V-Drive bracing

[carteaco]

I took my v-drive in for a check up. The local Hotrod boat shop asks why it doesn't have any bracing on the v-drive. This is my first boat and thats how I bought it. He says it needs a brace at the bottom and one about middle on each side and braced back to the stringers. Does it need it or not? If so...Pics would be a help. The boat is a Hondo Ski hydro, 427 BBC, single 1050 Holley. 11.5:1 on gas

[RiverDave]

There was a major debate about this on Hotboat a year or two back..

Can you post a picture of the current setup?

At the end of the day, people pretty much all agreed to disagree. Most agreed for play boats without much HP you don't need the tie rods and turn buckled that go back to the stringers..

RD

[carteaco]

Sorry no pics available. Boats disassembled. The v-drive is attached to the stringers via the mounting plate between the cases. The mounting plate has been trimed down to about 3" wide at the bottom of the case and extending to the stringer.

[stokerwhore]

http://i146.photobucket.com/albums/r246/bordsmnj/schiada001.jpg
on brace each side instead of two pictured. excuse the the mess. it will clean up nice pretty soon.

[RiverDave]

And so the argument that was on hotboat starts all over again.. LOL

IN looking at those braces pictured, I don't believe they are doing anything to support forward movement of the v-drive. Because of the way there made, I think it just bends the aluminum ever so slightly like a spring. Pre-loaded tie rods would work, but I don't think those aluminum deals do anything?

RD

[stokerwhore]

with 12 bolts through the stringers at the plate i don't think it's going anywhere regaurdless. i haven't learned enough YET to comment further other than guessing.:hmm:D

[wsuwrhr]

All that bracing bolted to a peice of wood.

Yea that ought to work.

And so the argument that was on hotboat starts all over again.. LOL

IN looking at those braces pictured, I don't believe they are doing anything to support forward movement of the v-drive. Because of the way there made, I think it just bends the aluminum ever so slightly like a spring. Pre-loaded tie rods would work, but I don't think those aluminum deals do anything?

RD

[Racey]

The bracing is an absolute must, period, end of discussion, i don't care what anyone else has to say about it, Having the V-drive braced back to the stringers will prevent broken prop shafts, un-necessary bearing wear, and if that isn't enough reason how about loss of power.

The absolute most important part of rigging a v-drive boat is strut to v-drive alignment, they have to be within thousands of an inch to align properly, this is done with total finesse before any hole mounting the v-drive is drilled, if you have never had to rig one from scratch then you have no room to talk about how close that tolerance is, and how even 1/16 of an inch off will cause major issues, it's amazing how hard it becomes to turn the shaft when there is that tiny amount of bind applied to it. If they aren't within that fine line of alignment tolerance you will create unecessary bind which will load the shaft, wear out the bearings in the v-drive, create vibrations, cause shaft whip etc.

So now we come to the infamous V-drive braces, what you have to remember with a v-drive is that every single bit of thrust that pushes the boat forward is because the prop shaft is pushing the v-drive, and the v-drive is mounted to the boat. what ends up happening if you aren't running braces is the v-drive plate twists (the bottom of the plate tries to go toward the nose of the boat) EVERY PEICE OF METAL BENDS EVEN UNDER THE LIGHTEST OF FORCES. It's not uncommon to have thousands of pounds of thrust pushing against that v-drive which will twist that plate more than you'd imagine, the braces put almost a complete stop to this because twisting force is yeild strength not tensile strength (it's far far easier to twist and bend a peice of metal than it is to snap one by applying pulling forces to it, don't believe me, take a peice of wire and bend it, pretty easy, now try wraping it around the fingers of each hand and stretching it to the snapping point....). Aluminum plate braces (almost like the ones pictured above) work great as long you are using very tight holes through the plates and stringers, to where you need a hammer to tap fasteners through. Pre-loaded tie-rods work great too, you just have to be careful not to preload them very much, because they will pull the v-drive out of aligment in the other direction. the only problem with those plates in the picture above is that they are bent at the v-drive end, they should come in straight to a block as near the case possible.

http://www.riverdavesplace.com/forums/attachment.php?attachmentid=48057&stc=1&d=1237834669

[Wheeler]

Here is another variation on bracing the V-drive.

