garytex

All the suppliers and overhaulers I learned about years ago for Marvel Shebler carbs are gone. Sorry, I was going to try to point you in the right dirrection. But the lesson, which was that there are good and bad parts manufacturers and overhaulers seems to be the same. 500 hrs on a carb is insane. They last for years. Find someone who knows good from bad from indifferent, and get the good parts and overhauls. I had to suffer through the sqame kind of bullshirt you are because I was using a bad overhauller who also used crappy parts. Find someone who knows the difference, and follow their advise.

The conventional wisdom is that the higher temps in the induction air resulting from the heat of compression from the turbocharger will vaporize fuel better resulting in more even fuel distribution. That is the theoretical, practical experience backs it up. The standard caveats apply. Every Venturi/jet combination is slightly different, and throws smaller or larger droplets of fuel. The multi hole jets that used to be (and may still be) available from Precision alternately were much better (my experience) or worse (others experience) in this regard. Additionally I personally didn't like the 1 piece venturies from Consolidated Fuels. They looked crudely formed (in my sample of 3) and made my engine run crappy, unburnt fuel in the exhaust manifold, 1600 Df egts, low static RPM. I guess that the drift is, that the potential is there for it to be better, but carb atomization can also make a difference. Good Luck

If I needed one now, I would go with the owner produced part route and beg GEE BEE to let me send him my old POS as a "Pattern" if he is far enough along to produce a part. Here again the relationship between owner and the installing A & P is critical. First the A & P must have enough experience, common sense, and confidence to make that judgement about the part. Will it work fine, last a long time? It is also important that the A & P thinks that you can understand what is happening enough to make a similarly valid value judgement, stand behind your decision, and not sue him at the drop of a hat. I have been blessed to have been exposed to several really wonderful (and a few just average) mechanics. And I have a really warm spot in my heart for all those good A & Ps. And also for someone like GEE BEE who will build a better mousetrap for us. Here! Here!

Don't forget the "Do nothing" alternative. With the advise of a good smart A & P, maybe you could do nothing. If the crack's only ouchie is an oil drip, let it drip, as it has been doing for a while now. We all unknowingly fly around with cracked heads and cases constantly. Think about the laundry list of things like that found on teardown at your last overhaul. But the engine was plugging along, making power, etc. Gary

Oops, not that exact price, what I ment was at that pricing strategy, which I am assuming is about half of the extrordinarily offensive Mooney price.

You should get run over at that price for the proverbial better mousetrap. I just bought one of the factory stinkers for $310, during a cleanup of pre-buy squawks, and not knowing any better. It looked like the flimsy short lived POS it evidently is. If I had known better I would have taped mine up and waited for your product. Well never fear, it'll probably wear out by next annual, 300 bucks down the rathole, then I can buy one of yours. What can we do to encourage and support your efforts? To the membership: Everyone should consider what they are comfortable doing to support and encourage GEE-BEE in his efforts, then do it. His work, supplying better cheaper parts for our airplanes, which frankly are getting somewhat long of tooth, is a refreshing change from business as usual. We need GEE-BEE and guys like him to be successful, or we won't be. Sincerely Gary

120 Grumman Cheetah ( its a fast one, and for sale) 10 M20 F bought in Dec. I fly a weekly 340 nm commute. 50 hrs is a lot for a strictly recreational flyer

Attached Images THAT'S THE TICKET!!! WHAT IS YOUR PRICING STRATEGY GOING TO BE?

