View Full Version : Power Suggestions

12-11-2004, 12:20 PM
In 1965 the designer (deceased) of Pogo, a Downeast/lobster boat style/pocket cruiser I am building, called for a Universal 4 cylinder, 70 hp engine. Ten years later he found what he considered the ideal upgrade, an Isuzu 'Pisces' diesel. For each engine he drew up detailed mounts/beds, which of course are very different. I don't think the Pisces is available, let alone still manufactured, but my experience and knowledge in this area is limited.

The Universal apparently yielded speeds to 14 kts. with this hull, and any engine, including a conversion in the 75 hp or so range would be ample, he figured. He built a Universal powered version for himself, and said he burned about 1-1/2 gal. an hour in the 1200 to 1800 rpm range (occasionally 2,000 rpm).

What should I be looking at? Would love a nice little diesel, but $14k new is way out of my budget. There must be a pretty good used market, no?


12-11-2004, 01:28 PM
You probably will not like my sugggestion, but have you ever considered an automotive conversion?

The professional lobstermaen in Maine would power their boats with auto engines that they would buy from a wreck, very cheap.

Loberstering is hard on an engine and worse, most used seawater cooling. Auto engines usually lasted only a year or two. Then they threw them away and got another out of a wreck. Teenagers were always a good source of wrecks.

12-11-2004, 01:48 PM
Originally posted by HarryH:
Would love a nice little diesel, but $14k new is way out of my budget. There must be a pretty good used market, no?There are used diesels out there but keep in mind that nobody pulls a good engine just because they want to spend $14k on a new one. A rebuild would probably be in order.

Gary E
12-11-2004, 01:51 PM
You did not tell us much about the boat, if we knew more, better sugestions could be made. Also new or used?

If you are happy with 75HP or so, several engines come to mind.

Detroit 4-53
Ford Lehman 4 cyl
Perkins 4 cyl
Cummins 4 cyl

Diesel forum and used engins are sold here..
http://boatdiesel.com/index.cfm?CFI D=2325940&CFTOKEN=97297975&CFApp=19&&Red=NRU (http://boatdiesel.com/index.cfm?CFID=2325940&CFTOKEN=97297975&CFApp=19&&Red=NRU)

There is a 4 cyl Lehman for sale here...

[ 12-11-2004, 02:05 PM: Message edited by: Gary E ]

12-11-2004, 03:05 PM
With apologies to ahp, do not be tempted with the automobile conversion. The reasons are extensive and a bit off this topic, so I'll leave the "why's" for another thread.

Marine diesel engines are rebuilt for many reasons, some good. A rebuilt motor from a reputable shop with accompanying warranty (at least a year or 1000 hours) is a very good bargain. In Toronto there should be several good private shops, as well as dealer rebuilds. I have heard good things about Precision Engine Rebuilders http://precisionenginerebuildersdirect.com/ but I don't have any direct knowlege about them.

I'm prone to advocating Perkins diesels in this horsepower range because they have such a long, good, track record for toughness and longevity and their parts & service distribution is very good. The downside is that they are a rather large motor for the hp. The Perkins dealer in Toronto is:

Diesel Distribution
389 Deerhurst Dr Units 3-4
L6T 5K3
Telephone No: [1] (905) 799 1544
Fax No: [1] (905) 799 1577

Yanmar is likely to be more available as these are so common in pleasure boats. Lugger would also be a good choice.

Most small diesels are engineered to have the engine mounts on 19" centres 'thwartships. An easy way to allow for any variances is to lay in your engine beds a few inches lower than spec's on the plans and have custom steel or aluminum mounts fabbed up by a welding shop to suit your engine.

Also, a bit of advice, if I may. This is going to cost you real money, but from the littany of comments I get from clients ("I wish I would have listened to you and spent the money...") I think that it is important. The type of boat you are building places the motor smack in the middle of the living quarters and , unlike a sailboat, the motor is running most of the time you are on board. Noise - or lack thereof - is a significant part of the enjoyment of your boat. Spend money and don't cut corners to install as many noise-abatement items as you can afford. It will seem like a big pile of cash for no performance increase, but later you will say it was the best money you spent. A quiet boat causes less fatique, less stress, is more comfortable, etc., etc., etc. Components I would suggest are:

* Anti-vibration mounts for engine, genset, and any belt-driven equipment
* Flexible shaft coupling
* Cannister-type exhaust silencer

* Acoustic mat or extra skin laminations in hull interior over propeller (48" wide x 24" longitudinally is good)
* Acoustic insulation on all deck underside and bulkhead surfaces of the engine space (not just between stiffeners, box them in, too)
* Gasket all hatches to the engine space with soft gaskets.
* Seal all openings into the engine space, e.g., motor controls cables opening.
* Line the interior of all engine space air inlet ducts with acoustic mat (allow extra volume in the duct to compensate)

Good luck with your project, I hope you find a good engine at a better price, and that your installation goes smoothly. If I can be of any help, let me know. Talk is cheap; design work is charged by the hour. ;) :D

12-13-2004, 10:03 AM
On this forum, one gets diversified ideas and outlooks. That's one of the things that makes it so durn interesting and educational. Thanks to all above.

I *have* given some consideration to a conversion, because of my budget...but this will be a workboat more than yacht in spirit and design only; I will be fishin' n cruisin' I hope, and I would like it to "look good, sound good, last a long time". A diesel is my dream/hope, and maybe with persistent browsing, perusing and yakking, something will cross my path that will be just fine, and be affordable too. One commodity I have is time; I am puttering along at less than breakneck speed.

Mmd..thanks for taking the time to create a detailed answer...and your kind offer of further help. I printed out your remarks and will stick 'em in my building folder to remind me details pay dividends. Ok if I send you email (or post) to pester you with questions on building this vessel? I think I can handle your "talk" rate (even if you bump it a bit <g>) and you shouldn't need your designer's pencil.



12-13-2004, 10:11 AM
Sure, feel free to e-mail me. BTW, I apologise for the Toronto-specific info - I made a boo-boo and failed to read the bottom of your post and presumed you were the forumite Harry who lives in Toronto. My bad.

Gresham CA
12-13-2004, 11:17 AM

Try these people here (http://www.tadiesels.com/used.html) . They are very helpful to me and, from what I've learned, have a good reputation.

Also, mmd has been very helpful to me and I trust his judgement.

[ 12-13-2004, 11:18 AM: Message edited by: Gresham CA ]

12-16-2004, 03:27 PM
This site has used diesel engines, including "running/take out".

Scruton Marine - Engines (http://www.scrutonmarine.com/Engines.htm)

PS 6,000 for a used Perkins 120hp, or "China Diesel" anyone? (starting at 3,500 CDN.)

[ 12-16-2004, 03:32 PM: Message edited by: WWheeler ]