Hot-rodding a C-Dory

Socrateur

Socrateur

Member
Joined
Feb 16, 2006
Messages
244
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C Dory Year
2005
C Dory Model
25 Cruiser
Vessel Name
Sea Skipper
Has anyone used a jack plate on a C-Dory, i.e., a bracket that can elevate the motors vertically? It appears that the lower unit sits pretty deep in the water, and I am wondering if a surface piercing propeller would benefit performance. Any comments from the forum theorists on this?
 
Good god why? I doubt if 5% of us C-Dory owners spend much time WOT.
 
Wide Open Throttle....

Might run faster briefly, then without cooling water :shock: , wouldn't run at all...

Charlie
 
We have had the C Dory 22 up to about 30 mph. We felt that the boat was a little skitterish at that speed. The C Dory hull is not a high speed hull, and I think that putting a surface piercing prop would make the boat slightly less stable. The surface piercing seem to have two real big reasons for use--one is very high speeds, and the second is shoal draft drive. A surface piercing prop is entirely different design than a conventional prop. One of the major use of jack plates is also for shoal running in shallow water--but you can achieve this (slightly less effeciency) with trim up.
 
WOT = Way Over Target!!!


If ya' want a hot rod, get a 40 ft Eliminator with supercharged twins = 2000 hp, a throttleman, a couple of helmets, and a hefty gas credit card max-out!

Then Join the Offshore Racing Circuit.

And don't forget to get a sponsor. Maybe Pepto-Bismol (and paint your boat pink).

Actually, that doesn't sound so bad, just think of the women!!!

OK, lets get started!

Who's gonna organize all this mayhem???

I'll start on the girls!

Joe.
 
Welcome to the Pub, Jay

I can see you have not spent much time digging through the thousand of previous posts or you would not have even suggested such a topic. Your question was very valid, but wasted on the "The Slowcees", they are the spokes animal's for Comcast Cable and if you have ever seen the commericals, anyone of the C-Dory group can be idenified with them...we like things sloooooooow....very slow unless there is bad weather moving in on us.

But to be serious a moment, the hull doesn't lend it's self to much over 30 mph, and that can be accomplished with normal rigging. But if you want your hull to perform a bit better then the designers intended, then you might want to look into adding a Armstrong Bracket to extend the overall length of the boat.
 
Sea Wolf":yb8satkv said:
WOT = Way Over Target!!!


If ya' want a hot rod, get a 40 ft Eliminator with supercharged twins = 2000 hp, a throttleman, a couple of helmets, and a hefty gas credit card max-out!

Then Join the Offshore Racing Circuit.

And don't forget to get a sponsor. Maybe Pepto-Bismol (and paint your boat pink).

Actually, that doesn't sound so bad, just think of the women!!!

OK, lets get started!

Who's gonna organize all this mayhem???

I'll start on the girls!

Joe.
Click to expand...

And don't forget to update your will. Please leave the money to the C-Brats Website. And give the girls phone numbers to Sea Wolf Joe! :roll:

If he gets that, he'd better update his will too.... :lol: :lol:

Charlie
 
Maybe I should race some of you for titles? I have had Sea Lion up to 36 MPH with the Suzy 90. :lol:

Actually I better step off before a cat owner wants to call em out.
Of course if I lost my boat i'd have to step up to a 255... well after I won the lottery...

Of course if I win a couple of cruisers racing for titles I could strap them together and put a ladder between them to use as a Tuna tower :P
 
I also have had my boat up to 37mph :shock: , suzuki as well but a 115hp. The boat does get a bit squirrelly above 30-33 but if it's flat it's manageable. I regularly run wide open if it's flat and enjoy making really good time on those longer runs to the fishing grounds. Not everyone likes to go Bambina speeds :lol:. I don't really know how much speed you'd get out of a jack plate but I would think on the CD hull that it couldn't be more than 3-4 mph tops with a 90hp. But I'm no expert . Good luck!

