Seems like the Long EZ has lots of room on top
so here is a variable length manifold that pops out of the
side of the cowl on take off and climb out. You need all
the power you can get to takeoff on short runways with canards.
At top speed where low drag is needed it close up flush with
the cowl surface and amx HP is generated.
This is two inch tube on a four inch center line radius.
Exact copy of the Lemans manifold. 240 HP at 7500 RPM.
You can tilt them back a few degrees to get a bit more
room for the alternator.
I further simplified the variable length feature when I realized the
plenum would hold the movably tubes in perfect alignment.
Now all you need is a push pull cable up to the cockpit.
A flexible control cable, a pulley and a large spring would also work.
A stuck manifold would be no more catastrophic than a stuck
constant speed propellor. Another advantage of this approach is
it allows a larger plenum. The injectors are installed in pockets
in the side of the plenum. I am sure Ed Klepies can make one of
these for you.
I should get a patent on this thing :)
On the other hand so far it does not look like anybody other than Tom is
interested in P-ports. Am I ten years ahead of my time again? :)
Paul Lamar
Barry Gardner wrote:
Paul,
Wouldn't you have to have a slot in the cowl where the snorkel could move from side to side?
Barry Gardner
Wheaton, IL
Better than that Barry.
Here is what it looks like in the take off mode when the pipes are four inches longer.
I think I can get that number up to 5 with a bit more tweaking.
Paul Lamar
Paul,
If the snorkel came out the side instead of the top, couldn't you just have a long neck on the snorkel and do away with the complexity of the cowl having to part (assuming that the cowl were big
enough to encompass the plenum when expanded)? After all, you'd have to design that extended cowl section to withstand cruise-climb 120+ mph winds plus a safety factor (not wanting it to go through
the prop, of course). If you wanted to design it so that inadvertent lengthening of the intake manifold in cruise flight wouldn't cause a calamity, you'd have to strengthen it to Vne or 220 mph plus
a safety factor. On the other hand, the long neck snorkel coming out laterally could just stick out farther, allow a streamlined shape, permit a close tolerance hole on the cowl, etc. At low speed,
it looks like a giraffe. At high speed, it tucks in. Of course, you'd have to readjust the fuel rail and injectors. Just an idea.
One other issue would be that wind pressure on whatever sticks out might tend to bind the sliding parts, whatever those might be. Have to design with tight tolerance and use low friction components
on the tubes.
I like the idea of being able to change the induction length to suit the rpm/hp demands.
Barry Gardner
Cozy #390
Wheaton, IL
Good point on the air pressure.
The thing is the cowl is not big enough to accommodate the plenum when it moves 5 inches.
If the snorkel come out the side you would need a more complicated fuel rail.
Wrap the inner pipes with one layer of teflon tape and use recirculating round ball bearings
on precision ground drill rod to guide the snorkel. Those parts are off the shelf.
You could also maybe use ball bearing drawer slides. A short section of thin rubber
hose right after the 180 will allow the inner pipes to move around a bit and
accommodate the movement of the outer pipes and the plenum.
BTW here is a real cool looking snorkel on a JackPot racer. Could be for the oil cooler.
Paul Lamar
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