Strut Angle

[carteaco]

I just replaced the prop shaft seal on my Hondo Ski Hydro and found the shaft rubbin on the bottom of the log housing, the shaft angle is a little steep. The strut and log housing are gonna have to be replaced.
Can I take a degree out of the strut, tilt the v-drive forward a degree and make up the degree in the u-joint of the drive-line.
What's the max. deflection at the u-joint?
What's the min. space between the hull and tip of the prop?

[RiverRacer]

I'm not a hydro guy but I think shaft angle is steeper than on a flat??, but regardless if the boat works the way it is don't change it, it will change the handling big time. If the shaftlog is rubbing just reset it so it don't rub!. Why are you replacing the strut, is it cracked????..

[carteaco]

The strut is chrome, pitted and the bore is somewhere between 1.25 and 1.375. I had to sand a 1.375 bushing down to fit the bore. But not cracked.(never had it checked)

[carteaco]

Does a hydro need a steeper angle to lift the tail?

[RiverRacer]

Like I said I'm not a hydro guy, but "wags" our resident hydro guy will clue you in on that stuff!.. But you need to strip the chrome and get it checked, cracks don't show up with chrome, that goes for any hardware. If all checks out get them Zinc plated to eliminate rust!..

[gfinishline]

If it has a 'used' strut bushing, the shaft will rest on the bottom of the thru-hull. If you "take out one degree" you will need to 'at least' move the prop back to help lift the hull. How does the boat run now? Does it lift the tail? Other than repairs, what are you trying to do? I personally like low shaft angles with "wings" on the struts of hydros, it makes them very 'forgiving' durring shut down and quicker off the rope.

[carteaco]

The strut bushing is new. The boat handles fine, but its my first boat, nothing to compare it to. I have read somewhere that you can gain some speed by taking a degree out of the strut angle. Primarily, I'm trying to fix a bad situation (prop rubbing on log). The remedy is move the log to miss the shaft or change the shaft angle.

[wagspe208]

Flattening out the angle does increase top end. It also makes it leave slower (after you pass ?? degrees, every boat different). The common hydro angle is 6 to 7 ish.
I have little experience with lower hp stuff (under 800 ish). I will testify that shaft angle and prop placment is critical to a good handling piece in the 850 and up hp level.
And "hydro expert". LOL That is funny. The only thing I know is how to drag out a 4 month project to 10 months.
Wags

[FC-Pilot]

Flattening out the angle does increase top end. It also makes it leave slower (after you pass ?? degrees, every boat different). The common hydro angle is 6 to 7 ish.
I have little experience with lower hp stuff (under 800 ish). I will testify that shaft angle and prop placment is critical to a good handling piece in the 850 and up hp level.
And "hydro expert". LOL That is funny. The only thing I know is how to drag out a 4 month project to 10 months.
Wags

Yes, but you are still making progress.

Paul

[carteaco]

The strut angle is 7 deg.

[carteaco]

The srut angle is 7 deg. + or - .1

[wagspe208]

The srut angle is 7 deg. + or - .1
LOL...you are already closer than the guy that built it already. He guessed about 6 to 8. LOL
Boat guys are not to picky.
Wags
BTW, since you are really measuring a tenth or 2 of a degree won't matter.. Half..maybe, 1 degree..start seeing changes.

[RiverRacer]

Flattening out the angle does increase top end. It also makes it leave slower

Like I said I'm not a hydro guy so this is new to me, why would a shallow angle make it leave slower?, with a steep angle you're pushing up and not forward so it would take longer to get going, but pushing forward would get you going quicker wouldn't it, what am I missing here????...:D

[gfinishline]

Art, when guys 'miss the set up' the tail lifts too soon and it will drop a sponson. This causes the hull to drag down and often forces the boat off course. The boat will actually go "thru the water" for the first few (30') feet. I feel the "trick" is to make the boat leave with both sponsons out of the water (wheely) and then settle back lightly on the sponsons, (mid track) then going to heavy on the sponsons thru the lights. "lots of bite, then "tip toe" loading, then NO flight". IMO, 7 degrees will work just fine for under 190MPH.

