Ben Hur surface drive

[stupidbaker57]

47559

47560

47561It's been a while since I have worked on my "project" 'cuz I've been waiting for a parts from the machine shop, but I finally got them. I just received my rudder that sells for $795 retail but used on Ebay it was only 40 bucks. I steering bar is wood but only for design purpose. It'll be steered by cable and pulley.

[DeanFHobart]

I'm curious as to how much you have in out of pocket cost, including the motor, fittings, welding, rudder, etc. ?

Thanks.

[stupidbaker57]

This is just a ball park number, but close

Boat 200 (I built it)
Engine 60 Ebay
suface drive 120 Ebay
prop 100 Ebay Ron Hill
rudder 4 Ebay
steering wheel 5 swap meet
misc. nuts, bolts and steel stuff 50
machine shop work free I own a lathe

Seeing the look on the face of the guy with the $20,000 boat as you pass him.....PRICELESS

[Mark75H]

Get it wet!:)

[Ron Hill]

As a man who has yet to test his DIY Outboard, let me say, "Don't rush him",

I tend to think Stupidbakers says a lot here! LOL!!!!

[curbman]

I am waiting for the video, oh and yours to Ron. I would like to see some video.

[stupidbaker57]

I just wish Ron and I weren't on different coasts. We could have a DIY shootout to see who's the fastest.
I'm looking to get it wet next weekend.

[JohnsonM50]

Its very cool.. what to expect..? [what to hope for is obvious= Luck:D]
You will have to work out drive position so you can get it going, control it & make some speed, if comfort is an option that would be good too. The prop choice will be critical for several reasons. Maybe the most initially important, hope it doesn't vibrate. :eek: Good Luck on test day, Hope it goes good & faster than $20G's worth of financed tupperware-hardware. That wood be priceless:cool:

[zul8tr]

Cool rig :cool:
Take it slow first time till you get the feel and behavior :eek:
Tell us about the drive shaft lubrication means. Simply greased or?
Do you have other props to try?
What is the pitch and diameter of the prop in the pic?
It is direct drive, right?
What Hp?
How did you determine the length of the engine straight pipes?
What rpm are you shooting for?
Couldn't see in the pics but do you have a left sponson fin?
Based on steering performance and desired speed consider trimming some length off the rudder.

Good luck on test day :)

[stupidbaker57]

The shaft has a tapered bearing on the bottom for thrust running in #90 gear lube. The upper bearing is a sealed roller bearing. The prop is a Ron Hill 7.5 X 12 cleaver..There's no turn fin since this is not intended to race and I might want to turn right once in a while. If the rudder is too deep, then I will make a shorter one. Really don't want to cut this rudder because I want to use it on a furture project.

[Lil Stinker]

Was the Ben Hur designed for a Center fin? like the old Swift big B and D .

[stupidbaker57]

I'll check the plans, but I think the turn fin is incorperated into the left aluminum air trap. I'mm not running the air traps. I might not need the extra lift.

[zul8tr]

Kelly designed the turn fin into the left air trap.

http://www.boatsport.org/PDF/BenHur1.TextMark.pdf

[JohnsonM50]

A center fin would work just a matter of where & how big. A pal has a Wetback from Clark Craft, it origionally had a center & sponson fin. Whenever the sponson fin left h2o the boat would straighten till it re-set. made for some wild anticipations. Removing the center fin cured this so Id say one or the other.

[stupidbaker57]

For now, I just wanna go staight and work out any trim. If I wanna turn, then I'll slow down.

[Lil Stinker]

A fin may help you go Straight.

[JohnsonM50]

A fin may help you go Straight.

Gotta agree there but at least w/o air traps & fin its not likely to hi-side ya if it prop walks, might crab a little tho..;) Also if you need to turn some to hold straight in effect you'd be giving up speed in that of many trade offs

[stupidbaker57]

Cool rig :cool:
Take it slow first time till you get the feel and behavior :eek:
Tell us about the drive shaft lubrication means. Simply greased or?
Do you have other props to try?
What is the pitch and diameter of the prop in the pic?
It is direct drive, right?
What Hp?
How did you determine the length of the engine straight pipes?
What rpm are you shooting for?
Couldn't see in the pics but do you have a left sponson fin?
Based on steering performance and desired speed consider trimming some length off the rudder.

Good luck on test day :)

Sorry, I missed some of the questions.
It's not 1 to 1 ratio. I've got it geared down 16 to 21 which can be changed easily by swapping the sprockets or changing the number of teeth.
The Honda engine is 27 HP with an automatic trans. (at least I have neutral) with high and low speeds.
As for the exhaust pipe length, that was easy. I found a piece of SS tubing in the scrap yard, cut it in half and welded it on to the bike pipes.
These bikes rev high at 60 MPH, so I think 6000 is just about where it should be.

[zul8tr]

You will find that the straight pipe length is very critical to the power and torque output and the rpm where these peaks occur.

[stupidbaker57]

Here's the first picture of the final drive. I can change the ratio just by changing the sprockets.47591

[craigcraftdave]

Why not use the twin carbs? They run pretty good on stock carbs.

[stupidbaker57]

I had it on stock carbs, but one leaked and the other had a dirty passageway somewhere and wouldn't pull fuel tru it. I ebayed them and mounted up a snowmobile carb. It works pretty good on the trailer, but for the water I have a single tillison carb that I dejetted. We'll see how that one goes.

[craigcraftdave]

What are you using for a fuel pump?

[stupidbaker57]

The fuel pump is from a lawnmower/garden tractor. It's the vaccum type. 12 bucks at a lawnmower shop.

[craigcraftdave]

Very cool build. It looks like it will be fun.

[marchettih2o]

HECK OF A PROJECT!!!!...my hat is off to you...love stuff like this....obviously this is very experimental...yet, after you get some time on it...I think it would behoove you to install your rudder on the port side (or whatever direction you plan to turn) of the transom...the loads with the rudder just behind the prop will be immense and try to bend your drive at the *** end. Just my idea..but what you are doing, looks like it will be a hoot! Keep he momentium going...gg

[stupidbaker57]

Turnning???????????? I'll be happy just to go straight!

[marchettih2o]

yeah, ya got a point there...for sure...reminds me of the Honda Trail 70 engine a buddy of mine and I tried to put in a go cart...it became too much money to finish for our shallow pockets in the 7th grade.....but boy were we dreamers...george

[stupidbaker57]

Well here's the good news. The experiment is in the water. Started right up and ran nice with no vibration at all. Now for the bad news,,,,,,,,,,,,I grabbed a handful of trottle and began to plane. Motor sputtered, so I idled down since I lanched it close to my house, and idled to my dock. Upon restart the starter went clunk. After checking battery connections and putting the kicker shaft back on, I realized that the motor had seized up! Back to shop. I'll pull the motor and drive and throw on an outboard I have.48033

48034

48035

[JohnsonM50]

Well, at least with an outboard you can enjoy the boat & maybe 'back burner' the surface drive for another motor. Its a project worth persuing : :cool: I'm wondering if the demand for power over the need for motion to cool it is why it seized? By far- [real far] most boat motors are water cooled. Probably not just an availability thing but a need to overcome the always going uphill aspect of a boat & the water being almost 800x more dense than air. Wheeled vehicles have it easy compared.

[Ron Hill]

There is always next week...Look at Charlie Brown trying to kick the football...

Keep us posted, we are all interested!