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Engine Sync
Hamdog
Member Posts: 247 ✭✭
Hey guys,
Already missing the boat BIG TIME!! I check the forum everyday for ANY boating news from ANYWHERE. Helps with the withdrawal.
Thought I'd ask a question. My sync gauge as well as both tachs have been kaput now for about a season and a half. Even the Faria tap no longer works. Doesn't bother me that bad as we normally only make about a 15 minute run to drop anchor. But I was thinking maybe not having the engines in sync might be hurting the boat? Probably not off by 500 rpms or so but would like your opinion. Could I be damaging the boat? What if I made an hour run? What if I'm off by 1,000 rpms?
You guys see an issue doing this?
Thanks.
"Wetted" Bliss 2005 Rinker 342 - Black Hull - Twin Mercruiser 350 Mags - BIII's
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PC BYC, Holland, MI
I am with BD and use my rpm guages but first listen for the rolling purr of synchronized engines matching the same rolling pitch. I have a FloScan system and when one engine is even off 200 rpm from the other my burn rate difference can be up to 2 gph different. That's huge so 500 would be much more of a spread.
Hope everyone in the MW has a safe winter... the weather man says its going to be a record breaking nasty cold front!
Take care
LG - Mark
Thanks LG.
That 2 gph more fuel burn would obviously concern me since we are planning to make a 4-day exploration of the Lake this summer. I think I will look into the FloScan System next season. About what would one cost to purchase and have professionally installed?
Thanks,
Hamdog
Dream 'Inn III -- 2008 400 Express
Dream 'Inn III -- 2008 400 Express
Not sure what the labor cost would be. Maybe 6 hrs plus. For me it took about 8-10hrs. Its not hard to install. It just takes slow methodical time and reading the instructions over and over again.... Twin application is the 9000 series. Google FloScan. They are here in Seattle and a very trusted brand. I did mine about 5 years ago. Main unit around $600, plus the purchase of 2 fuel scanners, barb fittings and micron fuel filters placed prior to the fuel scanners came in around $800. That's a lot of coin but it paid for itself the first year. I actually increased my speed by 5 KNOTS and what I saved in fuel burn paid for the unit. I like the FloScan only because it is free standing from the GPS unit. However with my new Garmin 5400 touch screen I bought a couple of years ago with split screen options it would have been far cheaper to buy the Garmin fuel scanners and plug and played right to the Garmin. I can say the FloScan is always with in one gallon accuracy at 100+ fill ups so 1% accuracy rate is darn good.
I have penta 2006 5.0 270hps. So my computer options are very limited. I believe 2008 and higher, the options are nearly unlimited. If I had two year newer engines I'd skip the FloScan and go totally digital like the guys mentioned above with thier vesselview systems.
What ever you pick, just don't go another season without a fuel monitor. What ever the cost... its total worth every penny and more importantly piece of mind on true fuel remaining!
Good Luck
Another way to explain the gain in efficiency... my old speed gave me .95 MPG. My new average is now 1.1 even though my gph burn increased as I throttled up... my over all gain in speed made it up with better mpg.
Again twin 5.0 VP with the new ocean x DP drives two years ago. Salt water.... Clean painted bottom with 10ft dinghy and 9.9hp motor on transom / about 200lbs, genny, full fuel and water, weeks suppy for three. O yeah trim tabs at 20% and drives around 10%. So pretty happy with the results. Must be the wide beam. :-)
If I had 5.7s the RPMs would be slighty lower achieving the same speeds allowing for even a better fuel burn. My guess 1.25 mpg as my buddy's 29 chap with similar set up as mine gets 1.75 mpg. Now he is about 3000 lbs lighter.
LG
diesels equiv is exhaust gas temperature.. the lower, the better- the lower, the more complete the burn, the less smoke, and the less load on the engine.
a practiced ear can tell on both...
with either, there is a distinct sound when the engine is gasping for air, most evident on acceleration.. it is at these times, with a gasser, when the vacuum signal drops to -1~-5", or becomes non-existent.. this means means the engine is inducting all the air it can, but it also means the engine is injecting/jetting maximum fuel as well.. which tosses your air to fuel ratio, and washes cylinders with unspent fuel. your economy is spent right through your exhaust.
