• If you log in, the ads disappear in the forum and gallery. If you need help logging in or getting registered, send request to: webmaster@southernairboat.com

How much boat???

fred wook

Active member
I am building a Corvair engine for an airboat. I am pretty much following the conversions used for experimental aircraft. I am told that realistic HP is going to be around 100 horsepower give or take. I have posted about the corvair engine on this post before and appreciate the help. What I am stuck on is how much boat can i realistically push with this engine. I am not going to run dry, only swampy areas chocked off with vegetation (hydrilla and such) BUT, I will be in deep water most of the time. I would love to get fair performance with a large john boat style hull so I can still put some gear in and fish or whatever. Any input??? Thanks, Fred in SC
 
I had a Corvair engine on my Pietenpol but I got rid of it and went with a real aircraft engine. That 100 hp Corvair will give about the same performance as a Continental A-65 engine. I would stay with a 10 foot light hull and you should do fine. You won't have much power, but if you stay real light you can still cruise at 30mph plus. I had a VW 65 horse on a small boat and it was a blast. Put two people in and then it wasn't as much fun but it would still get up and go.
 
Fred,

i helped build one with a friend he put it on a 16ft modified vee with a bottom width of 56"

i suggest go as wide as your check book will let you this creates less draft

mike's boat would run at 28mph with two guys he used it for bowfishing, when he was loaded with fish he had a hard time getting on plane

hope this helps :)
 
wider the hull the better always!

the type of running your describe should not be any problem as long as later your not going to run dry.

The corvair depend on witch engine some where stock around 125-145 I remember form building my dragonfly play you can use the big bore cylinder kits form a VW shop on that corvair block to get even better
 
Hey, thanks for the input. I would really like to put it on a welded jon boat type hull, but I can't seem to find one with a really wide bottom without the length. Anyone know of a manufacturer of the top of their head??? Thanks Fred
 
Hey, thanks for the input. I would really like to put it on a welded jon boat type hull, but I can't seem to find one with a really wide bottom without the length. Anyone know of a manufacturer of the top of their head??? Thanks Fred
 
Try alumaweld
i see one of these when i was at bowfishing tourney in Mississippi
17ft long 72" at the bottom
 
wide and short is going to be more of a custom thing . Southern duck boats in Al would do it and think he has a dealer in your area just talk to Jason, also Ronnie's in LA. i will not mention the names but say be careful of the cookie cut hulls build be some. if you don't find some one close let me know maybe we can work out some thing
 
What do you think about a 12x7 lightweight aluminum hull like a Hamant, Classic, or Diamondback?? I m just wondering what kind of performance I could get out of it with minimal weight. The corvair engine only weighs about 220 lbs or so due to the aluminum engine case. I know I have seen these 12x7 ultra light hulls perform well with a 125 lycoming. I will be happy with at least a good planing speed. If I really had to, I could always go with more power (real AC engine) in the future if I needed but I have really put a lot of work into this engine and want to be able to use it. Thanks for the help..Fred
 
Fred,
what are you using for a starter?
we were advised to use a vw for there reverse rotation
but it was only 1.5 hp
so we used a subaru starter it has 2.3 hp and weights half as much!
just throwing that out there :)
 
Carpshooter, I am probably going to use the subaru starter also. I have seen several of them on ebay for about $50 or so. Did you leave the original belt driven fan cooling on the engine?? If so, how did you mount the starter? I was considering an electric thermostat controled cooling fan mounted just above the engine where the original fan was. I am pretty much following the aircraft conversion manual, but the AC application will have a prop blowing air over the engine where a pusher config won't. I'm not sure what kind of cooling issues I will have....
 
Fred
we did use the original belt config
i work in a tool and die shop we made a bracket to mount the starter off the block
we didn't have any cooling problems
but you know how things go so things work for some people and some don't
i hope this helps
Rick

ps we mounted the starter low to keep the weight low
 
Back
Top