[wagspe208]

I am with george.
I only know a buddy of mine with an old sanger started at 7 deg. He started decreasing the shaft angfle. As he did, he picked up mph. Eventually he got to the ridiculous angle of 5 or 5.5. The boat would not hook the prop. Just like one of the roundy round hydros. He had to feather, work, etc to get it to leave.
I never tried to change angle. Set it and forget it.
Wags

[RiverRacer]

Art, when guys 'miss the set up' the tail lifts too soon and it will drop a sponson. This causes the hull to drag down and often forces the boat off course. The boat will actually go "thru the water" for the first few (30') feet. I feel the "trick" is to make the boat leave with both sponsons out of the water (wheely) and then settle back lightly on the sponsons, (mid track) then going to heavy on the sponsons thru the lights. "lots of bite, then "tip toe" loading, then NO flight". IMO, 7 degrees will work just fine for under 190MPH.

Thanks George, always wondered why hydros always did wheelys, thought it was because they didn't have a plate, now it makes sense!..

[wagspe208]

Art,
I have seen a fuel boat guy add length/ flotation to the back of his boat. His reasoning was, when sitting in the water, shaft angle is x degrees to hull. It is not x to the water, it is x plus angle the boat is sitting (ass down). He added the flotation to make it sit more level in the water (at idle). When he launched, it did not lift the nose as much. Was a cool, crude experiment that worked. I think he quit racing shortly there after.
BTW, both passes in the same weekend. Only thing changed was ass flotation.
Wags

[Terrible toy]

The srut angle is 7 deg. + or - .1


I don't think you mentioned what kind of prop, rudder your boat has. Don't have any experience with ski hydros, but most I've seen when I was skiing have flat bottom props, and under hull rudders. In addition the engines looked to be back a bunch. Not much hope of getting one of those to pop the tail.

In a race hydro you use a surfacing cleaver type prop to lift the tail. I long ago threw away all our hydro engineering notes but, 7° strut angle is about right for a drag hydro. All the boats we built from Comp Hydro to UGH had similar specs on the engine, v-drive, strut location. The drivability was adjusted with prop, gearing and engine tune. When everything was optimized a boat would instantly pop the tail and a moment later drive the nose out of the water and not get on the right sponson for 20 or 30 feet.

[Terrible toy]

Come to think of it, I believe the Brendella, Cole and Hondo flats I drove had 7° struts.

[carteaco]

I'll have to measure the rudder. Looks like a basic under hull rudder. Prop is a new RB 11.375 X 16 Hydro Cleaver. I measured the hull and shaft angle with a digital level.

[RiverRacer]

Art,
I have seen a fuel boat guy add length/ flotation to the back of his boat. His reasoning was, when sitting in the water, shaft angle is x degrees to hull. It is not x to the water, it is x plus angle the boat is sitting (ass down). He added the flotation to make it sit more level in the water (at idle). When he launched, it did not lift the nose as much. Was a cool, crude experiment that worked. I think he quit racing shortly there after.
BTW, both passes in the same weekend. Only thing changed was ass flotation.
Wags

Very interesting, guess a hydro is no different than a flat to get dialed in just different, still a pain in the ass, LOL...:D

[71hallett]

Come to think of it, I believe the Brendella, Cole and Hondo flats I drove had 7° struts.I need some info on a strut. 75 hondo 5/8 runner. I am missing the strut and dont know what I need. Any info or answers would be great. Not sure what you need for info from me but I will try to answer any questions.
Thanks
Paul

[RiverRacer]

Well, George is the resident drag boat oficianodo here so just hang tight he'll be in here soon, he will set you "right"!...

[Retired Flatbottom Racer]

I need some info on a strut. 75 hondo 5/8 runner. I am missing the strut and dont know what I need. Any info or answers would be great. Not sure what you need for info from me but I will try to answer any questions.
Thanks
Paul

I think you need to contact Wayne Mettler. He worked for Hondo at the time your boat was built and should know what you need. Wayne also was the orginal builder of Canyons. I have his phone number, but it is at work. PM me and I will get it for you tomorrow. After you find out what you need you may want to try to find a used one. Ask Wayne about new or used. They are expensive. :mad:
My Canyon and my 79 Hondo both have 7.5 degree struts.

