Mazdatrix dyno is still down but here is a picture
of the dual 2 inch runner injector holders and
fuel rail. Fuel rail is easy to make even on a drill press
if you can buy some 3/4 by one inch aluminum bar stock.
Uses off the shelf MSD 50 pound per hour injectors.
Ford and Mazda injectors shown for comparison.
Any day now we will be testing the engine.
Paul Lamar
Cutting these injector holders are a pain in the butt.
All MSD injector dimensions appear to be metric.
One of the major problems is you need a 20 degree taper
so you can insert the O-rings in the bore. MSD has a cutting tool
for sale but it is $200 and it does not fit the #50 pound
injectors. I could put out a couple of hundred dollars
and have a custom cutting tool made.
I think I finally found an easier and cheaper way to do it.
Here is an off the shelf tapered mill from AirGas
with a 20 degree angle each side that will work.
The crooked line in the 2D sketch is the out line of the injector
body. The bore in question is about 13 MM but a 33/64 (.516)
drill will work. I then plan to ream it with a hand 17/32
reamer. The same drills, mill and reamers will work on the
fuel rail.
This can now be done on a drill press if you have the right
drills. The .975 injector body hole could be done with a 31/64th
drill instead of 12 mm drill.
The aluminum blocks them selves can be cut lickity split from
Industrial Metal Supply in San Fernando CA mail order.
Saves a lot of milling and their high speed saws
can do this in no time. Helps if you order ten or
more at a time. You send them the dimensions and they cut
them to exact size. No milling machine or milling required.
Great surface finish as well.
The position of the O-rings are also shown on the 2D sketch.
I am leaning towards bonding these things on to the two inch
tube with epoxy. Perhaps one small tack weld on each side
after bonding for insurance.
Paul Lamar
Paul, I admire your work and design. However, I think mine is a lot
easier to build. The intake will be finished in a week or so and will
include filtered ram air. In the photo you are looking into the still
open end of the plenum. The plenum is just clamped together. The four
injectors likewise are just stuck through the ports in the plenum at
this point but have an o ring which will seal when the fuel rail is
drawn tight. It is going together nicely so far. The runners, bell
mouths, and plenum will be a one piece welded assembly when finished
that is attached to the throttle bodies with hose and clamps.
Jerry
Only two attached photos were readably. Did you intend to send 5 photos?
Looks a lot like one of my 3D's :)
I did not want to get that radical as this engine does not belong
to me so I took a more conservative approach as to injector placement.
I have not built a plenum yet and won't. I don't need it for the
dyno runs. I will leave that up to the engine owner and builder as it
will not affect the dyno HP reading and he will need to fit it in his
cowl. This is mainly an exercise to see if we can equal the HP
per rotor and BSFC achieved in the Lemans engine.
I am glad that you are trying out the injector mounted outside
the trumpet opening. Widely used on race cars in the past but I still
have a few questions about it in regard to aircraft use. I am sure you
will let us know how well it works. If you pay shipping I will
be happy to test your engine on the Mazdatrix dyno when it again
becomes available.
Paul Lamar
The Rotary Engine NewsLetter. Powered by Linux.
ACRE NL web site.
http://www.rotaryeng.net
Copyright 1998-2005 All world wide rights reserved.
