Club Homepage Forums Classified Ads Buy & Sell - Everything But Airplanes Needed: O-200 Crankshaft...

I need an O-200 crankshaft to rebuild my engine (the original has a crack, discovered on its second run to TBO).

A brand new crankshaft is about $2500-$2700. I'm hoping to find a yellow-tagged used crank for significantly less. I haven't seen anything pop up on Trade-A-Plane or Barnstormers. Any ideas?

AVAILABLE FOR IMMEDIATE SALE

Continental O 200 crankshaft, just picked up from Aircraft Specialities last friday.
Fresh Overhaul, yellow tagged, boxed and ready to be shipped.
Crank ground 10/10,
Picts available on request.. Call for info Mitchell 813-356-9758 hiflier68 at yahoo

That advertisement is over 5 years old - I'm sure it's been sold by now.

But it does raise some questions: Any downside to a crank ground 0.010" undersize? Are the 0.010" oversize bearings prohibitively expensive? And I seem to recall one ground crank cracking because of improper technique (poor radius at the fillets and/or improper nitriding after grinding) - or is that an isolated case?

sorry kirk.............

Personally, if I needed a crankshaft for my C150's 0-200 because it was cracked/undersize/"red tagged"...I would bite the bullet and purchase a new one.
The reason? The crank is the largest and most expensive single component of the "engine", followed by the case, and then each of the cylinders.
Buying a "used" one, regardless of the "yellow tag" status or what the seller tells you, you really have no way of determining how many hours are actually on it, or if it was ever damaged... and should it fail you would have to tear the engine completely down to replace it again. Unless you know someone personally who is selling a good one who actually has records of the time and you believe what they say,... the truth is that most folks don't have spare 0-200 crankshafts laying around to sell. If it's good it's usually inside their case turning a propeller. Why someone would replace a crankshaft when the removed one was still "airworthy", that they could then sell to you, is really stretching believability.
I have seen 0-200 cranks on eBay and other places from time to time, and a "serviceable" 0.010 crank(they're always ground to at least that) sell for $1000 to around $1500 or so. For another grand you could have a NEW one that could last through at least four more overhauls.

0.010 bearings do cost a bit more. I seem to remember it was less than $100 more than standard bearings. The 0.020 bearings are expensive, when you can find them.

I'm the guy who had the broken crankshaft that had been turned down 0.010 with about a year of flying on it before it broke. It may have been that turning it down exposed a flaw (all steel contains flaws), it may have been turned improperly, or it may have suffered a prop strike that stressed it sometime in its life.

I would think the best bet is to buy a new crankshaft. It will have plenty of rebuild life on it and should be a "known" quantity. The second best bet is to buy a used crankshaft that has been serviced by a well known shop (the broken one I had wasn't). I would be reluctant to buy an eBay crank from an unknown seller, since you wouldn't know if the yellow tag had been forged or something.

That being said, I bought a used 0.010 crankshaft for my rebuild. It was a fresh turn from Rick Roman's and the seller was an FBO with a good reputation. I shopped for new crankshafts in Trade-A-Plane, but they all required I turn in a core (which I didn't have). The price without a core was crazy. I'm a little curious what would happen to a core. Does it get turned into a "new" crankshaft with dubious history somehow?

My original plan was to overhaul the engine - new cylinders, new lightweight starter, alternator conversion... the works.

I got as far as getting the crankcase overhauled by Divco (with the Heli-coil'ed studs) and the cam/lifters/rockers/rods given a clean bill of health. That's when the crankshaft came back as N/S because of a crack.

And then my wife and I found a house we liked, and bought it.

It's now coming up on two years since I last flew the plane (ever wonder where ramp queens come from?). Coming up with the $13k-$15k to overhaul the engine is not going to happen anytime soon.

So now my thinking is to just get back in the air. Replace the crank, put on four overhauled cylinders and reuse my accessories as is.

So, I'm at a crossroads - a new-limits overhaul certainly has peace-of-mind and curb appeal, but frankly the cost exceeds the value of the airframe.

A used crank and overhauled cylinders is less expensive, but obviously won't last as long. I'm guessing such a rebuild would be $4k. However, figuring my plane before in running condition was worth $15k, I don't believe it's value would be all that affected by the lesser rebuild.

If I can't find a used crank and have to put a new one in, then I'm adding up to $1.5k to the rebuild price. At that point it might make more sense to buy a used, running engine for $8k and hang it on the nose. And then sell off the reworked crankcase, cam, lifters, rockers and rods from my old engine. (but frankly, I hate selling stuff - running the ads, taking calls, haggling, etc.)

In the end, wife and me and baby makes three but I'll have a two-place plane. Maybe I just sell the airframe as is (what's an engine-less 150 worth? $4k?), and put that towards a Cardinal. But I'd hate to add another 150 to parted-out pile. And once a plane is gone, it's easier to justify not replacing it....

Lots of choices, no clear winners.