Two stroke expansion chamber software programs

Two stroke cylinder porting tips watch this before you. To build an expansion chamber, first you have to get a copy of gordon jennings 2 stroke tuners guide. Our engineered 2 stroke expansion chambers are engineered to your engines porting specs. A simple 3 stage two stroke exhaust calculator based on formulas of g. This is the place to talk about anything related to two stroke road race bikes. The official home page of our 2 stroke wizard tuned pipe. Its a good book to start with if you want to understand how a two stroke engine including exhaust works. How to plot two stroke expansion chamber cones on paper from. It makes use of the energy left in the burnt exhaust exiting the cylinder to aid the filling of the cylinder for the next cycle.

Rating is available when the video has been rented. Software for fine tuning and design of two stroke engine. You can also save and load the data by using the provided functions. Why is there a bulge in the exhaust pipe of my dirt bike. Performance fabrications is dedicated to manufacturing the finest bespoke hand crafted exhaust systems available. Expansion chamber, free expansion chamber software downloads. Fabbing up a complete 2 stroke pipe vintage dirt bikes. I got sick of the silly free programs and the expensive for sale programs and that wasteoftime 2 stroke wizard and so made my own expansion chamber calculator spreadsheet. My main concern is weather or not the expansion chamber would be damaging to the 4 stroke engine. Jan 15, 2005 ok, i had a question up a week or two ago about why two strokes have their expansion chambers in the pipes. High performance two 2 stroke exhaust port desig cheats tips and tricks added by pro players, testers and other users like you. Software for fine tuning and design of two stroke engine by. 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.

We now have a simple 2 stroke expansion chamber design program. I have heard of pouring gasoline in and shaking it up, then lighting it on fire. One other old way of calculating the dimensions of an expansion chamber relied on generic formulas that put the emphasis on the wrong things. Jul 25, 2007 exhaust pipe design with cone layout software by paul crowe if you have ever tried to layout a conic section on sheet metal, cutting just the right piece, that when rolled over and joined on edge, you have a cone with the exact shape, size and angled openings desired, you know its not easy. The software in addition to defining the geometry of the insert, it also indicates the processing steps for its craft realization. Most after market pipes are not tuned to your specific engine porting mods. Then after you read it about two dozen times, some of the expansion chamber theory will start to sink in, and youll know that the first thing that you need to do is pick an rpm that you want it to peak at.

Products gmc geoff morris concepts expansion chambers. There are a few software programs available for 2 stroke simulations. How two stroke expansion chambers work and why you should care. It is the 250cc to 500cc sized bikes that have seen a marked increase in second hand values. How to plot two stroke expansion chamber cones on paper from software duration. 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. 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.

For instance pipe calculators would determine the belly diameter based on blairs maximum size 2. Graham bell, two stroke performance tuning, isbn 0854293299. In the 80s tony was instrumental in the development of expansion chamber engineering and to this day is one of the foremost experts in the field. Some items i have in stock and some items i believe i can get in within a reasonable time.

The arrangement of the intake and exhaust ports in a two cycle engine affords a unique opportunity to use the exhaust system to influence the intake sequence. This technique only works on two stroke engines, which is why you see it on a lot of dirt bikes but not on street bikes. Small values of kh are best suited to grand prix engines with narrow power bands, larger. The expansion chamber that sick bike parts and pirate cycles sells seems to be proportioned well, although i suspect the lead in pipe will be smaller than ideal for maximum power.

But because of the limited worldwide activity in twostroke engine development, program sales. The stock pipe is basically a straight pipe anyway but i want to pit a straight pipe on it with a new school silencer on it. Google a the two stroke expansion chamber design ok i am not sure that will yield anything but the point is that there is some fairly serious science and math involved in an expansion chamber. Twostroke oil is expensive, and you need about 4 ounces of it per gallon of gas.

High performance two 2 stroke exhaust port desig hack. When the exhaust port shape is decided from time area targets etc. What happened was the 4 stroke sounded pretty annoying and i like the sound of a 2 stroke with a pipe, but it doesnt work the same on a 4 stroke. Im building a little street legal 30s style hillclimber out of a 73 dt1250. Hence, more people are now looking at restoring and tuning these bikes. That bulge is called an expansion chamber, and it is used to increase the horsepower of the engine see this page for a photo. The one i have been using is call mota, from ian williams tuning. Freedownload 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. Freeware 2 stroke expansion chamber exhaust calculator program. Using the expansion chamber to basically supercharge the combustion chamber with sonic waves was still going to be the norm, for now.

