Howfy folks,

Not really sure where to start, but lets give it a good ole college try. Speaking of college, I am in an AMT school and its going great! I'm learning all kinds of cool stuff and I'm making some connections with some really good people in our industry. Anyways, I came across a deal on a 520 that is for sale up here in MN. I'm trying to do some research on it, so what better place than the BCP forums?

The IO-520-D in question has about 1800 hours total time. Its last overhaul was in 1986, and it was operated for about 90 hours. The engine was pulled for an IO550 installation about 1997 and has been sitting since. Before the case was split the seller took the engine and ran it a bit. She made static RPM and MP and compression checked out. The engine is pretty clean on the insides, however there is a bit of corrosion on three of the cylinder walls but a chrome treatment should fix that. If not, a replacement cylinder isn't too expensive. The crankcase has a minor crack in it, but the AD that applies to cracked TCM cases states that this one is field repairable. The only major gotcha is with the crankshaft; It needs to be replaced since it is a non var crank.

Any suggestions? I'm open for thoughts.

Cracked case, bad crank, corrosion ... how are the cam and lifters? Probably gnarly by now but worth looking I guess.

Since you asked, my gut feel is this is a factory reman candidate and perhaps worth a portion of core value, as they'd replace case/crank/whatever else and send you back an upgraded engine with all the current bits. If you were getting a smoking deal on it and could do this work yourself it might be viable, but right off the bat you're looking at a costly overhaul with only the things you've described.

Are you expecting to overhaul this yourself as part of your schooling, or pay an engine shop to do the work?

colopilot wrote:Cracked case, bad crank, corrosion ... how are the cam and lifters? Probably gnarly by now but worth looking I guess.

Since you asked, my gut feel is this is a factory reman candidate and perhaps worth a portion of core value, as they'd replace case/crank/whatever else and send you back an upgraded engine with all the current bits. If you were getting a smoking deal on it and could do this work yourself it might be viable, but right off the bat you're looking at a costly overhaul with only the things you've described.

Are you expecting to overhaul this yourself as part of your schooling, or pay an engine shop to do the work?

whoops, I fat fingered this one. The seller described the cam and the lifters as in good condition. He tried to explain that the camshaft still had the corrosion resistant finish that TCM applies to it. I wasn’t really picking it up, but my instructors said it was in good shape and I’ll take that as a good thing. I should also mention that one of my instructors personally knows the seller, he described him as being a good guy and a straight shooter. He kinda implied that I should go pick that up today if I was able to.

I would plan on building this in our recip engine course. My instructor for that class was thrilled with the idea of building it in class and was open to help with anything that I might need.

In the event that it turns out to be a bad deal, I still have the option of donating it to the college. Let’s just say that they could use a new engine and that we could use a tax write off.

Engines always look clean on the inside at first glance, for the most part. Oil-bathed metal always looks nice.

How many hours TT since mfr? Ever been overhauled before and had any work?
Cylinders = disposable
Case = not the end of the world, but maybe find a core with an uncracked case. A cracked case is no big deal to fix when you already own the engine and have to deal with it. If you're shopping cores, move on. Of course, some things like that are only found in inspection.
Known bad crankshaft = showstopper. You're running out of things to make the core a good investment.

Unless the price of this core is just amazing, I'd pass. Good reputations and tales of the engine running good at one time are useless. People often don't know what they don't know about the issues that can be found on an 1800 hr engine. Will the guy guarantee stuff in the bottom end to be serviceable like Wentworth does? Probably not. I wouldn't if I was just some guy selling one engine.

Zzz wrote:Engines always look clean on the inside at first glance, for the most part. Oil-bathed metal always looks nice.

How many hours TT since mfr? Ever been overhauled before and had any work?
Cylinders = disposable
Case = not the end of the world, but maybe find a core with an uncracked case. A cracked case is no big deal to fix when you already own the engine and have to deal with it. If you're shopping cores, move on. Of course, some things like that are only found in inspection.
Known bad crankshaft = showstopper. You're running out of things to make the core a good investment.

Unless the price of this core is just amazing, I'd pass. Good reputations and tales of the engine running good at one time are useless. People often don't know what they don't know about the issues that can be found on an 1800 hr engine. Will the guy guarantee stuff in the bottom end to be serviceable like Wentworth does? Probably not. I wouldn't if I was just some guy selling one engine.

I’d consider the price of the core to be pretty great. Most cores I’ve been seeing usually sell for $10,000ish. This one is going for $2,500.

This one has 1800TT, mfg dates to the mid 70s. Last OH was 1986, ran for 90 hours then pulled and pickled. Sat dissasembled (inside) for a number of years. The guy doesn’t seem to want to sell it anymore, more interested in parting it out at this point. If I can make up my mind, I’ll see if he will garuntee it, an excellent suggestion sir.

If I remember correctly, there are many different styles of that IO-520 engine in that they started out as a Phase I, then Phase II and so on. I don't know how far they went but the later ones are 7 stud humpback cases. The old ones probably aren't worth much because . . well. . . they cracked all the time.

Yeah it’s a light case, and like you mentioned, it’s cracked. It’s repairable, but it’ll probably crack again somewhere else.

I’m starting to feel like the gist of things is to pass on it and put the 2k into other problem areas. Let’s just say there are a couple of those..

If it were me, I'd pass. I have a hard time believing a serviceable run-out core is still worth 10k based on what I got a low time 520-F for, but maybe it is. $2k is at the high end of what I'd even start talking to the guy on and that would just be a place to talk him down from.

