garytex

In 200 hrs the rings will be well broken in. This and other break in polishing could account for some of your observations. I'm faster than I was this summer too. "Ah que culero", is how we say it in South Texas. Gary

Whew! thats a list. The other side if the coin is that when it's all done, you can probably coast for a while. Good luck, Gary

Thanks, Guys. I'll report back after we get to the bottom of it.

I have seen high silicone readings get folks to find and cure airbox leaks letting sand in and maybe dodge an early top. And high aluminum leading folks to wrist pin end cap galling. And high copper to rocker shaft bushing wear. I think that it is good info to have every 100-200 hrs. Gary

Of late I notice that my fuel flow bounces around, fluctuating up to a couple GPH in a few seconds. It is progressively getting worse over the last couple of months, is steady at the beginning of a flight, seems to get worse after about 15-30 minutes of flight. Turning on/off the boost pump, radios, makes no difference. It also is affecting the fuel totalizer, which used to be spot on, which recently told me 31 gal burned, and I pumped 24. It's going to my mechanic next week. Anybody played this game before? We will round up the usual suspects, but there are a bunch of them. It would be nice to have some other folks experience with this. THANKS, Gary

A '60 model will have a O-470, and probably have a strut braced wing.

Actually I think the issue is germane for the A1A engines. As uncounterweighted engines they evidently are more stressful to props, and generate the highest incidence of prop tip breakage (3-4" off the tip) of any engine per The Avaition Consumer. Shutting down quick is important, and should be occasionally mentally practiced.

They vary some depending on prop, mine is 2100-2300 RPM for an A1A (no counterweights) in a 67 F. Mine also shakes harder below 2550, so thats where I usually run it. Some, I think the Cs also have "not under a certain MP". It is a torsional vibration issue, although the usual thing that breaks is prop tips. The A1A has a high or the highest rate of loosing 3-4" of prop tip of any ac engine I read somewhere. I can't remember the source, but it wasn't a bad source. I think your J has a counterweighted crank. Do you have a red arc?

I am assuming that's why 20-20 is all that is in the POH

Additionally, according to a little half assed research I did, if the pulses hit a natural harmonic frequency, evidently it sure enough could break the crank.

DaV8or: It was quiet, and turned in around18 -19 mpg. And yes I think it squeezes detonation margins, as my first concern. Crank torsion is a second. Both together are enough for me to feel that the quiet side of it is inadequate benefit to use it as a regular practice. Too bad, as it was really quiet.

Fantom is right on track. You have a bad plug, or something that is equally pressing. Find it and fix it before it bites you. Check resistance across the offender, it may be very high.

I thought of a valid reason not to run 20 - 25. Crankshaft torsion. The crank winds up and unwinds with power pulses from the piston power downstroke. Crankshaft dampners help ameliorate this I think. We have none on the A1A motor. And running like that may do nasty things to the crank. I want to talk to an engine designer about that. Is it "lugging" the engine?

The dew in South Texas, even 20 miles inland is really rust and corrosion promoting. Anything left exposed goes downhill quickly. Washing the salt air off is important, so is wax.

Auto belt work fine, lasta long time

Dav8or "Every mechanic I've asked has glazed over in that "Oh God, please don't make me do that" look then tell me everything is fine,It's not a big deal." The biggest problem is getting to the intake in front of the RSA. Schedule the work for a time that the lower cowl will be off for other work. Then just hook up a shop vac on the pressure side and spray the usual suspects with soapy water. Aditionally the super lazyman's quick and dirty check is to remove the cheek plates and at idle, spray the runner connections with carb cleaner and look for an increase in idle rpm. Don't back your cheeks into the prop. As an aside, the best common sense AC mechanics I have run into have been in small shops, older guys with lots of experience who still enjoy the "figguring it all out" part of the process. I must have been very lucky, as I have run into a series of good, smart fair ones. And every time i have paid too much for something, there have been four or more guys in the shop.

