Paul,
Yes it is a little confusing to talk about it. Thanks for the pictures.
I believe George`s graphical information is helpful and I can look at
the area of time I am interested in. I would suggest editing it so it
only shows 360 degrees of e-shaft rotation but this is not mandatory.
Before we determine where the apex starting point is, we have to define
what part of the cycle we are most interested in seeing.
It should be noted for everyone that George and I are speaking
about two
totally different places of fuel injection. Perhaps we should be on
separate threads. George is concerned with manifold air speed and how
that affects the transfer of fuel from the manifold injection point, to
its arrival into the Intake area labeled 'A' in the first photo of
How-wank-works, jpeg Paul posted.
I am only interested in what happens in the chamber space between apex
seals as depicted by 'C' in the second picture in the series. Lets
consider that my injectors are placed about where the label 'INTAKE'
is shown, then you can understand that I would want the fuel to start
injecting into this area 'C' about this rotor position.
Now look at the third picture in the series and note that the injector
could still be injecting well past this position before the following
apex seal closes the intake port and immediately afterwards the fuel
injection port. Also note that Mazda new research engines with the
hydrogen injector at 12`clock position probably injects at this time as
well. Again mixing a wee bit of hydrogen with the other hydrocarbon
based fuels increases the flame front speed.
Why am I trying this injector location? I am trying to test a theory
that spraying fuel directly into the housing intake chamber will help
improve fuel burn efficiency. Mazda research engines appear to be going
this way and they are economy and emission driven of course. This is
not direct injection in the normal use of the phrase, as that would be
injecting on the compression side of the stroke.
Housing intake chamber injection supposes that, by delaying the
injection
of fuel until the exhaust port closes, we may save some fuel from going
down the exhaust port. My second reason is probably the influence of
too many years designing for Japanese clients. That philosophy states
that if an idea is reduced to its minimal size and simplicity its
functionality will increase and surrounding components can also be
reduced in size. Usually the merits are not immediately apparent.
Several questions remain. How much heat will the rotor lose when
fuel is
contacted with it?
Is cooling the rotor by spraying it with fuel a good thing?
How to mount the injector tubes? I am open for all opinions here..
I have done a design using a 15.1mm ID stainless pipe that will
have an
O-ring seal on the inner housing and a taper NPT thread on the outer
part. This would screw into the outer housing sending the pipe into a
bored step in the inner housing. Obviously the hole is being drilled
fairly perpendicular to the inner housing. The challenge is sealing on
the outer housing. It is not flat in this area and sealing with Teflon
thread putty would be marginal.
I therefore have purchased the 2nd generation alloy aluminum brazing
rods
from an outfit named Technology Products in Florida. These rods still
require the welded area to be 200 degrees below melting point of the
housing metal however. Heat dissipates rapidly in the housings so that
also means a lot of heat has to applied into them to bring the welded
area up to at least 550 degrees. I am concerned the housings might get
deformed.
Has anyone done any welding on the rotor housings and then run them
or at
least 'mic' them to see if they are still true? I don`t consider TIG
welding on the inner liner to be a problem because it so precise and
localized. I want to build up the aluminum housing thickness around the
injector mounts before drilling and tapping and hence my concern. Ditto
on the P-port intakes, with the same technique and same concerns.
Doug in Japan
Just some ideas:
The injector spray tip should be as close as is possible to the housing
face. So the longest injector and, or, a rather fat mounting tube to
hold the injector. Welding the housing inside or out is not on the
table. The housings are closer to the stiffness of hard rubber than one
could imagine. Even screwing in a sleeve with an "O" ring boss is not
acceptable. Perhaps an "O" ring groove in the sleeve at the housing face
would be fine.
There would only be the coolant pressure to contain. On the outer
surface, A deep "O" ring groove in the sleeve adjacent to the surface. A
fat "O" ring in this groove to fit snugly in the groove. A cover ring
with a 45 degree angle inside and a diameter big enough for 4 8-32
socket heads screws into the housing to clamp the sleeve in place. Also,
if it turns out that a case bolt is in the perfect location for the
injector, it can be removed with minimal fear.
The rotor will not be measurably affected by fuel spray. The fuel spray
will never make the trip from the nozzle to the rotor, as radiant energy
from the 350 degree rotor will turn the fuel into a gas as it leaves the
nozzle. A good thing.
The main advantage of injecting into the housing, is that with no fuel
in the inlet tract, radiant energy from the rotor face sees nothing to
violently expand, and thus reduce volume into the engine. Secondly, the
tuned lengths will respond to a steady state media that does not change
mass with the fuel delivery rates.
Top oiling may have to be increased as more oil will be consumed with
the fuel without contacting any surfaces to be lubricated. A small price.
I can make pictures if need be.
Lynn E. Hanover
Lynn, we have had no problems welding thin SS P-port tubes to the inner steel liner.
No detectable distortion or no effect on the dyno.
http://www.youtube.com/watch?v
---------------------------------------------------
This jpg should help.
Paul Lamar ...No rotor no motor.
Lynn,
Thanks a heap. I share your design philosphy. Yes on both side by side
injector inserts and P-port inserts, I was planning to groove on the
insert sleeve circumference itself in two locations. Yes direct
screw-in inserts can be problematic because NPT threads are difficult to
position exactly, and if the insert bottoms out on the inner liner it
could cause a small distortion or interfere with flex charteristics.
The DEKA IV injectors are only 15mm in diameter so I can slip a 19mm OD
tube in fairly easily with room to spare to seal the outer part. The
back side of the inner liner will be drilled and the hole tapered to an
angle slightly narrower than the injector tip profile. I can bring
the injector tapered tip to about 0.5mm from the inner housing but
probalbly will back it off to 0.7mm.
Thanks for confirming my concerns with welding. Obviously you have
'Been there done that' so I appreciate your experience. About TIG
welding the intake P-Port tube. Are you concerned with localized
embrittlement? I know the chromium in stainless metals tends to migrate
when TIG is used.
I understand your outer 0-ring cap design so no need for a drawing.
That would work if the housing area around the injector tube location
was flat. Unfortuantly it is not. My choice location for the fuel
injectors is to place them on each side of the oil injector hole. One
challenge - that area angles inward towards the center of the housing.
About 4mm or "8/32". I would have to fill it in or mill out the high
spot for a diameter of at least 30mm around the center of the insert.
Neither solution appears doable for various reasons.
No I haven't considered JB Weld, and won't:) I had originally intended
to screw in a one inch long male threaded tube with a smooth bore ID of
19.1mm. The 19mm sleeve with its reamed 15.1mm ID would have grooved
O-rings top and bottom, that contact both the inner housing step bore
sides and the inner dimension of the outer housing threaded tube. Two
4mm set screws 90 degrees apart around the circumference (4mm could
lock the sleeve to the outer screwed in pipe..
One trick I learned over here is to insert the sleeve, tighten the set
screw until it bites into the inner sleeve. Loosen the screws, take out
the sleeve and just drill the marked area a tiny bit creating a
concave point. Install sleeve again and tighten the set screws. The
sleeve is not going to move in any direction
Great news on the fuel behaviour. Bad news on having to inject through
the top:(
I was hoping I could get away with adding oil to the fuel, but like you
said it may be vaporized and become fuel before it acts a lubricant.
Doug in Japan
Synthetic oil does not vaporise until over 500 F. Put some in an oven.
Tracy adds oil to the fuel and sometimes if you add too much the crankcase starts
to fill up. It can't be all burning. The apex seals are oil cooled. Without
the oil they over heat.
Paul Lamar ...No rotor no motor.
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