School Pjoject - Ben Hur Hydroplane

[Seanj85]

Welcome shovelguy,

Been a while since the build and i cant remember if there were one or 2 that went in on angles, i know the transom was definitely angled back. The rib that connected to after planes may have been angled as well, although I couldn't tell you for sure. I want to say that most went in straight at 90.

As for the girders, you are correct in assuming there is no template except for the scaled drawing (which is a bit rough for sure). You're going to have to scale it up. We did this on a couple sheets of taped together foam core before transferring it to meranti ply. We wound up having success using an architects scale.

As for sponsons I believe (although I could be wrong) that you can scale them up and template them off the the same scaled drawing as your girders. Figure out your partition between girders and sponsons on template and slice it in half. Ours needed some adjusting to fit right. I found that an electric hand held planer was a very useful tool for this.

I don't remember seeing a plan for the air traps, but a member on here (Gary) recommended running them straight back with about a foot of space left over from transom.


As for material we used mahagony and meranti ply, which wound up being about 40 lbs heavier than the recommended material. If I were to build it again I would use maybe a fir instead of their recommended Sitka spruce and instead of meranti I think I would use the 1/4 in okoume as it is lighter and than the meranti. We used meranti and the bottom is built like a brick ****-house.

I hope this helps, again it's been a few years since we completed this build. Other recommendations would be to really read through and study the plans throughly several times before getting dirty. If you have additional questions don't hesitate to ask, good luck with the build. Would love to see your progress along the way. Start a build thread! Good luck!

[Shovelguy79]

Thank you very much for your detailed response. I know that no plan set is perfect but I do have to admit that they give me a headache at times. I will do my best to scale everything and I'm going to study the plans in depth before I actually cut anything. The photos from your project have helped me a ton already. I emailed Clark Craft and asked about the angles, if I get clarification from them I will share it here for sure. The boat looks like so much fun and I know that the entire time that I am working on it I will be daydreaming about cruising down the lake in it. Thank you very much again for your reply and I appreciate your help. Cheers

James

[Seanj85]

Before starting i found thinking about the entire scope of the build to be a bit overwhelming as well. There is a lot going on, and the plans are pretty in depth.

Breaking it down into small steps and setting weekly goals was the key to getting it done. Start with templates for ribs. Then think about material for each rib, read thru the plans on each rib, from there start your layout on girders, I wound up stapling the girders template directly to the two pieces of material and cutting it out from there.

Take your time with each step and carefully consult the plans every step of the way. When you break it down into little steps it's like anything else. Just takes time (and money)

[rock]

Did any of the kids get to drive it?

Rock

[Instigator]

Clear white pine works well in place of the unobtanium Sitka spruce.
Ive built several boats w/it w/no problems.

And yes to the 1/4” Okume.
Rock strong and gorgeous grain for stain/varnish.

I used mahogany on my first boat because it was much easier to source.
That boat was a pig accordingly.
While building you don’t think it’ll make much difference but it does.

I just found a local source for Okume and I think they’re at $100 for a sheet of 1/4”.

And yes to the air traps if you want the hull to lift/fly and be fast.
Research Stock or Modified hydroplane racing and every boat will have air traps.

Gary

[Seanj85]

Did any of the kids get to drive it?

Rock

Yes had about 5 kids drive it. Did it under the radar during covid. No problems except for a fuel line issue.

[Spaceman Spiff]

Is this hydro able to be modified slightly to allow for a seated driver? Or would that upset the performance too much? I'm not looking to go over 50. On the Clark Craft website it says it can be made as a non-racer that can carry 2 passengers. But how could that be done with the driver laying/on knees as illustrated?

Stephen

[Turtleherder]

If you want a small sit down hull check out Dillon racing http://www.dillon-racing.com/EZTunnel/plans-m.htm

[Spaceman Spiff]

If you want a small sit down hull check out Dillon racing http://www.dillon-racing.com/EZTunnel/plans-m.htm

Thanks. I've actually been on that site for about the last year hemming and hawing about which one to do. Along with Muskoka, Glen-L, and Clark craft. That video of Sean flying across that choppy water is what's selling me on the Ben Hur. I built a modified Minimost XL with a 50hp Merc from the Muskoka seaflea site and it was fun and stable on fairly calm water, but wouldn't turn for crap.

[Spaceman Spiff]

I bought the full-size plans for the Ben Hur from Clark Craft awhile back, but I've decided I'm not going to build it because my left knee is pretty bad and not getting any better. If I make another boat, it will probably be the Aquarod, where I can sit down in it.

If anyone wants these plans, I will ship them off at no charge in the US.