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Old 02-10-2008, 06:13 PM   #41
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RE: Design

FF,
I sure agree the over pitch boat has merrit but only with an over powered boat ... not hard to find. Several big problems emerge with over proping. 1. The first and most important is the loss of a big chunk of the engines top end. What if Marin is 300 rpm over proped ? He would max out at 2200. But he not only will loose 300 rpm but the next 2 or 300 rpm as well because his engine would be over loaded and so he may loose as much as 600 rpm and about 50 hp. What if ETA at anchorage is after dark bucking head seas and head winds both unexpected ? Would he resist the temtation to over load his engine and speed up ? No one knows exactly where ( rpm wise ) the over load condition will start. 2. There will be considerably more thrust at idle engine speed so idling in gear will result in much higher speeds at idle. When I reproped my Willard I noticed a big reduction in idle speed ( boat speed ) around harbors. Not good constantly shifting in and out of gear. On the plus side there will be a bit less fuel consumption and maybe a bit less noise and vibration. It seems Marin is interested in neither. I'm not really picking on Marin and the above example is a bit extreem but a major engine supplier ( Westerbeke ) states in thier engine brochure all marine engines need to be proped to achieve maximum rated rpm at WOT. Sounds like they don't want thier engines over loaded.
Eric Henning
30 Willard
Thorne Bay AK
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Old 02-10-2008, 10:26 PM   #42
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RE: Design

Marin, FF, Adam T, Dark Side, Ken, Jay N and Vinny,
As Marin said I misquoted Northern Lights ( Lugger ) in a previous post .. but not by that much. It came from PMM October 2000 pgs 128 and 129. Here it is.
" How do we keep a lugger engine, or any other marine, preforming well ? I asked Dick Gee, vice president of engineering at Alaska Diesel Electric who joined the company in 1965 as a mechanic, and McElroy, the sales director. The answer: Keep the oil clean, keep the fuel clean, " and don't baby the engine." If it's a new engine, the answer is the same. The advice at Alaska Diesel Electric is to load a new engine and work it hard. " I used to tell people to drive it like like they hated it," says Gee. Later at a TrawlerPort fourm sponsored by PMM, McElory tells the audience:" Beat it up ." In normal use the company recomends operating a propulsion engine at a load factor of 50 to 70 percent of it's maximum power. A manufacturers fuel consumption curve is needed to identify load factor. Devide the amount of fuel being used by the maximum possible consumption and you'll have the factor. On an engine that turns at a maximum of 2200 - 2400 rpm, the ideal operating range is going to fall in the general area of 1800 to 2000 rpm." End of quote. !800 for and engine rated at 2200rpm and 2000 for an engine rated at 2400 rpm. Since the Lehman engine is rated at 2500 rpm it looks like the magic number is 2100 rpm cruise. Respectfully submitted:
Eric Henning
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Thorne Bay AK
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Old 02-11-2008, 02:01 AM   #43
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RE: Design

Like I said, what they say you should do and what they actually do themselves are two different things. Also, Dick was talking about new engines, not old thumpers like the Lehman. We are running our two Lehmans using the advice and power settings Dick recommended to us when we bought the boat (which also happen to be the same power settings the previous owners of our boat used for the 28 years before we bought it).

Anybody who operates a Ford Lehman at 2100 rpm in cruise will soon be shopping for a new engine. This 1950s engine will not hold up under that kind of treatment. Our diesel shop alone can list a number of owners who have demonstrated this to be the case, much to he owners regret.

According to the people who created the FL120 in the first place, the optimum continuous operating range for this engine is 1,700 to 1,900 rpm. One can wave around all the engine power loading/rpm theories one wants, but the experience of thousands of boaters using this engine from the mid-1960s to today shows that if you want 12,000 to 14,000 hours out of this engine, you best stay inside that 1,700 to 1,900 rpm band for normal cruise power.

Now I don't have a clue how modern, high-speed diesels should be run, or turbocharged diesels, or two-cycle Detroits. We don't have that type of engine, so I have no reason to learn their proper operation. Dick has told me the operating parameters of a "modern" marine diesel like their Luggers is WAY different than the way on old thumper like our FL120s should be operated. We have followed his advice to the letter and so far have had excellent performance from our engines. They don't smoke except on startup and in 100 hours, each engine uses a half quart of oil or less.

As to Steve D'Antonio I know the name but I don't know anything about him nor do I know what theories he espouses about diesel operation. I gather he writes for Passagemaker, but since I don't read that publication I have no idea of his position on their staff. So I don't have any opinion at all about his experience or qualifications.
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Old 02-11-2008, 04:54 AM   #44
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RE: Design

All I can say regarding the "run 'em like you hate 'em" statement is that apart from break-in, I don't know any engine expert who actually follows that advice with their own engines.

