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OS 110 pumped cracked case

Old 08-08-2014, 09:43 AM
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YellowBlueBird
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Default OS 110 pumped cracked case

This engine was purchased just over 4 years ago but was not flown until last February. The airplane has never been crashed and the engine has not dents or dings of any kind that would indicate abuse. The case cracked 4 minutes into the flight and was running well up until that time.

Here is the question, would it be reasonable for me to move the good parts to a new case? Since the case must have a sleeve installed that looks like the most likely place to have difficulty. Is it reasonable to move the sleeve from the old case to the new one?

Thank you

Jerry
Old 08-11-2014, 06:52 AM
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Bax
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It's most certainly reasonable to move good parts from one case to another when making such a replacement. We do that all the time when performing repairs. If you have a good piston/ring/liner set, why repurchase when you have to replace the crankcase? Same with bearings. If the bearings are good, you don't need to replace them. A little heat to the case will allow them to slide right out, and you just heat the new case to slide them home there. Just check things out care fully. If only the old case is what has a difficulty, then you don't need to replace anything else.
Old 08-11-2014, 09:29 AM
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YellowBlueBird
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Thanks Bax,
I will start the disassemble tonight. Any tips on getting the sleeve out?

Jerry
Old 08-13-2014, 06:43 AM
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Bax
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Usually, the sleeve just slides right out with a little finger pressure. If it's a bit stuck, you can push it out with a piece of wooden dowel. A really tight one will need the case heated a bit. Usually, though, the finger pressure is enough.
Old 08-13-2014, 08:13 AM
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YellowBlueBird
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The engine is apart except for the rear camshaft bearing. Everything looks good. No sign of rust.
What keeps the piston pin from rubbing against the sleeve on the back side? There is a keeper that prevents the pin from moving forward and contacting the front side of the sleeve.
Is there a way to get the rear camshaft bearing out? It seems to be rather tight.

Thanks for your reply and time

Jery
Old 08-14-2014, 07:06 AM
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Bax
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One end of the piston pin has a teflon button. This rubs against the cylinder liner and keeps the steel pin properly located inside the pistion.

You need to heat the case to remove the inner camshaft bearing. Then just rap the open end of the cam housing on a piece of wood to get it out.
Old 08-14-2014, 10:37 AM
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YellowBlueBird
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THANK YOU THANK YOU THANK YOU
I was about to put it together backwards. It makes sense now. when the part came out and hit the bench I thought the steel end came out first.

I marked the position of the cam shaft on the old case when the piston is at top dead center. There were no timing marks that I could find. Hopefully this will work.

Jerry
Old 08-15-2014, 06:40 AM
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Bax
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There should be a dot on the side of the cam gear. That dot will be in line with the pushrods. Please see the attached pic:


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