Engine Synchonizer

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Svend
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Engine Synchonizer

Post by Svend »

I want to remove my engine synchronizer on my 1976 Trojan F30 Express with 2 318's

has anyone done this?
What needs to be done...
I don't want any connections between the 2 engines?

I have read that some synchronizers actually sync the running of the 2 engines, but i don't think trojan's like mine had that set up...
I think think it was just a meter at the helm that was hooked up to the tach connection on engines? Can someone confirm...

Thanks!!

Svend
1977 Trojan F30 Express, With Dual 318's with Electronic Ignition
Raymarine EV 100 Auto Pilot
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prowlersfish
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Re: Engine Synchonizer

Post by prowlersfish »

Hard to confirm with out know what brand and model synchronizer you have . But if its just a flashing light or a gauge then its just hooked up to the tach wires or - on the coil . I suspect that's the type you have . Normally just done at or near the tach .
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P-Dogg
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Re: Engine Synchonizer

Post by P-Dogg »

PO removed mine -- installed some dual tach/synchronizer get up.

I removed THAT and installed port n starboard digital tachs, compliments of ebay. My mechanic, nursed from analog gauges since birth sez, "ENGINES DONT CHANGE BY 1 RPM LIKE THAT!"

Ahem, yes they do, you just cant tell with defacto auto-averaging analog gauges. I get them close by the digits, then finish tuning by ear. I open my eyes, and magically the numbers match! I find a stiff throttle helps.

Twin engines that differ by 20 RPM produce a throb every three seconds. Physics works! You can synchronize engines without resorting to a synchronizer.
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captainmaniac
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Re: Engine Synchonizer

Post by captainmaniac »

I had to disconnect my original synch a few years back when something went weird with the electrical system on one engine and the 50A breaker blew..... (insurance company put it down to lightning strike) but the engine it kept running by pulling 12V DC power - with reverse polarity - from the OTHER engine, THROUGH the engine synch! Know what? 18 gauge wires or whatever they are that go to the synch aren't designed to carry 30 amps, so things kind of melted pretty quick...

In any event, replaced with new wiring (with in line 2A fuses!) and a new synch. Basically the synch is just connected to each coil as Prowlersfish has said, and the gauge is just indicating if one coils is firing faster than the other (and by how much). That's the 'old school' way, and how most of our F series boats would be set up.

A lot of more modern boats use 'throttle by wire' technologies (as opposed to how we have cables between controls and throttle / transmission linkages). For the newer stuff that runs 'by wire', they basically have a computer or electronic control module between the controls and the engines. And in multi-engine setups they can have a button that you press so one throttle lever controls speed on all engines, via the computer or control module. NOT a cheap upgrade for your '77!!!!

To P-Dogg's point, with a bit of practice you can synchronize engines by ear (when out of synch you will hear a droning sound that is faster the more out of synch you are, advance or reduce throttle until the drone slows down, and eventually stops), but the audible approach works a lot better at speed. In close quarters maneuvering and at hull speed or less - like approaching or trying to work your way around a marina - you are less likely to be able to detect the engine speed difference by sound, so a gauge to tell you how close they are does still come in handy there.
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AwayOnBusine$$
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Re: Engine Synchonizer

Post by AwayOnBusine$$ »

Removed the sync from my flybridge. Still at main station. Is it possible that this could be the reason why currently I have no Temp or RPM gauge readings at both stations for the starboard engine.
F32 Fly 1975
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