It IS common on trucks and busses to rev to the pin on each and every acceleration .

On a Coach its necessary as the transmission is usually only a 4 speed and it takes max rpm to be fast enough for the next gear to not lug too long.

"What if ETA at anchorage is after dark bucking head seas and head winds both unexpected ? Would he resist the temtation to over load his engine and speed up ?"

With an under $100 Exhaust Gas Temperature Gage , an owner can run as hard as desired with NO danger of harm.

"Not good constantly shifting in and out of gear."

If a boat cant be shifted in and out of gear at idle , its sure gona be hard to dock when frequent shifting fwd to rev is the norm.

The old fork loft remnants might not love it but a proper marine tranny (Twin Disc) will hardly have a hassle in the few thousand hours a pleasure boat gets.

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Old 02-11-2008, 09:52 AM   #45
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RE: Design

Marin,

Steve D started as a marine mechanic/electrician in '88 and worked his way up to VP at Zimmerman Marine in VA, where he oversaw the repair yard and new construction of Zimmerman's new boats. He recently left to start his own consulting business. He does a lot of lecturing and clinics and he has a book in progress.

I took his "boat systems" class at PMU a few weeks ago and was very impressed with him.
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Old 02-11-2008, 10:36 AM   #46
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RE: Design

Let's not compare apples and oranges. Marin makes a valid point regarding aged machinery and historical technology. Everything wears out (entropy). That mad dash we may have made to catch the school bus when we were younger (much younger) now results in us missing the bus. The same applies to machinery. You can flog the heck out of that new car (for a while) but don't try it with your classic 1966 Dodge Duster with the 426 Hemi- something's gonna break.
The 400HP advertised in the latest Rice Rocket isn't the same 400HP that the 426 Hemi. I realise that 400=400 BUT it is developed under different opperating parameters. So, baby your aged engines and as others have so correctly stated, service them properly, don't worry about performance (or percieved lack therof) and enjoy the ride.
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Old 02-11-2008, 11:04 AM   #47
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RE: Design

FF makes a good point about having an EGT. Our boat has one (a single instrument with a dual readout) and it's very useful. It's the only way, really, to know what your engine is actually doing. I'm used to EGTs because of aviation, but it's a very handy instrument on a boat, too. As a point of reference, at 1,700 rpm the EGT on our engines is 600 degrees. At full throttle it is more than double that.
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Old 02-11-2008, 12:47 PM   #48
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RE: Design

deAntointio and the Northern Lights boys make no noises reguarding special considerations for old engines, turbo engines or 2-cycle engines. And I don't buy this old engine talk at all. Any engine in good condition should be able to work hard. If an engine has worn out parts they should be replaced.

Eric Henning
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Old 02-11-2008, 01:52 PM   #49
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RE: Design

Could be wrong but I think what these guys are saying is -- not to run at WOT all day, etc. -- but rather, making the general point that a well-used engine is healthier than one underutilized and under loaded.* In this month's PM Steve advised someone to run his engine up to WOT at least 5-10 minutes per *season* just to make sure it doesn't overheat and can provide rated RPMs if needed.
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Old 02-11-2008, 01:57 PM   #50
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RE: Design

Ah yes, you just can't beat an old style diesel engine that has lots of torque and is slow running. I have an old Volvo in our boat (MD-47 late 1950 vintage) that turns a maximum of 2000 RPM and develops a whopping 82 HP with 200 Ft/Lbs of torque. All this massive power is run through a 3:1 reduction gear to a four blade 32X20 prop. This means that at our regular cruising speed of 7 knots we turn 1600 RPM, the prop turns at just over 500 RPM which makes for a fuel consumption (averaged over 5 years of running) to about 1.75 GPH.
Now, I know that this engine will one day give up the ghost but until then I sure don't want to pull it just for the sake of having an engine with less than the current 8500 HRS and as long as parts are available I can do a complete overhaul in the boat and the parts are all readily available in Europe with about 10 day delivery!!
The boat by the way is a converted ex commercial fish boat of common West Coast design, 36 feet in length.
I also appreciate the simple design, want a manual, look at any diesel engine theory book and that's about it !
Oh well, I guess all the fancy electronic controls etc are just the result of our wanting cleaner air to breath so I can't really fault the lawmakers for the new regulations but still - I love my old diesel
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Old 02-11-2008, 04:22 PM   #51
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RE: Design

Eric,
A Chubbie is a Chung Hwa- mine is a Present 42
Steve


How were you able to make that determination? I've tried to find a way to tell whether mine was made at Chung Hwa or Chien Hwa. I'm under the impression that almost all 34's were made by Chung Hwa but the "odd" sizes were often made at Chien Hwa on the other end of Taiwan. According to the information I have the same fellow that owned Chung also had an interest in Chien.

