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Rapidchaser
Joined: 26 Feb 2006 Posts: 198 Location: Edmonton
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Posted: Mon Mar 06, 2006 8:34 pm Post subject: jet overdrive |
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Ok Guys I really need to know; Has anyone ever heard of an overdrive in a jet boat??
By the way thanks for all the feed back on river reading. _________________ FORD=Power for the thrills of life!
Keep the wet side down! |
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Gator
Joined: 15 Jun 2005 Posts: 60 Location: Beautiful Downtown Glide, OR
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Posted: Tue Mar 07, 2006 1:05 pm Post subject: |
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I think Nash had one in there American, I don't know if Hudson did or not. In all seriousness I have never heard of an overdrive in a boat. If you did have one you would only be loosing speed and horse power. The primary design of one is to provide lower rpms for a vehicle that has little or no resistance when it is running such as a car running on flat ground with no perceivable load. There is to much drag from the water on a boat. |
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MidwetJetSprint
Joined: 29 Jul 2005 Posts: 160 Location: Chicago Metro
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Posted: Tue Mar 07, 2006 4:24 pm Post subject: |
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Kind of like using a Power glide trans I have seen Lenco 2 speed trans in Drag Jet Boats but thats a who nother story Big HP _________________ Old Age and Treachery always Overcome Youth and Skill! |
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Rapidchaser
Joined: 26 Feb 2006 Posts: 198 Location: Edmonton
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Posted: Tue Mar 07, 2006 6:30 pm Post subject: overdrive |
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Hey thanks a million guys. I bought this boat , it is a 23 footer.
I bought it from the Man who manufactured it (Les) He said it had an overdrive which keeps the rpm down around 25-2800 .
Its just that this is the first I ever heard of such a thing. The engine is a 460cid. and I'm hoping I will be able to do at least 30mph.
Is that expecting too much? It is a big aluminum boat and seems to be very well made. The guys been building them for over 30 years. Boy! do I hope I didn't make a mistake.
A race boat she is not!! but I hope to spend a little time on the rivers and lakes with my family and do a little fishing (before I cash in)
I really appreciate the come backs from you people it is very kind and most helpful. _________________ FORD=Power for the thrills of life!
Keep the wet side down! |
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Cavefish
Joined: 18 Jun 2005 Posts: 130 Location: Klamath, CA, USA
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Posted: Tue Mar 07, 2006 6:53 pm Post subject: |
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I have seen underdrives used, the thought being that the pump would be more efficient if it was turned slower than the motor up there at 7200. I do not know if it worked out. _________________ -Jesse |
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Gator
Joined: 15 Jun 2005 Posts: 60 Location: Beautiful Downtown Glide, OR
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Posted: Tue Mar 07, 2006 9:22 pm Post subject: |
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Hey Chaser, I had a friend with a 20 ft North River and a 350 Chev with pump and he would do 50, but cruised at 30. Another friend had a 22 North River Scout ( open hull no front window) with a Yamaha 200 ob jet and would do about 40 so I don't think you will have any problems. I have a 18 North River with a 115/80 merc jet and at sea level I will do 31 on gps and at 5200 ft with 700 lbs of people I can still do 27 and that is with out changing the jets in my carbs. My boat weighs in at 1175 dry weight. Good luck and enjoy, I know I enjoy mine. There is one thing though that you might want for your boat. I got my wife to pay for mine. Sorry she is one of a kind.
Gator |
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Rapidchaser
Joined: 26 Feb 2006 Posts: 198 Location: Edmonton
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Posted: Tue Mar 07, 2006 10:46 pm Post subject: overdrive |
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Mr. Gator (heavy on the Mr. ) I heard through the grapevine,
that Brian Clement started using these overdrives with a lot of success for the heavier boats so I'm going to do a little research.
Ive also been told that It's no big deal to take it out. Just unbolt, slide the engine back and re-bolt. As far as the wife goes (mine) I've been payin her for almost 46 years, I figure she owes me at least the price of the boat.
But I ain't holdin my breath till I collect lol
Thanks for the info guys. Cheers,
Emery _________________ FORD=Power for the thrills of life!
Keep the wet side down! |
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Gator
Joined: 15 Jun 2005 Posts: 60 Location: Beautiful Downtown Glide, OR
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Posted: Tue Mar 07, 2006 11:15 pm Post subject: |
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I have had my wife for 38 years this may, and we have a pretty good deal worked out. I pay for her toys, dolls, beanie bears n such and she pays for my toys such as guns, boats, broncos etc. I think so far I am ahead. Looks like we have a couple of keepers. Let us know how the over drive works
Gator |
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Aluminum Squirt
Joined: 15 Jun 2005 Posts: 46 Location: Sacto, CA
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Posted: Wed Mar 08, 2006 11:58 pm Post subject: |
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To piggyback on what Cavefish said, yes, that's the idea. Get a prostock style motor spinning 7-8,000 RPM's and underdrive it so you can spin a regular A (I guess a A cut is the most hydrodynamically efficient imp, or something like that????) cut impeller. There was a pretty lengthy conversation over on the Hotboat forum about this. Some of it was useful, most of it was the regular Hotboat board drama. Anyway, I digress. The bottom line is that its not common but there are a few drag guys that have made it work. Now a 2 speed powerglide would be an interesting idea, at least for a play boat-Aluminum Squirt |
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slowpoke
Joined: 15 Jun 2005 Posts: 31
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Posted: Thu Mar 09, 2006 9:01 pm Post subject: |
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Regarding speed. My buddy has a 23' hardtop Heliarc (did Rob C. help on these hulls?) with a stock 502EFI and a Hamilton 212 and he does 50 mph according to GPS. |
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Rapidchaser
Joined: 26 Feb 2006 Posts: 198 Location: Edmonton
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Posted: Thu Mar 09, 2006 11:00 pm Post subject: |
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Hi guys and thanks,
I did a little research and one of the things I found was that the 460 industrial marine engine, has the same torque at 25-2800 as it does at the 35- 4000 rpm range.
The difference being that with the overdrive, it is more economical fuel wise and will still do around 30 mph.
Now if I can take my source correctly, I will be more than happy with that speed (especially if I hit one of those things that seem to grow and move around in the rivers
I'm hoping to put a lot of hours on her this summer, maybe get a few miles out of it too
worst case scenario I can take the overdrive out and buy a cheep refinery somewhere
Cheers to all!! _________________ FORD=Power for the thrills of life!
Keep the wet side down! |
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