plane I am putting it on is a midwest extra 300s. I was going to put it under the engine box but the muffler will be right there.. I think it will get too hot there... If I put it inside the plane will I have interferrence with the radio?

All and any info would be great.
Thanks

Paul

RE: hooking up a engine with CDI Ignition
 

The metal rod is ok as long as you break electrical conductivity at the ends with plastic or nylon clevises or links.

You can use the same type of switch for the battery that you use with the radio.

It doesn't really matter where you put the ignition module as long as two things remain constant, the second of which is extremely important with 3W. Number one is that the plug wires have to reach the plugs. The second is that a 3W ignition likes very much to be kept cool, so pay attention to cooling air and the mounting method. Other than that the location doesn't matter.

Not a very good idea to place the ignition next to the receiver, so keep a little (as much as possible) separation there.

RE: hooking up a engine with CDI Ignition
 

Ok that is what I was looking to hear..

I would like to keep the rod short for the throttle. If I move just a servo up to the front of the plane. What is to close? and If I do it so it is about 6" from the carb. Will that mess with the rados? I ask all this cuz I just want to do it right the 1st time. lol

Thanks

RE: hooking up a engine with CDI Ignition
 

What you want to watch out for is keeping the servo away from the iginition and battery.....6 inches should work just make sure you range check before you fly.

RE: hooking up a engine with CDI Ignition
 

Interference and servo position varies with the installation.

I've installed the throttle servo only an inch behind the engine and only a couple more away from the ignition without any problems at all. Care was taken to eliminate any conductivity sources and higher end products were used, so maybe that helped. There are others that have had nothing but problems even when they had 12" between the major components.

It all comes down to using your head, using good products, eliminating any metal to metal contacts, making sure everything is tight and won't loosen up, and some good range checks before the first flight. Engine off and engine running. Don't use a PCM receiver when doing the initial range checks. Change to PCM only after you have determined that all is well.

RE: hooking up a engine with CDI Ignition
 

The MOSt IMPORTANT thing is a proper antenna down range check. Less than a 15% reduction in range with the engine running compaired to engine off. Use a PPM RX.
REMEMBER IT AIN"T GOING TO FIX ITS SELF IN THE AIR ON THE FIRST FLIGHT

RE: hooking up a engine with CDI Ignition
 

Terry,

It will indeed fix itself in the air. Unfortuately it always results with a sudden stop upon impact with the ground. Usually with the operator yelling "I don't have it!!"

RE: hooking up a engine with CDI Ignition
 

lol Yep I have seen that before.. Range check. I have see peaple do then in so meny ways. What I do is keep the antenna down and walk untill I have a rado prob. Then I will tern from side to side walking to the plane untill the prob stops.

So what your telling me is at that point I should not get less 15% from that point. Is this right..

Paul

RE: hooking up a engine with CDI Ignition
 

With a gasser (and hopefully a glow) you should do 2 radio checks. One with the engine off, and the other with the engine running. If the two checks are different by more than 10 or 15%, then don't fly until you isolate and fix a problem that was indicated by the range checks. Personally, I use a minimum distance of 125 feet as the least amount of range I will accept prior to a gltich. This is in addition to the 10-15% rule.

RE: hooking up a engine with CDI Ignition
 

AS I put this engine in the plane I am going to put some pics up to see what you all think about how I am doing...... This should be fun.. Nothing like doing some thing for the 1st time lol

RE: hooking up a engine with CDI Ignition
 

That ain't fixing the RF problem, thats fixing the PROBLEM.

RE: hooking up a engine with CDI Ignition
 

I had no idea it would be so hard to dril a strate hole in a dowl rod for the engine mount. It would be ezer if I had a dril press but I do not have one.

Paul

RE: hooking up a engine with CDI Ignition
 

It can be difficult. There used to be a product called a Higley drill and tap guide that would let you get the hole started straight for some distance before you had to finish the rest by hand, but I don't know if they are available anymore. One of those tools often used by kit builders that has likely fallen out of favor due to the lack of builders.