[gfinishline]

"Canyon = DiMarco" "007 = 8 degrees" "Wayne's welding = 7.5 degrees" If you have no strut, do you know where the V-drive was mounted? 96" 98" 100" ? OH! we are talking about 'resessed flat plate struts' right? ART. "TT" all things considered, you can list the names of your old race boats, but you can't compare "Irv's rocker rocket" to the other two brands. HA HA!

[FC-Pilot]

71Hallett, I'm glad you came over here as you will be able to get more specific answers here. George (Gfinishline) has forgotten more than I could ever learn about drag boat (heck any type of boat for that matter). The more specific the info is the better info he will be able to give you.

Paul

[Terrible toy]

"Canyon = DiMarco" "007 = 8 degrees" "Wayne's welding = 7.5 degrees" If you have no strut, do you know where the V-drive was mounted? 96" 98" 100" ? OH! we are talking about 'resessed flat plate struts' right? ART. "TT" all things considered, you can list the names of your old race boats, but you can't compare "Irv's rocker rocket" to the other two brands. HA HA!

George you know more about the history of those boats then I do. I was just the monkey behind the wheel.:D

What I do know is that I bought a 2 inch runner Brendella from Irv in late '77. That boat was really a ski boat hull with a little bottom blue printing. When it ran well enough to win a few races Irv came up to me and said "Billy, It's time to build you a real race boat". That was a shock because I thought it was a real race boat. Irv's answer was that he would never put someone he didn't know in a super light weight hull.

He had a brand new XH511T factory Hondo that he gave me to put my engine in.(Which was 10 miles per hour faster then the Brendella) Over the next four years he built me a series of boats. Each a little lighter and with less rocker then the one before. Don't know if he was changing the rocker in the mold or after it came out. Maybe you can shed some light on runner depth, because all the boats were called 5/8 runners but the later boats measured 7/8s?? As a last historical note Irv claimed that Jim Cole's TR boats were splashed from his Hondo. I have to admit that the two Coles I drove for other owners looked a lot like Hondos.:rolleyes:

[71hallett]

What and were should I measure to give you the info I need?

[pwderman]

George you know more about the history of those boats then I do. I was just the monkey behind the wheel.:D What I do know is that I bought a 2 inch runner Brendella from Irv in late '78. That boat was really a ski boat hull with a little bottom blue printing. When it ran well enough to win a few races Irv came up to me and said "Billy, It's time to build you a real race boat". That was a shock because I thought it was a real race boat. Irv's answer was that he would never put someone he didn't know in a super light weight hull. He had a brand new XH511T factory Hondo that he gave me to put my engine in.(Which was 10 miles per hour faster then the Brendella) Over the next three years he built me a series of boats. Each a little lighter and with less rocker then the one before. Don't know if he was changing the rocker in the mold or after it came out. Maybe you can shed some light on runner depth, because all the boats were called 5/8 runners but the later boats measured 7/8s?? As a last historical note Irv claimed that Jim Cole's TR boats were splashed from his Hondo. I have to admit that the two Coles I drove for other owners looked a lot like Hondos.:rolleyes:

I'm just repeating what was posted on PB by Jim Lange, who was involved with both Hondo and Cole, that the Cole was splashed off the Hondo with more attention to detail???

[Terrible toy]

I'm just repeating what was posted on PB by Jim Lange, who was involved with both Hondo and Cole, that the Cole was splashed off the Hondo with more attention to detail???

What the heck, how'd you get in the middle of this Jon?:D:D Have no idea what he did for Hondo or Cole but he was a driver. One boat I know he drove was the BGH Californian. I guess if he backs up what Irv said, that Cole did splash his boat. Wonder what he meant by "attention to detail"?

[Terrible toy]

What and were should I measure to give you the info I need?

Is the v drive in the boat? There has to be bolt holes and perhaps a recessed area where the old strut was. If the v drive is in it just measure the angle of the output shaft and that's your strut angle.