Dave, I wonder if this might have been part of your (and My) eratic fuel flow indications? Does it run smoother now?

There was a consortium that did the buy every ticket bit in the '80s, I can't remember exactly how it turned out. but they did have a problem getting all the tickets bought. I think that they were plying a game that had some partial rewards, and came close to breaking even.

DaV8or. I am recently having eratic fuel flow indications that are getting worse with time. JPI suggests that it might be spark plug wire leakage. They say download the trace and look for spikes. Also I understand that if there is a 90 elbow anywhere close it will bamboozle the ensor on a pump driven system (but not a gravity flow). When I ask about possible induction leaks, they say there is no blue staining, so therfore I don't have a leak. Case closed. That is dangerous bullshit. Induction leaks eat cylinders, especially if you are running ROP. Bitter experience speaking here. I will PM you my phone number. Call me this weekend. There are several ways to test for induction leaks. I've seen a couple of leks, and there was no blue staining. Gary

Jose, great idea. Does the hose make the turning radius bigger? Or does one just override it somewhat with the brakes. Does the truss ordinarily bottom out against the other tube when we turn? Thanks, Gary

love the ketchup packet idea

Jetdriven, your "IF"s are the most compact and cogent list of precautions Ive seen. They cover the bases. Well done. Gary

Scott from Iowa: Please note that speed was MPH, not Knots. It was a calculated true airspeed using a Garmin 396 E6B function based on IAS, temp, barometer and altitude. The plane has a boat full of SWTA mods and I think maybe is particularly straight. It runs 165-175 mph true 30 to 50df lop at 8.5-9 gallons all the time. Oddly enough, throwing more fuel at it makes almost no difference. The engine noise changes a little bit, and I pick up maybe 2 to 4 or 5 mph, thats it. It just smooth won't go much faster. Carusoam: All those things you mentioned preyed on my mind. The progressive nature of the fuel burn event (the faster it burns, the more pressure it generates, the more pressure it generates the faster it burns) combined with the slow movement of the piston not "running away" from the burn event and generating space as rapidly to regress the burn worried me. Kind of akin to the reloader that doesn't change a powder speed or charge weight jumping from lighter to heavier bullets. Bad things happen. We can manipulate the burn speed some with low MP, and very rich and very lean mixtures, but I wonder if it is enough to be safe from detonation that far over square. I watched like a hawk for any CHT up, EGT down excursions that would indicate detonation, saw none at all. Danb: We have the same plane, and my red arc is different than the one you cite. Mine is 2100 to 2300, and I am unfamiliar with any associate MP limitations. Perhaps I am missing something. Can you enlighten me? I had a 20 min descent from altitude today and came down at 2000 rpm, and MP built slowly from 20" to 25". All seemed good. It was really quiet. ANYONE ACTUALLY FLOWN LIKE THIS? Thanks, Gary

I was stuck under a 3000 ft layer yesterday, and bored, and set up like this. Peak EGT was about 100 df lower than at a higher RPM, noise was waaaay down, CHT's all just below 300, no particular engine vibration, I lost about 8 MPH and 1GPH from 2500 rpm, seemed like a nice way to ease along. I didn't keep it that way too long, I just couldn't stand the fear that I might be doing something insidiously damaging to the engine. Probably not, but I thought I would poll the membership, and see if anyone else has any experience with this. Book shows 19" MP with 2000 RPM Thanks, Gary

3 is a hot cylinder anyway, and it is the factory cht location. The old gauge is required to still be operable after installation of a JPI, and theoretically (legally) in the bayonet location in #3. Frequently that means that when an additional engine analyser is installed, #3 gets some odd, not in the usual bayonet location thermocouple. One common thing mechanics do is to put in a spark plug gasket thermocouple. If placed under the bottom #3 plug temps will be in the range you indicate, and in summer, much higher. JPI says "don't do that, it'll scare you" They're right. Check your thermocouple location and type on the offending cyl. Been there done that. Luck, Gary