Question for GN7

[WESTERNAERO]

don't get me wrong, the bolt on surface steel strut is more than strong enough for a lake/river boat. I was only saying that the surface mount doesn't make much diff at speeds under 80 or so as far a drag. Your setup will handle more power than you are giving it. There have been GNs pushing more then 1000HP with surface bolted struts and 1 shafts(Aquamet22 or K Monel), they may have given up a little in top speed due to drag, but OK so far as strength.

The biggest issue I have with you current setup is the rusted chrome at the weld. Campbell Carl had a similar strut and the weld failed due to the rust. Its hard to tell exactly how much the strut is effected unless you remove it and strip off the chrome. But the strut itself is pretty stout, like somebody planned to put so power to it.

Thanks for your time and opinions GN, I do appreciate it. Hope I'm not bothering you with this on this site, I know you spend most of your time on PB. I would like to get the V-drive area here up to speed here though.
This boat was original rigged by Dimarco with a blown BBC. It probably explains why this boat is setup originally with the strut angle and position very close to what other guys are changing to with their Howards and Spectras. I'm with you on the chrome, it makes me nervous not knowing whats under there. Just one more reason I'm planning on changing it.

[gn7]

That thing looks like it was built to take some power. Didn't mean to make too much of the strut, just a heads up that the chrome can hide some stuff. I seriously doubt it would ever fail catastrophically. Just keep an eye out for cracks that night appear in the weld area until get around to replacing it.
Odd that your shaft hole is off like that. Not sure the strut was suppose to have a shorter web, as much as I think somebody oopsied a little when they done cut it. They are usually with the strut in place, and a shaft run thru the strut with a hole saw on the end. If they don't watch what they are doing, the hole saw can walk down the hull a little before it bites in and starts cutting.

As for PB, that place is a spin off of the original HB, and the V drive guys were the first ones to make the move when HB was flaming out. The V drive forums there still get the majority of the posts. Each site kind of takes a direction from the start and heads in a general direction. Not sure why, but the V drive forums there are kind of petering out. Jet and dyno forums are still holding their own pretty well. But the V drive forum has taken a dip lately.
Still WAY more boating content at PB and here than there is at RDP. That place is 100% lounge, and by invitation only. No party crashers allowed unless you sit down and shut up. They will let you know when its your turn to speak, and what to say, and to who. Place is foocked up.

[wannabe]

Yeah, this is Buzzz. Paul goes by FC Pilot. you will see him around.
And yeah, when I have something that I don't need, I give them away for a pretty good deal. I just figure that I would have loved to get a deal like that when I was starting out, so why try to get rich off of something that I am not using. I did a boat less motor for a case of MtDew, parts for cheap and even a guitar or two. I am glad that the kid digs the guitar. That instrument kept me out of trouble and out of spending cash for many years.
Now, Bob, I don't mean to argue, but I do have one question; Do you really think the strut gets almost equal force front to back? I see prop shafts break all the time. Even one on a TAF today. They always break right at the back of the strut. NEver seen one at the front.

[gn7]

the wear patterns in the bushing are reasonably even front to back, with slightly more wear towards the back at the top. Most of the wear is between 11:00 and 2:00. We, as well as most people run 2 bushings. It the rear was the only one that wore, we wouldn't bother with the front piece.

Shafts break where they do because of the key slot. They always break right at the back of the prop, and the end of the key slot. The key slot creates a stress riser, any slot milled into a shaft. Thank goodness, because if it didn't, then the shaft would and could break anywhere along its length, and you can imagine the disaster that could create.
the LIFT of the prop on the shaft isn't what breaks them, its the torsional twist, not different than when a crank snout breaks. Which BTW, also ALWAYS break at the end of the key slot, and very seldom at the front crank throw arm, which is the next most likely spot.

Input and output shafts on the V drive, same thing, always at the end of the key slot. Occasionally END of the gear splines.

Broken a couple output shafts on desert M/Cs as well. Splines and key slot are the bane of all power shafts.

Every crank snout I have ever seen snap, broke behind the t gear at the end of the key slot. All the power is transmitted thru the damper, and there is no mechanical connection between the damper and T gear, yet never once seen a snout snap between the 2 in the middle of the key slot. The front crank throw arm sees every HP being passed thru the crank, as opposed to the rear crank arm the see near nothing. (opposite a car engine). The front arm is the second most likely place to break the crank. But never in the middle of the snout.
Just like the prop shaft breaking behind the strut, this is not caused by up forces, or some directional thrust, its 100% due to torsional twist.

[WESTERNAERO]

I've started drawning up the new strut. What do you think? Have anybody ever used the engine mount as the gusset/brace before, is this wise to do? Opinions are welcome, it's much easier to change the CAD drawing now. Thanks.

[gn7]

I've started drawning up the new strut. What do you think? Have anybody ever used the engine mount as the gusset/brace before, is this wise to do? Opinions are welcome, it's much easier to change the CAD drawing now. Thanks.

There are guy that do it and swear by it. Greer Rush swore about it. TGN 24 boat had it for one race, and at the next it was gone.
I'm kind of neutral about myself.

[78Southwind]

Very Nice...

[WESTERNAERO]

I wonder if maybe it would be TOO rigid, or maybe being tied together like that you might get some really bad harmonics every where. Hmmmm?