Jerry Hey wrote:
Paul, can you give me the exact locations for the lower center
engine
attach points? Are there clearance issues I should be aware of?
Thanks, Jerry
Here is your drawing and a drawing of what I did.
My drawing shows the holes inside the front motor mount brackets
but it will work just as well with them out side the brackets.
Here too is the firewall dimensions that came with the KIS Cruiser.
Unfortunately I don't have the drawing on the position of the
brackets
here so perhaps Charlie can send you a sketch. Maybe later today I
can get
that
info.
Jerry,
Here is the latest drawing showing the locations of the front gear
lower
mount attach points. I have changed the reference in the drawing
from the
top of the firewall to waterline zero. This makes more sense for
you as the
two upper motor mount holes lie on the waterline zero line. The
thrust line
is exactly one inch above waterline zero. I have the four lower
attach
bracket bolt holes located with reference to WL0 and the firewall
centerline.
Let me know if you have other questions or need other reference
measurements.
Charlie
Jerry, If you are going to put the diagonals outside of the nose gear
brackets
(9.5 inches apart) try an X under there and see if it clears the oil
pan. Are you
using s stock oil pan Charlie? If you put them inside the brackets
they need
to be 4 inches apart. The brackets themselves are 3/4 inch thick
aluminum plate.
Paul,
I don't have an engine yet so I don't have an oil pan either. I'm
getting the feeling I need to commit to an engine before the mount is
built. If that's the case, let me know and I'll (gulp) make the call
now.
Charlie Smith
KIS Cruiser 4021
Not to worry. I think Jerry has at least one stock oil pan lying
around to check.
Paul Lamar
Charlie, as long as the engine is a 13Bm no problem. No need to buy
one until you are ready. If it is a 20B then we need to go back to
the drawing board. Everything changes. Jerry
If it is a 20B you will also need to do a different cowl. As it is
the distance from the water pump pulley to the nose gear strut is
critical on the 13B with the stock cowl.
Paul,
Being a bit of a neophite here, my recollection is that a 20B is the three rotor engine. If correct, I don't have any intention of having that much power. It would likely rip the firewall off the thing assuming I didn't kill myself before getting the chance to do that. It will be a two rotor engine. My first pick will be a Renesis with an older RX-7 as a second choice. I'm still in my formative months and wanted to get more of an education here before plunking down money on the engine. If I am to make a mistake I don't want it to be a simple one. I prefer big complicated mistakes.
As for the thrust line, the builders manual states the thrust line is level one inch above waterline zero. When I went to measure for the lower gear attach point, I put wateline zero on the firewall to use as a reference for the gear measurements. It was then I realized that the upper mount attach points lie on that line. I will leave to Vance to comment on the impllcations of having the thrust line one half inch above design. If he thinks its OK then its fine with me too. I trust his opinion implicitly. I had simply copied your drawing to locate that point in previous prints. It didn't seem to me it would be different plane to plane. However, one inch above the waterline is the factory callout. The biggest problem I see it could cause is at the spinner. That could be a good deal of work even at one half inch getting the thing centered enough to keep from looking crooked.
Charlie Smith
KIS Cruiser 4021
The problem with raising the thrust line position (BTW I did not raise it on mine. I moved
the mounting points.) is..... you will have to redo the cowl. A lot of messy work.
It also affects the handling of the airplane. Generally not a good idea to change
the thrust line position.
Paul Lamar
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