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Unread 09-28-16, 03:15 PM
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n86121 n86121 is offline
bigcheese
 
Join Date: Nov 2003
Location: Potomac Airfield~!
Posts: 318
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Smile Over the years I've done two engines

Good afternoon!

My original engines were turbo TSIO 360A factory, which meant light case etc.

When the front one developed a crack, over the Chesapeake bay at dusk, I replaced with factory new. When a mechanic failed to properly torque the rear, and the main bearings shifted, I replaced that one with an overhaul by well trusted local engine shop.

Both went to heavy cases and larger crankshaft, thus become tsio 360AB.

My suffering and research were extensive.

An old timer at Continental (Dick Conrad?) told me in the 90's that with these upgrades made it the same engine that gets an 1,800 overhaul time in a Seneca, but the airframe mfrs set the tbo, not the engine mfr. Cessna never had reason to increase the tbo to recognize this on an aircraft out of production.

Basically what I found out was that the bottom ends go and go and go. One friend who flew 135 cargo with Senecas said the bottom of their engines were up around 4-5,000 hours! Obviously heavy regular use, but relevant nonetheless.

For me, whenever a cylinder would get weak, I would replace with NEW, because I wanted zero cycles of metal heat fatigue. An overhauled cylinder may physically meet spec, but may also have 10,000 hours on it.

When it came time to OH rear engine, 4 out of 6 of my cylinders were low time, and simply overhauled, and two bought new. BIG savings. Like a good barkeep, I had arranged with local shop to set aside a heavy case for me when the time came.

I always run oil analysis, bore scope, etc. If the compression is reasonable, and the oil analysis is happy, then there is nothing critical wearing out.

It has been a few years, (ye gods), but I think a decent overhaul by reputable engine shop would be around $25-30k each?

I have also replaced both turbos with the newer style, and I recall about $3500 each new. Can be replaced at OH if needed.

So far so good!
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David Wartofsky
Potomac Airfield
10300 Glen Way
Fort Washington, MD 20744
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