The pressure inflates the flat sheet into its final rounded shape. Expansion chamber for 2 stroke what do u recommend. If you need it urgently then i suggest you contact us first i expect that any orders will be sent within 7 working days, if there is any problem with stock availability then after 7 working days you will have the option of a full refund. Npp neils power pipes handcrafted custom pipes and. I put an expansion chamber 2 stroke pipe on a 4 stroke once just to see what happened. Racingsm software has features for many different areas 2 stroke exhausts development, drag racing features, simulators, carburetor tuning, connectingrod analysis etc with all this knowhow along with lufo racing heritage, we believe this is a very fair price. What will a two stroke run like without an expansion chamber. Mota and its related set of programs have been developed to simulate the performance of highoutput single cylinder twostroke engines.

Two stroke motors are more efficient that four strokes for a few reasons. Bigger carburetors, higher compression ratios, altered port timings and expansion. I have a few different 450 silencers, ill probably use one of those. So i was wondering if i could take my old expansion chanber off my 2 stroke and put it on my 4 stroke. With smallbore engines you may push the compression ratio up to perhaps 6. New version of 2t exhaust calculator it is a freeware 2 stroke expansion chamber exhaust calculator program download at. Free 2 stroke expansion chamber calculator software update. Look very good and i understand this program gave excellent performing pipes to others. This coefficient kh is called the horn coefficient, with typical values between one and two. This was on a 49cc 4 stroke pitbike engine, not a scooter. Unlike 4 stroke engines, two stroke engines require the expansion chamber and stinger reduced diameter over distance at the end of pipe. Twostroke engines do not use fuel efficiently, so you would get fewer miles per gallon.

An expansion chamber is an exhaust system used on a two stroke cycle engine to enhance its poweroutput by improving its volumetric efficiency. Read my expansion chamber theory page to get a full understanding of how expansion chambers work and click here to read more of the details of this spreadsheet. It also took a solid month or two for me to learn the factors involved and how to maximize the tuning. Two stroke engine and exhaust design software post by gerrit sun jan 17, 2016 10. This small java applet uses design rules according to, and, to size a tuned pipe for a 2 stroke piston engine. Petals reed valve in the 2 stroke engine with reed valve admission, the identification of petals more adapted to the reed valve and to the engine is essential to maximize the performance starting from the intake phase. This cylinder has two exhaust ports and five transfer ports so enter 2 in the no. Slowly tony evolved his own leading approach to developing pipe dimensions.

Sonicspeed shock waves are timed to arrive just in time to stuff the fuelair that escaped through the two stroke s exhaust port back into the cylinder just before closing four stroke exhausts can work in similar ways, but because the four stroke is more like a. But im curious as to how an expansion chamber would affect a four stroke engine. If you really found out what goes on with expansion chambers, you know its a fairly complicated thing. If any of you have any ideas on this please share them, thanks. Two flat representations of the required finished pipe are cut out of sheet metal. I was wondering how to decarbonize my stock expansion chamber.

This version is limited to 1 license per windows computer without time limit and can be used offline. The best method i have found is to heat the pipe red hot and burn the oil out of the carbon then it basically falls out of the pipe. But because of the limited worldwide activity in twostroke engine development, program sales were limited and further development was curtailed. On one end of the pipe a fitting is welded and highpressure water is pumped into the cavity between the sheets.

The software uses mathematical formulas that are approximations of reality, and the. It is also very good for expansion chamber designs. Fourstroke expansion chambers general dirt bike discussion. Dynomatontwostroke is a dosbased simulation that was originally. Two stroke engine and exhaust design software north. Moreover you can have advices for the development of the engine thanks to the help of tested formulas for intake, exhaust, blowdown and transfer. The basic theories of two stroke tuning were not seeming to change based on what method the fuel was delivered.

Go subscribe to nicos hollaendaren yt channel for more 2 stroke stuff. Very simplified explained, a good expansion chamber works like this. This program is a member of color expansion ais contest. I noticed a paragraph addressing squish velocity dynomation 2 does not calculate this parameter, but its creators know that it is an important design feature so they steer the user to the sae for blairs software andor tom e. This program calculates the dimensions for both double and triple stage diffuser expansion chambers from a few basic engine dimensions.