[RiverDave]

I'm not a v-drive guy by any means, but in my humble opinion the heim joint program would be the way to go. That way you could ever so "slightly" pre-load the plate to deal with the forces being imparted on it under load.

RD

[Sold Honda bought Hondo]

I have 81 hondo ski hydro 455 olds 40 gear 12x16 cleaver...no braces of any
kind although they are on my list. I put plastic wire tie on the prop shaft between the prop and strut and there is about 1/16" extra space.The shaft will move forward that 1/16 under load but never enough to damage the wire tie. I don't have a lot of hp...yet but i do run the boat plenty hard. I am having problems with flex in other places. The toe kick was broke both sides,
directly above the stringers when i got the boat, fixed that and my repair is still holding.....now the flex in the gunnels (sp) has cracked the inlets on both fuel tanks.I am trying to figure out some kind of bracing to tighten things up and still let it move around a little

[Sold Honda bought Hondo]

Since i posted that my 81 caught fire and burned down......and i now own the boat of the OP....and it is one flexi ass flyer...I'm i process of re-rigging it. I am running the rails all the way to the gear box with a 3"x 1/4 flat running down the outside of the stringer and some kind of 4 bar deal attached next to to gearbox and attached to the rails. When i drove it the gearbox was moving about 3/8 inch.
Does anyone else around here have/had a hondo ski hydro?
thanx
mike

[44jim AKA Lil Rat Bastard]

Hey Mike. You got that boat running?

[Sold Honda bought Hondo]

Well it was...and then i took it all apart...all the way apart..My major achievement so far..about 70 sq. ft of bondo on the bottom...nuthing thick..just smooth out the knots and flush the blast plate.

[44jim AKA Lil Rat Bastard]

Call me if you need a hand

[Sold Honda bought Hondo]

Done on one side
http://www.riverdavesplace.com/forums/picture.php?albumid=281&pictureid=2150
http://www.riverdavesplace.com/forums/picture.php?albumid=281&pictureid=2149







and partial inside....new tow kick, transom plate and white epoxy down the middle
http://www.riverdavesplace.com/forums/picture.php?albumid=281&pictureid=2146

Just shot a gal. of feather fill on top...block with 36" long board...and do it again and it might be straight for paint...I was embarrassed on the last one...bright red sack of rocks...That wont happen again

[racerden]

The bracing is an absolute must, period, end of discussion, i don't care what anyone else has to say about it, Having the V-drive braced back to the stringers will prevent broken prop shafts, un-necessary bearing wear, and if that isn't enough reason how about loss of power.

The absolute most important part of rigging a v-drive boat is strut to v-drive alignment, they have to be within thousands of an inch to align properly, this is done with total finesse before any hole mounting the v-drive is drilled, if you have never had to rig one from scratch then you have no room to talk about how close that tolerance is, and how even 1/16 of an inch off will cause major issues, it's amazing how hard it becomes to turn the shaft when there is that tiny amount of bind applied to it. If they aren't within that fine line of alignment tolerance you will create unecessary bind which will load the shaft, wear out the bearings in the v-drive, create vibrations, cause shaft whip etc.

So now we come to the infamous V-drive braces, what you have to remember with a v-drive is that every single bit of thrust that pushes the boat forward is because the prop shaft is pushing the v-drive, and the v-drive is mounted to the boat. what ends up happening if you aren't running braces is the v-drive plate twists (the bottom of the plate tries to go toward the nose of the boat) EVERY PEICE OF METAL BENDS EVEN UNDER THE LIGHTEST OF FORCES. It's not uncommon to have thousands of pounds of thrust pushing against that v-drive which will twist that plate more than you'd imagine, the braces put almost a complete stop to this because twisting force is yeild strength not tensile strength (it's far far easier to twist and bend a peice of metal than it is to snap one by applying pulling forces to it, don't believe me, take a peice of wire and bend it, pretty easy, now try wraping it around the fingers of each hand and stretching it to the snapping point....). Aluminum plate braces (almost like the ones pictured above) work great as long you are using very tight holes through the plates and stringers, to where you need a hammer to tap fasteners through. Pre-loaded tie-rods work great too, you just have to be careful not to preload them very much, because they will pull the v-drive out of aligment in the other direction. the only problem with those plates in the picture above is that they are bent at the v-drive end, they should come in straight to a block as near the case possible.

