IO-550 in Katmai?

[Rich Karlgaard]

This is my first post. Blame Kevin Moore for introducing me to your wonderful airplane and this terrific site.

I co-own an SR22, which I love, not the least because the 310hp TCM IO-550N is simply the best bigbore engine piston engine in production. The new turbonormalized SR22 (Tornado Alley adds a TC to the IO-550N) uses a composite prop, to remove some of the upfront weight added by the turbocharger. The I0-550/Hartzell ASC II composite prop is the quietest, smoothest combo yet, according to those who've flown it

Is there a day when we might see a Katmai with the TCM-IO550N or IO550R? That would add weight over the IO-470, of course, but some of that weight could be offset by the Hartzell ASC II prop.

I would find the larger engine useful for escaping ice or summer turbulence that much quicker in the mountain west.

[kwmoore]

This is my first post. Blame Kevin Moore for introducing me to your wonderful airplane and this terrific site.
Love taking that kind of blame. ;) Welcome!

...because the 310hp TCM IO-550N is simply the best bigbore engine piston engine in production.
You might find some controversy on this point. The IO-550 has done well in the SR22 and Col350 for the past couple of years. In its current incarnation it seems to be a very reliable engine. This wasn't always the case. You may recall that it wasn't too long ago that a significant number of SR22 owners uncovered very troubling lifter and camshaft problems. Likely TCM has had significant incentive to concentrate on improving this product, particularly because of Cirrus' burgeoning market penetration. That's a good thing for everyone.

In contrast the IO-470 has had a 5+ decade history of reliability in such applications as Cessna 185, 205, early 210's, 260se, 310, early Bonanzas, and has earned such descriptions as "bulletproof" and "ultra-reliable" by Aviation Consumer, Steven Ells (AOPA Pilot) and Cessna Pilots Association.

It will be great if TCM can live up to those standards going forward with their IO-550 engine.

The I0-550/Hartzell ASC II composite prop is the quietest, smoothest combo yet, according to those who've flown it

Is there a day when we might see a Katmai with the TCM-IO550N or IO550R?
I was very pleased with the smoothness of my previous 260se's. In my opinion they gave up little or nothing to the IO-550/6 point engine mount combination in the SR22 in this regard. Likely the new prop-engine combination you cite is at least as good, maybe better. I'll let you be the judge when I take you for your ride in my Katmai later this year! :D

Yes, an IO-550-powered 260se (er, that's 300se ;)) is on the near horizon. This has been discussed in several other threads on this forum: for example click here (http://www.260sepilots.org/forums/showthread.php?t=304) and here. (http://www.260sepilots.org/forums/showthread.php?t=367) Todd can provide such details as he wishes to at this time, but I think it more likely than not that you'll be hearing something about it in just a couple of months. :cool:

[nworth]

Rich,

Welcome to our little corner of general aviation! Hope we will be hearing more from you. BTW, I enjoy your blog.

[Rich Karlgaard]

Kevin --

Thanks for the links on the previous I0-550 discussions. My interest is climb rate between 10,000 and 18,000, mainly to escape typical western summer turbulence, but also to get out of ice trouble, should I ever so blunder.

To that end, I loved the turbocharger in my T182T. I also loved the wing extensions. I remember 900-fpm plus climbs from 14,500 to 16,500 in that plane without even trying. What I did not like was the T182T's ride in turbulence and its lack of a parachute.

By contrast, the SR22 is more comfortable in turbulence in level flight and descent. The exception is when one is flying the normally aspired SR22 over 12,500 feet, hot, heavily loaded and trying to outclimb turbulence. That is no fun at all. I remember a long, long two minutes trying to get from 12,500 to 13,500 near Mt. Shasta last August. I envy the TN22 owners.

What kind of climb rate does the I0-470 Katmai see between 10,000 and 18,000 (over a range of temps and weights)? What improvement would you see with the IO-550?

[kwmoore]

What kind of climb rate does the I0-470 Katmai see between 10,000 and 18,000 (over a range of temps and weights)? What improvement would you see with the IO-550?
With Tina, Byron, and miscellaneous toddler accessories on board, I was usually still at least 200 lb under MGTOW even with full fuel in my 260se's. I didn't do a lot of flying at 11,500-12,500, but my experience was in the summer so density altitudes were even higher. I recall climb rates of 500-800 fpm in those circumstances depending on weight & temperature, turbulence etc. I was almost never concerned enough about climb to actually use Vy (76 KIAS, less at altitude). My typical climb speeds were more like 80-90 KIAS, well above Vy. As I didn't have oxygen, I didn't go above 12,500.

I know that Todd & Glen (2099X) have oxygen and operate sometimes in the low-mid teens; perhaps they or others can comment.

I don't know how to accurately extrapolate climb performance at altitude for the future 300se/stol. I'm sure Todd will give us a report soon: the engine and prop for my plane will soon be transplanted from his Katmai demo and replaced by an IO-550! :) :)

[nworth]

What kind of climb rate does the I0-470 Katmai see between 10,000 and 18,000 (over a range of temps and weights)?
When I fly to the Bahamas, I generally climb to FL17.5 eastbound from Miami to Bimini to guarantee engine out glide to land. The added glide was the main justification for adding the long wings -- they add more than 10%. They also aid in the climb, of course.

I don't recall all the details, but best as I remember, I experienced no problems at all making these altitudes. I make these trips in spring and summer, VFR, so I can pick my own route (shortest land to land distance).

The typical regime is to hit the east coast at 9,5000 (Miami Class B stops at 8,000) then set climb in the AP for about 600 FPM. All at best power (about 68% when I start) leaning using the engine monitor as I go to retain about 100-125 ROP (actually I start slightly richer until I can only pull 60% or so power, then go leaner just cause I'm chicken). At these altitudes and powers, I can climb with cowl flaps closed and CHTs all below 360.

As I recall, the plane just steps right on up at indicated air speeds well above 100 kts at the start decreasing to about 85 kts in the 14's or so. I believe AS did not pass through Vy (about 70 kts at these altitudes and with the extensions) until about 15,500 at which point I lowered the climb rate and made it up the rest of the way at about 300 fpm. The plane could clearly have gone higher when I stopped.

I would estimate the plane was about 450 lbs under gross when starting this climb. During the summer runs, temps on the ground are 95f/35c. Using the 2 degree per 1000 ft rule of thumb for lapse rate would basically put OAT at about 0 Celsius at the apex of climb. (However, I don't recall checking OAT actually).

Hope that helps.

The question has me interested and I just had my O2 bottle filled so I may give this a try later this week. Will report back with the results if I do.

[n2099x]

I haven't been over 15,500 in a year so I don't remember the numbers. On one trip in June I fueled in Grand Junction Co. heading east using every bit of usefull load maybe even a little extra. We were at 16k over Aspen and still climbing at 400ft a minute. I routinely go back and forth across the Sierra's in the mid-teens during the summer with no problems. I just firewall it and lean all the way up, ajusting the cowl flaps as needed.

Glen