Degree tool?

[danlandberg]

I

that sorta sounds like a reference to short circuits, need input...

mh-aerotools has a free java app for tuned pipes. not great but they work, for a freebie.
be warned, you need a fairly old java to run it, unless you install it and run it that way...
also has a very handy silencer calculator, you can punch in various figures, get an idea of what attenuates what, and it actually works very well

sticking the stinger or outlet pipe virtually all the way into the pipe reduces a lot of the noise. just make sure it isnt sitting halfway into the "reversion" cone, it stuffs things up seriously.


me myself use 2 stroke wizard pro..i preferred version 3 to 5, and cant really say anything about the "duel" add on program now supplied with it(only tried making one with the extension once, maybe if i had more patience to experiment with various mesh sizes?). pretty cheap, seems to work ok though.

never had a justifiable reason to buy any expensive stuff like "MOTA"... all the forum blurbs elsewhere say it pops out dimensions fairly similar to the cheaper 2 stroke wizard anyways.

I'm looking at one on Google Play, it asks a couple of specs, and a couple of targets. Want to put in factual readings, build one out of cardboard, see how it looks and then go from there.

 

[danlandberg]

One of th

I
I'm looking at one on Google Play, it asks a couple of specs, and a couple of targets. Want to put in factual readings, build one out of cardboard, see how it looks and then go from there.

One of the questions is exhaust port length, I assume that is the measurement from piston skirt to exhaust manifold flange. I know what height and width is all about. Don't know how good the calculator is, but if it has me build some crazy looking thing then I guess I'll know. Your right, "short circuit" I think I may have one at times. LoL
Can't stop wanting to build stuff.

 

[HeadSmess]

200 GSM paper, or very thin cardboard. the only "straight/untapered" sections on this template was the first piece, the belly, and the stinger..

lay out the conical templates with some free software called cone layout... divide the pipe up into sections, i tend to work on round mm per segment, and tweak the pipe design to get nice workable figures...ie, 270mm with an increase of 9mm divides into nine 30 mm sections increasing by 1mm very easily who cares if the powerband is at 7,543 rather than just 7,500 rpm?

found that aiming for anything over 8000 rpm is a waste of time. with these at least. another reason i gave up on porting, its too much effort laying up a new pipe to suit all these new dimensions each time.

the best bet is to do as described in jennings book... use a stub exhaust, experiment with best intake length until the engine has plenty of grunt, then design the pipe for those dimensions.


the more bends the better, except it gets hard to join them all. started a thread on hydroforming and thats about as far as ive gotten... still dont have a new tig or a pressure washer to pump the profiles up with. when i do, might start experimenting with the ports again once a pipe takes twenty, thirty minutes rather than twenty, thirty hours!

jag did make the effort to calculate the flat profile needed to make a 1.5" tube with 180 degree bend on a 5 inch radius. two curves, 10.3 and 12.8 inches from memory, marked at 78 degrees included angle... never been confirmed though. making a tapered section is slightly more awkward.

my first pipe went underneath, with only about 3 sharp bends, then i flattened it to clear between tyre and pedals...dont do this! it stuffs up all your calculations! they work on changes of dimension. flattening is obviously a change of dimension.

 

[Archiwax]

I printed this and stuck it on a piece of plastic on a piece of plastic and drilled a hole in the middle.

 

[danlandberg]

I have a couple of 180° protractors I could use to make a degree wheel.

 

[45u]

I have one I use on my radio control motors and big ones for motorcycles. I think I will adapt the small one to work. If you know of anywhere to get 1/5 scale parts should have them if not you can get one here.

Never mind did not know they went up so much.

 

[danlandberg]

Add the link please. Would like to see a pic.

 

[45u]

http://www.davesmotors.com/DDM-Engine-Degree-Wheel-Tool-GPDW.html

 

[danlandberg]

Thanks