As far as I can tell from looking at different boats is that the stories of different "families" finishing boats is probably true for the early boats at least. The quality and complexity of the interiors is widely varied sometimes.

If you have some type of insight into which yard built what I'm interested.

Ken Buck
40 Puget Trawler which could have been a La Paz, Marine Trader, Tradewinds, Golden Coast, or Clipper had it been sold somewhere else originally.
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Old 02-11-2008, 09:19 PM   #52
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RE: Design

Firefly, I'm going to enjoy the ride .. all the way to Thorne Bay from the seattle area .. gonna take at least a month and a half. Do you have a Dodge Duster ? I have a 73 Buick 455 Centurion and I love that car like Penta loves his old Volvo. I'd much rather drive the 455 than our later Buick LaSabre. Old engines can be rebuilt completly if parts can be found. Not so much the whole boat .. just the propulshion system. Like cars, if I were to rebuild the engine in my Buick a brake line hose could burst tomorrow ect ect but the engine would perform like new.
Adam T, I do that. I run for about 3 min at WOT ( 3000 ) and then back off to 2800 for 10 or so min every month or so. 90 to 95% of the time I cruise at 2600.
Ken, I have no idea .. Chung Hwa from Chien Hwa. I must have sounded knoledgeable by accident. John Tones, I'd love to hear your old Volvo run. Here on Prince of Wales Is over half the boats are more like yours than otherwise. We will be in your area perhaps at Pender Is ..Otter Bay May 2 to the Albineers meet.

Eric Henning
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Thorne Bay AK
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Old 02-12-2008, 12:39 AM   #53
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RE: Design

I dunno what Dick Gee from Northern Lights, Steve D'Antonio, etc said about engine operations in Passagemaker as I don't read it. However, I can tell you that Dick makes a big distinction between a modern diesel and one from the 1950s, just as anyone who has experience with engines, be they cars, airplanes or boats, knows there are major differences between engines of different eras. Metallurgy was different, design was different, heat tolerance was different, the ability to resist valve float was different, injection systems were different, and on and on and on and on. If I operated the radial engine in the Beaver I fly-- an engine designed well before WWII and built no later than the end of that war--- the same way I operate the current generation of piston engines in the Cessnas I sometimes fly, I'd be dead-sticking the Beaver to an emergency landing pretty quickly. Probably on the first takeoff, actually.

Shoot, even the operational parameters of the engines used on 777s made today are different than the operational parameters of the engines used on early 777s because of advances in everything from metallurgy and ceramics to gas path design, fan blade design, all sorts of things. Run the first engines like the current ones, and the first ones will come apart. And this particular turbofan evolution has only spanned 14 years, not the fifty years that separate the Ford diesel that was used in the FL120 and a modern Lugger, John Deere, Cat, etc.

Dick's advice to my wife and I regarding "old engine operation" extends to more than just the throttle settings, too. For example, he told us with the Ford Lehman 120 to never put multi-viscosity oil in it, and never use synthetic oil in it, both of which are used and recommended by the modern engines his company makes. To be fair, I have talked or corresponded with people who use multi-vis or synthetics in their FL 120s and they claim no problems. And it may in fact be okay, although my NL friend has told me why he doesn't think so.

But the FL 120 established its reputation as a 12,000 to 14,000 hour engine in recreational marine service using single-weight dinosaur oil and relatively conservative power settings back in the 1960s and 70s. American Diesel can cite instances where FL120s went some 25,000 hours before needing an overhaul. So whether or not this kind of operation is good for the engine is not even worth discussing---- it's been proven countless times that it is.

Are there other ways this engine can be run? Continuous high power loadings, high rpms, synthetic oil, etc.? Maybe. But a theory espoused on a forum or by a magazine writer does not carry the same weight in my book as the actual operational history of the engine.

Now if marine diesels only cost a few thousand bucks each like a gas engine it might be worth seeing what would happen if I used current diesel operating philosophy on an engine that was designed and built before many of the people preaching this philosophy were born. But it would cost us about $50,000 to repower our GB if the experiment didn't work. So in this case, it seems to me to make more sense to stick with what's already been proven to work wonderfully. The fact it's also the way the people who really know this engine recommend to operate it pretty much seals the deal, at least to my way of thinking.