The edges of the two identical flat cutouts are welded together forming a sandwich. There is this nice animation of a 2 stroke engine with an expansion chamber. This will get you started by providing, for your engine, the dimensions of an expansion chamber with a 2stage or 3stage diffuser. Could it give a four stroke the two stroke famous bighit. I have been into 2 stroke bikes for over 28yrs and i have bought and tested many exhaust pipes on all the bikes i have owned to find the best one for my needs. Most street bikes use four stroke engines the basic idea behind an expansion chamber is to use the momentum and pressure of the.

May 24, 2017 faster computers and better aiming of the fuel was played with. This is critical to the pipes blowdown efficiency and the pressure build up. 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. When designing my h1 pipes, we ran three different programs, mota, bimotion and another that i dont remember the name of. The worlds leading 2stroke engine simulation software for 3. Turners two stroke racing for his squish velocity program. I didnt really like many of the pipes but a few were ok but i wanted more. Windows software racingsm software available for windows platforms desktops, laptops includes 27 programs which will help you on your 2stroke development. This will get you started by providing, for your engine, the dimensions of an expansion. The calculations are assuming a speed of sound in the exhaust gas, which is not known exactly. I obviously have no experience with tuned exhaust systems on these engine, but i do have experince with them on other 2 cycle engine, all rc model engines. Without a pair of really good chambers you will never get much power from you rd 350 ypvs. Building your own racing expansion chambers rdrz 350 ypvs why should i even bother making them. Why do twostroke engine exhaust pipes look so strange.

Two stroke engines, by their very nature, require some of the plumbing you note in your question. Specificaly written for gokarts engines, but will do any 2 stroke. The expansion chamber is the most tunable component on the modern two cycle engine and dramatic gains in power can be achieved with the correct design. This will get you started by providing, for your engine, the dimensions of an expansion chamber with a 2stage. Feb 22, 2017 how to build your own expansion chamber without any special tools. Expansion chamber exhaust design software i have just bought and installed this 2 stroke wizard tuned pipe expansion chamber design software package. A 20mm of main cone length can make the difference of 100 rpm. We also have a simple 2stroke expansion chamber design program. In the design form first select the water cooled and reed induction options from the dropdown menus. But because of the limited worldwide activity in two stroke engine development, program sales were limited and further development was curtailed. Also be sure to download mota expansion chamber design software to figure out those cones in the first place.

I have plans this winter to put my yz 125 motor in it but i would like to see how this little motor runs with a good pipe vs the stock one that i think is holding it back. How to build your own expansion chamber without any special tools. It is the two stroke equivalent of the tuned pipes or headers used on four stroke cycle engines. We also have a simple 2 stroke expansion chamber design program.

Its very complex, and if you want to know more i can recommend you to start with reading a. Just a quick update on the progress of the freeware 2 stroke expansion chamber calculator software. It will simulate one of the cylinders of a multicylinder twostroke engine provided that the cylinders are identical in layout and dimensions and each cylinder has a seperate exhaust and induction system. My goal is to get a nicer sound, i dont really care for performance though it would be nice. Cold rolled sheet metal i used 18 gaugelots of welding rod i used a 110v wire feed welderrubber stoppers for isolation.

If you have access to an industrial oven its your best bet, but you can use a propane or oa torch. What i have learned about them in general, is they provide more power, however it is at the one rpm range where they are tuned, and always at the expense of torque at lower rpm ranges. You would burn about a gallon of oil every 1,000 miles if you used a twostroke engine in a car. North american two strokes general two stroke discussion.

Two strokes are extremely sensitive to exhaust design. Do it right by doing it yourself this screenshot is sheet 1 of 4 sheets. Two stroke design instead you can enter the data of your cylinder with extreme facility and precision, and then analyze the port areas and the timing area in the engine cycle timing for each phase. To learn more about how expansion chamber exhaust systems work, read this great primer. The software uses mathematical formulas that are approximations of reality, and the software made for homecomputers uses even more simplified formulas because good simulation of expansion chambers requires much more computerpower than you homepc can offer. I have personally tried the less expensive expansion chambers you will find on ebay, or from. The chambers is the single most important thing when it comes to tuning the 2 stroke engine. My professional 2 stroke expansion chamber design software is more sophisticated than other programs that only use a few basic formulas.