Synchronizing

Inquiry --***** For those of you with twin screws.*

Are your engines synchronized (Glendenning) or some other system?****** KJ

once upon a time they were. then I lost one of the magnets from on the shafts. Since then I have learned that the transmissions have different gearing, so synchronizing the shaft rpm didn't make any sense.

Now I run the engines to the same rpm (close) according to the harmonic vibrations I can feel. nothing more scientific than that.

So what kind of synchro makes sense?

Same here. *Run them both up until, usually the Starboard engine tac is at the RPM I want to run and then adjust the port engine until it harmonically matches. *No real reason, other than the port engine throttle is a little smoother and adjusts, fine tunes, a little easier.


-- Edited by Edelweiss on Sunday 23rd of October 2011 11:16:27 PM

Having had Lehmans for near on 14 years I would venture that using the words 'sycronising and FL 120's' in the same sentance is probably a bit of an Oxymoron.

KJ wrote:
Inquiry --***** For those of you with twin screws.*

Are your engines synchronized (Glendenning) or some other system?****** KJ

Click to expand...

*Used to be a Glendenning install and service tech...

What is your specific*question?

While I think Glendennings are great...they are on*expensive side...the single control/slave engine feature is nice

Yes, my engines have a synchronizer.* it works great.* Turn it off around the harbor.* Keeps 'em running smoothly.* Less vibration is a good thing.

I have a Glendenning and love it. It's one of the most reliable pieces of equipment on the boat.

psneeld wrote:KJ wrote:
Inquiry --***** For those of you with twin screws.*

Are your engines synchronized (Glendenning) or some other system?****** KJ

Click to expand...

*Used to be a Glendenning install and service tech...

What is your specific*question?

*

*********I am trying to asses the pros and cons of synchronizing, and the*Glendenning units themselves, or other system that may be in use.*** KJ*

*

Nice thing with a Glendenning is they have attachments that allow you to attach accurate tachs if you don't already have them...they are reliable if installed correctly but are pricey for what you get on slow turning engines...definitely worth it on high speed craft for vibration eminimization.

Cheapo electronic units usually don't work well and aren't all that accurate...and sometimes maintenance problems...at least the ones from a few years ago were.

I would be tempted to just go with REALLY accurate tachs and just adjust by the numbers.

I've got a Glendenning but it isn't working correctly at the moment so I stopped using it. The slave engine rpm fluctuates small amounts, any idea what the issue could be? As to the attachments for tachs how is this accomplished? Does the Glendenning get it's tach info from the engine itself or from the alternator?

check the drive cables that are hooked to the glendenning, they might eed to be lubed* with wd40, check for kinks in the cable also

KJ wrote:
*
*********I am trying to asses the pros and cons of synchronizing, and the*Glendenning units themselves, or other system that may be in use.*** KJ*

Click to expand...

*

*I didn't mention the brand.* It is Accusync.* It has proven very satisfactory.

Glendennings do suffer from bad cable runs...need lube or new...AND unkinking. The engine takeoffs do wear and need annual or more lubing. An intermitent one may have a loose electrical but if I remember correctly...they tend to be a more on or off condition electrically.

The tack takeoffs on all engines are mechanical...that's how the Glendenning actually works by turning cables that keep the engines in synch by mechanical means...not the trick is how to control the engine throttle...gets a little tricky if the engine is computer controlled and the throttle linkage is hard to adapt.

I have a gauge that indicates which engine rpm lags. I move the throttles to center the needle on the gauge and the engines are the same rpm. Much more accurate than the tach's. No idea who makes it or how it works.

*
My Tollys synchronizers are the old-world flashing-light style split screen in a circle that is recessed inside a well shaded, heavy duty, white, and adjustable angle encasement for viewing even during bright sun conditions on the bridge... dont recall mfg brand.* One is on upper and one on lower helm, both work great... been using them for years, came on the boat when purchased!* Either one function, as long as the ignition is turned on with engines running i.e. the engines started at that helm.* If I started engines at either helm I wont turn the second helms ignition to on position to activate its synchronizer for fear of causing some sort of unexpected electrical problem maybe it wouldnt hurt, but activating synchro lights on the unused helm would be pretty much unnecessary and I like to error on the side of caution whenever possible!*
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I listen to the corresponding (synchronized-harmony) sound of both engines to really tell if they are running in sync.* My tachometers are OK, but not perfect by any means in reading exactly the same when engines are truly in sync.* Anyway, although the harmony sound of synchronization being my fail-safe Ive found that the old-world flashing-light type synchronizers perform right on the money to meet my synchro needs.* I bring the flashing lights into perfect synchro flash and then listen carefully to the synchronized engines purrrrr in harmony together!* Theyve been accurate at any speed and give me a good synchro visual to use as backup to my harmony seeking eardrums!

