Well that didn't go as planned...opening pandora's box.

So I pulled everything down to ready to remove cylinders, then had one of the engine shop guys come help me pull the cylinders for my piston upgrade.

#1 and #2 no problem, pulled #3 and there is a lifter that's chewed up and it would appear that I have an issue with a cam lobe.

This "inexpensive" horsepower upgrade just changed gears.

On a brighter note, it sure will be easier replacing the two studs on the impulse coupled side of my case for my pmag...with the engine off the airplane.

I guess we all get little surprises like this somewhere in our aircraft ownership tenure...

Well, Poop. That's what I said when he showed me. Poop.

Look at it this way, you could have found this out the hard way while flying or being grounded somewhere away from home.

That's what I told my wife...

I'm trying to find some positive in it, and honestly, even finding it now, in MY hangar instead of anywhere else, is a pretty big blessing. Not being airborne when making the discovery is great, but not having my airplane stranded somewhere is good too.

Never fun to find in any case.

RVDan said:

Never fun to find in any case.

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I feel compelled to point out the pun...just in case readers didn't notice.

DanH said:

I feel compelled to point out the pun...just in case readers didn't notice.

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Thanks for connecting those. It's a good way to lifter spirits after finding something like this. Hopefully nobody will bore us with more engine puns though. People might get cranky or go off their rocker.

Snowflake said:

Thanks for connecting those. It's a good way to lifter spirits after finding something like this. Hopefully nobody will bore us with more engine puns though. People might get cranky or go off their rocker.

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Simply galling Rob. We have little tolerance for this kind of talk.

Scott - very sorry to hear about the extra engine work. Not a nice surprise under any circumstance.

Much better to find it now though, than to wonder why your engine was making metal during the break-in with the new pistons...

Nicely said Snowflake and JonJay

I feel your pain

After a 4 hour flight back to Wisconsin from Colorado in September, I was chasing a few oil leaks and discovered a crack in the case (o-320) near the propeller. This has turned into an engine upgrade to a new O-360, new engine mount, new gear, new cowl, new prop, and while I?m at it ? completely new panel and wiring. This has become a very expensive oil leak?? but a good excuse for a major upgrade. Unfortunately, my understanding wife will not get the new car to replace her 200,000 mile Honda Fit. But she did get to pick out the new engine color!!

Thanks guys

I appreciate the humor. And, yes, it will be nice to know a reasonable baseline for engine break-in and oil sampling moving forward.

My wallet is gonna hurt though. My dad, who just put a factory reman Pponk in his 182 was incredibly unsympathetic..."Welcome to aircraft ownership, son."

Ha.

O-320 question

How many hours on your engine?
Total Time?
Time since top overhaul?
Type oil used?
Additives?
Thanks.!!

Times...

About 1950 total time, about 550 SMOH. I bought it two years and about 120hrs ago.

Unfortunately, the airplane came from the Chicago area, and the other 430hrs were put on by the builder and 2nd owner over a span of about 20 years. My belief is that a small amount of corrosion turned into a great abrasive when I started flying it regularly.

I used aero shell 15w50, previous owner used Phillips XC 20w50. No additives that I?m aware of. Oddly, at least one (I think two, but I cants find second one) oil sample came back with no alarm bells, but again, I had no baseline for comparison.

Compressions were consistent (aviation style leak down compressions) from before purchase through my two condition inspections... low 70s/80.

Knowing what I know now, (which still isn?t much) I believe that a cranking compression test similar to what we do in the automotive world would have shown a discrepancy on the affected cylinder.

I also now wonder, since I had no basis of comparison, how much my issues of low static rpm with my previous prop and lack of ability to perform at my home field elevation of 4600? are related to this worn cam lobe.

Going to the higher compression pistons AND a good cam should be a nice treat now...and it will live with CamGuard in it moving forward.

The good news . .

punkin said:

Knowing what I know now, (which still isn’t much) I believe that a cranking compression test similar to what we do in the automotive world would have shown a discrepancy on the affected cylinder.

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This test is about leaks, neither a spinning test, or static leak down would identify a spalling lifter or worn cam in the initial phase of wear. Nothing you could have done short of pulling a jug and internal inspection, or just assuming it was going bad and discounting the purchase price accordingly.

But the good news: The best way of discovering a serious engine problem is on the ground.

Better to be pistoff than piston.

Sometimes the crankshaft won't crank, the spark plugs won't spark, and the pistons, well, they don't work too good either.

BillL said:

Nothing you could have done short of pulling a jug and internal inspection, or just assuming it was going bad and discounting the purchase price accordingly.

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Depending on the amount of wear, a check of lifter movement would indicate a worn lobe but, in this case, maybe not during the pre-buy.

Scott,
I feel your pain. I let someone fly my plane, and he had a prop strike. During the IRAN inspection, I had 9k in uninsured repairs discovered, to include some cam shaft corrosion. The upside is, I only paid for parts, so that was my bright side.