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1988 21' (yup, 21') C-Dory jet (yup, jet), $5000
- Thread starter dotnmarty
- Start date
jimandlaurie
New member
I see this unique boat is back on the market again.... wish I had the $.
tom&shan
New member
I'd be curious as :hot :hot :hot :hot - (excuse my language),
as far as how it handles. Looks to me like it would skip all over the place. Anyone have any ideas?
Tom
as far as how it handles. Looks to me like it would skip all over the place. Anyone have any ideas?
Tom
Chris Bulovsky
New member
I'd dump the engine and install an outboard. Bet it would handle just fine then. The transom would need a little work from the looks of it. Can't tell how the transom was constructed from the pictures........Hmmmmmmmmm
Chris Bulovsky
Chris Bulovsky
tom&shan-
You asked about the jet boat's handling.....
Jet boats have very different steering response than propeller driven boats.
Their steering is based on the control of the direction of the jet stream, and, although not as firm or positive as a prop driven boat, is workable in forward drive AS LONG AS THE THROTTLE IS APPLIED AND THE JET THRUST IS BEING DELIVERED.
Back off on the throttle, and you have very little or no steering, since you have no thrust! A few of the jet nozzle designs add a rudder or skeg of sorts, but it's nowhere near like having the skeg of an outboard or an I/O, or the rudder of a conventional drive.
Reverse is accomplished by a diverter which drops down at the rear of the jet nozzle and deflects the thrust forward, making the boat move rearward.
Neutral is done by dropping the reverse diverter half-way down and splitting the jet thrust half and half. This is complicated by the fact that the jet stream is spinning after coming out of the impeller, and the boat in "neutral"
crabs its transom around to one side.
Control with a jet is thus far less precise than with propeller propulsion. Skippers used to more common propeller drive systems are usually amazed at the lack of positive control with jets. They really get tricky around other boats and docks!
Different jet drives have somewhat diffent control systems, and each type has it's own pecularities that must be learned.
Most folks also have a common myth that jets can be run over shallow areas and through gravel and rocks with impunity.
It's true that the intake grate can help block out some of the rocks, etc., but the tolerances between the outside radius edge of the impeller and the cylinder (wear ring) it turns in are very tight:
,005 clearance= racing tolerance
.010 clearance= normal, acceptable clearance
.015 clearance= too loose, allows water to flow back forwards around edge of impeller, loosing a large %age of the thrust and wasting energy. Wanna run some gravel through that jet pump now?
I also think that big V-8 (small block Chevy) would be pretty heavy for the boat at 21 feet, especially in light of the semi-dory's need for a light propulsion system. What's that motor weigh? 600-800 lbs?
Just some thoughts!
Joe.
You asked about the jet boat's handling.....
Jet boats have very different steering response than propeller driven boats.
Their steering is based on the control of the direction of the jet stream, and, although not as firm or positive as a prop driven boat, is workable in forward drive AS LONG AS THE THROTTLE IS APPLIED AND THE JET THRUST IS BEING DELIVERED.
Back off on the throttle, and you have very little or no steering, since you have no thrust! A few of the jet nozzle designs add a rudder or skeg of sorts, but it's nowhere near like having the skeg of an outboard or an I/O, or the rudder of a conventional drive.
Reverse is accomplished by a diverter which drops down at the rear of the jet nozzle and deflects the thrust forward, making the boat move rearward.
Neutral is done by dropping the reverse diverter half-way down and splitting the jet thrust half and half. This is complicated by the fact that the jet stream is spinning after coming out of the impeller, and the boat in "neutral"
crabs its transom around to one side.
Control with a jet is thus far less precise than with propeller propulsion. Skippers used to more common propeller drive systems are usually amazed at the lack of positive control with jets. They really get tricky around other boats and docks!
Different jet drives have somewhat diffent control systems, and each type has it's own pecularities that must be learned.
Most folks also have a common myth that jets can be run over shallow areas and through gravel and rocks with impunity.
It's true that the intake grate can help block out some of the rocks, etc., but the tolerances between the outside radius edge of the impeller and the cylinder (wear ring) it turns in are very tight:
,005 clearance= racing tolerance
.010 clearance= normal, acceptable clearance
.015 clearance= too loose, allows water to flow back forwards around edge of impeller, loosing a large %age of the thrust and wasting energy. Wanna run some gravel through that jet pump now?
I also think that big V-8 (small block Chevy) would be pretty heavy for the boat at 21 feet, especially in light of the semi-dory's need for a light propulsion system. What's that motor weigh? 600-800 lbs?
Just some thoughts!
Joe.
starcrafttom
Active member
I emailed the seller and heres his reply
Tom, I've only had it for two years, and it had been sitting in a field for
6-7 years before I bought it. Took a lot of work, for one, the engine was
frozen from sitting , so I pulled that and rebuilt it. A lot of clean-up and
it IS a fun boat, I've used it in lakes, like Washington, and many others,
and have had it out in the sound quite a few times, mostly out of Point
Defiance. At high speeds it is a handful, I think a couple of fins on the
bottom near the intake plate for the jet would really help. A couple of guys
are in touch with me, thinking about buying it and converting it to
outboard. It is unique also with the open cabin design rather than a
hardtop. I wanted to cherry it out, resolve the high speed handling issue
and keep it the way it is simply because of it's unique-ness. I still might.
I was looking forward to going to your rondevous with it, and if it doesn't
sell I will. I know it's not your typical C-Dory, which is a wonderful boat,
but I hope I would be welcome to attend. Thanks for your interest, Alex
Tom, I've only had it for two years, and it had been sitting in a field for
6-7 years before I bought it. Took a lot of work, for one, the engine was
frozen from sitting , so I pulled that and rebuilt it. A lot of clean-up and
it IS a fun boat, I've used it in lakes, like Washington, and many others,
and have had it out in the sound quite a few times, mostly out of Point
Defiance. At high speeds it is a handful, I think a couple of fins on the
bottom near the intake plate for the jet would really help. A couple of guys
are in touch with me, thinking about buying it and converting it to
outboard. It is unique also with the open cabin design rather than a
hardtop. I wanted to cherry it out, resolve the high speed handling issue
and keep it the way it is simply because of it's unique-ness. I still might.
I was looking forward to going to your rondevous with it, and if it doesn't
sell I will. I know it's not your typical C-Dory, which is a wonderful boat,
but I hope I would be welcome to attend. Thanks for your interest, Alex