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Art, your point is well made but missing two important considerations

One he replaced both power plants with new so you need to deduct that difference from the 60k say less 15k (7500 per side) for everything new. I don't know if you could replace your complete power from props to pulleys for that but should be close.

You need to also add it the resale value into the boat for his re-power, my thought is it would add 25-30k in returnable value. after all he has presumable replaced with new his complete drive system in including gauges. All things being equal I would pay 30k more for his boat then I would for yours, perhaps even 35k.

So now run your numbers not with 60k but with 20k difference and the numbers will be more real, and more appealing.

The net sum for what he did is not unreasonable as you would make it. Most boats in this class have diesels and that makes them more marketable as more people are shopping for them.

Just a fact, I know you like your gas engines and you should, just not as many people share your love of them and that makes your boat harder to sell (less buyers).
I for one would not have a large boat with gas if it was near free. I currently own two other boats with gas (outboard) and have owned 2 other boats with gas inboards both less then 30 foot in the past and they provided great pleasure and performance.
 
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SCOTTEDAVIS said:
Art, your point is well made but missing two important considerations

One he replaced both power plants with new so you need to deduct that difference from the 60k say less 15k (7500 per side) for everything new. I don't know if you could replace your complete power from props to pulleys for that but should be close.

You need to also add it the resale value into the boat for his re-power, my thought is it would add 25-30k in returnable value. after all he has presumable replaced with new his complete drive system in including gauges. All things being equal I would pay 30k more for his boat then I would for yours, perhaps even 35k.

So now run your numbers not with 60k but with 20k difference and the numbers will be more real, and more appealing.

The net sum for what he did is not unreasonable as you would make it. Most boats in this class have diesels and that makes them more marketable as more people are shopping for them.

Just a fact, I know you like your gas engines and you should, just not as many people share your love of them and that makes your boat harder to sell (less buyers).
I for one would not have a large boat with gas if it was near free. I currently own two other boats with gas (outboard) and have owned 2 other boats with gas inboards both less then 30 foot in the past and they provided great pleasure and performance.
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Scott - there is great truth in what you say and in some factors you add.

Over the length of a decade and one half there are many “cost”, “ease of use/maintenance”, and "resale" considerations that can become weighted heavily toward one type engine or the other... in respect to engine brand as well as correctness of engine installers’ expertise and their provided actions. I believe due to experience and lessons learned as well as listening to boat owners’ stories about their power train breakdown/costs/needs and also to marine mechanics accountings... that the 15 yr accounting-interval in difference twixt new diesels installed and new gassers installed (considering all things equal re boat owners' ease of use and ongoing good maintenance procedures) will show somewhat reduced cost for gassers if all expenses were to be put on an excel spread sheet... including install, repair, and boat resale at 15 yr end... but I have no rock solid proof on that premise. And, I’m not ever going to have that proof... seeing as a 15 yr blind test utilizing two duplicate boats in drive train comparison would blow me away!! LOL Heck, I’d have to take one boat out for 300 mile jaunt and then jump into the other for same jaunt, during same season, to keep things equal on a comparative basis... accomplishing those turnarounds just for test purposes would make me dizzy and I may fall overboard off one or the other – lmao!

That said... there is no reason I know of that any boater owner should not happily utilize the power source they prefer. This 21K lb when fully loaded, self contained, little 34’ Tollycraft play-toy-cruiser (some call a trawler - lol) we jaunt around in is about as large a boat as I believe applicable for gassers. My personal break point for gas to diesel power is at or below 38 to 40’ on pleasure crafts (depending on weight, hull design, travel-use, and other considerations). BTW: Regarding gassers... 350 cid turning out no more than about 270 hp max are the ones that can last for many thousand hours. Once a 350 marine gasser is hopped up and/or run steadily at more than 60% of its power rating (or propped incorrectly) the engine life-span will be substantively reduced. IMHO, marine 383’s, 454’s, 460’s, 427’s, 429’s and the like are fun to rod around with... but are fuel guzzlers that in the not too long-run can become costly replacements... just waiting to happen; making diesels a true savings in comparison. When I imply cost benefits re gasser to diesel on relatively small cruisers – it is non-hopped-up 350 cid Chevy’s to which I refer; standard power 318 Chryslers and 351 Fords can last a long time too; but, unlike plentiful Chevy parts their parts are not so easy to acquire!