KJ wrote:
Are your engines synchronized (Glendenning) or some other system?******

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*We syncronize our engines the 100% reliable*way, which is by ear and feel. Never had a problem getting them in sync at any rpm using this method.* The SW tachs on our boat offer "suggestions" as to actual rpm.* They're close, but not close enough to use for syncing the engines.* We've adjusted them a few times using a*strobe*timer on the drive pulleys on the fronts of the engines but the tachs drift off again almost immediately.

But neither I nor my wife have ever had any difficulty syncing the engines by ear and feel, so as long as the tachs get us in the ball part of the rpm we want to run we're good.


-- Edited by Marin on Monday 24th of October 2011 05:02:53 PM

A pair of shaft , rather than engine tach 's might make hand setting easier.

I am with Marin on this one. Another thing that always made me feel kinda weird was the synchronizers that only use one power lever after you get them synced up.....that is just not natural. I have run on some big sportfishes with BIG engines from the flybridge and you just don't get the "tactile" feedback necessary to sync by ear/feel(like doing 25kts at 1700RPMs...wind and water noises dominate). So I imagine synchros on those boats to be necessary....or not.

If you get right down to it, why synch them??? To get rid of that annoying wahwahwahwah.....and if you can't hear or feel it, who cares????!!!!...


-- Edited by Baker on Wednesday 26th of October 2011 10:57:27 AM

Baker wrote:
I am with Marin on this one. Another thing that always made me feel kinda weird was the synchronizers that only use one power lever after you get them synced up.....that is just not natural. I have run on some big sportfishes with BIG engines from the flybridge and you just don't get the "tactile" feedback necessary to sync by ear/feel(like doing 25kts at 1700RPMs...wind and water noises dominate). So I imagine synchros on those boats to be necessary....or not.

If you get right down to it, why synch them??? To get rid of that annoying wahwahwahwah.....and if you can't hear or feel it, who cares????!!!!...



-- Edited by Baker on Wednesday 26th of October 2011 10:57:27 AM

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*John, with Accusync you still operate both throttle levers.* For the sync to work, the engines have to be within 15% of the same speed.* Then it brings them into sync.* You can still accellerate or deellerate an engine by bringing it out of the 15% window.* The flick of a switch turns it off completely.* I do not have it on in a harbor as I tend to steer with the throttles and gears in tight places.* Works for me. YMMV.

Several years ago friends bought a 34' Olympic. Only five or six were made as Olympic could not compete against the less expensive Bayliner model of almost identical size and configuration. The boat had two Volvo diesels driving through V-drives. We went out on this boat a couple of times. It had an engine syncronizer but at lower rpm the syncronizer would "hunt" in and out of sync periodically. The dealer who sold the boat said this was a characteristic of this particular syncronizer. It was fine at higher cruising rpm.

But at slower speeds it was almost as annoying as not having a syncronizer at all and having the engines slightly out of sync.

In any event we've never felt a need for a syncronizer on our GB. While we never drive from the flying bridge anymore, on the few occasions we did steer from up there in the past we had no problems syncing the engines by sound and feel, either, even though we were quite removed from the engines themselves. Feel was the more obvious indicator than sound up top.

Forgive my ignorance but I just purchased a 48 foot Californian with DD 6-71's. On my first cruise after purchase I hit the sync switch at about 1200rpms and the port tach went to 0? I turned the switch off and the tach came back. Does this mean that my Port motor is the slave and when adjusting just use the STBD lever or am I completely off base?

knot head that is how the glendinnings work on the sportfish i run.it is important to have your engines in synch when trolling for tuna and marlin

I don't know how accurate synchronizing has to be to reap it's full benefit...something like less than 15 rpm difference...but reduction in wear from harmonic vibration is the real reason to sync I believe.

psneeld wrote:...but reduction in wear from harmonic vibration is the real reason to sync I believe.

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Synchronizers are installed purely for comfort. There may be nano-benefits in increased efficiency related to load sharing but it is probably too small to measure.

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RickB wrote:Synchronizers are installed purely for comfort. There may be nano-benefits in increased efficiency related to load sharing but it is probably too small to measure.
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******** Amen.........(Whew!)

Back to KJ's original question - I have a "vintage" Glendenning synch. By appearance, it looks pretty close to what they're selling today. It was inoperative when I got the boat. Took about 2 hours and $2 to get it functioning (prior owner fancied himself an electrician, I think). It works like a champ and I found the single stick operation not hard to get used to and somewhat useful. As others have mentioned, I do not use it in traffic areas or close quarters. Glad I have it, but I don't think I'd spend the $ to equip if I didn't.