Shadrach

Is it your contention that a naturally aspirated P&W 1340 with a compression ratio of 6.1 to 1 has the same FF/HP ratio requirements of a naturally aspirated O360 with a compression ratio of 8.5 to 1? I agree with everything you've said conceptually. However, at a more granular level, the general numbers you've given are just that, general. They must be fine tuned by application as the range of configurations of both NA and Turbo Charged engines vary significantly. Look at Mooney's apples to apples HP/FF ratio specifications in 1966 and 1968 for the same engine... 1966 M20C POH - 2600, 26inHg 90% (162HP) 13.4GPH= HP/FF ratio of .0827 1968 M20C POF =2600, 26inHg 91.2% (164.1hp) 16.5GPH = HP/FF ratio of .1005 Lets look at the specifications for F model IO360 with near perfect F/A distribution. 1968 M20F POH 2700, 28.4inHg 99.9% (198.8hp) 18.6GPH - HP/FF ratio of .09309 You cannot possibly believe that there are no other factors besides Turbo Supercharging and normally aspirated associated with FF, CHT and detonation margins? Do you think we can just throw thermal efficiency (HP/per unit of fuel) and the associated increases in ICP and reduced detonation margins out the window for a 1 size fits all for NA engines and a one size fits all for TSO/IO engines with a range of C/Rs, Piston speeds and boost levels? All of those variables affect CHTs and detonation margins. Fractional differences in HP/FF ratio have a profound effect on power, CHT and detonation margin but more so at the extreme lean and rich edges of ignitable mixtures. According to a widely published graph by P&W, best power mixture (highest ICP) is at .08. and too rich to ignite is at .125. According to P&Ws own graph the engine (assuming NA) will make full HP from ~.08 to ~.094. Help me understand how raising the FF of a 1964 O360 M20C from the HP/FF ratio of .0827 shown in it's POH to the FF/HP ratio of .105 shown in the 1968 POH for the same O360 M20C will cause cylinder scuffing? Lycoming and Continental have their own graphs mixture graphs and while they are conceptually identical to the P&W graph, the numbers are not.

The recommendations I have read online for FF/HP are all over the place. Including in Mooneys own POHs and operating manuals. Prior to 1968 Mooney did not give FF numbers for full throttle, max RPM, full rich operation in the M20C POH. The 1968 POH calls for SL 18.2GPH @ 2700RPM and 28.0 inHg. I would treat that as a minimum for any C model. I think many C models come up well short of this number. What's more interesting is the staggering difference in FF numbers between the POH for 1966 and 1968. 1966 only gives numbers for 2600RPM and starts at 2500MSL (Std. Day). Comparisons below. I continue to believe that the early C models do not get enough fuel even if they have excellent fuel distribution (which they don't). Given the distribution characteristics of carbureted engines, some cylinders are likely running at max ICP. Noting take off EGTs is a good start to understanding the problem. Those of you that continue to that believe Raw EGT numbers don't tell anything are free to continue believing in the face of contrary evidence, but I'd not recommend it. 2500' 1966 - 2600RPM 27inHG and 14.4GPH 1968 - 2600RPM 26inHg and 16.5GPH Difference of -1inHg and 2.1GPH 5000' 1966 - 2600RPM 24.5inHg and 12.9GPH 1968 - 2600RPM 24.5inHg and 15.7GPH Difference of 2.8gph 7500' 1966 - 2600RPM 22.5inHg and 11.8GPH 1968 - 2600RPM 22.5inHG and 14.4GPH Difference of 3.6GPH 10,000' 1966 - 2600RPM 20.25inHg and 10.6GPH 1968 - 2600RPM 20.2inHg and 9.2GPH Difference of -.05inHg and -1.4GPH

Maintenance manual leaves a lot to be desired in terms of information. I would think it far easier to get the mag out with the battery box removed.

Clean everything thoroughly, assemble, and run it another ten hours.

There is no magic procedure that works under all circumstances. There is a simple, methodical, process that starts before shutdown. That process is best complimented by an understanding of the what is happening under the cowl. It goes something like this: 1) Engine set to 1000rpm at shutdown ICO. 2) At restart, if the engine is hot, fuel was pushed into the manifold. The engine should be treated as if it is primed and ready to start. Hit starter and enrich if/when engine fires. 3) If the engine does not fire or quits before the mixture can be enrichened, there is likely no longer adequate fuel in the intake to support combustion. A brief 2 count shot of prime should be adequate to deliver a combustible mixture to the intake. 4) Rinse and repeat being conservative with the prime until the engine starts. It's a rarity that anything beyond #3 is needed.