RE: hooking up a engine with CDI Ignition
 

It ain't that easy even with a drill press, since any irregularity in the wood grain will lead the drill point astray. Even so, I don't know how I would be able to build planes without a drill press. If you don't want to get one, then you probably need a set of stand-offs, available from many sources.

RE: hooking up a engine with CDI Ignition
 

I have one but it is broke.. The part to fix this one is just bout what it would be for a new one I think..

RE: hooking up a engine with CDI Ignition
 

Ok this mite sound bad but is there any one that has some pics on how they did the engine mount.. The way 3w as it in the instruction is not making much sins to me. It looks as if I need to take a 1/4 ply wood and put on the engine and them I can take 3/4 dowls from that to the fire wall. Can you help me out on this one....
Paul

RE: hooking up a engine with CDI Ignition
 

The easy way, without getting fancy, is to obtain a couple of 3/4" wide blocks of maple cut to the length you need for the engine standoff distance. Those maple blocks have to be about 1/4" to 1/2" wider than the distance between two engine mounting lugs. That's 1/4" to 1/2" to each side of the engine. Basically you now have a pair of 3/4" thick maple blocks that extend 1/4" to 1/2" past each side of the engine mounting holes, and as deep as the required standoff distance. Place one block so in spans a pair of engine mounting holes and mark the 3/4" width for the hole centers. Do the same for the other pair of engine mounting holes. You now have a pair of solid maple engine mounting blocks. Getting fancy and making them lighter is only a matter of cutting away anything on them that you determine you don't need or serves no purpose regarding rigidity. Total spent: about $2.00. They last forever.

RE: hooking up a engine with CDI Ignition
 

On my 3w The carb is in the back of the engine, and there is only 3 holes for were the engine mounts. I do not like the set up of the engine. What I am going to do is take some pics of what I got and what I have to work with and see if I can figure out how to put the pics on here.....

Sorry to be a pain on this but I just want to do this right the 1st time lol
Paul

RE: hooking up a engine with CDI Ignition
 

Put the engine on a peice of 1/4 plywood. Draw a circle, mark the bolt holes. Make as many as you need. Drill-grind-saw out the middle. Glue them togather. A little heaver than stand offs but much better support.
Or just buy comerical stand offs.

RE: hooking up a engine with CDI Ignition
 

Terry,

If someone is actually reading and following the 3W directions, they will have noted that 3W does not like standoffs and voids warranties if you use them. How they know that you used them is beyond me, but what do I know. Your plywood method works good, too.

BTW, I hear that you are about to get a lot busier;)

RE: hooking up a engine with CDI Ignition
 

Ok now this mite sound stuped but I got to give it a shot.. I need to add some lb to the nose of the plane.. I got a piece of 3/4 ply and I was thinking of makeing a fire wall out of that.. Then I can take block and put between the 3/4 and the fire wall. the block will only have to be 1/2"

That looks as if that mite just be the lbs I need and It would be ez to put the engine on it.. Now does that sound stuped or what?

RE: hooking up a engine with CDI Ignition
 

Well I tryed all the ideas that you all gave my + the stuped one that I cam up with.. It is just not working out.. I keep running in to probs.. So what I had to do was cut a part of the fire wall off so that the mufler will fit.. I just used 1" dowl rod for stand offs... That has got to work the best.. Im trying to up load a pic but it is telling me that the pic is to big.. I will try to get it in so you all can tell me if it it is going to work on not..

Thanks
Paul

RE: hooking up a engine with CDI Ignition
 

The dowls broke when I did a good snug. so I thought I would try doing it this way. look at the pic and tell me what you think about it...

I trying to find a good place to put my ingiation. I was going to put it under the engine box but it looks like it will to close to the mufler.. what do you all think..

or I can put it on the side of the box but with the carb being in the box will that be a prob..

Thanks for all your info..
Paul

RE: hooking up a engine with CDI Ignition
 

I vote for photo 5....modual on side of engine box! Capt,n

RE: hooking up a engine with CDI Ignition
 

If it was mine I would NOT put it behind the muffler. Your install reminds me why I avoid rear carb engines.