Maybe this guy wants to donate it to the school for the tax write-off? It might be better than what he'll get for parts since the case and crank have nothing aside from scrap value, wearable components are shot, reusable stuff like cam has 1800 hours since overhaul (and who knows how much time before that), a few cylinders are boat anchors, etc. Perhaps he doesn't want to sell it whole because reality already set in.

On the other hand airboat guys love these things, they buy them cheap and run them until they explode. He might have luck there...

I have to say, the title of this thread keeps cracking me up. Not because of the funny "peanut butter jelly time" meme but because this core sounds like peanut butter.

Zzz wrote:I have to say, the title of this thread keeps cracking me. Not because of the funny "peanut butter jelly time" meme but because this core sounds like peanut butter.

Haha! That's awesome. I have to agree that this core sounds like junk. No crank, cracked light case, a cam that looks ok but may not measure or NDT ok. Probably best to let him part it out or donate it to the school himself.

pilotryan wrote:

colopilot wrote:Cracked case, bad crank, corrosion ... how are the cam and lifters? Probably gnarly by now but worth looking I guess.

Since you asked, my gut feel is this is a factory reman candidate and perhaps worth a portion of core value, as they'd replace case/crank/whatever else and send you back an upgraded engine with all the current bits. If you were getting a smoking deal on it and could do this work yourself it might be viable, but right off the bat you're looking at a costly overhaul with only the things you've described.

Are you expecting to overhaul this yourself as part of your schooling, or pay an engine shop to do the work?

whoops, I fat fingered this one. The seller described the cam and the lifters as in good condition. He tried to explain that the camshaft still had the corrosion resistant finish that TCM applies to it. I wasn’t really picking it up, but my instructors said it was in good shape and I’ll take that as a good thing. I should also mention that one of my instructors personally knows the seller, he described him as being a good guy and a straight shooter. He kinda implied that I should go pick that up today if I was able to.

I would plan on building this in our recip engine course. My instructor for that class was thrilled with the idea of building it in class and was open to help with anything that I might need.

In the event that it turns out to be a bad deal, I still have the option of donating it to the college. Let’s just say that they could use a new engine and that we could use a tax write off.

I don't know crap about engines, and I don't know your instructors or your school, but I know people, and the highlighted portions of your post would make me come up with some imaginary expenses that would prohibit me from being able to buy that engine, even if I already said I was going to. One thing you learn in life is that people (ALL people) can be staggeringly dishonest without ever seeing or believing that they are telling anything but the gospel truth.

Seems like your instructors have everything to gain and nothing to loose from you buying the engine. If it's such a good deal, why don't they buy it? It's the priest and the choir boy all over again, if you ask me.

And by the way...tax deductions don't equal losses, so don't think that this can be a stinker without most of the stink sticking to you.

As always...good luck!

I’m going to take this as an opportunity to learn from past mistakes. During the 185 rebuild, a lot of you guys suggested some things that frankly, I didn’t care to hear about. Since the, I’ve spent a huge amount of time trying to find hay in a stack of needles. Let’s just say that it still hurts to think about what I’ve done wrong and what could’ve gone better. I don’t want to do that again, so I’ll pass on this engine. Thanks guys!

pilotryan wrote:I’m going to take this as an opportunity to learn from past mistakes. During the 185 rebuild, a lot of you guys suggested some things that frankly, I didn’t care to hear about. Since the, I’ve spent a huge amount of time trying to find hay in a stack of needles. Let’s just say that it still hurts to think about what I’ve done wrong and what could’ve gone better. I don’t want to do that again, so I’ll pass on this engine. Thanks guys!

Experience is what you get when you don’t get what you want.

I think all of us have lots of ‘experience’. Accepting it can be difficult, but necessary for progress. Good on you Ryan

Good call Ryan. I just sold a IO-520D core. It’s being shipped straight to Continental as an exchange. It has a light case and non VAR crank. Core is it’s best and highest purpose. I suspect Continental MAY re-use the connecting rods. I expect the rest will be melted down.

Ryan,
I am glad to see you posting again. I would love to hear and see any updates you have on the 185. It was a great project and you have helped me to see where not to get stuck. You have been a valuable teacher for me and did not even know it. SO lets see some pics of the 185 and see where you are in the project.

We would sure like to see your airplane make a trip back home to Montana/Idaho also!

Dang Ryan, I feel like I've watched you grow up on this site.

Plane ownership has been part of my own maturing too. Like you I didn't want to hear what I didn't want to hear, now I listen a lot more carefully.

Nice to see you posting again. I always admired your demeanour, especially when there was a lot of criticism floating around.

Good luck with school. I think you are well on your way to becoming a very well rounded aviator.

Good decision, good job. Glad to have you back!

pilotryan wrote:I’m going to take this as an opportunity to learn from past mistakes. During the 185 rebuild, a lot of you guys suggested some things that frankly, I didn’t care to hear about. Since the, I’ve spent a huge amount of time trying to find hay in a stack of needles. Let’s just say that it still hurts to think about what I’ve done wrong and what could’ve gone better. I don’t want to do that again, so I’ll pass on this engine. Thanks guys!

Crap. I was looking forward to some good entertainment...

Kidding, of course.

Thanks guys, I appreciate the kind words.

I will find an engine for this thing eventually. I really wanted to build something for myself in my recip class that's coming up. Maybe instead I could bring my engine in and diagnose it's issues.

Hammer wrote:

pilotryan wrote:Bleep bloop. Insert stupid get engine quick scheme here.

Crap. I was looking forward to some good entertainment...

Kidding, of course.

Don't worry, I feel like there is some quality entertainment in my current predicament in the paperwork sector. Undocumented mods = no annual = no flying. Thank god for DERs and Aeropod inc.