Quote: Piloto Well, a second application for it for the same price. No need to worry anymore about bottles. Thanks for the tip. José

Swingin, based on the amount of wear I saw on my intake tube flanges, it might pay to take a look at your next chance. One of mine was worn almost completely off on one side of the flange from working in its socket. No fix, replace. In fiddling with one of the leakers today noticed that it can leak without telltale looseness in runner. So a secure (non shaking by way of hand, but harmonically vibrating) intake tube can still be a leaker. So if you are a hangar tinkerer how do you check? I'm not all that excited about blowing my shop vac dirt backwards thru the intake manifold, which is the old school way to pressurize the intake with high volume low pressure air for the soapy water bubble test. I didn't think to ask Jerry what he used. Maybe compressor air. I wonder if there might be enough valve overlap to let the relatively lower volume compressor air escape out the exhaust on these engines? If so, one could probably rotate the prop a little and get everything closed. Mags and mixture off please. The 6 cyl continentals sure sound like it at idle. Booo bowlbow bo-bo bo-bo Reminds me of a long duration auto cam from the 70's. The amazing thing is that current technology coughs up smaller engines that make more power, and purr like kittens at idle. The down side is that a farm boy can't work on them any more. Thats what I like about aircraft engines, they are still simple and based on the technology I learned as a boy and can understand. But the other side of the coin is that we are giving up the efficiencies (and the maybe the inscrutable failure modes) of the new technology.

Once again, thanks for all the good additional info. Gary

avaitoreb: The demand regulator sounds useful, puff, puf, puff. ghovey: It would usually be just me, but occasionally my wife and son also. I will have to ponder. Maybe best to let the 13 yr old son fall asleep in the back below 12,000, rather than hyping him up. Thank you both for your input, this is exactly the type of info I had hoped to hear. Gary

ghovey: 22 cubic feet about right? 17000 ft IFR Rockies O2 failure? Did you know when it failed, or notice you were passing out? None of that for me, please.

Mine showed up as a leaner cylinder. Another odd thing, Jerry says the flange itself is worn almost off on one side on my #2 tube.

Another F (IO - 360 A1A) came in to Hill Country Avaition within the last couple of days for annual. Rough engine throttled back was also a squawk. Except for one jug that had been recently worked on, all intake tubes were leaking.

"I find the Company's curiosity regarding these animals now completely satisfied" Lewis and Clark Journal after three in a row grizzly bear hunts resulted in the bear persistantly chasing the hunting parties for quite some time.

Off topic, sorry. Are there any Prairie Dogs around Bruning? Or is that more towards the western part of the state? I am trying to put together a flying-shooting thing for my son anf myself. Plague seems to have zapped the Texas panhandle population. Thanks, Gary

Looks like a baffle leprechaun to me.

Johngreen, you Jack La Lane you, 56 beats a minute! Which marathons did you say you ran? Swingin: Yes I'v noticed that feeling of tiredness, and even sometimes a lingering headache. It sounds like the size to buy is one that would cover a couple of round trips, to obviate the refill hassle. In my younger days I kept a full air cascade system for filling scuba bottles (south texas, in the 1970's, long way to dive shops) so the self refill seems natural. Skypilot, I like the dial up the altitude feature regulator mentioned, and wondered about that. If you need O2, how could you multiply flow times altitude reliably? GeorgePerry, We haven't seen your brother Rick for around here lately. I spose he'll be back. Even those of us who like him are a little embarrassed by the "Somewhere in Texas, a village is missing its idiot" impression he has been making. All: Seriously, thanks for all the advise. I have a Pulse oximeter, but didn't do much with it, as I had no cure for the reading. I'll start paying attention. Gary

I notice that I get the stupids at relatively lower altitudes these days, noticeable at 12000 ft, and my new magic carpet gets me up there so much faster that I'm considering one of the portable O2 systems. Which system seems to be the way to go? I've seen the ads; canulas, mustashes, masks, mizers, there seem to be plenty of options, and reasonably priced. Does O2 seem to help with the stupids? I'm thinking most of my use will be around 12,000, with occasional forays maybe to 15 to catch a really special tailwind. In other words, not very frequent use. Thanks, Gary

The last time i flew it there was no other indication besides the higher egt, and I was at peak and leaner. Must have had some 1 plug firing effect going on. I also wasn't paying the best of attention, either, with a recalcitrant GPS, encoder intermittant, really noisy radios from a condenser failing in the right mag and the 11,500 ft stupids going on. Well we'll see how she flys after all the fixing.

