speaking of speed

[flyguy]

I know everyone respects Whitman's designs so I have to relate this one. Jim Lewis took me for a demo ride in his Tailwind a few years ago as I was considering buying one. We were blasting back and forth across the Sacramento valley at maybe 75 % power on the Lycoming 150 hp he has. Doing about 180 statute. I mentioned that the controls were rather stiff at that speed so he pulled the power back to 2000 rpm and retrimmed.
That RPM is not even listed in the Cessna manual and has to be about 50% power or lower. Just at the bottom of the green. After everything settled down I checked the airspeed and GPS and we were doing 160 statute. Is that 160 on 75 HP? Sounds impossible, but the GPS confirmed it. What an airplane. Absolutely cracked me up. We both had a good laugh.
Darryl

[Forrest Barber]

Re: speaking of speed

Wittman brought the Tailwind to Taylorcraft in the 40's, Steve was involved with the Air Racing when my Dad was in Cleveland. A few of the "secrets" are the wing intersection at fuselage, very sloped windshield inside wings, very small wing area, light weight, and of course "run" that engine at high RPM , if I recall correctly the C-85 was run as high as 2950RPM. The Goodyear race ship "Estralitia" was built here at 2D1 and they ran the engine ,a C-85, at 4150RPM.

[VictorBravo]

Re: speaking of speed

if I recall correctly the C-85 was run as high as 2950RPM. The Goodyear race ship "Estralitia" was built here at 2D1 and they ran the engine ,a C-85, at 4150RPM.

In order to run a C-85 at high RPM safely (and by safely I mean without breaking it catastrophically but wearing it out fast is OK), you have to address the issue of the center main crank bearing. The Formula One racing organization requires that you replace the center cylinder hold-down studs with through-bolts (Like the O-200 I believe) to hold the case halves together in the center.

2950 RPM won't hurt the engine much as long as you have it cooled and oiled well enough, but you are definitely wearing out everything faster. and a small problem in the engine will turn into a big problem a LOT faster. There is a REASON Formula One racers get to and from the race on a trailer, folks

[Ed O'Brien]

Re: speaking of speed

In nature there is a concept called " longevity v dynamic expenditure of energy." Bullets travel fast and die quick. Humming Birds and field mice have heart rates that are scary. Everything that lives fast, dies James-Dean-young. The only exception seems to be couch potato'd pot bellied boys, like myself. During the recent Denver Blizzard, I sat on my ass for very long periods of time... between engagements behind the snow shovel.

It seems unfair that this should be the case. That middle aged men watching 24 football games in a row aren't some how extending their lives. One day I intend to take this matter of fairness directly with God. Though I doubt it will make any difference. Engines follow the same basic rules.
With Happy New Year Regards;
ED OBRIEN

[flyguy]

Re: speaking of speed

If I owned a Tailwind I sure would want to take GOOD care of the engine. Setting one down in the rocks and bushes would probably be really exciting. Can't think of anywhere that I would want to go that fast anyway and I'm sure the novelty would wear off pretty soon. Now if I was instrument rated and had a loaded panel I might be pleased to own something fast.
There is a 4 cylinder engine that is built in Socal that is loosly based on the pontiac Iron Duke straight 4. It uses components from the small block Chevy and is 200 ci. It's aluminum version is pretty light. I always wanted to see someone put one of those in a small racing plane. Various versions produce from 200 to 750 HP with 450 being a "normal" number. Wouldn't that be a hoot. I have the guys catalog somewhere. Fontana was the name I think.
DC