The Homebuilt Engine, Part 1

If you've read the latest 'Sport Aviation' you were no doubt impressed
by the 'New Engines for Experimental Aircraft' (page 35). The
infomercial shows a few engines with prices starting at about ten
grand, topping out at more than $50k, chump change for all those folks
dedicated to revitalizing grass-roots aviation in America.

For a whiff of reality, go over to GM's industrial engine page and
take a look at their V2400. In fact, don't just take a look at it,
figure out some way to get your hands on one.

Now turn it upside down and call me on the phone.

Once we have the thing running inverted we'll figure out how to
fabricate a carbon-fiber sump and valve cover. Carbon-fiber because
the alternative is cast aluminum and odds are, we don't have the
required depth of machining talent to produce a finished product from
a raw casting (although the guys did exactly that for the O-290-G back
in John Thorpe's day). With carbon-fiber we can fabricate the things
locally.

What do we get for our trouble? A 75hp water-cooled engine that
produces those 75 horses at an rpm suitable for twirling a prop.

What do we do with it? We put it in a Pietenpol. Or any other low-
tech, two-seater.

(Why invert it? Because that puts the thrust-line in the proper place
without filling your forward vision with cylinder heads and
radiators.)

Is it expensive? Probably. It's being manufactured in Brazil and the
way our Bail-Out Bucks are depreciating, we are well on our way to
becoming a Third World Nation. But it's an INDUSTRIAL engine, meaning
there's going to be a lot of them available.

Inverting an engine is fairly common in aviation; there's some tricks
to it but no mysteries.

Why the Pietenpol? Well... why NOT? It's a proven design and the
weight of the V2400 is close to that of the Model A. It's a two-
seater, which is almost a necessity if you want to stimulate grass-
roots aviation, and its fabrication calls for only a modest level of
skills. Indeed, if you participate in building a Primary Glider you
will have experienced virtually all of the skills needed to build a
Piet.

Food for thought.

-R.S.Hoover