Sark
 
I think I can glean from all of the background chatter that no one has used jack plates or surface piercing props on a C-Dory! And it looks like I shocked some of your sensibilities by mentioning a hot-rod CD! :roll: No, I am not surprised, but my purpose for posting this topic was only partly whimsical exaggeration. I actually am interested in the possibility for pushing the performance envelope of the hull a bit higher. For example, putting twin 115s on a CD25 with oversized twin piston trim plates. The combined 230hp would probably push the hull upwards of 40 mph on a lightly loaded boat, and the big trim plates might stabilize the ride nicely. Why would a person do this? Aside from the thrill of going where no man has gone before with CD performance, I could get to where I'm going more quickly when needed. I will be boating around the San Juans in the years to come and although slower, long distance cruising will be a priority, I can envision times when being able to blast (relatively speaking) from Lopez to Friday Harbor for lunch, for example, would come in handy. And for normal cruising, it's always nice to have extra power when you need it. I'm just speculating, of course. Perhaps I just need to spend more time on Lopez in order to unwind from my current existence and learn to cruise at Pub speed. :beer
 
Socrateur,

Have you tried to miss a log in the water while going 40 mph???

Motors and hulls don't work very well after a high speed log strike!!!
 
Jay. The Armstrong bracket system on the TomCat 255 catamaran is a type of "Jack Plate".

In the thread, "C-Ranger Tug Questions Answered", a NE dealer mentions he has put 200 hp outboard on a CD-25 and mentions the performance of 43 mph. Great risk is entertained by powering a craft above the manufacturer's design specifications.

Some of the older C-Dory designs used offset stern brackets to power the 25 foot fishing models.

John
 
I can understand your quest for more performance and can see the advantage of a jack plate. It might be nice to be able to run that engine down a little lower in a following sea and then raise it up for flat out hauling on clam water.
I'm just about done machining an intake manifold that the twin 40's will share. On the joint intake I'm mounting a 671 blower with nitrous...hope to be able to break the 35mph barrier :)
 
Revving up a C-Dory with a surface prop sounds good. Speed is the one thing I love which I had to give up with my 22.

I am not sure, but my concern would be with the shape of the hull and resulting performance. At higher speeds I suspect all you will do is lift the boat out of the water (as expected) but further back onto the flat part of the hull and pound yourself to death in any kind of chop (much less any swell and I mean any). There is not enough deadrise ("V") amidships to cut through any chop or swell. This is not unlike a John boat running flat out as an airboat and is bad enough with rated engines, IMHO. The tradeoff to being beat to hell is with an airboat you need a flat hull to run over things that are not aqueous. Maybe that is your goal in the San Juans (high end yacht dingies in Roche Harbor?). Prop walk will also be a problem as without any sort of "V" in or near the water you will have to rely on only the skeg for steering. Anyway I would love to see this if you do it.

BTW, see http://www.well.com/~pk/SPAprofboat.html, point #1 at the end of the article which indicates boats with hulls like C-Dories are poor candidates for surface props. Maybe you could contact this guy for more info?
 
Have you tried to miss a log in the water while going 40 mph???
Click to expand...

LOL. I suspect we may have had similar scares. The fastest I have been on the water is 88 knots. I will never do anything like it again.
 
Jay;
When I bought my 2005, CD25, I was looking at the 115HP HONDAs so I could get counter rotating props. The factory guys, at that time "encouraged" me to keep the power under the rated 200hp.

I have the 2x90HP HONDAs, and aside from the prop rotation, I have been very happy with the choice; especially after a 500NM trip this last June. I did a lot of practicing to learn the quips of Sea Angel which has kept the 'DINGS' off the hull. As to speed, I run heavy and can reach 34kts on the flat at WOT while watching the FF Meter cut my 900NM max range down to 289NM with a full tanks.
 
Definatly some "Joint Intake " goin on Ken !
How about the new 300 Suz on the 25'. Ill rig it if someone wants it !
You know in Maine they have the Lobsterboat races as well as Tugboat races .
I can see a C Ranger Tug racing circuit forming already.Hotrod Yanmars...

I envision a day when we can get major sponsorships from detergent manufacturers and male enhancement makers for our racing C Dorys . Vinyl wraps and bulkheads drilled for lightness . Maybe some carbon fibre parts and a bit of titanium here and there...............
Ok I gotta go to work now..........
 
we need to scare up some deals on some fire proof suits that are chocked full of sponser patches....Hey, we could call it the Cdory Racing Association Professionals
 
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