Nice Bike Hookworm! I can tell that's one of Dean's pipes. How's the low end?I just put this tuned pipe from a mini crotch rocket on and it is the bomb.
I had it up 36.2 mph on flat ground and it is very smooth.
The page is at: http://www.bevenyoung.com.au/mota.htmWe now have a simple 2 stroke expansion chamber design program. FREE download here:
This program is not a part of MOTA, but it has been put together by the same engineers as a starting point for those wishing to begin from scratch. It calculates the dimensions for both double and triple stage diffuser expansion chambers from a few basic engine dimensions. The information used in the program's calculations was taken from the books ‘The Basic Design of the Two Stroke Engine’ and the book ‘Design and Simulation of Two Stroke Engines’; both books are written by Professor G.P. Blair of Queens University Belfast, and published by the Society of Automotive Engineers. You are well advised to read at least one of the books mentioned above, since they contain the author’s academic lifetime of knowledge on the two-stroke engine.
There are several coefficients used in the design of the expansion chamber – these are a function of the engine’s state of tune. Those used in this program have been chosen for petrol engines, and are in the range 50cc up to about 500cc per cylinder. It is doubtful these formulae would work on small capacity glowplug engines, since the exhaust gas temperature is much lower, and the engine speed is much higher.
very cool setup!I just put this tuned pipe from a mini crotch rocket on and it is the bomb.
Hey, so what bike did you get this one off of (or what ebay auction?) I've got a 65cc tuned pipe coming that I'm going to try to fit to my 67cc HT, but its going to take a lot of cutting and rotating to get the exhaust routed properly. Should be better than stock at least.I just put this tuned pipe from a mini crotch rocket on and it is the bomb.
I had to braze a bracket on the back, and bolted it to seat post clamp.I took a rubber hammer and made a small dent so it would fit frame a bit closer.The header pipe was slightly off so i heated it up and pulled it out .It is a nice looking pipe and it sounds really nice as well.I had it up 36.2 mph on flat ground and it is very smooth.
For those who are interested in explansion chambers I'm posting a link to a small web site that has an animation of how it all works, with an expansion chamber. Mufflers only quieten the sound. shown are cut away views of carb, engine, and chamber. It's in color and watching it for a few seconds can explain much.
As I mentioned before there are expansion chambers for low range performance, mid range, (which I used) and high rpm range. There is also
what's called a "Torque Chamber" and it is what's shown in the site. (it has the parallel spacer in the tube where "range" chambers are made of all tapering sections of tubing. The torque chamber increases torque accross all RPM ranges. You don't feel a boost of power like you do with an RPM range oriented chamber.
I don't know if anyone downloaded the free expansion chamber design software I posted the link to a few post back. My little motor is just 30 some cc's so I'd have to multiply several times by the software's size thresholds to design a system and then reduce it by the same factor to keep it to scale.
But give this a look:
A RUNNING 2 STROKE ENGINE:
A two-stroke
I didnt like the noise level so I built a silencer that was almost double the inside diameter so I could get more packing in and give the ehaust more room to expand before leaving. MUCH quieter, and still sounds GREAT....My bike sounds just like a chainsaw... & I love it!!