They are so simple and fun that ive always enjoyed tinkering with them. The power listed on this guide is from experience not claims. Bigger carburetors, higher compression ratios, altered port timings and expansion. Two stroke tuners handbook 2 another mistake commonly made, sometimes even by those who have enjoyed some success in modifying two stroke engines, is to believe in a kind of mechanistic magic. This 2 stroke engine animation, article and diagrams are courtesty of.
Two stroke performance tuning chapter 3 porting and cylinder scavenging today, when we take a look down the cylinder of a two stroke engine, we find its walls literally filled with ports to handle the induction, transfer and exhaust phases of gas flow through the engine. Bells fourstroke performance tuning book, this book goes into extreme detail regarding performance tuning a twostroke engine. The website does not intend to compeed with any other website dealing with 2 stroke tuning, and the information shared is not at all as thorough as. I usually recommend this book along with gordon jennings two stroke tuners handbook, because this book has what the first one doesnt and vice versa. Freeware 2 stroke expansion chamber exhaust calculator program. Each intake port can be locked to a fixed timing relation with the exhaust port. This engine modelling software allows for the complete prediction of engine performance from torque to fuel consumption to exhaust emissions.
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. Velosolex s 3800 2stroke tuning and engine design books. There are many ways to boost the power, one of which is by installing a tuned pipe. Those of us who have grown up in the japanese twostroke.
The software in question the inexpensive stuff is great for someone who just does not have the math skills to wade through what seem to be a text book of complex formulas. Twostroke tuners handbook by gordon jennings pdf manual. Although there is really no shortage of books on the subject of 2stroke tuning and preparation, i knew that an active software programme would be able to offer so much more. At the end of the article i recommend the oil that has worked the best for me.
The newest info i have is the twostroke tuners handbook by gordon jennings. Two stroke engine and exhaust design software page 2. Graham bell starts off by saying that he doesnt believe port time area and its all about the duration the ports are open. This engine modelling software allows for the complete prediction of engine. Do it right by doing it yourself this screenshot is sheet 1 of 4 sheets. 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. May 03, 2012 twostroke tuners handbook by gordon jennings pdf manual. In this second video of the series on 2 stroke expansion chamber exhausts. Reviewed in the united states on november 20, 2014. On a stroker things like matching the ports to the liner, crankcase to transfers etc. Free 2stroke tuning info, pdfs and software free tuning and maintenance info, plus links to our original tuning pages that started it all off. The way a two stroke motor works causes them to be f. The website does not intend to compeed with any other website dealing with 2stroke tuning, and the information shared is not at all as thorough as. If you are a novice or beginner then this book is for you.
If you are looking for an interesting doityourself science project, get the software, by all means. This 2 stroke engine animation is accompanied by an excellent article with several 2 stroke engine diagrams and indepth explanations of the 2 stroke engine cycle. The morbidelli 125 twin road racer is a rotary valve engine. Very informative also gordon jennings book on twostroke tuning is an excellent book. Here is a pdf of gordon jennings 2 stroke tuners handbook. Basic 2 stroke tuning by eric gorr changing the power band of your engine is simple when you know the basics.
Great tool for those who are building exquisite format exhausts, one of the largest benefits of this module is that it can be used with any exhaust formula results. The most common mistake is to choose the wrong combination of engine components, making the engine run worse than stock. My first attempt at pipe design was a miserable failure. Over the years i added several other books on the subject to my library, the two books mentioned. Get it if you want to squeeze peak performance out of your 2stroke engine.
Great book, but ill guess the world has moved past that info. Calculates required ranges of jennings or blair angle areas, mean areas and time. Jennings book talks about port time area and porting the cylinder to have peak efficiency at a certain rpm. My passion is in motorcycle hillclimbing and in this sport we tune the engines to produce the most. Calculates required ranges of jennings or blair angle areas, mean areas and time areas. Basic 2 stroke tuning changing the power band of your dirt bike engine is simple when you know the basics. Balancing the crank dynamically, getting correct piston to bore clearance, using good rings with correct end gap, matching piston weights. Those of us who have grown up in the japanese two stroke. Two stroke performance tuning a disc partially cut away and attached to the end of the crankshaft opens and closes an inlet port in the side of the crankcase. Also gordon jennings book on two stroke tuning is an. The trend in high performance two strokes has continued towards more case volume, however each engine and application differ. Software for fine tuning and design of two stroke engine.
The piston crown opens and closes the exhaust and transfer ports. In keeping with having fun and i was if only jennings had that softwarewow, no mountain tall enough. Gordon jennings was a life long motorcycle enthusiast and writer who worked as an editor for cycle magazine and motorcyclist magazine. Split your calculated 2stroke exhaust up to 42 sections with regular length or even more with irregular lengths. Our specialist engine tuners will be able to help you with every aspect of your tuning and servicing. The businesses and individuals that purchased the original dynomation 2 stroke program were pleased with the capability and accuracy of the software. Twostroke tuners handbook gordon jennings i heart stella. Typical figures for engines with porting and other plumbing arranged solely and effectively for maximum horsepower at peak revs would be about 115 psi with. Dec 28, 2015 after 43 years, there is very little not known about rd engines, porting and pipes. The official home page of our 2 stroke wizard tuned pipe. Buy two stroke tuners handbook by jennings, gordon isbn. A twostroke or twocycle engine is a type of internal combustion engine which completes a. But once you get through it, 2 stroke engines will be as familiar to you as your own hands.