Don 't forget, the Ford of England Dorset engine--- the engine the Ford Lehman 120 is based on--- was a complete failure as a truck engine, which is what it was designed for, because it proved to be very trouble-prone when operated at the higher end of its rpm band and under high power loadings. One specific I have read about this engine was that when operated a lot at higher rpms the fuel injection pump failed fairly quickly to the point where it was not uncommon to have to replace the pump two to four times a year. Where the Ford Dorset proved very successful and extremely reliable was in relatively low power, relatively constant but moderate rpm applications like cranes, generators, pumps, and smaller farm tractors. Which is why, when you look at the manual, it is referred to by Ford as an "industrial" engine. Which is also why it proved--- at the time--- to be an ideal engine to power slow boats like recreational trawlers.




-- Edited by Marin at 03:06, 2008-02-12
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Old 02-12-2008, 04:51 AM   #54
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RE: Design

But it would cost us about $50,000 to repower our GB if the experiment didn't work.

Only at a bakery.

With a pair of International DT 466 with under 10,000 miles avilable at most truck wreckers for $2000 to $5000 , a set of wet exhaust manifolds OTS at marine exhaust of Alabama , your under 10K with modern motor mounts IF your old trannys are OK.

For your sized boat the DT 360 would be better match and really LOW TIME take outs are aviliable even cheaper from moat Skool districts.

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Old 02-12-2008, 04:56 AM   #55
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RE: Design

"I'm used to EGTs because of aviation, but it's a very handy instrument on a boat, too. As a point of reference, at 1,700 rpm the EGT on our engines is 600 degrees."

Folks like me that can not possibly overload their setup can still judge the exhaust condition with a heat gun.

With our zero maint , zero risk dry stack , we simply use the gun on the stack , and log the temp / rpm.

Other folks can read an exhaust manifold spot before the water is dumped in the exhaust.

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Old 02-12-2008, 11:21 AM   #56
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RE: Design

FF---

Your repower solution might work for someone with the time to screw around finding engines in a wrecking yard, modifying them to work, cutting up the engine-mount stringers to fit the replacement engines,and so on, but that someone isn't me. If we had to repower the boat it would have to be a drop-in solution using a pair of proven, marinized engines, probably Luggers. Also, anyone buying our GB in the future would not be interested in a boat with a pair of wrecking yard engines in it. We'd sell it faster for a better price with a pair of brand-name engines in it. The market for GBs and other production boats is not quite the same as the market for homebuilts on ex-Navy launch hulls
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Old 02-12-2008, 12:20 PM   #57
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RE: Design

The following was recently posted by Kevin Redden over on the T&T site. I'm not posting this to support or reinforce anything I've said, only that given the discussion on this forum of how much power does a boat really need Kevin's comment represents a factor perhaps worth consdidering. The quote includes the comment Kevin was responding to.

The subject of the discussion on T&T is "Powering a 50 foot trawler."

-----Original Message-----
> Hull speed on your boat is about 9.5 knots. It takes 106 hp to power it
> at hull speed. Add 20% for a safety factor and you need 122 hp. Go with
> the 135 hp continuous duty John Deere.

Kevin said:

"When selecting the proper engine size to drive a boat, calculating the HP
required to drive the boat to hull speed IN CALM WATER is only a part of the
problem.

"When the weathers Gods dictate that the Fit Hits The Shan, and it's blowing
40 with 8 foot seas, that puny HP number you calculated for calm water
conditions becomes pretty meaningless. In high winds and heavy seas, you
need significantly more horsepower to both hold her head into the wind and
seas, and to make any headway against them.

"I don't have the formulas close at hand to calculate this additional HP
requirement, but I certainly would not size an engine just to the calm water
hull speed calculation."


-- Edited by Marin at 13:21, 2008-02-12
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Old 02-12-2008, 07:05 PM   #58
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RE: Design

Ken,
Charles on this website has the most informative information I have seen anywhere- http://www.geocities.com/charlesculotta/ChungHwa.pdf- this is listed under one of his many published articles. Charles also numerous creative solutions these boats may need in the way of repairs.
Steve
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Old 02-12-2008, 07:13 PM   #59
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RE: Design

Ken,
I was also fortunate enough to get the general arrangement blue prints of our boat in the original plastic wrapper marked:
Chung Hwa Boat Building Co., LTD
K.E.P.Z.
Kaosiung Taiwan
Republic of China
Steve
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Old 02-13-2008, 03:30 AM   #60
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RE: Design

"We'd sell it faster for a better price with a pair of brand-name engines in it."

No sweat , get a pair of Mitshubishis and paint them Deere Green if the buyers are more interested in "name brand"..

A couple of decals Deere will finish the conversion.

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