To be clear, shutting down does not flood the engine. If we are going to use an analogue for the fuel that boils into the intake after shutdown, it would priming. No properly rigged Lycoming is flooding itself on shutdown. They will typically start in a few blades provided a ham-fisted pilot has not flooded the engine by unnecessarily priming.

Indeed. Terminal velocity for a human falling belly down with extremities extended is 120MPH. Nose down terminal velocity must be considerably more for most planes given that they will travel faster than 120mph in level flight from thrust that is just a fraction of their weight.

In my experience with various carbureted and injected Mooneys, C and G models always have hotter CHTs than E and F models despite having slightly lower C/R. IO360 operators start get concerned when their CHTs climb to levels that many O360 operators would be tickled with. The factory jetting appears to sub optimal, especially on the earliest models. No one cared before engine monitors. However, now that we have them, it easy to make comparisons between models. I don’t know that it translates into more frequent cylinder work for than the carbureted models. Everyone has been conditioned to be uncomfortable with CHTs >400°. There are many C model owners that have put lots of time and effort into their baffles and seals but still struggle to keep CHTs < 400°. Many have take off EGTs in the 1400s. With a CR of 8.5:1, all take off EGTs really should be no higher than about 1300° and preferably less to be rich enough. No matter how perfect the baffles and seals, any cylinder that is < 200° ROP at full power in the climb is going to run hot. If it’s running < 150° ROP, it’s going to run really hot.

This has happened to me a few times. This is why I am very particular about who fuels my plane.

It’s never better in flight. Nevertheless, my dad flew with an overhead speaker and a mic until the late 70s/early 80s. Seems insane to me today but it was the norm. I use it on the ground sometimes in the same way I would use a handheld.

Does it work? Can be nice to have under limited circumstances.

It sounded as though both engines were making power until inmpact.

I believe the nut holding the assembly together is pinned. Which means the installer’s options for fine tuning the tension are limited by the notches in the castellated nut aligning with the pin. try backing the nut off one notch.

I like to think so but I don’t always personally live up to it. That being said, you and I both know that that’s not the part of your comment that I was commenting on.

That’s ground retract speed. They retract faster under aerodynamic load.

I heard that Dan Gryder is en route to Kuzhenkino to investigate. We should have something definitive by Tuesday.

The Patey Brothers would be too nice to tell you that you're full of shit on this one...but I'm not.

You've seen plastic brake line plumbed directly into a caliper? That’s a new one for me. I've only seen it on the supply to the brake cylinder. No pressure and no heat.

I think there may have been a bit of an "I can't have her anymore so no one will" sentiment. This guy still felt sharp when he hung it up. He quit flying because he lost his stomach for the risk of instrument flying and VFR only flying was so boring to him that it was not worth it to continue. As much as I like XC travel, the most fun you can have in an airplane is in a low powered, tail dragger...preferably with tandem seating and the wings on top. I feel sad that he was blind to the absolute joy of flying for the sake of flying.

Just be grateful that your mechanic is a 'first do no harm' kid of guy. I can envision a number of scenarios where someone unfamiliar with the system might decide to be more invasive in their investigation. I have an inbox full of DMs on jobs started that were not properly finished. I won't name names but one owner had a mechanic clamp the cable for the up/down lever to the elevator push rod tube next to the pump. Flaps worked fine on the ground but pitch changes would raise the flaps in the air....

Yes, but there is rarely a rush to retribution in these kinds of situations. There was likely a more immediate reason for Prigozhin’s elimination beyond simple retribution.

Video looked like a bit like a falling leaf before rolling off to one side and becoming inverted nose down. Engines were still making power until impact. Trying to imagine the ride down as watch the footage turns my stomach in knots.

No greater compliment than a professional's confidence. I took a shorted mag to a local shop for repair. The mechanic who I knew and had worked with before told me to take it back to the parts washer and start breaking it down. We had it completely IRAN'd in about an hour. He then asked if I needed him to swing by my hangar later to inspect the installation and sign it off. I already had another IA lined up but the offer in and of itself meant a lot.

Which is good. However all applications that I have seen are subject to pressure from the weight of the fluid.

Likely more so. I speak with some experience when I say that Richard Collins personality had a lot to do with his decision making. His P210 was based a few hangar rows over from my Mooney at HGR. I was a pretty low in the airport hierarchy the few times that we crossed paths and it was clear he had no interest in even casual pleasantries. It became clear that he wanted to remain clear of the community in general. I don't mean friendly not familiar, I mean...well aloof is the kindest descriptor that comes to mind. I think his decision to scrap the 210 was driven by his general feelings towards the type of person that he felt would be in the market for a 9000hr P210.