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VW engines for airboat
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My HIO-360 don't even come close to that HP. I have heard that LEO is running a 180 or 200 HP prop on his, it could have been another post though, just recalling that off the top of my head which is about all thats left LOL. Less hair up there every day it seems 
Scotty
Scotty
dantheairboatman
Well-known member
sometimes it's all about the build.
Des Moines Boater
Well-known member
I would not go larger than a 10 foot hull with a Corvair, VW or Continental 65. I had a Corvair on my Pietenpol aircraft. It was 100 hp but it didn't perform as well at the Continental 65 I replaced it with. My second airboat was a little 10 foot Aircat with a 65 horse VW. There is a picture in my gallery. It was a fun little boat but nothing compared to the O-290 Gilileo I got for my third boat.
The VW engine can be a great little engine to put on a boat, but make it a very small and light weight boat. VW's are cheap to build and lots of after market parts. Great Plains can build a super engine or you can build your own. Get something bigger than the stock 1600 cc engine and soup it up. Most 100 horse power engines give about the same push as a real 65 horse aircraft engine IMO.
The VW engine can be a great little engine to put on a boat, but make it a very small and light weight boat. VW's are cheap to build and lots of after market parts. Great Plains can build a super engine or you can build your own. Get something bigger than the stock 1600 cc engine and soup it up. Most 100 horse power engines give about the same push as a real 65 horse aircraft engine IMO.
leo_081103
Well-known member
this is my 1600 cc VW airboat, 11Ft x 7.5. fiberglass hull all of which i built myself.
the VW is somewhat heavy at around 200 lbs ( whole engine out of a beetle ) for a 45 hp output ( common set-up with pict 28 carb ). 57 hp for pict 34 and 65 hp for the Weber 40 progressive 2BB which is i think the most economical.
My set-up is the 65 hp. I wanted it as stock as possible as far as reliability and cost is concerned so the only mods are the 009 Distributor, Weber 40 carb and i installed a Compufire module. I can easily ( but not cheaply ) squeeze 90 to 100 hp at a great compromise on the other end.
I swing a my own design 70" x 36" - 7" wide wood prop on a 2:1 Redrive i designed. Yes, I designed and built the Redrive myself BUT dont be careless because I am an engineer ( not bragging ). The drive design is a thorough and well financed project. I have put most, if not all, of the design factors in it. Like basic weight considerations to materials selection and fatigue design, stress concentrations, gyroscopic precession, harmonics, proper power couplings and effect of prop load at engine PTO. As a consideration example, the bearings are expected to fail at 2000 hours but I will change them around 600 hours or when there's a sign of possible failure.
I made the engine stand stiff so they wont flex on propeller gyroscopic forces therefore a good mounting/shock isolation has to be installed.
My hull weighs around 200 lbs based on the materials consumed.
Performance: it planes at 15 mph in deep water at 3500 engine rpm, 10 on shallow at 3000 rpm. top is at least 35 mph ( max gage number) , i got to change speedometer to see what really top is. I run limited ground coz i dont have polymer ( polymer= added weight ). I may change to 70 x 30 - 9 in for push/smooth ground/sand running or 70 x 42 - skinny for speed.
My magic FIGURE!!! : " I cruise at 25 mph at @10 liters per hour ( @2.5 gallons/hr).
leo_081103
Well-known member
by the way, VW Beetle has the noisy reputation on the road but this Airboat can sneak up even on plane. I can recall how i sneak in to the hot girls in the beach
I designed and installed my own extractor type exhaust system with a main 9:1 expansion chamber muffler lined with fiberglass, a series of expansion points and it's a Free Flow. I was expecting something from the design BUT i did not expect to be amazed that I have no drop in RPM, well maybe not noticeable for that matter and all I can hear is prop. Of course, not to mislead you, I am only at 670 fps prop tip speed at full power and just 351 fps at cruise! All prop alright.
I designed and installed my own extractor type exhaust system with a main 9:1 expansion chamber muffler lined with fiberglass, a series of expansion points and it's a Free Flow. I was expecting something from the design BUT i did not expect to be amazed that I have no drop in RPM, well maybe not noticeable for that matter and all I can hear is prop. Of course, not to mislead you, I am only at 670 fps prop tip speed at full power and just 351 fps at cruise! All prop alright.
Now there is an original boat ! I like it cause ya put yourself into it Leo. Anybody can just go spend money but when a boat has some of you in it, it just makes a better boat. That little boat is just plain awesome.
