The International Cessna^® 170 Association

I am considering buying a 52 170b with a 1100 hour SMOH 145hp engine.
It was remanufactured in 1968. (35 years ago) That figures only 31 hours per year. The compression seems good with 75,74,72,75,72,and 74 compressions a year ago. New slick mags were installed last year. It drips a couple of tablespoons of oil a week and uses about 1/2 quart of oil per 6 hours with no blow-by coming out of the tube. I have not seen the logs yet to see how the plane was flown or if it sat idle for many years. I hope to see and fly the plane soon before I have an annual done for a pre- buy inspection. The plane is in great shape and great interior and instruments. I just question the engine with so many years on it. Any advice on the engine would be helpful. GARY

""I am considering buying a 52 170b with a 1100 hour SMOH 145hp engine. ""

I would not worry about the years, just the maintinance.

Clearly it has sat a lot over the years, but like Tom says, all you can do is look at the maintenance records and determine it's present condition. The compressions themselves are a good indicator the upper end can make rated horsepower if everything else works properly. Long periods of idle-ness can lead to internal rust/corrosion. That's the major effect of inactivity. You can use a boroscope to see the upper ends of the cylinders and perhaps observe the rust spots but guess what the verdict is if rust is indeed found? (My Baron had plenty of sitting around in Florida when I bought it, the upper cyl's were rusted above the piston-ring travel areas, ...but it flew fine, didn't burn oil and an inspection by the TCM field rep led him to recommend that I just fly it and enjoy it! I had fully expected him to at least try to sell me cylinders.)
Have an annual inspection performed as a pre-purchase inspection, and if it passes without a lot of monetary necessities,...set the price and buy it.

I'm flying behind an engine overhauled in 1968....

One more tip when buying,....it's generally opined that chromed cylinders withstand the rigors of idle-ness better than steel cylinders. Chrome won't as easily rust.

I would like to be an optomist about this but... I've owned over thirty airplanes and can tell you that I got burned twice (shame on me) with engines that had been sitting for periods of time without use and the camshafts were rusted. This can take up to 100 hours or more to manifest itself as a problem as the camlobes grind themselves away. Then it's an overhaul. So just be prepared for that possibility.

Dave, just curious - what kind of engines were they? Russ Farris

Russ.... they were airplane engines!

Russ

O-470 A (or J ) in an early 180 and a Franklin 220hp in a Stinson 108 but don't blame these particular types of engines it is a problem much more general to most all types of engines. In both cases the airplanes were bought cheap enough for me to end up not loosing too much. In the case of the Stinson five years ago I ended up loosing all my labor to overhaul it but did recover all the money invested.

The moral is if you're buying a plane with the old calendar time and it has sat for longish lengths of time be aware and adjust your price to cover at least part of the risk. The bad part is it can take up to 150 hors to evidence itself.