http://www.riverdavesplace.com/forums/attachment.php?attachmentid=48057&stc=1&d=1237834669If I may Racey, make that an absoulte must with all HP flattys or hydros. #197 hasn't used them forever, just larger than normal angle mount plates w/no sandwiching. I think most high HP V-bottoms set up correctly and not used offshore don't need the extra bracing. Again, if everything is finessed fit correctly. Just my 197 cents worth of input.
DV

[RiverDave]

The Hydro is looking tits!!! When will the top be done?

RD

[Sold Honda bought Hondo]

If I may Racey, make that an absoulte must with all HP flattys or hydros. #197 hasn't used them forever, just larger than normal angle mount plates w/no sandwiching. I think most high HP V-bottoms set up correctly and not used offshore don't need the extra bracing. Again, if everything is finessed fit correctly. Just my 197 cents worth of input.
DV
That is the exact kind of brace i was thinking of! The bracket where it mounts the sandwich plate...is that cut and welded or bent in a press brake? And it looks like the sandwich has brackets on both sides where it mounts to the stringers?
I had the 79 out a couple times before i took it all apart..it was one flexi ass flyer compared to the 81...had skimpy little 3x2x48" rails and no bracing on the gear box and the upper rudder mount wasn't even tied into the rails because the rails were so short. I got some 3x3 and the rails will run all the way from transom to gear box with your style of braces.
thanx!

The Hydro is looking tits!!! When will the top be done?

RD
Last night:D.....red and 1/2 gal. clear coat....came out good, almost no dirt,got it to lay down plenty smooth (and i am not a painter in any manner shape or form) I go out an hour later and 2 moths had crashed and burned right in the middle of the deck.No biggie..i know how to sand and polish...probably cause i'm not a painter. lolhttp://www.riverdavesplace.com/forums/picture.php?albumid=281&pictureid=2161
Been working on the inside..filled holes in stringers with hardwood plugs and a layer of cloth on stringers to get them straight and smooth. Shipment from US Composites be here today...more epoxy to finish floor and carbon fiber to cover stringers. New blast plate , rudder and strut ready for powder coat, found a decent std/std crank (427 the last one kissed a brng and was 20/20)
it's at the machine shop for polish....Time to finally start putting things together.....I am soooo tired of sanding... With luck i be in the water in 30 days.....and for those who don't know:
I went from never owning or driven a boat,(oct 14 '09) i bought this without a motor from "The Great Mouser":bowdown:http://www.riverdavesplace.com/forums/picture.php?albumid=281&pictureid=2163
To this
http://www.riverdavesplace.com/forums/picture.php?albumid=281&pictureid=2167
With some of this,http://www.riverdavesplace.com/forums/picture.php?albumid=281&pictureid=2164
To this ouch:(http://www.riverdavesplace.com/forums/picture.php?albumid=281&pictureid=2166
And no...i didn't jack this thread, cause i bought this...it belonged to the op....http://www.riverdavesplace.com/forums/picture.php?albumid=281&pictureid=2162
Did most all of it myself.......except for some help from http://www.riverdavesplace.com/forums/picture.php?albumid=281&pictureid=2165
My bestest buddie in the 'hole' wide world.....:p

[Dave Sammons]