I know that not everyone is an engineer but anyone can ask questions and educate themself about how things are built. An airboat is an educational process. I have learned something from every one I have ever had. To me the build is as much fun a running it.
When ya build it yourself, every part of the boat has a story to be told in it. To me that creates VALUE not just expense.
Great little boat Leo. I know you are proud of it and it makes me proud just to see it.
Scotty
I know that not everyone is an engineer but anyone can ask questions and educate themself about how things are built. An airboat is an educational process. I have learned something from every one I have ever had. To me the build is as much fun a running it.
When ya build it yourself, every part of the boat has a story to be told in it. To me that creates VALUE not just expense.
Great little boat Leo. I know you are proud of it and it makes me proud just to see it.
Scotty
leo_081103
Well-known member
Thanks Scotty.
Being an engineer doesnt mean you how to build something that would work, an engineer can only estimate and check. My habit is to allow adequate safety margins PLUS tons of add-on experiences from my learnings/mistakes and from other people. By the way, i have learned a lot from you guys here and i will put them learnings in my new project 14 Ft 160 hp 1.6L 4 cyl. Toyota Airboat. It is already in progress.
Anyways, anyone can build something, as you said, put yourself into it--- oh, include putting the wallet too. It's the other half of the project
Just do your homework, ask for help if necessary and regularly visit SA! You may not find exactly the answer But you'll surely be guided to finding it. Add to that, browsing SA is like browsing a book never written before, you always get to read and pick up a learning. The real world of airboating.
Proud---? D@mn sure. If you've only witnessed which is louder when I ran along with the jet skis!
Just in case if it is of interest: Total Cost ( all in including trailer) = $4,135.00
Boat Cost = $3,655.00 Trailer= $480.00
Being an engineer doesnt mean you how to build something that would work, an engineer can only estimate and check. My habit is to allow adequate safety margins PLUS tons of add-on experiences from my learnings/mistakes and from other people. By the way, i have learned a lot from you guys here and i will put them learnings in my new project 14 Ft 160 hp 1.6L 4 cyl. Toyota Airboat. It is already in progress.
Anyways, anyone can build something, as you said, put yourself into it--- oh, include putting the wallet too. It's the other half of the project
Just do your homework, ask for help if necessary and regularly visit SA! You may not find exactly the answer But you'll surely be guided to finding it. Add to that, browsing SA is like browsing a book never written before, you always get to read and pick up a learning. The real world of airboating.
Proud---? D@mn sure. If you've only witnessed which is louder when I ran along with the jet skis!
Just in case if it is of interest: Total Cost ( all in including trailer) = $4,135.00
Boat Cost = $3,655.00 Trailer= $480.00
leo_081103
Well-known member
you're getting hot there cold, you almost got it. the engine is of the same family but i dont like the MR2's supercharged engine. the MR2 had the supercharged 4AGZE 1.6L 145 hp engine with later version at 165 hp.
i aimed for the 20 Valve 4AGE engine normally aspirated. it is rated to 160 hp & weighs around 300 lbs. the big plus is that it was built like a mule for power. it's max torque is located at 5500 rpm! and at this rpm & max torque combo, you'll get around @126 hp. coincidence for airboat use? man, you need not modify any cam or timing.
the prop for this engine on my shop is a 78 x 42 - 12 inch wide. the drive is already being fabricated... am very excited to get this rig in the water. maybe in a month or so.
hey scotty, that would be a good project. i hope you can have it direct drive because those small diesels rev high. i think if it is in the 3500 rpm region, you may have to opt for a 1.5:1 to 1.75 redrive. just a guess.
i aimed for the 20 Valve 4AGE engine normally aspirated. it is rated to 160 hp & weighs around 300 lbs. the big plus is that it was built like a mule for power. it's max torque is located at 5500 rpm! and at this rpm & max torque combo, you'll get around @126 hp. coincidence for airboat use? man, you need not modify any cam or timing.
the prop for this engine on my shop is a 78 x 42 - 12 inch wide. the drive is already being fabricated... am very excited to get this rig in the water. maybe in a month or so.
hey scotty, that would be a good project. i hope you can have it direct drive because those small diesels rev high. i think if it is in the 3500 rpm region, you may have to opt for a 1.5:1 to 1.75 redrive. just a guess.
I had a new 1985 MR2 and what a blast. My wife and I did the coastal rout to California and after a day at Disney land we got in the car and I drove at 100-120MPH (Hy-way tractors were doing 100 MPH) till I thought I was seeing MOOSE in Wahington! :lol: 6000 RPM for 11 hours! :twisted: