older v-drive has no reverse

[tentantoes]

Hi all, new to the forums and thankful to have found them. My dad told me last week he would give me his ski boat if I wanted to rebuild it. It's an incredible boat, a 1970-something Mastercraft (I think). It is powered by a 455 Olds and started life as a jet drive when he first bought it brand new. Then as he was learning to barefoot he found that the jet chopped the water too badly, so he converted it to a v-drive. I don't know anything about what all he did, all I know is that it has no reverse gear, it's forward or nothing at all! I also remember that he kind of slammed the gear lever back to put it in gear. I figured this was probably the cheapest way for him to go back then, but if I got it I'd sure like to be able to have reverse, but I know nothing about this stuff. Any pointers as to what kind of transmission I'd have to get?

I've also read that stern drives are more economical than v-drives and have wondered if it would be possible to turn the engine around and make it a stern drive. What would I be looking at to get this done? Being able to raise the lower unit of a stern drive does appeal to me. Thanks for your time.

[Capt-Ron]

In the early 70's I was involved with an SK drag boat. My boss was an avid skier and bought the bare hull which came with all the gear except an engine.
The V-drive was exactly as you describe, either in gear or out (no reverse).
We used the neutral for warming up the engine (Corvette) but after that the drive was left in gear.
I learned to ski behind this boat and when the starter spun and the engine lit you where out of the water with no drag. Maintaining 32 mph was little more than idle rpm.
Top speed: 105 mph as clocked by a cop buddy's radar. It actually scared me and I've never been that fast in a boat since.

As far as a sterndrive conversion, absolutely possible. Get out the check book.

Good Luck,
Capt-Ron

[marshmat]

Stern drive conversion? Definitely possible, but not cheap. An Alpha or Volvo SX would be the likely candidate in a single-prop drive. If you prefer more control and smoother thrust, the Volvo DPS or DPR, or maybe a Merc Bravo 3, would be in the running. In any of these cases you're looking at writing a cheque in the high four figures, maybe pushing into the ten-thousand-plus range if a lot of modification is needed or you want a fancy drive.

Replacing the existing V-gear with one that has F/N/R capability would not be difficult. Most modern V-drive transmissions are F/N/R. Not sure how much power you're getting out of that Olds 455 but the ZF 45IV comes to mind as a possible choice, it'll handle around 400 hp @ 5500 rpm in an application like yours. http://zf-marine.com/ZFR/Transmissio...on&GN=ZF_45_IV
Borg Warner and many others build similar units; the key is selecting the appropriate duty range, hp and rpm ratings for your particular setup.