the mummy lives

[SpecialT]

Re: the mummy lives

https://www.youtube.com/watch?v=_VfiPuheeGw

Go to minute 15:00

[Scott]

Re: the mummy lives

I disagree with leaning on the ground prior to take off. I think it just adds one more thing that can trip you up and there have been fatalities in the past due to takeoff attempts with the mixture contro still in the ground leaning condition.

Instead I advocate setting idle mixture lean to begin with. common practice is to set idle mixture so that there is a 50 rpm rise when the mixture control is moved to off. If you're within 1000' of sea level and it's a warm day, you end up with an unessesaryly rich idle, especially with carb heat on if equipped.

Hypothetically, if you're at sea level setting idle mixture to max rpm is good, because wherever you fly to is going to be the same or higher elevation which means the idle is only getting richer. If your field elevation is 3000' however you're likely to visit lower elevation airports so set you idle mixture at the lower elevation!

But set it near peak idle rpm. Better smoother idle, kinder to the engine, without introducing a risk (if you short cut your takeoff checklist)

[PA1195]

Re: the mummy lives

Well stated Scott. +50 rise is rich especially in climates subject to daily temp swings upward. If carb heat is applied that's plenty enriching prior to landing....the pop pop pop of rich overrun in the exhaust talks to the landing pilot. In aircraft with adjacent throttle-mixture (plus CS prop) the pre-takeoff leaning with the mixture out can be felt if the action at takeoff involves a practiced "all forward" eye-hand movement. But some planes with wide spaced controls (Cubs for example) can have problems at takeoff if the mixture isn't checked if leaned during taxi.

A half turn out of the carb idle mixture when temps fall below 0*F keeps it running, then back in when it warms up in the Spring.

Gary

[3Dreaming]

Re: the mummy lives

Yes! It's a shame Honda has avoided getting into aircraft piston engine manufacturing. Their engines certainly seem to be bullet proof. I was tinkering with British motorcycles when Honda arrived on the scene. All of a sudden there were smooth, powerful, clean and reliable engines, unheard of at that time. A similar shift never occurred in the aviation piston engine sector, the engines/technology is largely the same for 50+ years. Of course that does make them simple to understand and work on which is a big plus.

I note that the \continental tec 1 guide you posted does discuss LOP operations so an acknowledgement if not a recommendation.

Having owned and maintained Rotax 912 series engines, I think the shift has been made. The problem is mainstream aviation is not yet willing to change.

[Scott]

Re: the mummy lives

Yes, limited involvement but commendable effort offering double the HP per cubic inch, a step in the right direction.

The kind of shift that is possible however is that Honda typically achieves 3hp per cu in from stock engines that prove to be seemingly indestructible.

You're right though, the industry is resistant to change and that market research plus the small market and crazy liability record is no doubt behind the decision to stay away.

[PA1195]

Re: the mummy lives

I'd add quality engine monitoring to a fresh A-65 or other small Continental. I had a steam gauge 4-point EGT/CHT and manifold pressure gauge on my C-90 - PA-11. The variance between cylinders was noticeable and varied with throttle and rpm as expected. Carb heat added another layer of change. I guess it was due to air/fuel distribution and differences between cylinders - volumetric efficiency, valve timing, intake and exhaust flow, ignition components, and whatever. The MP gauge offered hints about intake efficiency (various air filters), cylinder seal (valves, rings, intake), carb heat box seal, and most importantly carb icing. I've only put a MP gauge on the Taylorcraft's C-85 Stroker so far.

Maybe they'd run better and last longer if we could monitor and adjust or optimize the performance?

Gary

[astjp2]

Re: the mummy lives

well I have to lean to take off, field elevation here is 4470 and density altitude can be 9000 on a hot summer day. If you have a stromberg on a 65, I used to go full lean and it didnt change anything, so I installed a Marvel dribbler and now I have a mixture that actually works on the O-200. considering I have no electrical system, I also have no extra gauges except a ball slip and skid indicator. Just fly it and use your tach to control your power level...not much else to do on a 65 with a stromberg....Tim

Keep
It
Simple
Stupid

Too many people spend more time looking at crap in the cockpit than looking outside~