Rebuild, replace, or convert a 220???

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CypressHunter
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Rebuild, replace, or convert a 220???

Post by CypressHunter » Sat Jun 25, 2016 9:19 am

I've been running my 220 for 6 yrs now on a 13' 6" cottonmouth wit a 70" signature series. It's a single mag with 535133 Pistons. It's a tired worn out motor but is reliable as hell. For awhile I was only running on 5 cylinders. I replaced the one cylinder that was blown and kept running her.

Like most 220's it burns, blows, and leaks oil but as long as I keep it full it does everything I need/want it to.

I don't get to ride as much as I'd like to now with a 5 month old daughter and plans to have another kid in a year or two. I've been keeping her maintained and saving a little pocket change hear and there for the future.

Now in the future I am looking at a few options

1. Do a whole top engine and keep going ( I have a few std cylinders greased and bagged in my garage for a rainy day )

2. Break it all the way down and do a complete rebuild - top and bottom

3. I have some junk cylinders in the garage as well and have them channel chromed to do along with options 1 or 2

4. Convert it if I decided to break it down.

5. Sell it all and start over.

I am trying to figure out what the best bang for the buck would be
13' 6'' Cotton Mouth 220 GPU 70'' signature series

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goldhunter_2
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Re: Rebuild, replace, or convert a 220???

Post by goldhunter_2 » Sat Jun 25, 2016 10:32 am

sell an start over gives you the option to buy a better hull in the process

otherwise if your going to do it do a complete rebuild an a 520 conversion
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jeepinocala1111
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Re: Rebuild, replace, or convert a 220???

Post by jeepinocala1111 » Sat Jun 25, 2016 10:59 am

goldhunter_2 wrote:sell an start over gives you the option to buy a better hull in the process

otherwise if your going to do it do a complete rebuild an a 520 conversion

I have a project going it is a 520 conversion that I am deciding to sell because I am buying a new airboat and do not have the time to finish this build but I have just about everything to finish the build and will sell it at a super low price being it would help with buying a new airboat if you are interested here is what I have and a absolutely one time this week only price because after I buy my new boat I will not need the cash or want to let it go that cheap.

6-520 cylinders with valves and springs in them
6-520 cylinder gasket sets
6-pistons
6-NEW piston ring sets
6-valve covers
engine block cleaned and ready to be bored for cylinders
chromed crankshaft
complete bottom end gasket set
aircraft fuel pump
898 camshaft
gears basically rest of engine
a new bearing set complete with crankshaft oil seal
intake tubes
push rods and tubes


What it needs is the machining to fit cylinders and a post added for a second mag.
Most is cleaned up everything is in great condition I have over 4 grand into it. If I don't sell it this
week then I will build it and who knows what it will go on maybe a generator for my house. :scratch:

broncobill
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Re: Rebuild, replace, or convert a 220???

Post by broncobill » Sat Jun 25, 2016 6:43 pm

First mistake would be a chromed crankshaft on a 520 conversion. You would be better off buying a good STD/STD crankshaft. I didn't see anything about rocker arms.

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Re: Rebuild, replace, or convert a 220???

Post by jeepinocala1111 » Sat Jun 25, 2016 7:39 pm

I also have the rockers arms but why would you be against a chromed crank? The only reason the crankshaft are nitrided is to make a VERY thin outside layer a bit harder chrome is hard but heck what I'm selling these cylinders alone are worth it.

lorick
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Re: Rebuild, replace, or convert a 220???

Post by lorick » Sat Jun 25, 2016 7:47 pm

I'm with goldhunter start over sv540 is the ticket. jmo

jeepinocala1111
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Re: Rebuild, replace, or convert a 220???

Post by jeepinocala1111 » Sat Jun 25, 2016 8:00 pm

lorick wrote:I'm with goldhunter start over sv540 is the ticket. jmo
Why a straight valve? I only offered this because it's a super cheap price and I'm going with a car engine. So even if I built it I have nothing to put it in.

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John Fenner
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Re: Rebuild, replace, or convert a 220???

Post by John Fenner » Sat Jun 25, 2016 8:56 pm

Chromed and ground to standard crankshafts break due to the craggy edges at the fillet grinds at the throws.
I never finish anyth,,,.

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Re: Rebuild, replace, or convert a 220???

Post by jeepinocala1111 » Sat Jun 25, 2016 9:50 pm

John Fenner wrote:Chromed and ground to standard crankshafts break due to the craggy edges at the fillet grinds at the throws.
This is new to me never heard this but this crank came out of a running engine. So your saying junk the crank and move on. I'd like to see a chromed crank that was broken never see one. So whe chrome a crank at all?

broncobill
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Re: Rebuild, replace, or convert a 220???

Post by broncobill » Sun Jun 26, 2016 8:17 am

If you remove the radius journal of a crankshaft it is prone to break due to a sharp edge. All cranks in Aircraft engine have a sloped journal. When a crank has been chromed that shaft has been ground well below tolerance and filled back in with chrome material. this process makes it weak. Should not be used in a converted motor. Been there done that. Learn a lesson the hard way.

