If you would, share some details of your experience before, during, and after here on this thread or in PM. Thanks in advance.
-We had time to plan. We decided about a year out to go with the Pponk. Our previous engine was approach its 1500 hr TBO and we were starting to see some pitting on the cam when we replaced a couple jugs with replacement OH'd units due to cracks around the spark plugs. It had not been OH'd in 20 years. We went ~200 hrs past TBO (to get our $ worth from the OH'd cylinders before pulling the plug.
-Our prop was near dimensional wear limits anyway and would require replacement soon enough regardless, so switching to the STC-compatible prop wasn't really that much extra in the big picture. Did need to get a new spinner and backplate, but we got so much for the only ones on e-Bay there was little $ pain there (182 spinner backplates are apparently made of a precious metal :wink2
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- We wanted the ECI Titans because of the ported intakes increase the nominal hp by a good margin. We are fortunate in that the batch we got never got tagged by an AD. There is a proposed AD floating out there for them now, but in an unusual turn, the FAA got b!tch-slapped by NTSB for having incredibly poor reasoning for it, and I don't think it will see the light of day again. Everyone has their cylinder company horror stories. They are all equally good/bad, depending on whose watch you using.
When we were getting close to ready for the swap we called Steve Knopp and described what we wanted. Turned out he had a nearly-finished unit exactly as we wanted it, just put on the new accessories (TCM mags, Plane Power alternator, Tempest vac pump, Bendix starter). The engine he had was a 1,300 hr TT O-470-U core. He'd be getting our 5,000 -U core in exchange. Freakin' awesome for us. No $ penalty for that age differential.
We timed all the logistic to minimize downtime (our total downtime was one month). Did all the work with a local A&P/IA at Corona (he's in Texas now). Shipped the carb to Pponk to work their magic with an OH and the new larger jets. Sent our tach and prop governor out the same day to get worked up (new markings, new governor settings). Pulled the engine mount and shipped to Kosola in GA 2-day delivery. One of our partners gets great FedEx rates....
Oops...forgot to send Pponk the oil filter extension for the new engine...little delay there...
Took about a week for Pponk to finish the engine the new engine was crated and on it's way south to us.
Bolted everything back together (new Lord mounts, of course), engine just slipped right on the OH'd engine mount. Highly recommend doing the engine mount, ours required 5 new sections, and they did a reinforcing mod as well to handle the extra power.
Ground test the unit real quick, looked good. One of my partners had the test flight, I was on the ground with a radio (non-towered field). The engine was purring. Finally had my turn 30 minutes later, and that engine seriously felt as smooth as a turbine. Like, zero vibration. And that was just with a static prop balance. I still clearly remember how smooth it was. At 800 hours now, not quite the same, though it is still pretty smooth at cruise RPM.
We did have some leak issues with the 2-blade McCauley prop about a year later, but they did a good job covering the repair under warranty. I suspect the prop had been sitting on a shelf a bit too long and some seals had degraded a bit before we got it.
Most recently we did have some metal in our filter and oil analyses a few months back. Iron and aluminum mostly. Had a couple hot cylinders. Found #3 and #4 needed some minor valve work, and looked at the lower end where we could see. Lifters were pitting, and some atypical wear on the cam. Our A&P (different guy) was concerned about the cam, but after consults with Steve Knopp and the TCM service bulletins, we concluded replacing the lifters was all that was needed, that we caught the problem before the cam wear was a really problem. We completely flushed the oil system (even dropping the pan and flushing the prop governor and cooler).
Never conclusively proved where the metal came from, and we looked everywhere we could reasonably get to, including pulling the starter. We suspect this issue was caused by a bit too long of a down-period last year (minimal flying for 6 months), possibly combined with the fact that we found one of the mags to be 8+ degrees advanced, which likely caused the hot cylinders. That peeved us more that little bit, as it was a different IA who did our annual that caught that issue. Moral of that story is to switch which IA does your annual every few years (which has been our policy since the beginning). The mag timing shift was probably due to normal wear-in of the points on the mag unit that we had proactively OH'd at the prior-year's annual. Now I know to frequently check the timing on newly OH'd mags. 10 years into ownership, and I still learn a lot of new stuff every year.
Seems to be doing better, but the next oil change will tell the rest of the story.
That is the long story of our Pponk...
