2 stroke engine expansion chamber design software

Expansion chamber for 2 stroke motorized bicycle engine. From a 49cc racing engine, to a gp 125 engine, or a 1500 mercurial triple engine, or a 250 kart engine, racingsm software suits all. Fourstroke expansion chambers general dirt bike discussion. Two stroke petrol engines are preferred when mechanical simplicity, light weight, and high powertoweight ratio are design priorities. There is no 2stroke displacement limit for our software, for example you can have a 125, 250, 500, 700 singlecylinder and our modules will work flawlessly. Two 2 stroke exhaust expansion chamber calculator using 3 methods.

May 03, 2018 to calculate bmep we need to first caclulate the swept cylinder volume of the engine and use a simple equation with swept volume as well as target rpm and rated power on the engine at that rpm. The businesses and individuals that purchased the original dynomation 2 stroke program were pleased with the capability and accuracy of the software. We now have a simple 2 stroke expansion chamber design program. This will get you started by providing, for your engine, the dimensions of an expansion chamber with a 2stage or 3stage diffuser. The first commercial twostroke engine involving incylinder compression is attributed to scottish engineer dugald clerk, who patented his design in 1881. Two stroke engine and exhaust design software post by oldjohnno sat jan 16, 2016 8. Cold rolled sheet metal i used 18 gaugelots of welding rod i used a 110v wire feed welderrubber stoppers for isolation. This is important because it determines the time duration. So whether you have a 50cc road bike, a 500cc motocrosser or a classic racer, we will design the perfect exhaust system for you.

The software equations used are derived from the work of professor gordon p blair who carried out the most comprehensive scientic study of 2 stroke engines ever undertaken and published by sae society of automotive engineers. Small values of kh are best suited to grand prix engines with narrow power bands, larger. File type pdf two stroke engine expansion chamber design software two stroke engine expansion chamber design software unlocking the secrets of 2 stroke expansion chamber exhausts e1 this is the first video in a series looking at the science and mysteries of 2 stroke expansion chamber exhausts. The chambers is the single most important thing when it comes to tuning the 2stroke engine. On a twostroke engine, an expansion chamber or tuned pipe is a tuned exhaust system used to enhance its power output by improving its volumetric efficiency. New version of 2t exhaust calculator it is a freeware 2 stroke expansion chamber. The chambers is the single most important thing when it comes to tuning the 2 stroke engine. Expansion chamber calculations by an excel workbook file. Professor blairs tests proved that thereturn waves timing can be calculated fairly closely using the straightdistances and the pressure wave speed in the pipe for that distance. This project was done while i was in school for mechanical design. Hence, more people are now looking at restoring and tuning these bikes.

In a twostroke engine, every stroke leaving top dead center is an expansion stroke i. As the 2 stroke engine animation below shows, a twostroke engine in its purest form is extremely simple in construction and operation, as it only has three primary moving parts the piston, connecting rod, and crankshaft. This expansion chamber is not the product of simple correlations as for other products that abound on the web, but an automatic design created by mota which is a full wave action 2stroke engine simulator. But because of the limited worldwide activity in twostroke engine development, program sales were limited and further development was curtailed. Nov 02, 2019 for introductory material on 2 stroke engines please see the following links. Dec 11, 2018 using the plot cone dimensions from the two stroke freeware expansion chamber calculator i show how to draw a cone plot on to flat papers to be traced on to sheet metal. Two 2 stroke exhaust expansion chamber calculator apps on. The crankcasescavenged engine, employing the area below the piston as a charging pump, is generally credited to englishman joseph day. Motax contains all the features found in mota plus expansion chamber. Performance fabrications is dedicated to manufacturing the finest bespoke hand crafted exhaust systems available. I learned that many of the pipes built are compromised to give max ground clearance or. How to design a two stroke expansion chamber performance. If you want the best pipes for your engine, be sure they are timed to fit your porting. Direct comparison between different types of exhausts for the twostroke engine, on the left you can see the engine and its exhaust, in the.

We also have a simple 2stroke expansion chamber design program. Exhaust pipe muffler for 2 stroke 47cc 49cc engine mini pocket bike condition. Otherwise, your porting may peak at 8,000rpm but your pipe may reach max resonance at 9,500. Without a pair of really good chambers you will never get much power from. However, unlike most later twostroke engines, his had a separate charging cylinder. In a two stroke engine, every stroke leaving top dead center is an expansion stroke i. This will get you started by providing, for your engine, the dimensions of an expansion chamber with a 2 stage or 3stage diffuser. While moving downwards after ignition, the piston exposes the exhaust opening, and the burned gas streams into the exhaust pipe like a high pressure shock wave. Two stroke tuning by alexander graham bell excellent book. File type pdf two stroke engine expansion chamber design software two stroke engine expansion chamber design software unlocking the secrets of 2 stroke expansion chamber exhausts e1 this is the first video in a series looking at the science and mysteries of 2. For a 2 stroke engine the tuned pipe is the section of the exhaust system that begins at the exhaust port and ends at the end of the converging section. The blueprints for this model are in the book beginners guide to solidworks 20. Expansion chamber design virtual 2stroke engine simulation.