Wow!

Also check connections on master switch, especially if they are spade connections. They evidently can get a little corrosion and the field will be intermittant.

This M20F is new to me, I have 10.5 hrs in it, and a new complex high performance signoff. It and had an occasional rough #2 left mag. My mechanic pulled the plugs, all of which have huge gaps, and obviously haven't been gapped since the overhaul. Oops!, #2 bottom is oily. Logs show #2 has been a problematic cylinder since overhaul 800 hrs ago. Within 200 hrs of overhaul, 1 or two at a time, the overhauled cylinders from J & J in Pleasanton, TX have been replaced with ECI IFR (their brand name for a pressure annealing process) head rebuilds on new through hardened steel barrels. #2 has been replaced or overhauled (can't tell wether it has been the same jug or exchange from the logs) twice. Borescope shows #2 has a slight shiny spot on the cyl. wall, and has shown highest compression of all the cylinders for several years before and after replacement. My mechanic, Jerry Stanton at Hill Country Aviation thinks it has been pumping oil (which sealed the compression ring and yielded the higher compressions) for a long time. Off comes the jug, lots of carbon on the piston sides and rings, and "something doesn't look right" I'm thinking that when we measure it we'll find no choke, and that's why it has been pumping oil since the word go. Jerry is a good, smart mechanic, and a great diagnostician in his own right, but he also knows when to seek advise. He calls Mark at Custom Airmotive in Tulsa, who is an overhauler both Jerry and I think a lot of. He says "#2 is a stinker on that engine and shows the most problems of any of the jugs." (oddly enough, as an aside, Aviation Consumer did a statistical analysis of cylinder Service Difficulty Reports years ago, and found that #2 was a statisticaly significant problem child on both Lycoming and Continental engines. This is wierd, as #2 is on the front of a Lycoming and usually runs cold, and on the back of a Continental, and runs hot). "Look at the seal surfaces on the intake runner. It is the longest in the system, and prone to harmonic vibration. It then leaks and then the cylinder leans out and runs hot. I also frequently see case cracks around the base of #2 " We look, sure enough the intake sealing surface gasket shows uneven contact around the circumference, narrowing to about 1/32nd on one side. We had also noticed some oil on the case there too, and I'm thinking "oh no, please, no crack" (which is the opposite of what Washington D. C. mayors think, I guess). I had noticed #2 running occasionally hotter EGT, but chalked it up to only one plug firing and a slower flame front still burning in the exhaust manifold. The previous owner typically ran 50 ROP, and 75%, so a lean cylinder might have been really toasty. The cylinder is off to Mark for a good measuring, to see if it is serviceable. I'd say that it pays to replace those intake tube gaskets if a jug is off, and not reuse the same one over and over. Here is the take away. According to Mark, you can feel slop in the runner when it has vibrated and compressed the runner gasket loose if you shake it. (of course, more than 3 times is a sin according to Father Murphy). I have no "feel" to tell you about, as the jug was off before we heard about this, but maybe it is worth a little shake, next time the cowling is off. Gary

There are a couple of books out there that can be helpful. "Light Plane Maintenance" is one that I can remember. Truly ancient Aviation Consumer articles, from the 1980's have nice how to articles in them. There was another one the title was "Owning and Maintaining...then some aviation words to that effect. Search Amazon. The point is to learn enough that you are able to actually service your wheel bearings, spark plugs, oil and filter, etc without screwing it up, and to be able to converse with your mechanic from a reasonable enough base of knowledge to understand what he is talking about. All the systems on an airplane are blood simple, and easy to understand. Not like recent cars which are way to smart to be able to figure out. Once you start changing your own oil, and spending some time looking at your engine, you will feel more comfortable with your plane. You may not have the most knowlege at first, but nobody cares about your plane like you do. Go for it. Gary