For sheer power for money and driveability the best setup would comprise of. If i remember right, jennings was the editor of a great magazine, cycle. Most of my friends and i rode 2 stroke street bikes and welcomed the knowledge that jennings put forth. His port time equations dont even include rpm, you input the dime. Dynomotion 2, mota v 50, and tom turners tsr software. Nov 26, 2017 in this second video of the series on 2 stroke expansion chamber exhausts.
But because of the limited worldwide activity in twostroke engine development, program sales were limited and further development was curtailed. We look at how the exhaust port timing edge is determined by the port in relation to the top of the piston and how that. Turbo and even supercharger setups of various configurations can be very useful, however, they are often more complicated with 2 stroke tuning than with 4 stroke applications on a tangent, i did witness a 50cc turbo 2 stroke bike that would do over 150mph, but i digress. A myriad of different aftermarket accessories is available for you to custom tune your bike to better suit your needs. Mota for windows slide show of features millions of tuning variations possible. 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. Two years before finishing school i started racing 50cc motorbikes and started tuning 2 stroke engines. Petals reed valve in the 2stroke 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. Stan stephens tuning are the uks number 1 two stroke tuning firm. Hi performance two stroke porting software program youtube. But because of the limited worldwide activity in two stroke engine development, program sales were limited and further development was curtailed. It lets you quickly to optimize carburetion, ignition timing, spark and transmission ratio, when change, the weather conditions, the compression ratio, the height of squish, the squish band, the exhaust opening angle and the gasoline used. In motocross its usually a compromise between best peak hp and good early off the pipe power.
Twostroke waveaction engine simulation motion software. Im working on gathering enough parts to build a triple cylinder rd400 and at some point ill need to sort out the porting and exhaust. First rule of 2 stroke or any tuning is to make it like it should be, i. Racingsm software has features for many different areas 2stroke 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. Two stroke performance tuning chapter 3 porting and cylinder scavenging today, when we take a look down the cylinder of a twostroke engine, we find its walls literally filled with ports to handle the induction, transfer and exhaust phases of gas flow through the engine.
Very interesting book, lots of great insights and tidbits of knowledge even for those who dont plan to tune any two strokes any time soon. I have been running high performance 2 stroke engines for around 30 years in my dirt bikes. Jenning vs graham bell, 2 stroke tunning books motorcycle. 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. I bought a new two stroke piston engine on special for the purpose of showing how to measure up exhaust port area and timing to plug in to the 2 stroke expansion chamber exhaust software. Everyday low prices and free delivery on eligible orders. Software for fine tuning and design of two stroke engine by. The newest info i have is the two stroke tuners handbook by gordon jennings.
If your looking for the best from your 2 stroke mad biker designs has its own dedicated tuning arm under mad biker developments not content with being one of the premier parts suppliers in the uk from world renowned companies, such as brembo, dymag, samco to name but a few. Gordon jennings and crossflow two strokes boat design net. Gordon jennings 2 stroke tuning pdf everything2stroke. Hello select your address todays deals best sellers gift ideas new releases gift cards customer service sell. The idea is to get an education in cause and effect. Nov 11, 2010 jennings book talks about port time area and porting the cylinder to have peak efficiency at a certain rpm. I cannot find a book or guidance about porting a crossflow engine. His tech articles were the first things we read on the way back from the mailbox.
The software in addition to defining the geometry of the insert, it also indicates the processing steps for its craft realization. The old adage of stuffing cases on every project just isnt true any more. New feature of racingsm software, the 2stroke exhaust segment splitter. I remember jennings insisting flow in must equal flow out and make it as flowable as possible. Geared specifically for gp and kart racers, this hardback treasure has turned out to be a great reference source for questions on the logic and concepts that pertain to tuning a 2 stroke for maximum performance. This section describes the basic function and the most important processes in the 2stroke cycle a tuner need to consider in general and with the bimotion tuning software in particular. Gordon jennings 2 stroke tuning pdf if this is your first visit, be sure to check out the faq by clicking the link above. I regard this book to be one of a pair of nonacademic tuning books to own. Two stroke tuners handbook jennings moped wiki moped army.
Setup two stroke is the universal software for optimal tuning of all 2stroke engines. After 43 years, there is very little not known about rd engines, porting and pipes. Near the end you will be presented with the latest and best software for design and analysis of 2 stroke pipes. Free 2 stroke tuning info, pdfs and software free tuning and maintenance info, plus links to our original tuning pages that started it all off. It clearly shows the air fuel mixture as a green mist while entering the engine through the intake track. Two stroke engine and exhaust design software north. How to design a two stroke expansion chamber performance. Two strokes can function with significantly better.