X-Mozilla-Keys:
Putting the prop flange at 44" in front of the firewall puts it 5" in front
of stock.This requires that you make a new engine cowl. My cowl differs from
the stock one in that it is 5" longer and is built to provide for a 14"
spinner. It has no cowl cheeks and is rolled from .063 6061 aluminum on an
english wheel. Most of the ideas on the design of the cowl were based on
suggestions from Everett Hatch.
Having a 14" spinner gives 2" more width to
the cowl at the nose. More room inside the cowl is a good thing to have on an
RV-4, especially when omitting the cowl cheeks and trying to fit a wrapover
intake manifold. As it is, there is just 5~6 inches between the rotor
housing and the cowl. Engine movement has to be accounted for. For the
manifold, I am using the four port manifold cut off right where it makes the
90 degree turn upward.Then I will have a 1/2 inch thick plate welded on to
it to form a flange to which I will have the wrapover manifold connect. This
is the point at which progress has been suspended due to home remodeling.
It's hard not being able to work on the plane for so long. I had to stop in
May because I got sent away for business for the summer.
At this point, I'd like to solicit advice- do I go to two 2" I.D
wrapover tubes, (4 into 2) or four 1 1/2 " tubes (4 straight tubes)? In
using two tubes, I'd have one tube feed the front chamber and one feed the
rear. I assume that all the runners would end up in a dynamic chamber
somewhere near the plugs. And do I make the runners out of aluminum or lay
them up out of fiberglass? Anyone?
Brian Trubee
Redmond, Wa
I am going with thin aluminum tube 0.049 bonded together with high temp
epoxy. That stuff is too hard to weld unless you find an artist.
The epoxy manifold is too labor intensive for me.
If you are talking four port I would go with four 1.5 inch tubes.
Just a guess on my part. If you are going six port maybe 1.5 feeding
center and 1.75 feeding outer. Again... just a wild ass guess. Paul
Yaw I am sure would go with smaller to keep the velocity higher.
Right Paul?
Paul Lamar
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