As we head toward future decades in our lives I look forward to when I (Might) decide to kick back a little and really get deeper into more boating. Utilizing a completely different craft than our little Tolly, Alaska to points south with SF Bay/Delta as home ground could become my/our swan song into the sunset. No firm decisions made yet on this... and who knows what factor world events will play into this dream... but, I’ve always got my eyes and ears open!

Happy Boating Daze... Cheers!

Art :D
 
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The biggest problem on this forum talking about twins and singles is that 99% of the time the comparison is between a single w half as much power as the twin and the twin w twice as much power as the single.

If there's any interest at all about objectivity thinking about twins and singles in boats w the same amount of power is necessary. Only then will one be talking about the real differences between singles and twins. Otherwise the conversation will be mostly about a 240hp boat w 760 cu in engine displacement compared w a 120hp boat w 380 cu in. Not talking about twins and singes.

So to compare T&S re the 36GB you'll need to find a 36 GB w a single 240hp engine or a 36 GB w twin 60hp engines. Then you'll actually be talking about the differences between twins and singles.
 
Well put Art and I wish you good health as you look toward your future, may you and yours enjoy it.

As an interesting point to longevity of gas engines and hard use. I captain an air-boat a couple days a week (mostly during the cooler tourist months). cool way to pick up a few bucks and the tips are great, I call it my gun show money. :)

My friend Bob has two air boats Airboat Tours in Vero Beach Florida - Capt Bob Airboat Adventure Tours and we run the snot out of them. These are cast iron big-block V-8's making 425hp. airplane engines would not like the use/abuse we give them and are 3 times more expensive to buy and repair. Full power starts from idle to WOT (4300 rpm) to next spot then idle for a few min then WOT again. We use 5-8 gal of fuel per trip and run from 4-6 trips a day, each trip is an hour.

The oldest boat is in for an engine rebuild (it was running fine but he wanted to not have any issues coming up to the next season, and needed to spend some money or pay more to .gov) The motor has 4250 hours on the Hobbs,runs fine and uses a qt. in 5 hours use, don't let anyone tell you that gas motors are wimpy. They are NOT quiet motors.

Regards.
 
SCOTTEDAVIS said:
Well put Art and I wish you good health as you look toward your future, may you and yours enjoy it.

As an interesting point to longevity of gas engines and hard use. I captain an air-boat a couple days a week (mostly during the cooler tourist months). cool way to pick up a few bucks and the tips are great, I call it my gun show money. :)

My friend Bob has two air boats Airboat Tours in Vero Beach Florida - Capt Bob Airboat Adventure Tours and we run the snot out of them. These are cast iron big-block V-8's making 425hp. airplane engines would not like the use/abuse we give them and are 3 times more expensive to buy and repair. Full power starts from idle to WOT (4300 rpm) to next spot then idle for a few min then WOT again. We use 5-8 gal of fuel per trip and run from 4-6 trips a day, each trip is an hour.

The oldest boat is in for an engine rebuild (it was running fine but he wanted to not have any issues coming up to the next season, and needed to spend some money or pay more to .gov) The motor has 4250 hours on the Hobbs,runs fine and uses a qt. in 5 hours use, don't let anyone tell you that gas motors are wimpy. They are NOT quiet motors.

