bertram31.com

has anyone installed Yanmar 440's or other high powered diesels in a B31?

Timmy,

Three words: Yes - Dumb - Don't

Br,

Patrick

Yes they have, I turned down 2 31's in the past with that request.
One was a "money no object" deal.
If done right, it will work.

The main problem is because of the dead rise and the lift it creates and the speeds the big engines produce, you end up lifting the boat in the rear above the water. When you do that you loose stability and it chine walks which is a very dangerous condition.

Now adding prop pockets does counter act some of this problem.

Your looking at 125 to 135k to do the job right(engines and gears are 70k of that) because you do need propockets cut into the hull to swing the prop and also much more beefed up engine beds and running gear because at the speeds that it will produce with the short wheelbase of the 31, you will pound the livin crap out of everything and it better be nailed down tight.

But as I get older, I quit talking people out of doing things that aren't practical.

My motto now is, as long as you have the funds, I've got the time.

BTW, the above job comes with a helmet, 5 point harnass and hans device.

With Pat at the helm in his hat at those speeds, I do believe we could achieve lift off.

good motto

If you have to change the 31B that much, do you really want a 31?

If the ride would be too rough and money is no object, you could always make the first B31 hydrofoil boat. That would turn some heads

Sean,

A guy named Harry Larsen actually converted an old Bayliner single engine I/O into a retractable hydrofoil...



I was aboard a troup transport as an asault boat coxwain, (LCM-8), which on temporary assignment in Guantanimo Bay, Cuba. The Gitmo Naval Base had two combat support boats converted to hydrofoil, used primarily as chase boats. Watchin' 'em running around in the bay was awesome. Had to be doing about 60 mph on full tilt. Fast for those days, (1963)...

Br,

Patrick

probably a good choice on the Bayliner so the hull is out of the water!! I remember about 20 years ago one of my buddies bought one of these brand new and we took it for a ride in foot and a half seas- I was in the back and every time we hit a wave the sides buckled- needless to say that was the last time I ever got ion that boat!!

Jack,

Bruce needs to add another one,

Oxymoron #73 Bayliner boat

Mark

I was with a friend of mine running in his 18 foot bayliner in the Delaware getting pounded to death in 1 to 2 seas and he says "sometimes when I look in the bildge I see chunks of foam and fiberglass floating in there". That was the first time I was in a Bayliner and the last.

Capt Pat,

That was cool, despite their choice for the hull. Someday I'm going to retire and build stuff like that in my backyard. Have loose plans for a hydrofoil boat, a hovercraft, and maybe even a boat/car (worst of both worlds)...all kinds of silly stuff. I hadn't realized there were already guys out there who converted regular boats into foils. If I did that to a B31 I'd probably get shot by someone in this crowd though

All their photos and their movie were shot in calm water. I wonder what happens when you are up on the foils and pop into a good wave that is big enough to hit the hull. Would it be like tunnel-hull sneeze, the boat just suddenly stops? Or would you skip right out of the water to then land hard. Did those guys at Gitmo use them in rough weather?

Sean,
Your in good company with a bunch of boat plans and stuff sitting around. I have a complete Berkly jet unit in the attic? It's been up there so long I would take $100 bucks for it if someone would come pick it up. I may even give it away if somebody promised me they would stick it in a boat and run it...any takers?