Boy, I sure don't want to start a big debate here. I respect the work and ideas that other guys have done(not afraid to copy once in a while:D:D) but, at least in a 1200 hp K boat or most any sprint boat for that matter, where we have to deal with a very short stringer and not a lot of room for braces(not that I haven't done them) you will see VERY few of the fore/aft bracing done in these types of boats. It has been my experience that properly braced from the stringer the flex, over and above the the normal movement of the hull, is minimal.
I do recommend a 1/2 centerplate and front and rear sandwich brackets extending all the way to the case and a high up the case as you can go...
A few examples from the last few years out of my shop...

http://www.performanceboats.com/gallery/data/500/medium/1517wn81.jpg

http://www.hotboatpics.com/pics/data/500/5187dn1.jpg

http://www.performanceboats.com/gallery/data/500/medium/CIMG0004.JPG

http://www.hotboatpics.com/pics/data/500/5187lvd1.jpg

First three were all Biesemeyers, the last in a 20ft Raysoncraft. Again, we have had success running high horsepower circle boats like this for a long, long time. I have seen many braced a whole lot less than I do with no problems....
So at the end of the day, probably the better braced the vdrive is the better...but it has been done other ways with no issues...

[Sold Honda bought Hondo]

Those sandwich braces are plenty stout! And it covers the area where mine was flexing....It looks like those stringers are all bigger than mine..
3 3/4 x 1 1/4 and the rail kit was 54" long and 2X3x1/4...and wasn't even attached to rudder support.
Only running maybe 500 hp now but next motor will be much more. New rails from transom to v-drive..3x3x1/4..capped the stringers with cloth and carbon fiber and epoxy.
And now that i see the sandwich deal i like it too...less brackets. You build some impressive equipment...it's ok if i copy you?:cool:

[Dave Sammons]

And now that i see the sandwich deal i like it too...less brackets. You build some impressive equipment...it's ok if i copy you?:cool:

Hey, I wasn't the first guy to do it! Don't get me wrong, I am still a big fan of Fore/Aft braces(prefer the hiem joint set up), but, like I said...the stouter the better! Shoot me a PM and we'll talk on the phone if you have questions!
Dave

[Sold Honda bought Hondo]

I liked that sandwich thing so much i copied it..I couldn't find little pieces
like you used, all i could find was big piece of 1" stuff..it was really big but i bit the billet and cut it in half and made it work.


I don't have those big machines everybody else has to make big things smaller but i have this neat hand held carving tool with a 7 1/4" round blade with really sharp tips that makes these things that look like real metal flake. i just need to remember that they are really hot. I have a heavy duty 9"
surface/mill that makes it all smooth.

It's kinda messy doing it that way but at least it's noisy. I think my neighbors
like the noise, they are always telling me about it, and i know the guy next
door must really appreciate it, me getting up so early for work, I hear his
boss at p.d. doesn't put up with employees being late for work although
there probably isn't much he can really do, all the employees carry guns.

I didn't want to make it all shiny, that must be the easy way because
everybody seems to do it that way. I drove all over town looking for some
kind of black paint that didn't leave marks from my paint brush but all
i could find was this stuff in a spray can..It looked better right after i
painted it, but after it dried it got all wrinkly.

I need to get more bolts for it, i used up almost every one i have and i don't know it will be strong enough to keep all that wood from bending but if
it does i will use the the other half of that piece i found even it makes it
look all big...and if it does......I'll just name it..big things deserve names,
right?

I was thinking "Dave Sammons super billet gear box sandwich" :cool:
Oh..almost forgot pictures

http://www.riverdavesplace.com/forums/picture.php?albumid=296&pictureid=2253http://www.riverdavesplace.com/forums/picture.php?albumid=296&pictureid=2251http://www.riverdavesplace.com/forums/picture.php?albumid=296&pictureid=2250http://www.riverdavesplace.com/forums/picture.php?albumid=296&pictureid=2249:drunk

[RiverDave]

I liked that sandwich thing so much i copied it..I couldn't find little pieces
like you used, all i could find was big piece of 1" stuff..it was really big but i bit the billet and cut it in half and made it work.


I don't have those big machines everybody else has to make big things smaller but i have this neat hand held carving tool with a 7 1/4" round blade with really sharp tips that makes these things that look like real metal flake. i just need to remember that they are really hot. I have a heavy duty 9"
surface/mill that makes it all smooth.

