JD Designs a 3.5 OB Vee

[Jerry Dunlap]

Occassionally we see a post regarding outboard monos/vees. It has been my experience that most outboard vee hulls were "performance challenged" -especially when it came to handling in a corner.

Joe Monohan, 707 Specialities, decided to sponsor 3.5 Outboard Mono at the 2004 NAMBA Nats this summer at Legg Lake. After he sponsored the class, Joe e-mailed me and said I'd better bring down a 3.5 OB Vee.

Having run 3.5 vees, I basically knew the inherent problems with the handling. I decided to design a boat and built if from wood rather than use an existing fiberglass hull. It has been my contention that the poor handling was a result of running too small a boat(Prather 3.5 Vee is a good example). I made my boat 33 1/4" in length with a 10 1/4" beam. The bottom has a 20 degree vee with 1/2" wide ouside strakes and two 1/2" wide strakes on the bottom - one on each side. The keel entry at the bow is more like a Ranger bass boat and the bow is blunt.

The radio box is forward and a Mikie Z fuel cell is elevated for better fuel draw. I have three digital servos in the radio box(didn't hook up mixture for the first running). A set of Prather Products Outboard ride plates are attached to the transom. The motor is my CMB Green Head with Irwin Quiet pipe.

Ran the boat for the first time today - best running 3.5 Outboard Vee I've ever run. The prop that seemed to work best was an Octura X438. I managed to run up on a log with a bunch of spikes and poke a hole in the bottom. I stuck some radio box tape over the hole and continued running.

Here's some photos.

JD

 

[Jerry Dunlap]

Another photo

 

[Jerry Dunlap]

The cowling is a Dumas 7.5 cowl. Had to keep my tunnel heritage somehow.

JD

 

[Jerry Dunlap]

My wife thinks this is the ugliest looking boat I've ever built!!! I don't know whether to call it "The Ugly Duckling" or "Das Ugly Boat." But, the sucker sure works!!

JD

 

[Jerry Dunlap]

Here's some set up shots.

 

[Jerry Dunlap]

Another

 

[Jerry Dunlap]

Here's a shot of the bottom. You can see the hole where I ran over the spike. I was lucky it didn't do more damage.

JD

 

[Jerry Dunlap]

Last shot. Transom view showing the 20 degree vee. I'll repair the hole in the bottom and then paint the boat.

JD

 

[Slideblues]

HOLY COW!!!!!!

And a Greenhead on tha back too!!!! Very interesting design JD,

I have wanted to put a mod K&B on a Seaducer 21 and try it, but never did.

Kinda lost me with the Dumas cowl, But hey if it works ......DO IT!!!

 

[Chris Cohea]

UJ..

You old Funny Dunny.....

Funny part is I bet you clean up at the nats with that boat.

The 2002 Nats that was the very first time I had seen these run and they all had a ugly ride to them,but I do remember you rockin' all over the course to take the win...

Chris

 

[nitrotoys]

It may look ugly, but sure looks like it will run well.

I think it is awesome design.

Tom

 

[TomMoorehouse]

you should have an offset windshield, a rasied casting deck, a couple pole chairs and it will really will look like a bass boat! hehehe could you imaging beating them with a bass boat.... would be too funny!.... get a ranger boats decal for the side!

 

[Bob Kensill]

No slam intended on your design,but why do you and Grim make such blunt fronts on your boats. Am I missing something or does air flow over them as well as a "streamlined" one. Or is it just easier to build fast that way.

Bob

 

[CySlyde]

I can see it now... JD's Bass Boat Shoot-Out, First Annual.... :lol: i like it man very cool

 

[Tunnelbill]

Hey JD,

How does the Pro Pipe work? Getting ready to set one up on my Tunnel. Thanks Bill

 

[Jerry Dunlap]

Re: Blunt fronts on your boats

The "blunt front" design is really easy to build. The frames are glued to the deck, the side pieces glued to the frames, sheet the bottom and the basic hull is done. I also felt that a "sled" design might help in dampening the side-to-side ride action of most OB Vees. Also, it doesn't look like anything else on the water(other than a drift wood log ).

Re: Pro pipe

Is that what Irwin is calling the 3.5 Quiet Pipe? I like the one I'm running. Without question, it provides the best sound suppression.

JD

 

[wswatzell]

Very Cool! B)

 

[wswatzell]

Also, it doesn't look like anything else on the water(other than a drift wood log  ).

A really fast moving drift wood log!! LOL!!!

 

[[email protected]]

Man that thing looks like a barge......lol :lol:

 

[Mark Anderson]

Jerry

The pictures really don't do the boat justice. It is much uglier in person. Glad to hear it ran well. I like the idea of loosing the cowl and adding a bass boat deck to it.

Have you been running those little blue fuel filters long? I had several of them come apart and plug up needle valves. Kind of funny that part that is put in to catch debris before it causes a problem turns into a debris maker. I switched to the sullivan crap traps.

Mark