Output Shaft

[hondo Jim]

The Out Put Shaft Coming Out From The V-drive. What Would It Take To Twist This Shaft And How Much Horse Power.does Anyone Have Any Ideas????????

[Moneypitt]

The Out Put Shaft Coming Out From The V-drive. What Would It Take To Twist This Shaft And How Much Horse Power.does Anyone Have Any Ideas????????
Depends on what you hit??? Seriously, I've seen the key twisted before, ruined the coupler, but never really seen an output shaft twist...........MP

[hondo Jim]

Alittle Mud, Buggered Up The Edge Of The Prop Alittle

[Rexone]

I've seen a lot of them break. Depends on the diameter (there are several), the material, and the HP.
I've seen a lot fail in ski racing over the years, mostly higher HP turbo stuff. Crack lots of times starts at the end of the key but I've seen them break elsewhere also. Metal fatigue over time.
The bigger the shaft the better for power. Casale common sizes are 1" , 1 1/8", 1 1/4", and 1 3/8". They may make larger than that, don't know.

[beaverfab]

What I have seen is the boats making 500 hp or the 11 second and slower boats twist output shafts more than the faster boats. My idea is that they hookup and do not slip. Not having the power to overcome the force of the water and twist the shaft more than boats with moor HP. Just my .02 j.j.

[gn7]

yep that's an interesting thought, no one broke an output shaft in about 3 or 4 seasons of GN racing, a bunch of us pull out the blower motors, in mild n/a's and break 3 outputs and 1 set of whirlaway dogs at the Bluewater 300. Go figure.

[hondo Jim]

Seems Like It Would Twist The Prop Shaft First Becouse It Is Smaller Compared To 6-12 In.

[gn7]

no, it doesn't like that, the prop shaft acts like torsen (sic) bar the output shaft is so short that almost any twist is too much twist, thats why a LOT of guys run larger output shafts than prop shafts and a step coupler.

[VDRIVERACING]

no, it doesn't like that, the prop shaft acts like torsen (sic) bar the output shaft is so short that almost any twist is too much twist, thats why a LOT of guys run larger output shafts than prop shafts and a step coupler.
Rush set us up with a 1 3/8" output shaft, turning our original 1" prop shaft....

[wsuwrhr]

Rush set us up with a 1 3/8" output shaft, turning our original 1" prop shaft....
Too bad he didn't send that package from PRISON.
Brian

[adjones419]

no, it doesn't like that, the prop shaft acts like torsen (sic) bar the output shaft is so short that almost any twist is too much twist, thats why a LOT of guys run larger output shafts than prop shafts and a step coupler.
We twisted a few in our P/E hydro...stepped up to a bigger size and used a reducer to keep the original propshaft. Haven't had any problems since!

[Boatmike]

Good 411! I may have learned a few things here. Good post!:D
Maybe i will not have to worry about it with all of the big HP my motor will be generating LOL......:D :D :D

[Mr. V-Driver]

The Out Put Shaft Coming Out From The V-drive. What Would It Take To Twist This Shaft And How Much Horse Power.does Anyone Have Any Ideas????????
Attn: Hondo Jim,
R U currently having some sort of problem with your particlar application???
We fixed this guy up, check out the pic. 1", changed to 1 1-8" :)

[Rexone]

Think about this too.
The prop shaft and the vdrive shaft are locked together as one in a coupler. (well in theory).
Any misalignment of the prop shaft with relation to the vdrive shaft puts a side load on both. Vdrive shaft being shorter... guess what... it takes the hit.
Also many vdrives don't have braces and actually move a little (doesn't take much) when you hammer the throttle. V-drive moves... changes shaft alignment... puts side pressure on shafts in coupler. Over time, metal fatigues from all this and normal use as well. Result... shit breaks.
Prop shafts break too but it's usually not at the coupler (although I have seen them break there), but behind the strut. Longer the shaft hangs out of the strut (in this case long is not good :D) more likely to break off there. Just some more useless trivia. :D

[VDRIVERACING]

Think about this too.
Also many vdrives don't have braces and actually move a little (doesn't take much) when you hammer the throttle. . :D
By braces, do you mean like struts from the Vdrive angled to the stringers?

[Rexone]

yes more specifically from the vdrive plate to the stingers. Or in the case of the C500 many attach them to the case since there is no plate normally.

[HM]

I had a coupler break once - straight down the key way. Casale told me that was common for couplers with key ways at 180 out to break down the key way, and all the newer ones (well...20 years old +) have key ways at 90 out.
I also seized the cam on my blown mouse motor at about 90 mph, without a whirl-away, and the power of the water on the prop ended up spinning every key way inside my motor. It was a bit of a wild ride coming to a stop.

[gn7]

Think about this too.
The prop shaft and the vdrive shaft are locked together as one in a coupler. (well in theory).
Any misalignment of the prop shaft with relation to the vdrive shaft puts a side load on both. Vdrive shaft being shorter... guess what... it takes the hit.
:D
and with the coupler (in theory) locking the output to the prop shaft that leaves even less output shaft left to absorb the torque(twist), because the part inside the coupler is now physically locked and acts as though it's as large as the outside of the coupler, and that short little part that's left has to take quite a bit of abuse, and the splines don't help matters

[watergun4u]

Seems Like It Would Twist The Prop Shaft First Becouse It Is Smaller Compared To 6-12 In.
jim bro, you got to understand that the out put shaft is a softer metal then the prop shaft, and ,Beaver fab is correct, the lower the hp, the more the prop grabs, with no burn, causing the stress on the out put shaft!i can 99.99% garentee you thats whats going on, you need MORE HP, and a different cam!!!!!!!!!!!!!!!!! tye:D

[adjones419]

By braces, do you mean like struts from the Vdrive angled to the stringers?
You can buy v-drive plate braces from Rex Marine...I just did and they are nice and polished! You can also use a 4-link bar setup with Heim joints, which is typically used on hydro setups.