Regards.
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Scott - TY for good wishes and same back at cha! Yesterday I measured my BP... 129 / 73! At 61 yrs I'm still runnen with the youngsters! A life of sports, boxing, weightlifting, hard work... and of course boating/swimming/free-diving all play a part. :thumb:

Congrats on your Gun show $$$. Air boats sound like and look like a blast O' fun to play with, never been on one myself. There are a few air boats “quietly” stored indoors at our Marina... I think they are govt guys who go out looking for “delta” plantations – if you get my drift! :facepalm:

As you are getting long hours use from your monster gas engines... I can't help but wonder if the long time between rebuilds on airboat motors isn't due to less need for consistent/ongoing torque as well as so often and so pronounced rpm changes?? Needs for torque at constant rpm happens continually to almost any engine when it (or they) push heavy-lug pleasure craft (or work boats) through, or over, the water. Maybe cruiser engines should have an electronic system that constantly makes the motors alter their rpm levels instead of staying at same rpm for hours on end... often actually same rpm for their entire life!

By George!! Maybe we have uncovered a secret to increased marine engine longevity! :dance: :speed boat::socool:

BTW - I love your boat!
 
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SCOTTEDAVIS said:
...
As an interesting point to longevity of gas engines and hard use. I captain an air-boat a couple days a week (mostly during the cooler tourist months)...
My friend Bob has two air boats Airboat Tours in Vero Beach Florida - Capt Bob Airboat Adventure Tours and we run the snot out of them. ...They are NOT quiet motors.
Click to expand...

On airboats, the ear protectors aren't supplied because they hand out shotguns for practice.

img_174054_0_df237ea0b1a52417426d984d701c0d19.jpg
 
So true Mark, interestingly the props make the most noise esp. the tips.
 
Art said:
Scott - TY for good wishes and same back at cha! Yesterday I measured my BP... 129 / 73! At 61 yrs I'm still runnen with the youngsters! A life of sports, boxing, weightlifting, hard work... and of course boating/swimming/free-diving all play a part. :thumb:

Congrats on your Gun show $$$. Air boats sound like and look like a blast O' fun to play with, never been on one myself. There are a few air boats “quietly” stored indoors at our Marina... I think they are govt guys who go out looking for “delta” plantations – if you get my drift! :facepalm:

As you are getting long hours use from your monster gas engines... I can't help but wonder if the long time between rebuilds on airboat motors isn't due to less need for consistent/ongoing torque as well as so often and so pronounced rpm changes?? Needs for torque at constant rpm happens continually to almost any engine when it (or they) push heavy-lug pleasure craft (or work boats) through, or over, the water. Maybe cruiser engines should have an electronic system that constantly makes the motors alter their rpm levels instead of staying at same rpm for hours on end... often actually same rpm for their entire life!

By George!! Maybe we have uncovered a secret to increased marine engine longevity! :dance: :speed boat::socool:

BTW - I love your boat!
Click to expand...


My assistance tow boat is probably somewhere's around 4500 hr also...maybe more..and still pulling strong.

Maybe it's because it gets varies load and rpm all the time...it also gets abused all the time...every week for the summer and lots of the spring and fall.... it gets run for hours (light loads) at well over 210 degrees, and the overtemp buzzer driving me nuts .....pulls for hours at 3000 rpm AT THE PIN (severely overloaded) with the prop surging from cavitation to unground boats, severely overloaded pulling 100 plus foot barges with cranes and tens of thousands of pounds of building supplies, towing for a lot of that time with the prop dragging through the mud dinging clams, oysters, logs, etc....yep...pretty hard lives under all the conditions that people say will shorten their life.

The thing that keeps engines running for a long time is.... use rather than non-use and basic maintenance. My engine gets cheap (bulk) oil at 200 hr intervals. It also doesn't get aligned when misaligned or props redone when dinged or the cutlass changed when it makes the instruments vibrate so bad they are hard to see.

The engine has gotten me home in 11 seasons every time, with just minor on the spot jury rigging at times. I have run it for weeks with major exhaust leaks that sprayed salt over it and crusted dry, ran it for a week with a pencil eraser sized hole in the side of the raw water pump.

