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Converting to diesel

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Ron Brassord

Guest
" I run a 30' 87 Luhrs Alu

" I run a 30' 87 Luhrs Alura [round bilge full keel 10,000 pound boat] with a 260hp gas v8 engine, and would like to convert to diesel. The gas engine will push the boat up to 16-18 knots,but at prohibative fuel costs. Running at half rpm gives 7-8knots and three gallons per hour which is OK. A 200hp diesel would exceed $25,000 installed, which is not an option.
Since I always run at half the hp of the v8 gas engine, my question is, would a smaller diesel, about 80-100 or less hp do the trick. My objective is to get the dependabilty of diesel as well as the economy. I know I would clearly limit the top speed, but I never use it anyhow. I also might be more able to find a smaller used diesel and do the installation myself.
Trial and error could be very frustrating and expensive, and any first hand knowledge would be appreciated. Ron Brassord Lighthouse Point Fl. "
 

kim

Regular Contributor
" Better to put in the recomme

" Better to put in the recommended HP diesel, regardless of cost. If you put in a small diesel she will work like the devil to go anywhere, and wont last long.Also you may not have power enuf to move the boat when you need it, as in a head wind or for close manouvering. If you put in say a 100HP diesel, that does not mean you will get half the performance of a 200HP unit.

If you shop around and find a good rebuilt or good running take out, you can do the job for less. Keep in mind you will at least double your fuel mileage, and in an extreme case like my boat, I quadruppled my mileage!! Yep went from 6 to 8 gals per hr to around 1.5GPH at the same given cruise speed. Not only that you get instant starting, no dangerous gas fumes, dependibility like you dream about, and no ignition parts to carry around. Go diesel and good luck. Kim. PS, in my area the Isuzu seems to be the motor to run. Several of the commercail fisherman I hang with have the 6 cylinder model between 185 and 230 HP. Mine has the least amount of hours (2500) and one guy has over 30,000 (Yes 30 thousand) hours and all with little or no problems. Keep a super clean fuel system, and change oil religiously. Oh, the guy with 30K hours did have his valves done at 15K hours, but still not bad. "
 

rick

Regular Contributor
" Ron,
I have to disagree wit


" Ron,
I have to disagree with Kim. Did you know that Luhrs, and most other manufacturers, uses a heavier stringer system in their diesel hulls? This also includes: heavier engine mounts, larger diameter shafts, larger transmissions, heavier struts, larger props, and in many cases a more aggressive lamination schedule in the hull. Oh and don't forget the larger induction vents to supply all of the extra air the diesels need, and, of coarse, the heavier batteries and cables. You know, you can put a big block in a Pinto and it will run like hell... for a while. That is, until the frame cracks, the shaft wrings, the brakes overheat, well, you get my drift. A reasonable option would be to install a new 8.1 gas engine. This "Next Generation" of gas engines incorporate computer controlled multi-port fuel injection, which gives greatly improved performance and economy. Distributorless ignition systems eliminate those "spare" ignition parts everybody worries about and they start easier than a diesel. Especially when it's cold out. The performance is much better than the diesel, the cost is about half and the fuel economy is much better than what you have now. By going with a larger HP engine, you'll hardly have to crack the throttle, yet still have the power for any situation which might arise. I wouold recomend the Crusader 8.1 MPI (385hp)You never know, you may enjoy running at 30+ knots! Also, don't forget the soap money you'll save by not having to scrub your transom after every trip. Good luck "
 
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Ron Brassord

Guest
" I am listening and appreciat

" I am listening and appreciate the good advise. None of it is off base that I can see. Thats the delema.
For many years we cruised a 38 foot 20,000 pound sailboat with a 4-108 diesel at 6 knots on .5 gallons per hour. That's about 14 miles on a gallon! It's hard to adjust to power, but a must.
My thinking with the Luhrs and a small diesel is to treat it as a trawler. I know of many large trawlers running on a single Lehman 120 for instance. They can't get more than hull speed, and are no way as efficient as a displacement hull sailboat, but they also don't break the bank on fuel.
There has to be the best method for the best result, and I'm still looking.
Thanks again fir the imput Ron B "
 

kim

Regular Contributor
" Rick has some valid points,

" Rick has some valid points, but if you stay within the same rough torque range, beefing up the shaft, stringers, etc is not needed. As to the cold starting:B Diesels today are equiped with glow plugs, and where I have my boat in Maine and typically start it in 30 degree weather, usually without the glow plug, thats no longer an issue. I try to use the glow plug but sometimes I forget and it only turns over two or three times and starts. Warm weather starting I think can be done by hand!!!As far as the soot on the transom, try Walker Airseps to eliminate transom clag. The gas engine Rick speaks of is a great choice, but its still gas. You cannot compare aplles and oranges and you started this chat by asking about diesels. Hate to say it but both Rick and I have good points, but why not go to your local diesel dealer and pick his professional brains, and to be fair hit the gas engine guy up in the same trip. Take notes and good luck. Keep us posted, and think diesel. Kim "
 
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Ron Brassord

Guest
" Again, everything said is va

" Again, everything said is valid, but, I'm still rassling with the idea of a small diesel, and make believe I have a trawler.
I've been to the diesel fellows, and got a price of $28,000 for a Cummins six na, installed.
The gas boys tell me to budget about $12,000 plus for the high teck V8 installed.
My boat is very clean and solid, but still a 1986. and it doesn't seem prudent to invest in either deal, considering return on investment, although, I intend to keep the boat.
I believe I can handle the installation of a smaller diesel myself on my own dock, and the cost of a rebuilt could be kept to maybe $5,000.
We are retired, live on the intercostal in SE Florida, and most of our cruising is confined to 'no wake' areas anyhow.
There were over 600 30 Aluras built, and I was hopeing to hit someone who has gone this route before.
Thanks for your sincere input Ron B "
 
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Doug W

Guest
"Ron,
Have you thought of a


"Ron,
Have you thought of a Merc. D-Tronic Diesel? A 200hp is about $11.5k-13.5k if you shop around the web.
Luck
Doug"
 

kim

Regular Contributor
" Ron, also remember that if y

" Ron, also remember that if you repower to diesel you have automatically increased the resale value of your boat considerably. Good luck and post what plan you go with. Kim "
 
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Don Murray

Guest
" Ron, Another diesel that cou

" Ron, Another diesel that could be considered a direct replacement is the Peninsular Engines series of V8 diesels. The range of horsepower is 190 to 340hp. If you had a 200hp V8 in your boat it will fit nearly exactly. It weighs only 1000lbs.
Give Matt Koning (president)a call at 616 530 1298 and I'm sure he can help you out. See his web site: www.peninsulardiesel.com. Ask him about a rebuilt diesel -he has a few available

Tell him Don Murray sent you-Good luck! "
 

Cayennita

New member
I had an Alhura 30 in St. Croix with a turbocharged 4 cylinder Yanmar. 5.5 kw generator a,so diesel. Refrigeration, a/c, electric c stove and head, winlass, etc. 14 knots top speed and cruised at 12 but I usually stayed at 10. Very economical. 3/4 gph
 
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