Here is some idea of the Aux duct layout.
Two things to note is that the main duct roof slopes down to form a hump,and the floor is horizontal ( making a ski slope hump ), to reduce the area where the Aux side ports intersect.
And the spigots floor should be parallel to the duct floor, and the roof has all the angle change to make the oval ( with ears ) to round transition.
Jan also let on that the shorter he made the septums between the main and Aux ducts, the more power appeared.
I dont know how short is too short, but in the TM kart cylinders I make the wall end shorter than stock by grinding it into a radius, instead of the square shape I have drawn.
Ive got a thing thats unique and new.To prove it I'll have the last laugh on you.Cause instead of one head I got two.And you know two heads are better than one.
- Virtually all of the complication of the early mechanical fuel injection
systems involves changing the fuel flow to follow the air flow. This was
and continues to be a result of the carburetor induced mindset that to
respond to a power demand change, you must first change airflow to induce
the new fuel flow.
- The diesel fuel system has always been a model of simplicity, but it is
probably too much of a mind stretch to use as the model. But far closer to
home, racers have achieved excellent results with Hillborn derived constant
flow fuel injection systems. It consists of a pump, a throttle valve, and a
couple of bleeds. The fuel is volumetrically adjusted to the engine size.
During operation it is totally insensitive to air flow - a perfect Al Bundy
"Don't Know - Don't Care". It is still in the top of the heap for shear
power and reliability - its major fault is over rich part throttle, but
someone invented a dejection system and is putting it in somekind of beat up
old furren kar - that's supposed to take care of that.
- After coming over to the Dark Side, you realize that all the driver wants to
do is control the POWER by the throttle - not the air. Since power is first
order related to the amount of fuel burned and second order related to the
amount of air, its backasswards silly to control the air and let the fuel
catch up. Control the fuel and let the air catch up.
- This mind reversal now reduces the fuel control to RPM vs Throttle Position
-easily done by a "stolen" diesel system or simple injectors where the
firing rate is controlled by rpm and the pulse width by the throttle. The
rest is all air control.
- As an exercise for the student, go rethink the fuel air mixture tables vs
power stuff. BUT - keep in mind the tables are for Air Constant - Fuel
varying. Re plot them holding fuel constant - air varying. A very
different picture occurs. Suffice to say that thru reasonable regions,
power will remain approximately constant and directly proportional to fuel
with much less effect of air changes. Remember once more - the existing
table gives you power with the air held constant. Rethink them with the
fuel held constant.
A 24/7 Reed flap with a servo override could make the subtle air mixture adjustments.
Here is some idea of the Aux duct layout.
Two things to note is that the main duct roof slopes down to form a hump,and the floor is horizontal ( making a ski slope hump ), to reduce the area where the Aux side ports intersect.
And the spigots floor should be parallel to the duct floor, and the roof has all the angle change to make the oval ( with ears ) to round transition.
Jan also let on that the shorter he made the septums between the main and Aux ducts, the more power appeared.
I dont know how short is too short, but in the TM kart cylinders I make the wall end shorter than stock by grinding it into a radius, instead of the square shape I have drawn.
I figure with a hump/slope in the roof you don΄t utilize the backpulse as good as it could be done?
As the pulse will mainly hit the piston.
If having whole ducts roof flat but with an angle of 25 degree, and the hump in the floor instead, how would it compare?
Now the first prototype is being manufactured! It has not been easy to solve the increase in cooling of inside transfer. The prototype produced now has a 60% chance of success(survive the casting). Just keep my fingers crossed now
No amount of experimentation can ever prove me right; a single experiment can prove me wrong.
Now the first prototype is being manufactured! It has not been easy to solve the increase in cooling of inside transfer. The prototype produced now has a 60% chance of success(survive the casting). Just keep my fingers crossed now
Did you look into 3d printing also? Especially with small batches of small displacement cylinders 3d printing is quite competitive in regards of pricing. And that with a success rate of normally 100%.
Did you look into 3d printing also? Especially with small batches of small displacement cylinders 3d printing is quite competitive in regards of pricing. And that with a success rate of normally 100%.
I have a lack of knowledge in 3D printing!
Read below and became a bit unsure if it would be so much easier and 3d print.
If this does not work, it's something I have to look at.
""Thermally Induced Stresses
Your model in Aluminum is 3D-printed using M3DP which is basically a layer-wise welding process. The layer-wise powder melting and its solidification leads to thermally induced stresses upon the cooling down of the melted powder. A design that is not suitable for M3DP can lead to build failures and/or part deformations due to large thermally induced stresses. It is therefore essential to consider the process-specific restriction while designing the part. We advise you to round off or fillet the edges in your design with a minimum radius of 3 mm. Also, avoid sharp edges for the same reason. Try to avoid large material accumulations and, in general, favor organic shapes over edged designs."
edited: because I didn't understand the context of what I wrote
No amount of experimentation can ever prove me right; a single experiment can prove me wrong.
SwePatrick, as I said the hump in the roof is part of reducing the sudden area expansion within the duct where the Aux ports intersect.
And as far as flow is concerned the humps angle change is so gradual that the returning gas flow stays attached so it does not create any drastic
turbulence or reduction in stuffing efficiency.
In any case the very quickly reducing area above the piston is so small , if you draw a tangential line from the hump to the port face , that at that stage , any inward flow is practically nil.
Proof of the above assumptions on my part is that if you grind out the roof hump in a TM cylinder power is lost , if you add a hump to say a PVP superkart ( read Aprilia copy ) cylinder , power goes up.
Speaking of PVP cylinders, they are all 3D laser printed directly off the CAD file,and have no reliability issues as the raw casting is hipped and stress relieved prior to machining.
Ive got a thing thats unique and new.To prove it I'll have the last laugh on you.Cause instead of one head I got two.And you know two heads are better than one.
mmm just hoping for the best! can not afford to fail
trapped gases trying to escape through the molten metal
cores not vented properly, gas needs to escape but via a path, usually through the core prints not the metal.
Or heavy shrinkage due to over heated metal and no feeders or risers in the right place.
What alloy?
Why 'can't afford to fail'? Just cast another one, I'm assuming you have the patterns.
SwePatrick, as I said the hump in the roof is part of reducing the sudden area expansion within the duct where the Aux ports intersect.
And as far as flow is concerned the humps angle change is so gradual that the returning gas flow stays attached so it does not create any drastic
turbulence or reduction in stuffing efficiency.
In any case the very quickly reducing area above the piston is so small , if you draw a tangential line from the hump to the port face , that at that stage , any inward flow is practically nil.
Proof of the above assumptions on my part is that if you grind out the roof hump in a TM cylinder power is lost , if you add a hump to say a PVP superkart ( read Aprilia copy ) cylinder , power goes up.
Speaking of PVP cylinders, they are all 3D laser printed directly off the CAD file,and have no reliability issues as the raw casting is hipped and stress relieved prior to machining.
I use the same method as PVP done earlier at the same place. Have you got any more info where did they start 3D printing and why they stopped using plaster casting?
Originally Posted by Flettner
trapped gases trying to escape through the molten metal
cores not vented properly, got gas needs to escape but via a path, usually through the core prints not the metal.
Or heavy shrinkage due to over heated metal and no feeders or risers in the right place.
What alloy?
Why 'can't afford to fail'? Just cast another one, I'm assuming you have the patterns.
It's not my picture, it's Frits
I have not failed yet! (I use 3d printed wax cores)
No amount of experimentation can ever prove me right; a single experiment can prove me wrong.
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