Sorry about the blank email. Sometimes I fail to change the format to text only....
---------------------------------------------------- Or When is an upgrade not really an upgrade? ? As most everyone knows, I'm always trying to improve my KR.? But much like building, every little change has a string of unintended consequences.? There comes a point where sometimes I think things would be much simpler if I had only left well enough alone.? But I'm getting old, and at the twilight of my career the governmenet pays me lots of money to do what I do, so I've spent more than my fair share on my KR finding out what works... and what doesn't. ? Three years ago, the tired old cylinders on my O-200 just gave up.? The compressions were way off and I had been nursing them along for many hundreds of hours, so I decided to install new cylinders, and while I was at it, installed the 8.5:1 pistons for an O-200-D.? I had heard those pistons weren't readily available, so I was quite surprised when Aircraft Specialties said they had them and could replace the pistons in my cylinder kits with the higher compression pistons.? Great! (I thought).? I got the new cylinder kits, did some minor port clean up in the cylinders, and went to put the engine back together.? That is when I discovered that Continental had changed to a tapered ring for the higher compression pistons.? No problen, I call Aircraft Specialties to order.? To their surprise, they couldn't get them.? And if they could, they were unaffordably expensive.? So I take my new pistons off to my friendly machinist and had him cut the top ring groove to fit the old style O-200 ring, and installed the pistons with the much less expensive rings.? That has turned out to work just great.? ? At the same time I did the top overhaul, I pulled my relatively low time magnetos off, sold them and bought a pair of P-mags.? After all, the P-mags only have one moving part, so what could possibly go wrong?? At 65 hrs, I had an edge connector on the PC card in one of the Pmags simply break.? I was a couple of hundred miles away from home on an overnight trip, so turned back and flew home with 2 cylinders not firing on one ignition system.? Emag was very good with their service and repaired the unit at no cost.?? ? The first trip to the KR gathering following the top overhaul and Pmag upgrade, my generator failed with what was clearly worn out brushes.? I guess they just wear out every 700 hrs or so.? Breaking down away from home is not only inconvenient, but a bit expensive.? What would have cost me $10 for a set of brushes at home ended up costing me $500 for an overhauled generator and two extra nights at the Holiday Inn in Mt Vernon.? The guys at SRT in Mt Vernon were kind enough to let me use their tools to change out the generator and didn't charge me for the shop time.? Man it would have been much less expensive if I had an alternator on this plane as they are usually good for the life of the engine.? So I promised myself I was going to upgrade to a new alternator before this generator needs brushes. ? I also had an older Delco pull cable starter.? With the higher compression engine, the old inefficient starter, and the light weight Prince Prop, when the engine would pass the compression stroke on a cylinder while turning on the starter, the prop would outrun the slow old starter causing the sprag clutch in the starter to release, then as the engine hit the compression stroke of the next cylinder, the clutch would grab again with a bang.? Yep, I creamed the sprag clutch in my starter... twice... at $350 a pop.? Ok, I promised myself to upgrade the starter as well next time I have money to burn and get serious about work on the KR. ? Now we are three years and 160 hrs down the road from installing the Pmags and high compression pistons.? My second starter clutch is failing.? On the return trip from the spring fly-in at Casa Grande, AZ, I apparently flew a good portion of the trip with one failed Pmag.? Turned out to be the same Pmag as what failed before.? This time the head of the Pmag was flopping around loose on it's mounting flange.? Emag explained to me there are 4 screws that hold the head onto the mounting flange.? Apparently they had failed to torque them properly 100 hrs earlier when they had repaired this unit.? So I was going to be down for 2 or 3 weeks while the Pmag made another round trip to Emag for repairs.? While I was dealing with that, I found someone that had just removed a low time Plane power alternator and B&C starter from his C-85 and was willing to part with them for a reasonable price.? Hot dog!? Now I can fix my starter clutch problem as well as replacing the generator with a much more reliable alternator.? That, of course required some wiring upgrades for the higher current output of the alternator, but I could finally retire the generator.? One concern was that the alternator can put out up to 50 amps, and my ammeter is only a 30 amp ammeter.? But my old lead acid battery won't accept a 30 amp charge, so the 30 amp ammeter will still work just fine.? Also, replacing the starter requires some major surgery to the engine as you have to cut off the starter gear pinion shaft inside the accessory case.? There just isn't any way to do it without getting a bucn of grit and metal into the engine requiring an extensive internal engine clean up.?? Once done, there is no going back to the old Delco Pull type starter.? ? So, I installed the new alternator and the super high torque, high efficiency B&C starter.? After 4 weeks, I had the engine surgery completed, the wiring upgrades completed, the Pmags back and installed, and the new alternator, regulator, and high torque super efficient starter installed.? Great news, that knocked 10# off the weight of the plane.? The bad news, it all came off the nose moving the CG a bit aft.? The new W&B shows that I should still be OK, but will have to be a bit more aware of loading in the baggage area.? I pulled the plane out, hit the new starter button, watched the engine spin like mad on the starter, but it wouldn't start.? The new starter spun the engine impressively fast, but the engine refused to fire.? Exasperated, I chocked the plane, set the throttle to low idle, walked around front and flipped the prop.? The engine lit right off.? Now that is truly strange.? ? The next day I got the KR out and ran into the same thing.? The engine would spin like mad, but refused to fire.? Again, a flip of the prop and it lit right off.? I rolled the plane back into the hangar and topped off the charge on the battery.? When I rolled it out, again, it would spin over and start.? I know the Pmags will start if there is 8v present.? Apparently the B&C starter is so efficient, it is pulling the system voltage down low enough that the Pmags won't fire.? After sitting for a couple of weeks, once again, the engine would spin over quite readily, but refused to start.? Great.? Now I need to upgrade the battery.? I have been using a lead acid motorcycle battery rated at 175 CCA (Cold Cranking Amps) for the last 19 years.? But now that I have "upgraded" the starter, I need more amperage.? So, the next adventure in spending is finding a suitable battery that isn't any larger (as I don't more room), but has more amperage available for starting.? About the only choice was to go with a LiFePo battery.? EarthX seems to have the best reputation and in their aircraft batteries have redundant battery management systems with a lead that can be connected to an EFIS or in cockpit LED to indicate if one of the battery management systems is failing.? For a mere $379, plus $40 for a battery box, I got a battery that is less than 1/2 the size of my old motorcycle battery, weighs less than 4# vs the 14# of the old battery, and puts out nearly twice the cold cranking amps.? (320 vs 175 CCA).? The engine spins at 350 rpm just on the starter and starts quite readily now.? The good news is that I have further reduced the weight of the plane by another 10#.? The bad news is that the further weight reduction was also in front of the CG, nudging the aircraft CG a bit further aft.? Still well within the CG envelope, but I do have to be careful about loading the baggage compartment. ? ? But, with a battery that will deliver amperage as fast as the EarthX battery, it will also charge at a high rate.? When I first start, I can easily bury the needle on my ammeter.? For now, I need to idle for about 30 seconds until the voltage regulator reduces the charge rate on the battery, otherwise I'll be exceeding the capabilities of my gauge and will likely release the smoke from the gauge.? The next domino to fall will be a new ammeter. ? I'm not looking for advice.? Just thought I'd toss out what I've learned during this adventure in spending for others to contemplate when thinking about upgrades. ? -Jeff Scott Los Alamos, NM ? ? ? ? ?
