Diesel/IO on a 22'

J

Jack in Alaska

New member
I had a brain fart the other day thinking about the incredible cost of fuel etc. Our dory's are very economical compared to other boat types but could that be improved??

Has anyone done any thinking, sketching, engineering or actually doing..........installing a small diesel engine coupled to an IO on a 22' C-Dory.? The OB would be removed, the transom filled in and the splash well revamped.

The fuel consumption on some of those small diesels is measured in quarts/hr. not gals. Granted it would not cruise at 25 mph. but so what. That speed is seldom possible where I run. 15-17 mph would be acceptable to me and my needs.
Just a thought. Any comments on this...........?????
 
OK, some comments:

Be careful to compare apples to apples. A modern outboard that would push your boat 16 mph compared to a similar sized diesel, for instance. I wonder if the fuel burn rate would be all that much different. What's the comparison of engine costs in that case? How many hours of running to make up the price difference?

As a quick approximation, I think a diesel burns something like 2/3 as much fuel as a gas engine if they're loaded the same. Calculate how much fuel you burn now and divide by three. That's about what you might be looking at for savings.

AND:

You'll be taking a C-Dory with NO holes below the waterline except the tiny bilge drain with a brass plug in it, and converting it to a boat with a HUGE hole in the back, sealed by a gasket which has been known to sink a lot of boats over the years. No thanks.....

Also, you'd be giving up a lot of room inside the boat. And adding a lot of weight.

Jeff
 
In Les's promotion of the Rosborough he has a lengthy discussion of diesel versus outboard, and outboard wins handily in most cases. It is an interesting read. I have been thinking about it for awhile and just stumbled across his website. www.usa246.com.
 
We did install Diesel IOs in the 27’ & 26’ C-Dorys. The weight was just too great to put the smallest one offered into a 22’ C-Dory. We did try a Yanmar Diesel Outboard (27 HP) and it worked OK but the smell was terrible. Noise was greater than a 2 stroke 90Hp, vibration was not too bad. You want better economy? Hang a 50HP 4 stroke on the back and slow down to 13 Knots.

Mark Toland
 
Mark Toland":2tuyoy2p said:
You want better economy? Hang a 50HP 4 stroke on the back and slow down to 13 Knots.

Mark Toland
Click to expand...

Yay, the well respected designer behind the C-22 comes forth with a truism we all need to be reminded of. Contrary to the "Gotta have a 90/100 - Bigger is Better" crowd, small has it's uses and works just fine. I'll still put my 75 hp Yamaha up against Sea Wolf's 90 hp Yamaha out in a normal 3 ft. swell, 8 second interval calm ocean and compare comfortable cruising speeds. Heck, I doubt if a 50 hp C-22 buddy boat would slow us down at all.

Now on Lake Shasta on an early morning glass lake, there might be a difference between the '50's top speed and ours, but Joe and I would be throwing things overboard to beat each other. No, Joe, throwing your spouse over the side isn't acceptable.... :lol:

Don
 
Unless you are just into screwing around with stuff (I am), putting an expensive, oil burning, hard to start, obnoxiously loud, diesel motor inside a perfectly good CD 22 would be disheartening to me. It seems though, unless you were super careful and got lucky with you engine and outdrive purchase, that you could do several years of boating, maybe even a lifetime of boating, before you ever made up what you spent initially buying and installing this setup. And then, I think you'd be surprised at how insignificant the amount of fuel is that you would be saving. Clearly, if you really want a diesel boat, you should just sell the CD 22 and buy a diesel boat.
 
Random diesel musings:

A diesel outboard would be a better fit for a CD-22 in order to save floor space, but the Yanmar 27 and 36 hp are relatively heavy and have quite a bit of vibration and smoke & smell issues. They are expensive, and they're illegal to sell new in the U.S. because of the emission codes. Yanmar Diesel Outboard Overview

Interestingly, I've heard that one could alternately burn biodiesel in one, and the exhaust would smell like someone's kitchen/french fries/popcorn/ Coney Island/ or Byrdman deepfrying frying a turkey. Ought to send the wasps and yellow jackets into a county-wide feeding frenzy, eh?

I believe someone, BRP (formerly OMC), I think, makes a multi-fuel outboard for the Marines and Navy Seals that can run on a wide range of fuels from kerosene and diesel to almost anything petrochemical and flamable, but the cost for one is astronomical and they're thought to be on the Black Listed Unobtainable Items of Potential Military Significance.

Joe. :teeth :thup
 
I think that a diesel motor really come to play when you get in to bigger boats. Take the 26 seasport pilot house for an example. You can order it with a big single, two motors or a diesel. In order to get that big of a boat on place and run 27 knots, what I have been told by several owners is its sweet spot, with a gas engine or outboards you are going to burn 12 to 18 gallons a hour. the bigg twin set ups being the worst. The factory and several owners claim 8 gallons a hour with the single deisel. So when you get into bigger fast boats I think the diesel has its home. As far as some folks unwarrented fear of I/0 and that gasket. If you look at the number of I/O's on the water and number that have been sunk because of the boot going bad I think you will find it very small. that being said I was on a small trihull ski boat when the boot went bad but we did not sink. One of the boat mags this month had a article on what causes most boats to sink under way and water over the transom was far and away number one. when I get home tonight i will try to find the article and reprint the hi lights.
 
Well.......I did manage to drum up some ideas both plus and minus. Thanks.
I will take Mark Toland's word and accept that it was tried previously and is not a feasible idea. It is interesting to think about though.
This is the stuff that goes through my head while waiting, now on the 4th day, for the 3-4's and occasional 5's to dissipate so I can go back out halibut fishing.
I just watched two 32'x10' Alamar charter boats go out. All I could see were big white sheets of spray and occasionally one or both boats airborne jumping from peak to peak. I am glad I didn't pay $225 for the "fun". A local aluminum welder told me he makes his living welding the bow structures back together on all makes of alum. boats.
 
The only problem with the diesel motor is it generally takes longer to offset the original purchase than most people keep the boat. The Seasport with the diesels is a good boat. But, I have been on a couple of charters that run with them and while they like the diesel, they often wish that they just would have gone with the gas motors as they have had significant trouble with them, require a good deal of expensive maintenance, repairs are rediculously expensive, they are heavy and it causes the scuppers to leak water into the boat when the boat is full of clients thus filling up the fish boxes with water as those seals are prone to leakage, and in general just are that happy of campers. I went on one with a very nice man, his daughter, and 4 fishermen and we had trouble planning the boat. It seemed underpowered to me. But, maybe it is just because they are chartering a boat that wasn't really meant to charter.
 
T.R. I was told by a shop owner with lots of seasport experance that when looking for used seasports not to get one with a kd 40 engine. the 41,42,44,were all good but the 40 (no longer made I think, but not sure) was a dog. He also said that a lot of guide boats had them because they were cheaper. i am really interested in some of the smaller new generation deisels.
 
Back
Top