18' v-drive & turning

[wagspe208]

I have a 1968 18 2+3 with a v-drive.
Big ass rudder hanging off the back.
Question is..this boat does not turn well. Especially at any speed. This is to be expected just by looking at the piece. No pivot point up front of the strut.
Is this normal? Has anyone put a turn fin up around the v-drive location and had better results?
Thanks
Wags

[mrfixxall]

I have a 1968 18 2+3 with a v-drive.
Big ass rudder hanging off the back.
Question is..this boat does not turn well. Especially at any speed. This is to be expected just by looking at the piece. No pivot point up front of the strut.
Is this normal? Has anyone put a turn fin up around the v-drive location and had better results?
Thanks
Wags

like any boat with a rudder,or jet propelled try throttling it through a turn,,it needs the water force to turn..my old ski boat was the same way..

[Speed Racer]

Hey Wags,
I grew up with V-drives, and found that they are very goofy as far as turning hard. Some I have had turn better to the left, some to the right. Compared to the typical, very predictable outdrive, the V- drive is certainly more 'exciting' to drive.

A fin on a flat bottom boat worked well, on a v, not so well. You might try some rudder experimentation. Have you checked with Glenwood in California?

Admittedly, my experience comes from 18' flatbottoms (Sangers and Hondos), and a 21' Howard day cruiser, with a V bottom.

My 1967 Ski Sporter V-drive will hopefully be done and in the water by opening day next year, then I might have some better data for you.
GG

[zelatore]

Any inboard boat with a single screw will turn better one way than the other. Doesn't mater if it's a ski boat or a big fishing trawler - it depends on the rotation of the propeller. You'll also notice they pull to one side when backing down - again, due to propellor rotation. Watch some old fishing boat guys someday with big single screw boats - they can make them dance just like a twin with some practice and by utilizing the 'walk' of the prop.

[wagspe208]

Oh, yes.. you can parallel park it to the right. It won't move to the left no matter what.
A ski boat turns on a dime. It has a turn fin. I guess mostly flat bottom..or very shallow v..never paid much attention.
I am a drag hydro guy, so not turning is no big deal. It will roll over so damn far on the v, though it will actually try to cavitate the prop if you are on it hard enough.
There is no forward pivot point. That is why I asked about the fin.
I am happy with the piece gong slow (relatively speaking...drag piece runs 150). Just was wondering if there way an easy fix. I am not energetic enough to go changing a bunch of rudders....unless I am positive it will work.

[zelatore]

I haven't driven a V-drive Donzi, but that seems a bit wierd.

Other v-drives I've run still display the reluctance to turn to one side at planing speeds, but nothing that severe. Without a direct point of referece, I'm afraid I can't help much.

Where are our V-drive owners? :confused:

[Captain Steve]

That's a good question , I have the same one, I just bought a 18' Barrel Back with V drive .My rudder is approx 8" wide by 17" tall. I was going to put a 6"to 8" tall skeg just in front of the the drive shaft exit hole . I have seen most of the drag boat guys do this but they have flat bottom boats. I guess I'm going to find out if their is a difference. I'm in the process of restoring the boat right now, the boat does not have a coupler for the motor to tranny its a 427 side oiler and a Warner Gear Velvet Drive 72C Can any one help? Also does anyone know who can do the seat cushions over? Thank's Guys
Steve

[wagspe208]

I believe most of the circle boat guys put the fin at the boat cg front to back...makse sense, easiest point to pivot is at the cg. That may very well be the cg with a heavy engine. Mine has a SBC.
Wags

[FlatRacer, aka BarrelBack]

Sorry for the late reply. My '67 18' 2+3 V-Drive handles like a dream. I can literally steer it with my pinky.
Is yours a big block or a small block?
Does it have the stock Donzi outboard (transom mounted) rudder with the horizontal element on top?
Is it harder to steer at speed, or the same at every speed?

Eric

[FlatRacer, aka BarrelBack]