It's kinda messy doing it that way but at least it's noisy. I think my neighbors
like the noise, they are always telling me about it, and i know the guy next
door must really appreciate it, me getting up so early for work, I hear his
boss at p.d. doesn't put up with employees being late for work although
there probably isn't much he can really do, all the employees carry guns.

I didn't want to make it all shiny, that must be the easy way because
everybody seems to do it that way. I drove all over town looking for some
kind of black paint that didn't leave marks from my paint brush but all
i could find was this stuff in a spray can..It looked better right after i
painted it, but after it dried it got all wrinkly.

I need to get more bolts for it, i used up almost every one i have and i don't know it will be strong enough to keep all that wood from bending but if
it does i will use the the other half of that piece i found even it makes it
look all big...and if it does......I'll just name it..big things deserve names,
right?

I was thinking "Dave Sammons super billet gear box sandwich" :cool:
Oh..almost forgot pictures

http://www.riverdavesplace.com/forums/picture.php?albumid=296&pictureid=2253http://www.riverdavesplace.com/forums/picture.php?albumid=296&pictureid=2251http://www.riverdavesplace.com/forums/picture.php?albumid=296&pictureid=2250http://www.riverdavesplace.com/forums/picture.php?albumid=296&pictureid=2249:drunk

LOL...

RD

[Marko]

Well... thats one way to do it. Usually you would use 1/2" for the center plate of the v-drive and build the braces to sandwich the center plate, coming as close to the box as possible. I suppose your way will end up adding some support as well, just never seen it done like that. Mr. Sammon's will know more though. :thumbsup

[Dave Sammons]

I liked that sandwich thing so much i copied it..I couldn't find little pieces
like you used, all i could find was big piece of 1" stuff..it was really big but i bit the billet and cut it in half and made it work.


I don't have those big machines everybody else has to make big things smaller but i have this neat hand held carving tool with a 7 1/4" round blade with really sharp tips that makes these things that look like real metal flake. i just need to remember that they are really hot. I have a heavy duty 9"
surface/mill that makes it all smooth.

It's kinda messy doing it that way but at least it's noisy. I think my neighbors
like the noise, they are always telling me about it, and i know the guy next
door must really appreciate it, me getting up so early for work, I hear his
boss at p.d. doesn't put up with employees being late for work although
there probably isn't much he can really do, all the employees carry guns.

I didn't want to make it all shiny, that must be the easy way because
everybody seems to do it that way. I drove all over town looking for some
kind of black paint that didn't leave marks from my paint brush but all
i could find was this stuff in a spray can..It looked better right after i
painted it, but after it dried it got all wrinkly.

I need to get more bolts for it, i used up almost every one i have and i don't know it will be strong enough to keep all that wood from bending but if
it does i will use the the other half of that piece i found even it makes it
look all big...and if it does......I'll just name it..big things deserve names,
right?

I was thinking "Dave Sammons super billet gear box sandwich" :cool:
Oh..almost forgot pictures

http://www.riverdavesplace.com/forums/picture.php?albumid=296&pictureid=2253http://www.riverdavesplace.com/forums/picture.php?albumid=296&pictureid=2251http://www.riverdavesplace.com/forums/picture.php?albumid=296&pictureid=2250http://www.riverdavesplace.com/forums/picture.php?albumid=296&pictureid=2249:drunk
Well Mike, like they say there is more than one way to do about anything!
She should work just fine for the amount of horsepower you have...Don't think the bottom half of the vdrive is gonna flex a whole lot...
Nice effort!
If you ever put any more HP in it(say 900 or more) keep your set up but get a 1/2inch plate for it as suggested and try and keep as much of the plate as possible from the top of the vdrive to the top of the stringers, kinda like the picture of the vdrive in the yellow GN I put up.
All in all I think you're RaceReady!!:D:D
Have a great summer with it!

