TCM, Honda Reveal More
So, you say you want a direct-drive, flat four engine that makes
225hp? That's pretty easy. Now, you also want water cooling, a
310-pound all-up installed weight (including radiators, water,
etc.), and electronic engine management? That's not so easy. And
you want it now? Well, that's impossible... but it won't be,
forever.
The Honda-engineered Continental engine was officially revealed
at Oshkosh on Wednesday, to a usually jaded group of reporters. The
release was distant from the actual engine mockup, so ANN went to
see the metal parts.
The engine is well-packaged; it's compact-looking and
well-finished. The traditional layout looks vaguely familiar, of
course; but the valve covers give this new machine a '4-cam' look.
No: it has just one cam, and 16 pushrods (there are 4 valves per
cylinder).
Four valves may seem like technological overkill on a 2700-rpm
engine, but John Barton, TCM's Chief Technology Officer, assured us
that, "there's still some useful gain" traded for that increased
complexity. It also makes the combustion chamber a bit easier to
package, in some ways.
The demonstrator engine has a single alternator mounted,
something that wouldn't support certification of an all-electronic
ignition. Mr. Barton told ANN, "We're looking at possibly putting
the second alternator near the rear of the engine, so that, in the
event of a belt failure, the pieces of the failed belt wouldn't get
in the way of the good one." While such mechanical redundancy isn't
required, it's sure nice to have...
It's not 'redundancy,' but robustness, that insures the
mechanical integrity of such a powerplant; and the Honda engineers,
knowing full well how much push each piston was going to produce,
designed a monstrously-strong five-main-bearing case and crank
setup.
The Powerlink FADEC will allow the 9.5:1 (compression ratio)
engine to sip aviation gas or 92-octane mogas, or presumably a
blend of the two.
Two motorcycle-style NGK spark plugs light each of cylinders in
this 370-inch mill, which has completed a number of shakeout
flights in the newly-painted test-sled Cesna 337. With the Honda in
the nose and the reliable workhorse Continental in the back, all
kinds of tests are still planned.
Certification date? Uncertain. Price? Not mentioned.
Applications? Interested OEMs and select STC applications; possibly
high-line Experimentals. Delivery? You guess.
Is it cool? You betcha.