Bob:

The EMS/Jomar engine synchronizer unit can be used as supplied for any two engines, whether they are the only engines on the plane, the two on one wing, the inners only, or just the outers.

By usingtwo uits on a four engined plane, you could lock the left pair with one, and the right pair with the second. Then, using the "Twinman" method you could sync the two pairs with the transmitter mixes and curves. Or you could use a third engine sync unit to lock the two pairs for absolute engine synchronization.

I have the EMS/Jomar uit on one of my twins, I like it very much, it works fine. But I've not seen it as a necessity. But if I were to build a four engined plane I would give the three-unit installation some serious thought. Two engines are bad enough when giving problems, three, maybe OK. But four? Hey, EMS, Help!

Bill.