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TheElevatorGuy
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Re: Rebuild, replace, or convert a 220???

Post by TheElevatorGuy » Sun Jun 26, 2016 8:25 am

Hey Dan, remember the GPU I had on my boat when you used to live down here? I had John Fenner retrofit a completely new aircraft 520 that I bought from an engine builder.......it runs great and I love it......what a difference in power! If you look in my pics on here you will see the before and after pics of my boat, I would have never attempted parking it on green grass like that with the GPU!!!

CypressHunter
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Re: Rebuild, replace, or convert a 220???

Post by CypressHunter » Sun Jun 26, 2016 8:28 am

Jeep thanks for the offer but I am still got a little bit of time before I do anything
13' 6'' Cotton Mouth 220 GPU 70'' signature series

Shutch
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Re: Rebuild, replace, or convert a 220???

Post by Shutch » Sun Jun 26, 2016 10:28 am

You asked for opinions so here's mine. I currently run a 220 conversion with angle valve 0470 cylinders on it. All I did was a top end complete. Not sure why you would want to go into the bottom end unless your oil pressure isn't where you like it. As for starting over with a Sv0540 that's a matter of opinion but, I hope you have plenty of $$. I haven't seen a Sv0504 no cheaper then 6k & I look constantly. Conversion is way cheaper or even just replacing the worn out cylinders with the Standard ones you already have. Just depends on which way you want to go. Just my 2 cents.

CypressHunter
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Re: Rebuild, replace, or convert a 220???

Post by CypressHunter » Sun Jun 26, 2016 1:04 pm

Shutch wrote:You asked for opinions so here's mine. I currently run a 220 conversion with angle valve 0470 cylinders on it. All I did was a top end complete. Not sure why you would want to go into the bottom end unless your oil pressure isn't where you like it. As for starting over with a Sv0540 that's a matter of opinion but, I hope you have plenty of $$. I haven't seen a Sv0504 no cheaper then 6k & I look constantly. Conversion is way cheaper or even just replacing the worn out cylinders with the Standard ones you already have. Just depends on which way you want to go. Just my 2 cents.
Only reason I'd go through the bottom end is piece of mind and knowing I have a fresh engine and that's if I dump the money into a conversion or spending the money to get chrome cylinders.

A 0540 would be nice but I don't see myself having the money for that anytime soon
13' 6'' Cotton Mouth 220 GPU 70'' signature series

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Re: Rebuild, replace, or convert a 220???

Post by jeepinocala1111 » Sun Jun 26, 2016 1:11 pm

broncobill wrote:If you remove the radius journal of a crankshaft it is prone to break due to a sharp edge. All cranks in Aircraft engine have a sloped journal. When a crank has been chromed that shaft has been ground well below tolerance and filled back in with chrome material. this process makes it weak. Should not be used in a converted motor. Been there done that. Learn a lesson the hard way.
I understand the worry if the radius was removed they are not removed. I would not have considered the crank at all if the radius was not there. Personally I'd be fine with using it but you have a point if someone is worried then just get another crank it would not be worth the worry.

broncobill
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Re: Rebuild, replace, or convert a 220???

Post by broncobill » Sun Jun 26, 2016 3:47 pm

Yes if you look at the crank you will see the radius because they cut the crank inside of the radius. But the only reason a crank is chromed is because it was damaged beyond .020 and was not serviceable. So they build it back up to specs using chrome. If it is a .020/.020 then you know if they added chrome it was cut below serviceable tolerance. You can see where the chrome meets the radius that is where it was cut. http://www.southernairboat.com/photopos ... G_1268.JPG

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Re: Rebuild, replace, or convert a 220???

Post by goldhunter_2 » Sun Jun 26, 2016 7:23 pm

CypressHunterq wrote: Only reason I'd go through the bottom end is piece of mind and knowing I have a fresh engine and that's if I dump the money into a conversion or spending the money to get chrome cylinders.

A 0540 would be nice but I don't see myself having the money for that anytime soon

Don't forget if you decide to do a 520 gpu conversion you still need to split the case open to do the machine work (boring ,decking, 2nd mag post), and it is well worth just going through everything once rather then coming back to do it avian latter IMHO
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Re: Rebuild, replace, or convert a 220???

Post by rjonesboy » Sun Jun 26, 2016 8:35 pm

I am a member of the broken chromed crankshaft club. If I were you, I would just keep replacing cylinders as they need it, as long as bottom end is reasonably good, and ride out. If I was going to do a 520 conversion, or high compression pistons, I would want a std-std crank. And the extra several hundred dollars you pay for it will be worth it when youre not sitting out in the middle of nowhere with a broken crankshaft. And with all the runout 470 and 520 engines now, the GPU engines are not going to be cost effective anymore, and I am still running two of them and broke several more :shock:

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CactusJack
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Re: Rebuild, replace, or convert a 220???