Sure I would never do these things if I didn't have to...and probably never with my own engine. But it doesn't mean that that the base engine is gonna come apart because things aren't perfect.

I have no idea when this motor will die...but as the owner once said...none of our fleet has ever just had one fail...they all have given us fair warning.
 
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Ask any flight school as to hours they get out of an engine versus a private owned aircraft that gets less then 2 hours a year of use.

Engines seldom wear out they mostly rot away, run every day and used they will go 10X's longer then tied to a dock. If not used then pickle them for storage.
 
SCOTTEDAVIS said:
Engines seldom wear out they mostly rot away, run every day and used they will go 10X's longer then tied to a dock. If not used then pickle them for storage.
Click to expand...

My experience with industrial equipment as well. Plenty of pumps out there with over 50,000 hours of use as just one example. Use it of lose it which is fine with me. I don't buy stuff to leave it collecting dust on a shelf or chained to the dock.:dance:
 
< Ask any flight school as to hours they get out of an engine versus a private owned aircraft that gets less then 2 hours a year of use. >

You bet , the T-28s used to learn to carrier Qualify in training were operated at full throttle many many times a day ,day after day, yet had the best record for being operational in the US Navy training command.
 
The twin versus single engine debate will go on for ever. My opinion is that it depends on the boats intended use. If you are marina hopping over short distances you will enjoy the docking benefits of twin engines. If you are going long distances repeatedly the single has definite economic and maintenance advantages.

Again relating to use. When we were in the United States 4 out of 5 trawlers we ran across were twin engine, In our five years in the Caribbean we have yet to run across a non local twin engine trawler less than 60 feet in length.

Of course in the Caribbean 4 out of 5 trawlers have a second wing/ auxiliary engine which serves several functions, docking, get home and spare generator.

As with anything with boats, figure out your intended use and then decide.

Marty
 
Bay Pelican said:
The twin versus single engine debate will go on for ever. My opinion is that it depends on the boats intended use. If you are marina hopping over short distances you will enjoy the docking benefits of twin engines. If you are going long distances repeatedly the single has definite economic and maintenance advantages.

Again relating to use. When we were in the United States 4 out of 5 trawlers we ran across were twin engine, In our five years in the Caribbean we have yet to run across a non local twin engine trawler less than 60 feet in length.

Of course in the Caribbean 4 out of 5 trawlers have a second wing/ auxiliary engine which serves several functions, docking, get home and spare generator.

As with anything with boats, figure out your intended use and then decide.

Marty
Click to expand...

Well put... backed up by years of 1st hand knowledge. Thanks! - Art
 
There will always be some ways to show that ther'e is one or two advantages of having a single but if you consider most significant differences the twin is clearly a better and more expensive boat. I am speaking of boats w the same amount of power.
 
Better is an elusive concept.....

Without a defining set of parameters...just a fleeting thought of no consequence....:socool:

That's why the debate always winds up back at the same place...better for some is not better for others.:thumb:

Now for some...twins with bow and stern thruster with a get home engine/shaft and both Sea Tow and BoatUS is a good idea.:rofl:
 
FlyWright said:
I agree with all twistedtree says here, but the easiest one to deal with is the dripless log water flow. My boat has PSS seals and I simply placed a "T" into each water line and connected a crossover line linking the two. Now either engine can deliver water to the other dripless seal. Normally this is only an issue if traveling more than 7-8 kts, but I added it anyway just to be sure. It was a simple 15 minute job and cost less than $10.
Click to expand...

Seems to me this should also be the approach for the tranny cooler. Our velvet drives need the cooling. I think I might well do these mods before heading south in Oct.
 
