Whip Strut

[VD CRUISER]

Under what conditions do you guys think a whip strut, or bushing in the shaft hole, is required? Also what are some ways to mount a bushing in the shaft hole?

[schiada96]

Marine tex epoxy to glue a fiber strut bushing. Is what I use to put it in the shaft hole. I think over 500 hp with a one inch shaft. On a 1.125 shaft with a long barrel on the strut about 700 hp over that I'd run a whip strut. My opinion for what it's worth :D

[Rexone]

Typically whip struts are rarely used any more and usually aren't necessary unless the prop shaft is extremely long (or extremely bent). Some guys like em but our experience is they're usually not necessary. Just my .015. :)

[schiada96]

Rex do you run one in your schiada? Looks to me like Stan at Schiada still puts them in a lot of high hp boats even with a long barrel strut.

[superdave013]

One came off my schiada and I'm kicking around if it sould go back on. Hummmmm
Some say ya and some say no. Some say that on a high horsepower deal that it could even cause bad handling due to the turbulance it would cause. Same with my bolt on strut that WAS not recessed.
What's everyones thoughts on that?
[ November 03, 2002, 08:26 PM: Message edited by: superdave013 ]

[Rexone]

No I definately don't run one, never have nor have I seen a need for it. And my Schiada is one of the smoothest I've ever driven. On a Schiada too since they ride so flat on the keel I wouldn't want that extra whip strut draggin at high speed. On a Schiada it would not be out of the water at speed.
Keep in mind, if your prop shaft isn't straight within tolerance to begin with it should be straightened or replaced. A whip strut may mask fixing this situation of a bent shaft but in my opinion is not necessary with a straight shaft.
I'm leavin for SEMA now, be back on the boards in few days. rexone out.

[boatguy222]

We have done several with inside Handmade fiberglass shaft logs, The last one I did I put it in with JB weld under the shaftlog of my Beisemeyer, We ran it pretty hard this Summer At a couple Nostalgic circle events, with NO problems, It keeped the shaft seal intact, and I had to change that seal every year I've had it for the previous 17 years! You Deside!

[Sked]

I would suggest that with a 1" prop shaft, if you have any more than 28 inches between the front of the strut barrel and the shaft hole you should use a whip strut. I usually install a drop through style immediately behind the shaft hole. With a fiber bearing it doesn't need to be water fed through the shaft log and hole as it picks up enough water from being mounted outside the boat. As far as the concern about turbulence mentioned by superdave013, I don't see this as being any problem as the spinning prop shaft will create about 4 times its diameter in turbulence with or without the whip strut.
[ November 03, 2002, 09:15 PM: Message edited by: JSSK88 ]

[boatguy222]

OK,
After reading SD and Rexone posts, I want to add that I am talking about attaching a strut bearing inside the boat under the shaft log. You don't want it to hang down into the water. eek!
I agree with Rexone "Drag is bad" in the water.
SD, you know what I'am going to say about your Strut, junk it!!, and get a drop thru!!! wink

[GofastRacer]

superdave013:
One came off my schiada and I'm kicking around if it sould go back on. Hummmmm
Some say ya and some say no. Some say that on a high horsepower deal that it could even cause bad handling due to the turbulance it would cause. Same with my bolt on strut that WAS not recessed.
What's everyones thoughts on that?Got to agree with Rexone, I don't think you need one either , just make sure the shaft is absolutely straight, I don't see a problem!..Now as far as that strut goes eek! eek! That is a swap meet item!!!... :)

[superdave013]

JSSK88:
as the spinning prop shaft will create about 4 times its diameter in turbulence with or without the whip strut.Now how did you measure that??

[schiada96]

I don't want to beat a dead horse but schiada still uses them. They glue a fiber bushing in the shaft hole. Like Rex say most fast crusers run flat on the keel so what turbulance could a bushing in the shaft hole cause? You can also shape the bushing. I think this would cause less turbulance than just the prop shaft coming out of the hull. wink
Superdave if your going to make 1100 hp with a one inch shaft I'd use a whip strut.
[ November 04, 2002, 07:20 AM: Message edited by: schiada96 ]

[superdave013]

I have an 1 1/8 shaft. Can someone post a pic of the in the hole set up? Mine is the old skool bolt on deal.

[Sked]

superdave013:
JSSK88:
as the spinning prop shaft will create about 4 times its diameter in turbulence with or without the whip strut.Now how did you measure that??Research. YEARS and YEARS of research, study, and testing.

[schiada96]

Sd didn't you know about the glass bottom jssk88? :D

[missilemud]

superdave.. jssk88 knows what hes talking about. try to run against him and you will lose for sure.

[VD CRUISER]

Thanks for the input guys. I haven't been using one and I use a 1" shaft with 900+ HP. I do however see about an 1/8" of shiny shaft behind the strut bushing, like the shaft is moving forward under load. I also have braces on the V-drive, what gives?

[superdave013]

missilemud:
superdave.. jssk88 knows what hes talking about. try to run against him and you will lose for sure.I never said he didn't. I just asked how he measured it is all.
I'm here to learn ya know.
[ November 04, 2002, 07:27 PM: Message edited by: superdave013 ]

[missilemud]

you could learn a few things i'll tel you that. he got me running real good a few times. good prop guy if you ask me .

[Sked]

VD CRUISER:
Thanks for the input guys. I haven't been using one and I use a 1" shaft with 900+ HP. I do however see about an 1/8" of shiny shaft behind the strut bushing, like the shaft is moving forward under load. I also have braces on the V-drive, what gives?Without seeing it in person it's difficult to diagnose exactly but you might want to check to see if the prop shaft or V-Drive output shaft is slipping in the coupling. Hard reversing would have a good tendency to pull things apart. I'm not looking at it and you may have already checked the obvious, just a thought since you already said you have braces.

[Sked]

missilemud:
you could learn a few things i'll tel you that. he got me running real good a few times. good prop guy if you ask me .Hey THANKS for the compliment missilemud. What are you looking for future discounts or are you just being nice so that I'll make time to come over and test run that new boat of yours? :D :D :D
[ November 04, 2002, 11:16 PM: Message edited by: JSSK88 ]

[missilemud]

jssk88..yeah thats it :rolleyes: :rolleyes: :rolleyes: :rolleyes: :rolleyes:

[missilemud]

and where are my props jssk88? geees a new boat and no props eek! eek!