value of engine?

[jeepinocala1111]

I am planning on building a 220 with 520 jugs and need to know if I decide not to change mine what should I pay for a bottom end 220? I am thinking for a good one it shouldn't be to bad? Also if I decide to sell mine after the build what is it worth? I'd be selling the complete engine no carb or propeller it has dome top high compression pistons everything else I believe is stock runs great and will not be until my engine build is done if I decide not to just use it on a second boat build for my son.

[rjonesboy]

I wouldn't build one without a standard crankshaft (hasn't been turned). And they are getting hard to find.

[trailerdon]

220 gpu's have been pushing airboats for years. They are fairly durable engines that can get the job done 90% of the time.
Down side: its a gpu that will almost never bring back a good $. Use it for what it is, when its wore out move to a/c

[jeepinocala1111]

220 gpu's have been pushing airboats for years. They are fairly durable engines that can get the job done 90% of the time.
Down side: its a gpu that will almost never bring back a good $. Use it for what it is, when its wore out move to a/c

What your thoughts I have 6 eci 520 cylinders complete still airworthy with pistons and all I am thinking of building either a pe90 or 220 gpu with the cylinders?

[Joe]

There's a guy,lycoming 1, selling aircraft 470 bottom ends for 1200.00 Couldn't you bore the case and put the 520 cylinders on it and have a true aircraft that would be a better unit and have a better resale value?

[jeepinocala1111]

There's a guy,lycoming 1, selling aircraft 470 bottom ends for 1200.00 Couldn't you bore the case and put the 520 cylinders on it and have a true aircraft that would be a better unit and have a better resale value?

I am told that the gpu has a better crank and after you take all the crap off of it then it is only around 10 pounds more.

[Joe]

I've never herd that. I was told the opposite. Never hear much of aircraft cranks breaking but have herd and seen alot of gpu cranks break. You could be right though,ive only dabled in aircraft and have alot still to learn.maybe one of the aircraft gurus will chime in and tell us.

[jeepinocala1111]

I've never herd that. I was told the opposite. Never hear much of aircraft cranks breaking but have herd and seen alot of gpu cranks break. You could be right though,ive only dabled in aircraft and have alot still to learn.maybe one of the aircraft gurus will chime in and tell us.

If you are right then I think I would just build a second boat cause my 220 will run dry with 4 people and go over some pretty nasty stuff while at it that was a mistake I hope to never run up on again But it came through for me.

[fletchster76]

GPU cranks break once they've been turned, until then they are pretty solid. I love my 520 conversion, but If I had it to do again I would have done as Joe recommended and had a AC 470 case bored for 520 cylinders. Couple builders have told me they are bullet proof and hold value. Jeep, from what you've always said, you have jam up 220, I certainly wouldn't tear a good motor down to build a 520. I'd sell it or run it until you build the 520 on another case.

[jeepinocala1111]

GPU cranks break once they've been turned, until then they are pretty solid. I love my 520 conversion, but If I had it to do again I would have done as Joe recommended and had a AC 470 case bored for 520 cylinders. Couple builders have told me they are bullet proof and hold value. Jeep, from what you've always said, you have jam up 220, I certainly wouldn't tear a good motor down to build a 520. I'd sell it or run it until you build the 520 on another case.

You are right I just got back from a ride the boat ran anywhere with ease so I am going to start hunting for a good 470 bottom end with a standard crank. I ran for a few hours most of the time around 2100 rpm my temp never got over 170 and the oil pressure stayed around 55 psi so it will not get torn down I am just considering a second air boat.