Heat should not be an issue with free wheeling a Velvet Drive. When I talked to their rep, he didn't think free wheeling was any problem at all on a 10 knot boat. He pointed out that Velvet Drives are designed to be used on sailboats and while under sail free wheel the prop. Granted, some boats have feathering or folding props, but not all. He suggested swapping engines every few hours to keep the hours even and lube the tranny bearings if we were concerned.

Velvet Drives pump the tranny fluid through an external water cooled heat exchanger. If the tranny is free wheeling the pump is not pumping fluid. Reverse engineering it to pump fluid while the tranny is free wheeling might be an engineering challenge?
 
psneeld said:
Now for some...twins with bow and stern thruster with a get home engine/shaft and both Sea Tow and BoatUS is a good idea.:rofl:
Click to expand...


Why didn't I think of that. I have always believed in backups. The only topper I have is a fellow I met who because of a last minute back out on a boat sale ended up with two identical boats, named the same and docked next to each other. Talk about spare parts

Marty
 
Someone recently posted, not this thread, that they fired up their wing engine, driving a counter turning prop etc, to complement their single when docking etc. Without the advantage of experiencing the system at work, it sounded a good "best of both worlds" idea.
(Oops, posted here too,see #43 supra)
 
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Re: velvet drives. My owners manual clearly states that free wheeling is acceptable with these transmissions. And I have.
 
Blue Heron said:
Re: velvet drives. My owners manual clearly states that free wheeling is acceptable with these transmissions. And I have.
Click to expand...
The Service Manual for Models 70C and 71 approves freewheeling, qualified by "under sail with the propeller turning,or at trolling speeds with one of two engines shut down".
Trolling speed is fairly slow. Perhaps BW are being cautious.
 
I have always considered trolling speed to be at least 6 knots and more likely up to 8..so I think most trawlers in the mid sized class would be fine.

Bay Pelican...I forgot sails in my last post...just in case all else fails including fuel tanks, etc....:D


Note...may be worthless but found this...

called Velvet Drive Transmissions/Marine today (864.843.9234) which is no longer a subsidiary of Borg-Warner and was directed to their technical department. The person I spoke to was named Jeff who explained that the transmissions can operate freewheeling safely if the speed is kept under 7-8 knots. My speed with the engine set to 1350 RPM last weekend was 6 knots.
 
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Thanks guys good info on the VDs. American Diesel had told me the opposite and frankly I hadn't gotten around to confirming it. I think I'll try the single option. The boat is so much quieter that way.
 
Daddyo,
When running both engines are they well synced?
 
Aren't dual engines for wannabe and allreadybe pilots? ... I wanna see someone handling four throttles for a four-engined boat! Like my Dad did with a B-17 over Germany.
 
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manyboats said:
Daddyo,
When running both engines are they well synced?
Click to expand...

Yes. I sink mine with an inferred tach within two rpm. Regardless of this there is a resonance that is greater then the sum. If I ever re-power ours I will convert her to a single.
 
BruceK said:
Someone recently posted, not this thread, that they fired up their wing engine, driving a counter turning prop etc, to complement their single when docking etc. Without the advantage of experiencing the system at work, it sounded a good "best of both worlds" idea.
(Oops, posted here too,see #43 supra)
Click to expand...

Bay Pelican's setup is a center line 28" 3 bladed left hand prop which has prop walk in reverse to starboard. Offset to starboard is a27 hp Yanmar driving a small right hand 3 bladed Max prop which has prop walk in reverse to port. The Max prop is automatic feathering. Because of the automatic feathering nature of the Max prop the small wing engine in reverse gives a greater prop walk to port than the main engine does to starboard. Thus it is easier to dock Bay Pelican to port than to starboard.
 
Daddyo if you repower you'll have different engines.

There must be some part of you're hull, struts or other factor that is causing the vibrations of your engines to "excite" a section of the hull bottom, a bulkhead or some other part that has the right/wrong length/mass that naturally resonates to certain vibration frequencies.

Do other people that have the same boat have the same noise "experience"? And what's different about their boat?
 
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