Post by CactusJack » Mon Jun 27, 2016 4:29 am

Let me see... you have a boat you don't use much, it runs and leaks and smokes a bit... but it runs :scratch: You have one child already, and want another next year :dontknow: and you are considering a major tear down and rebuild :dontknow:

I am just a dumb aussies.... but I would say a good plan would be to buy some oil to keep it topped up and some spare spark plugs when they are on sale cheap, for when it fouls.... some old pots and pans to put under the oil leaks.... then enjoy taking it for a blast occasionally :)

It is yours... you know it, you know what to expect to have to fix, it runs, its reliable.... spend as little on it as possible and enjoy the heck out of it is my recommendation :usa: But, what would I know :lol: :stirpot: :D
I was told I was wrong, once (not sure I believe it though)
If you can't blind 'em with brilliance, baffle 'em with BS
Airboat experience so far, limited to having bolted a gyrocopter to a flat bottom punt.... but THAT.... is about to change, bigtime :-)

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Re: Rebuild, replace, or convert a 220???

Post by jeepinocala1111 » Mon Jun 27, 2016 7:22 am

CactusJack wrote:Let me see... you have a boat you don't use much, it runs and leaks and smokes a bit... but it runs :scratch: You have one child already, and want another next year :dontknow: and you are considering a major tear down and rebuild :dontknow:

I am just a dumb aussies.... but I would say a good plan would be to buy some oil to keep it topped up and some spare spark plugs when they are on sale cheap, for when it fouls.... some old pots and pans to put under the oil leaks.... then enjoy taking it for a blast occasionally :)

It is yours... you know it, you know what to expect to have to fix, it runs, its reliable.... spend as little on it as possible and enjoy the heck out of it is my recommendation :usa: But, what would I know :lol: :stirpot: :D
Here you go coming into it from where and making sense crap your going to confuse everyone.

CypressHunter
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Re: Rebuild, replace, or convert a 220???

Post by CypressHunter » Mon Jun 27, 2016 11:01 pm

CactusJack wrote:Let me see... you have a boat you don't use much, it runs and leaks and smokes a bit... but it runs :scratch: You have one child already, and want another next year :dontknow: and you are considering a major tear down and rebuild :dontknow:

I am just a dumb aussies.... but I would say a good plan would be to buy some oil to keep it topped up and some spare spark plugs when they are on sale cheap, for when it fouls.... some old pots and pans to put under the oil leaks.... then enjoy taking it for a blast occasionally :)

It is yours... you know it, you know what to expect to have to fix, it runs, its reliable.... spend as little on it as possible and enjoy the heck out of it is my recommendation :usa: But, what would I know :lol: :stirpot: :D
You're r spot on but you missed the part where I said in the future
13' 6'' Cotton Mouth 220 GPU 70'' signature series

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Re: Rebuild, replace, or convert a 220???

Post by terrible ted » Tue Jun 28, 2016 8:13 am

I agree with don't fix whats not broken. Reliable is the best. low cost it great.

Yea don't hot rod something that was not meant to be hot rod. Meaning don't put to much pressure on a GP crank. Save your money But it is your money find and do what make you happy.

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CactusJack
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Re: Rebuild, replace, or convert a 220???

Post by CactusJack » Tue Jun 28, 2016 8:52 am

jeepinocala1111 wrote:
Here you go coming into it from where and making sense crap your going to confuse everyone.
That sure confused me?? :scratch:

For the future makes a difference for sure... I reckon run yours until it drops.... and do what Gold says and build another one... but keep yours to play with while you build the new one :salute: :thumbleft:
I was told I was wrong, once (not sure I believe it though)
If you can't blind 'em with brilliance, baffle 'em with BS
Airboat experience so far, limited to having bolted a gyrocopter to a flat bottom punt.... but THAT.... is about to change, bigtime :-)

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Deano
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Re: Rebuild, replace, or convert a 220???

Post by Deano » Tue Jun 28, 2016 9:06 am

Well CJack, since you are back semi-regular I guess you got moved and unpacked?
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but it is not the path to knowledge; it has no place in the endeavor of science."
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CactusJack
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Re: Rebuild, replace, or convert a 220???

Post by CactusJack » Tue Jun 28, 2016 9:19 am

Deano wrote:Well CJack, since you are back semi-regular I guess you got moved and unpacked?
Yup... was a nightmare and had a hip replacement coz it stuffed up after the move... have been building gyros again... have started making a ply semi deckover hull to suit Subaru EJ22' s so I can test run gyro motors on the boat and have some fun at the same time :thumbleft:
I was told I was wrong, once (not sure I believe it though)
If you can't blind 'em with brilliance, baffle 'em with BS
Airboat experience so far, limited to having bolted a gyrocopter to a flat bottom punt.... but THAT.... is about to change, bigtime :-)

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