Oh, yes.. you can parallel park it to the right. It won't move to the left no matter what.
A ski boat turns on a dime. It has a turn fin. I guess mostly flat bottom..or very shallow v..never paid much attention.
I am a drag hydro guy, so not turning is no big deal. It will roll over so damn far on the v, though it will actually try to cavitate the prop if you are on it hard enough.
There is no forward pivot point. That is why I asked about the fin.
I am happy with the piece gong slow (relatively speaking...drag piece runs 150). Just was wondering if there way an easy fix. I am not energetic enough to go changing a bunch of rudders....unless I am positive it will work.
Now that I've read your post a little more thoroughly, I think you may be referring to how the boat behaves in a high speed turn, rather than the the actual torque needed to turn the wheel. Correct?
Sounds like what you're experiencing is the difference between a race boat (or a tournament ski boat) and a pleasure boat.
I would NEVER drive my Donzi into a turn the way I drive my circle racer. The circle boat eats up turns, but then it has two big ass fins under the center of it as well as down pedal for the cavitation plate to keep the bow planted and hook the fins. I've seen some tournament ski boats with three fins.
In contrast, the Donzi bobs and weaves if I drive it too hard into a turn. It squirrels around so much, I fear it will trip on the keel and pop me out over the high side. Maybe this tendency to trip on the keel in tight turns is why they changed from a sharp keel on the barrelbacks to the more rounded keel on the '69 and later hulls.
I back the speed down to waterskiing speeds and take a wide steady arc when turning the Donzi at speed. I'd never crank on the wheel the way I do in the Bezer.
I view the Donzi as a pleasure boat and I treat it that way. It's really a scaled down V bottomed offshore racer, and as such, tip-toes gingerly through the turns like it's big brothers. You're never going to pull the kind of lateral G loads in a V hull that you can in a flat or especially a tunnel hull.
Eric

[mattyboy]

good info here guys, i was interested in a 427 side oiler v drive 18 but hearing these handling issues they seem not to handle the same as a i/o boat

[FlatRacer, aka BarrelBack]

To the contrary, Matty, my 18' 2+3 V-Drive actually handles marginally better than the I/O version I had previously. The bucking bronco action in tight high speed turns was just as present in the I/O as it is in the V-Drive. I think that's more a function of the sharp keel. The main difference I've found between the two is that the V-drive has zero steering torque felt at the wheel. Like I said, I can drive it with a pinky at any speed. Otherwise, the two handle the same.
I think of these hulls more as hot rods, not racers. Fast in a straight line and safe when driven sanely, but I wouldn't bet my life on their stability in a fast tight turn.

Eric

[wagspe208]

Sorry for the late reply. My '67 18' 2+3 V-Drive handles like a dream. I can literally steer it with my pinky.
Is yours a big block or a small block?
Does it have the stock Donzi outboard (transom mounted) rudder with the horizontal element on top?
Is it harder to steer at speed, or the same at every speed?

Eric
Yes..wheel turn easy..boat no. As I said...I guess it is what it is. I do have the stock rudder. Funny looking thing. Small block. I don't thrash this thing. It is old, and slow. I have tried to turn hard..she just does not do it.
I use the race piece to thrash (drag hydro...it won't turn either).
I asked about the fins to see if they might help. I guess they won't.
I am not unhappy with the piece. Don't let these comments discourage anyone from buying an old classic. I was wondering if this was normal, or there was room for improvement. It is no Porsche, though.
Thanks
Wags

[Speed Racer]

Super interesting thread guys..Thanks!
Flatracer- Very interesting and smart and insightful comments. Brings back memories of circle racing with my dad when I grew up.Where do you race, and can you post some shots of the race boat?

GG

[mattyboy]

must be the keel, turning at speed was never a problem in the 16 and the right prop on it torque steer was not an issue either

[FlatRacer, aka BarrelBack]

Small block. I don't thrash this thing. It is old, and slow.
Yes, my small block V-drive only tops out at about 52 mph, which is crawling compared to the flat, but I can take along four passengers and give them a ride that's faster than anything most of them have ever experienced before.
Because I have the flat, I have no desire to make the Donzi go any faster than it does. It's a great "sportboat."
Click on this link and read the story:
http://www.geocities.com/kool_toyz/honeybun.html
Eric

[FlatRacer, aka BarrelBack]

Super interesting thread guys..Thanks!
Flatracer- Very interesting and smart and insightful comments. Brings back memories of circle racing with my dad when I grew up.Where do you race, and can you post some shots of the race boat?

GG

I raced in the northeast in the late '80s and early '90s. I'll resume racing someday when my kids are a little older.

links:
http://www.geocities.com/kool_toyz/msamerica.html
http://www.geocities.com/kool_toyz/alreadygone.html

[FlatRacer, aka BarrelBack]

must be the keel, turning at speed was never a problem in the 16 and the right prop on it torque steer was not an issue either

Scott Pearson should have some insight as to the comparative handling of the sharp keel and round keel hulls. Wasn't the Thunderchicken boat a round keel?
I would guess the round keel hulls would be a little less "trippy" (?) in the turns than the sharp keel hulls.

[Speed Racer]

Cool Stuff!!!!

Lucky man!!

[v-drive]

Flatracer, I would like to ask you a few questions about the fuel injection on the Flatbottom. For some reason the board won't let me pm you so can you call me at 865-376-4511 before 11:00 est. Thanks, Richy

[FlatRacer, aka BarrelBack]

Just read your post, V-Drive.
E-mail me at eric.tolnes@verizon.net

Eric