You want a steel strut and I'm guessing someone here knows who makes them. Actually, struts are not all that difficult to fabricate if you can't find one. You just need a mill, good metal cutting bandsaw, machine lathe, Tig, and a welding jig of some sort.:D

[RiverRacer]

J.J. would be the one for that!.. 972 438 2277

[71hallett]

Is the v drive in the boat? There has to be bolt holes and perhaps a recessed area where the old strut was. If the v drive is in it just measure the angle of the output shaft and that's your strut angle.

You want a steel strut and I'm guessing someone here knows who makes them. Actually, struts are not all that difficult to fabricate if you can't find one. You just need a mill, good metal cutting bandsaw, machine lathe, Tig, and a welding jig of some sort.:DJust so happens I have all of the above. When I get the cases back from powder coat I will put in in and see what I have. Maybe this isnt a big deal after all. Thanks.

[ABBOTTCRAFT]

I don't think you mentioned what kind of prop, rudder your boat has. Don't have any experience with ski hydros, but most I've seen when I was skiing have flat bottom props, and under hull rudders. In addition the engines looked to be back a bunch. Not much hope of getting one of those to pop the tail.
In a race hydro you use a surfacing cleaver type prop to lift the tail. I long ago threw away all our hydro engineering notes but, 7° strut angle is about right for a drag hydro. All the boats we built from Comp Hydro to UGH had similar specs on the engine, v-drive, strut location. The drivability was adjusted with prop, gearing and engine tune. When everything was optimized a boat would instantly pop the tail and a moment later drive the nose out of the water and not get on the right sponson for 20 or 30 feet.


Here's our Sanger Ski-Hydro.. It spins a Menkins 11 1/2"X15" 3 Blade Cleaver with 29's...It lifts the ass end nice..

http://www.youtube.com/watch?v=E9aM_NeojdU

[RiverRacer]

Just so happens I have all of the above. When I get the cases back from powder coat I will put in in and see what I have. Maybe this isnt a big deal after all. Thanks.

None of it is a big deal, just have to approach it the right way that's all!..:D

[gfinishline]

I need to find my notes, then I'll tell you how many hydro struts we built with wings or added them to already used struts. This shows there are many ways to set up all kinds of boats.

[wagspe208]

I need to find my notes, then I'll tell you how many hydro struts we built with wings or added them to already used struts. This shows there are many ways to set up all kinds of boats.

Find them george. My old piece did not have wings. This piece does. They are about 1" wide by 8 to 12" long. (never measured).
Can't tell a damn bit of difference...I am sure it does matter....apples to oranges, though.
Wags

[gfinishline]

Steve, if your prop is lifting then the wings 'just unload the prop a little'. (get infront of the blades) Most guys who used "wings or strut flat spots" ran round ear/ non- cleaver type props. A V-drive cleaver prop (to me) is one that has a flat blunt trailing edge on every blade. That flat blunt trailing edge "opens up the water" and lifts the prop. It also seems to limit it's bite to around 75% + -. To make a slower (under 180MPH) hydro QUICKER (up to 85%) we would change the prop to rounded ear and add "wings or flat spots" to the strut. I personally like the "wings" on shut down. I tried to make them hold the boat UP right down to around 75MPH, so the tail didn't DROP AT SPEEDS.

[wagspe208]

I hate to show my ignorance again but..props are really black magic to me. I just find one that works ok, then stick with it. I know I am not getting the true potential of the boat/ combination. I am just looking for something that will hook the same and run a number safely every time.
I am running a 10 3/4 x 17 now. I know that is smaller diameter than most 8.0 guys run. It does not seem to man handle the boat, though. I don't get hardly any torque steer past half track, just some pressure on the wheel. I can dump the throttle, and it just slows down. I also get it that dumpinmg the throttle is not a good practice. Bad driving habit developed during bracket racing. It is hard to ease out when you are just passing the guy at the mph light and dont' want to break out.
Ok..so here goes..I would like my prop to slip a little more on the take off. It only slips to about 4500 rpm, then up to 5300 or so, hooks, back to 4700 or so, then climbs steadily. I am running 7400 through the lights. Not bad there I guess. I wouldn't mind running 7800 to 8 through the traps, though. So..smaller diameter??
BTW, it is an old menkins prop from god knows when. cleaver I guess...square back, wide blade
Wags