[Racey]

http://www.performanceboats.com/gallery/data/500/medium/CIMG0004.JPG



This right here in my opinion would be the best for an application where you don't have the room for for/aft bracing, or a combination of this and the oversized angle extending all the way to the case (billet block in the back, angle in the front or vice versa) :thumbsup

Lots of chips and time turning handles to make those on on a bridgeport, but well worth it :cool:

[Sold Honda bought Hondo]

Way cool! Just what i wanted...different and good enough....I was going to start with a thicker mid plate...figured a hun for material, hun for machine work and a hun for gearbox spacers...problem is, i have 3 gear boxes, all different gears..i have no idea what gears i will end up with...other than the olds motor likes 40's...
(ya olds motor....i have the fastest olds powered boat in town:p
and it gets almost 4 mpg and runs on 89 octane:D)

so changing gears/boxes is as easy as drilling 8 holes...and if the gearbox doesn't have a prop release the distance the box needs to move back just happens to be the same as the stringer bolts.

The 30"x14"x1" was part of fixture from a cnc i used to run...free..except for dragging it around for 3 years trying to figure out what to do with it.

900 hp? not this year.....besides...who would want to go that fast?;)

All that's left to figure out is drive shaft tube....it's ugly and heavy.
At what length does a drive shaft become a coupler and not need an 'explosion retention device' AKA 'blast can'?
I am @ 19.5 now and intend on moving engine forward to the point
where the drive shaft will no longer have a tube.
thanx much
mike

[RiverDave]

I would imagine you would always want a tube jsut to keep feet and hands out of it?

RD

[rivergames]

If you want to die or kill someone leave the tube off. :thumbsup


A broken drive shaft is probably the most violent force of destruction that can happen inside a boat

Think about a u-joint breaking @ the v-drive. The motor would spin the drive shaft all over the place

[Racey]

Put a tube on, it can kill you if it breaks, I've also heard stories about chicks hair getting sucked into the u-joints and scalping them..... no tube = no boating.

[Dave Sammons]

What RD, RG and Ray C said!!!

[Sold Honda bought Hondo]

So pvc pipe covered with carbon fiber just ain't gona get it:grumble:

[Sold Honda bought Hondo]

Well i'm up and running.........gear box is rock solid (but just for the hell of it i am going to build the same thing for the other side)......water was to rough for any real hard acceleration but i did a bunch of on the gas and off the gas stuff trying to figure out how much more acc. pump to give it and it had zero movement....

and i get to pat myself on the back a little...i replaced every bolt in the bottom of the boat..blast plate, strut, gas tank, shaft log...re-sealed the stuffing box and moved the rudder almost 3" to correct a hard pull to the right issue...

boat is bone ass dry and runs hands off straight.....even the motor is clean and dry...used one of those $45 one piece oil pan gaskets..no glue and no leaks

I did have one oil leak.......i normally don't let anybody else work on my stuff except for the machine shop....The last time anybody worked on something of mine was a motorcycle dealership i paid to mount and balance 2 tires on my 135hp gs1000....i made it 15 miles down the road scuffing in the new tires well into the triple digits on a freeway ramp sweeper...i felt the rear go soft...rolled off the gas a little and i was running dead ass flat...ever tried driving a forklift @80 mph? Anybody but me ridding would have died...old style bias tires..came off the bead about 60...3 lanes..i used all of them..got it stopped without a scratch....that was 1994...and the last time ANYBODY DID ANYTHING ON MY STUFF.

I had an issue with the prop release...it was half apart when i got the box...
not knowing exactly how it went together, and having a hundred other things to deal with...i sent it out to one of the local 'pros' with mention of an oil leak in that area...job was done on time..i paid the bill and installed the box and built the brace...2 weeks later i fill it with oil.. i dribbled a little, wiped it up..next day i had a leak..about a cup on my nice white epoxy floor...kicking myself in the ass for knowing better....i drag the box back...he takes it apart, finds a crack in the shift housing i probably would have missed, calls and tells
me the problem, i run home to get a spare and drop it off...he installs it same day...and no charges it....that kind of made my day..THANX JOEY!!:thumbsup:thumbsup