I am wondering if anyone is familiar with an item that plugs into your #3 throttle channel and syncronizes/matches the RPM's on a twin engine nitro plane. I am wanting to syncronize 2 Magnum XL70 four stroke engines on a Dual Ace. If you know the name of it and have used it, please share your thoughts and experience with it. Thanks

Best regards

Be very careful in trying to match rpms on twins, one will be a little less powerful than the other. You will end up with a lean engine if you are not careful, that is a dead engine on one side.
I tune one at the proper setting and than the other the same way, I do not try and tach to match RPM's I have seen others do that and the result is an engine that is not happy and stops in mid-air.
The plane will fly just great, both engines will function properly and No-one will ever know the difference

I agree, forget the synchronizer. Just make sure the engines are running properly. Do them one at a time with a final test of holding the plane with the nose pointing up to the sky. Make sure the engine does not slow down and stays constant. Shut it off and do the same with the other one. Refuel and go fly. I have no idea why people try to sync their engines. It is something that will happen if both engines are running properly most of the time. Do not try to force it or you could end up with an engine out or a lousy running engine.

I adjusted both my engine separately, then figure out which one is stronger. I also use the twin sync. I think the engines sound better synced up. The twin sync monitors the rpm of both engines then takes the higher rpm and slows it down and take the lower rpm and brings it up. I just make sure the lower rpm is set rich so that when its rpm is bought up it doesn't go lean. Also if you lose and engine with the twin sycn it automatically brings the running engine to the idle point that you set. to get the power back just bring the throttle stick to idle and when you advance it again you get control of that engine again. This saved me when one of my engines ran out of gas. No adverse yaw and I was able to safely get it back on deck. I run it on 2 o.s. 70 4 strokes on a hangar 9 twin otter. but I do agree with every one else to get the engine adjusted one at a time and dont rely on the twinsync to do it. The engine should run good without it and if it does not I dont fly it.

Thanks bigstew60, thats the info I am looking for. Who makes it/carries it and how does it hook up?.....nevermind, found the thread.

Thank you,
Ed

This is way to do it if you want to keep your plane alive and well. The only thing i might add is that once you have the first engine set, shut it down and then start and set the second engine without temptation of getting them in sync.

I agree that they sound great when they are in sync. But you need to ask yourself what is better. Good long life for the plane or the risk of a shorter life that sounds really cool?

More often than not when you use my method (and others) you will end in sync.......my OS 32f's are that way and I don't tach them at all. Sounds really good on a high speed pass!

I have two saito .62 four stroke on my h9 twin otter...with synchronizer.
If you tune up youre engines saperate they wont stall...and the advantage...they are in sync from 3000 to 10000 rpm...
You never get that without a sync system...and great sound when the engines are exact on the same rpm
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Guess I am lucky as my 32's operate much at a rpm range higher than most 4 strokes and they do sync, a really nice sound that everyone at the field comments on.

This is the reason why I want to try it. I can tune them no problem, but I do love the sound when they are in sync plus the peace of mind the system offers.

If your radio has a throttle curve function or a multi point mix you can use this to synchronize your engines. Simply tune up both engines so they run great, then determine the idle and the max rpm you want to run. Now say idle is 2.5k and max is 12.5k and you have a 6 point mix curve then each point is in 2k increments. I set up each engine where they are in sync at each mix point. Idle 2.5k, point II 4.5k, point III 6.5k, point IV 8.5k, point V 10.5k and Point VI 12.5k. The sync is all in the radio and not in the engine. Just make sure each engine runs good on its own. And always hold the plane vertically to check for lean tune on an engine just as you would for a single engine plane. Good Luck.

The best thing to use is an on board glow plug lighter. I would set him up to a toggle switch; when you take off or land, you keep the plugs lit.

That is an other advantage with the twin sync from Bill Wike....it has glow drivers on board...
Easy to start....and when the engines are on idle the plugs are on.
Another advantage...when one of the engines stalls, the other one follows at once ( till idle)
Then you can decide what to do..fly with one engine....or turn the other one off to.
If you work with The throttle curve function this will never work.
The system will also work with 2 different engines....one old and one new...os and saito...even if there is a different in power...doesn't mather because the system syncs on rpm

I am a happy user of the system


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