Engine cases with Borescope plugs, PLEASE!

Kiddo's Driver

Kiddo's Driver

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Jim
I know this is asking a lot, but can we get manufactured in borescope holes with plugs from the factory, PLEASE!
You should be able to borescope almost every inch of an engine's interior. It really isn't that much of an ask.

Even Grammarly knows this should be standard practice!
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Let'sgoflying! said:
They can’t make cases that don’t crack now, without more loss of material, so I would expect it.
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Yup, as appealing as access holes may sound, I would not want additional stress risers in my case halves, even if they were in a thick boss.
 
It's not a bad idea. I bet the stress at the top of the case above where the cam lives would be low enough to get away with it. I'm not brave enough to try it on my engine though without Lycoming blessing it.
 
Franklin engines had a removable top cover on the case.

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Of course, the cam was underneath the crankshaft and not all that visible, but better than what we have now.

The 65-HP Lycoming O-145 also had a top cover:

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But such large openings do weaken the case, which is why we don't see them anymore.
 
Kiddo's Driver said:
I know this is asking a lot, but can we get manufactured in borescope holes with plugs from the factory, PLEASE!
You should be able to borescope almost every inch of an engine's interior. It really isn't that much of an ask.

Even Grammarly knows this should be standard practice!
View attachment 148371
Click to expand...


Absolutely pathetic this hasn't happened. I mean they already redesigned stuff for roller lifters, can't have 1 or 2 extra plugs for borescope?
 
Would the oil drain plug give you at least some look at the lower half?
 
WDD said:
Would the oil drain plug give you at least some look at the lower half?
Click to expand...
In a larger Continental, maybe. Smaller Continentals have the tank under the aft end of the crankcase, and there is a bearing bulkhead across the case between the front and rear so that access to the front is difficult or impossible.

Lycomings have a lower wall to their case, above the sump, and it has only narrow gaps for oil to drain back to the sump. You won't easily get a borescope through those gaps. Moreover, get a single drop of oil on the borescope lens, and you can see nothing.

1766602945354.png

A bottom view of a Lyc four-cylinder case. Note that you have no access to the front half of the case, and there is again a bearing bulkhead between the front and rear. Like so:

1766603082786.png

You would also have to somehow weasel the borescope up and around the crankshaft and con rods to get at the cam and lifters, and good luck doing that without getting oil on the lens.

The sump on the sixes is longer but you still have no access to the front bay.

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Why borescope the innards when you can just buy a new $60k engine? Isnt that what GA is about? Seems like engine companies think so... Saw a used O-300 crank advertised for $15,000.

And for that reason, I'm out.
 
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