|
|
thanks for the replies, quite valuable. what I need to figure out now is if
the current mount is salvageable since I have reversed the engine rotation I
originally thought I needed. the rear rubber mounts are about an inch off
center(the wrong way now) I guess I would end up with short ears and long
ears if I try to use it as is. with all the triangles it appears that
modification means starting over again. I'm guessing that when I get way
down the road and try to build exhausts, then the gotcha' will grab me.
looks like it's time to order a redrive so I have something to measure off
of (oww, nice grammar!). mike, bring your redrive over, I got beer!
Kevin Lane Portland, OR
e-mail-> n3773@comcast.net
web-> http://home.comcast.net/~n3773
(browse w/ internet explorer)
----- Original Message ----- From: <keltro@att.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Friday, May 21, 2004 11:02 PM
Subject: [FlyRotary] Re: engine mount geometry
Kevin,
Ditto the advise from Marv! The Dyke Delta has its offset
at the firewall end of the engine keeping the prop flange
on the A/C centerline. FWIW
Kelly Troyer
--
Dyke Delta/13B/RD1C/EC2
> "kevin lane" <n3773@comcast.net> wrote:
> > > >
> I am fabricating the bed mount plate for my 20B in an rv-8. my
> understanding, from Tracy's advice, is to offset the engine about 1 1/2
> degrees to the right if I use his 2.85 drive. as I see it there is a
> centerline of the fuselage and a centerline of the engine/redrive. if I
> mount them such that they are 1 1/2 degrees out of parallel, then those
> centerlines will intersect. my question is where? ...snip... < < <
>
>
> I'm not an RV builder, but I did have the same decision to make when I
was
> fabricating the mount for the 13B in my Lancair LNC2. I temporarily
installed
> the cowling to the fuselage and found that in its normal position the
> centerline of the fuselage aligned perfectly with the centerline of the
cowl.
> I also noticed that there was a tilt to the flat face that would mate
up with
> the spinner, so I assumed that the c/l of the prop should match the c/l
of the
> fuselage, consequently when I built the mount all the offset was at the
rear
> of the engine. The center of the prop hub is aligned with the c/l of
the
> fuselage. From an aerodynamic standpoint, I don't know that it makes
much
> difference where the offset comes from, except that if you keep the
firewall
> end of the engine centered on the firewall, the c/l of the prop will be
offset
> to the left or right, as required. This would impact how the cowling
fits up
> to the fuselage and give you a convex surface on one side and a concave
> surface on the other where the cowling meets the fuse (when viewed from
above
> or below). Personally, I'd prefer to keep the lines of the fuselage
nice and
> smooth and symmetrical so aligned the prop hub's and fuselage's c/l's.
What
> happens under the cowling has little impact on the final external
appearance,
> ergo, I build in the offset back where it would be invisible. Just my
2c.
>
> <Marv>
>
> >> Homepage: http://www.flyrotary.com/
> >> Archive: http://lancaironline.net/lists/flyrotary/List.html
>> Homepage: http://www.flyrotary.com/
>> Archive: http://lancaironline.net/lists/flyrotary/List.html
|
|