As more and more people join the website, with more and more operational experience with these boats, I thought it would be interesting to get feedback from people regarding the observed performance of the Hydrodyne 18's with different engine and prop combinations. Does anyone care to share information on their experience with things like pulling power and top end speed with different engines and props on these boats from their own experience? I'm trying to learn partly for my own project so I can make some decisions on a prop but also I am just curious. Rarely does one see a boat that has seen so many different engine configurations.
Mark, My boat has a 1995 Johnson faststrike 150 which is a bass boat motor that produces slightly more than 150. With a 17 pitch prop it will hit the rev limiter at 6100 at about 50. I run an uncupped 17 and the speed is slight less and I don't remember the number. I have a torque shift prop which starts at 11 pitch and can go as far as 26. I have it adjusted to provide 5500 at full throttle and it indicates 55 max with that prop. I don't remember the biggest load I have pulled. jim
Intersting stuff. Thanks, Jim! I only used my boat once after purchasing it before the tear-down started for the restoration. My 1973 Hydrodyne had a 1983 Mercury ELPT 150 V6 on it when I bought it. It had no pitot on it and I don't know how accurate the old airguide speedometer was but I instaleld a new pitot (not an airguide pitot - just a cheapie) before I put it in the water and I was able to get 44 MPH out of it. However, I later learned that the entire subfloor was breached and waterlogged with wet floatation foam. This added a lot of weight so I suspect the boat would have done a bit better on top end if it were not for all of the extra weight. I never had a chance to pull skiiers with it - it was October when I bought it. I don't know what prop was on it other than it was stainless and I probably shouldn't have sold it with the motor. Oh well. Anyone else out there who can share some performance info on their boats or set-ups they've driven?
Mark, I found this old thread over at showskiers that will interest you: http://www.showskiers.com/phpBB2/viewtopic.php?t=1494 The type or size of the pitot will not change the speed readings. jim
Thanks, Jim Interesting thread. Someone had mentioned at some point that you need an Airguide Pitot and and Airguide equalizer tube to get accurate readings on Airguide Speedos but that didn't sound right to me. I do have new tournament pitots and equalizer tubes that came with my two new Airguides. I will say that they look to be heavier duty than the pitots one usually sees so if they don't offer any accuracy advantage perhaps they at least will be more durable. Those speedos go up to 55MPH so I have a third speedo (80MPH) that will run off of the engine shaft pitot. I'm one of those people who can't have too many gauges! (i.e., still not sure what I think of glass cockpits!) Best, Mark
Mark I run one airguide off of the engine and the two pitots go to a fuel selector valve so that I can choose which pitot to hook to the other airguide. The one on the engine is far better than the pitots. In the nine summers I have run the boat that way the pickup on the motor got clogged once. The others picked up trash 100's of times. On my daughters boat the two ptiot's are t'd together to one speedo. Both boats have new Airguides. The adjustable Airguides are the only way to go for skiing. What happened to your old Airguides? jim
I forgot to mention that I run one airguide pitot with the equalizer and one without as an experiment. The one with the equalizer has way more lag in it and I like the one without better. I intended it as an experiment and never changed it back. The one on the motor is more stable than either of the pitot setups. Go figure. jim
Jim I still have the black airguide speedometer. It looks and works just fine. If you want it you can have it. The needle is a bit more pink than it used to be but other than that it is fine. I'll try to email you a picture of it.
