And we thought we were in the dark ages...

[Lumps]

AVCANADA ? View topic - Efficient low altitude cruise (http://www.avcanada.ca/forums2/viewtopic.php?f=54&t=109376)

[Duck Pilot]

Quick way to destroy the engine and prop. Manufactures put a lot of work into designing aircraft, operate any piece of machinery outside its recommended designed limits for a prolonged period - it will eventually fail. Are these people test pilots?

[Capn Bloggs]

Lumps, Photofly is the only one advocating what he's doing. Everybody else on the forum (on page 1 at least) is either saying he's a loony or implying it. I don't see your point. :confused:

[tail wheel]

Why do people continually try to reinvent the wheel? :{

[Duck Pilot]

Training and regulations don't prevent stupidity......

[HPSOV L]

Doesn't that hark all the way back to Lindberg's technique for the P-38?

[Lumps]

Judging from the shaky knowledge of the others (or just running the I will defer to manufacturer line) Photofly appears to me to be on pretty firm ground. Poor sod is doing it alone too by the looks, and he's probably the only one on there that has flown DC-6s the way all big reciprocating engines were flown. Suck squeeze bang blow, why try to reinvent the wheel indeed!

[oggers]

Photofly appears to me to be on pretty firm ground. Poor sod is doing it alone too by the looks, and he's probably the only one on there that has flown DC-6s the way all big reciprocating engines were flown.

Not correct. BPfE said he flew DC-6s, made multiple posts and didn't think what photofly is advocating is wise.

"When I flew the DC 6 we always cruised lean of peak, in this case set by referencing a drop in the BMEP gauge. This was the approved procedure in the manual which was written in 1951."

[Spinner73]

Whatever the various opinions regarding engine operation - and there were a couple of differences there - these folk were almost invariably reasonable and polite, dontcha think, eh?
I know people laugh at Canadians for that, but it's a quality to be admired, for mine.

[Lumps]

Not correct. BPfE said he flew DC-6s, made multiple posts and didn't think what photofly is advocating is wise.

You're right I misattributed authorship, wasn't paying enough attention whilst reading.

He certainly questioned it, and their furiously polite exchange culminated in:

You are right there are countless combinations of all the factors that determine what power the engine produces. Specifically with respect to Manifold Pressure it seems to me that there has to be differences in the instantaneous peak cylinder pressures, flame front propagation rates, wrist pin peak loads etc etc between say 21 in and 2300 RPM and 27 in and 2050 RPM even though they generate the same percentage of power. To me that is a convincing argument to colour inside the lines of the manufactures power chart. I frankly don't know enough about the subject to want to experiment with unorthodox power settings. (BPFe)

He's healthily cautious fellow that knows what he doesn't know. Like Donald Rumsfeld.

I'd add that BPfE's skepticism could also come from the fact that the big radials he operated were capable of very high MPs (60" etc) and low power LOP with these MP's would indeed be very hard on the engine - specifically the ignition system which would struggle to properly ignite such a weak mixture. This is speculation, far more educated minds than mine trawl this forum and would be able to provide better insight.

(For me I'd be uneasy with the OPs settings too, but he's gone in with eyes open. The issue of resonance would be the one that would stop me doing the same - even though that model is not on the list.)

And yes the tone of the thread is admirable!