I'm not familiar with the vessel view set up, but I imagine it uses three keys to calculate- engine throttle position, engine vacuum, and injection duty cycles expressed in lambda. knowing those, and reconciling them with additional points of interest (such as fuel flow), you can mange those engines pretty well.. but you can do the same thing with your ears, if you're practiced enough- which most of us are, but we just don't realize and quantify in a way that's useful.
there is that bog sound that is unmistakeable, once you've nailed it down. If you can manage an engine from a higher RPM to a lower RPM, and tune in to the sound, listening for the bog to reduce or eliminate- I bet a dollar to a doughnut what your vessel view is telling you is what your ears already know, and that you've found optimum cruising speed....
I'm willing to bet that y'all already use that bog sound, and the levi dyno when trimming the tabs and drives, and just use the speedo and tach to confirm what you already know...
I don't trust gauges very much.. I wouldn't mind having a vacuum gauge on the dash, but that is quite a distance to run a hose and expect reasonably accurate readings- and it is a lot of exposure for that line/hose to develop an abrasion and create a vacuum leak..
The purpose of my rig is to float me out to a sand bar two or three times a week during the summer.. I could really care less about fuel consumption, unless it is way out of whack- and only then as to warn me that something is wrong. IF, though, I had interest in cruising any accountable distance, I would be very interested in fuel consumption- not because of costs, as that is just a part of boating, but instead in terms of distance and range... I like to have range.
drewactual,
Very good post and I am entirely in agreement. I enjoyed the lesson and I actually have pretty good ears for the way the boat is performing.
I will add that I have learned a few things. I have never used the trim tabs except for port to starboard trim and only a few times. I have also never used the "trailer trim" either but I do remember the marine guy when I was buying it telling me to "bump" the "trailer trim" a notch but I never did.
I will play around with everything this spring.
Thanks for all the info. This forum is another great reason to buy a Rinker!!
Hamdog
And this is kinda funny and revealing.
When I bought my 342, it was delivered from Lake St. Clair in Michigan to Lake Cumberland in KY and was my first twin engine boat. The biggest boat I had before was a Bayliner 2855, stripped to the bone with a single engine. Loved it but didn't know what I was missing.
Anyway, I had the 342 delivered to a local Marine Service Company where I had fresh bottom paint, new batteries installed and everything serviced. They preferred to launch it at a different marina due to water depth. So I had to take my new boat (alone, my wife was driving the car) about 15 miles to my new marina. Never even been on the lake before. When I asked when do I know to make the right hand turn, all I got was you'll just know. Now the telling part. I NEVER TOUCHED THE TRIM CONTROLS. Not that I didn't know to but more because I was as nervous as a cat in a room full of rocking chairs. And it was pouring rain with 20 mph winds!! I must have been an idiot.
Turned it sideways putting it into the slip and did a bit of fiberglass damage but I got it in and all that has been repaired. Much better Captain today but would not have given that day up for anything!!
Hamdog
LG
Pull the heads on an engine with some good time on it, or, get a good scope and peek down a spark plug boss..
Engines that have been treated well will have hatching still evident on the cylinder walls.. hatching is a purposely done scoring of cylinder walls that float the piston rings in a direction conducive to good seating, as well as scour the piston rings in a way that marries them to that specific cylinder for the life of the engine..
Improper air to fuel ratios will devour that hatching.. lean a:f runs hot... Rich runs cool.. the metals used in engines are intended for a specific range.. cooler is nearing as bad as hotter, in many cases, and especially for rods, journals, and bearings.. lack of quality oil, oil viscosity, and flow will devour it, too.. bad fuel (uhem, ethanol) is very **** them..
An engine that operates in the engineered environment, the one intended, will last a long dang time if properly maintained, given there are no manufacturers shortcuts.. I've not seen any notable shortcuts with merc.. move over to the automotive world, every maker has their tricks to cut costs, and that is frustrating..
If Al is watching this thread, an as an aside, I am wondering if merc has joined the dark side and are using plastic guides and pedestals/rocker arms like most auto makers are now?
You keep the 'tude, dude, and your engines will always take care of you.. that's my philosophy, anyway..