There is this nice animation of a 2 stroke engine with an expansion chamber. You can also save and load the data by using the provided functions. The 2 stroke engine cycle the characteristic feature of the two stroke engine is its means of operation. Just a quick update on the progress of the freeware 2 stroke expansion chamber calculator software. Without a pair of really good chambers you will never get much power from you rd 350 ypvs. Two stroke engine expansion chamber design software. As the forces in a two stroke pipe design have become more wellunderstood, designers have been able to create engines that take more advantage of them and in fact require an expansion chamber to run at all. This excel spreadsheet uses sophisticated mathematical means to determine the return waves shape, length, and peak which are used in additional formulas to determine the extra engine power the expansion chamber is contributing to the engine throughout its rpm range. The calculations are assuming a speed of sound in the exhaust gas, which is not known exactly. How twostroke expansion chambers work, and why you should. The worlds leading 2stroke engine simulation software for 3.

And there have been expansion chambers built for fourstrokes for years. A complete twostroke pipe has properly tuned header, convergent, belly, divergent and stinger sectionsa difficult process. Find great deals on ebay for 2 stroke expansion chamber and 2 stroke exhaust. With the traditional lubrication technique of mixing oil into the fuel, they also have the advantage of working in any orientation, as there is no oil reservoir dependent on gravity. Direct comparison between different types of exhausts for the two stroke engine, on the left you can see the engine and its exhaust, in the.

This program calculates the dimensions for both double and triple stage diffuser expansion chambers from a few basic engine dimensions. Freedownload here this program is not a part of mota, but it has been put together by the same engineers as a. The 2stroke engine cycle the characteristic feature of the twostroke engine is its means of operation. So now i will build a expansion exhaust for my ported and modified yamaha tzr250 tuned cafe racer using this program. The program takes your info and spits out a sheet with lengths and diameters. In a four stroke engine, there is only one working stroke against three negative strokes induction, compression, and discharge.

We shall send you a pdf document with the templates for manufacturing your exhaust. So whether you have a 50cc road bike, a 500cc motocrosser or a classic racer. Improve the performance of your two stroke engine with a torqsoft designed exhaust system. Here is the official description for 2 stroke wizard tuned pipe. 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.

Two stroke designmodification software the following are spreadsheets for different aspects of 2 stroke designmodification. Two stroke tuners handbook 2 another mistake commonly made, sometimes even by those who have enjoyed some success in modifying twostroke engines, is to believe in a kind of mechanistic magic. Building your own racing expansion chambers rdrz 350 ypvs why should i even bother making them. This small java applet uses design rules according to, and, to size a tuned pipe for a 2 stroke piston engine. Mota software, 2 stroke engine simulation software, 2 stroke exhaust design. As the forces in a twostroke pipe design have become more wellunderstood, designers have been able to create engines that take more advantage of them and in fact require an expansion chamber to run at all. Bigger carburetors, higher compression ratios, altered port timings and expansion. A simple 3 stage two stroke exhaust calculator based on formulas of g. But because of the limited worldwide activity in two stroke engine development, program sales were limited and further development was curtailed. As soon as you add 1 or 2 more cylinders to the mix, the soundwaves for lack of a better explaination begin to collide in a way that dis.

I guess 2 stroke exhaust system design is all about tradeoffs, and i think for woods riding it may be better to lose unburnt charge out the tailpipe at high rpm longer pipe then push burnt gases back into the motor at low rpm shorter, but thats just my totally nonexpert opinion. After our trial and test, the software was found to be official, secure and free. The blueprints for this model are in the book beginners guide to solidworks 20 level 1 here is a link to download the book that has the blueprints in it. On a two stroke engine, an expansion chamber or tuned pipe is a tuned exhaust system used to enhance its power output by improving its volumetric efficiency. Jan 19, 2008 we where both very surprised, after punching in his engine specs, that the resulting dimensions of the program expansion chamber exhaust is in all dimensions within 1mm to 4mm of his exhaust specs. Multiple dual exhaust pipes were simulated using virtual 2stroke software to find the optimal single. First the piston is moved downside from tdc to bdc to. It runs the tried and tested mota simulator many times, altering the expansion chamber dimensions intelligently between simulations, to produce an optimal expansion chamber design. Jan 28, 2011 i bought an expansion chamber design program, and it produced numbers more in line with what i though i should have from what ive been reading. This coefficient kh is called the horn coefficient, with typical values between one and two. Two stroke engine and exhaust design software north. Freeware 2 stroke expansion chamber exhaust calculator program.

Engineering acousticssonic supercharging of 2 stroke. Follow the link to my software site and go to the 2t exhaust calc menu. The high performance 2stroke engine is a pulse resonance engine which means that the operation in general and the scavenging in particular is not only dependent upon the pulses created from piston pumping but also from combustion properties. How twostroke expansion chambers work, and why you should care. However, the twostroke cycle can be difficult for some to visualize at first because certain phases of the cycle occur simultaneously, causing it to be hard to tell when. Free 2 stroke exhaust expansion chamber calculator youtube. There is no 2 stroke displacement limit for our software, for example you can have a 125, 250, 500, 700 singlecylinder and our modules will work flawlessly. Spark plug a spark plug delivers electric current to the combustion chamber which ignites the airfuel mixture leading to abrupt expansion of gas. Method 1 and method 2 two and three stage diffuser. Improve the performance of your twostroke engine with a torqsoft designed exhaust system. Why do twostroke engine exhaust pipes look so strange. There is this nice animation of a 2stroke engine with an expansion chamber. Jan 15, 2005 four stroke exhausts can work in similar ways, but because the four stroke is more like a positive pump, and not so dependent on the dynamics of gas inertia just to even run, the effect an exhaust system will have on them is going to be more subdued.