Motor cycle tuning twostroke by robinson, john, 1994, newnes edition, in english 2nd ed. Join facebook to connect with luc foekema and others you may know. A book for all interested in two stroke engines, their tuning and testing and in the intriguing problems of two stroke design. Graham bell is an acknowledged expert on engine tuning, with many years experience in this field.
Thriftbooks sells millions of used books at the lowest everyday prices. This is a highly saught after book by motorcycle enthusiests. Other books to his credit are modern engine tuning, two stroke performance tuning and forced induction performance tuning. It perfectly describes details about 2 stroke motors and exhausts.
A 2t racing engine without exhaustpipe is more like a turtle. Open library is an open, editable library catalog, building towards a web page for every book ever published. Discover delightful childrens books with prime book box, a subscription that delivers new books every 1, 2, or 3 months new customers receive 15% off your. On a 2 stroke, the way the exhaust works, the air in the expansion chamber can be very turbulant at certain rpm and throttle ranges. Graham bell steers you through the various modifications that can be made to coax maximum useable power output and mechanical reliability from your twostroke. Hij vat het heel sportief op en ik ben het ook geheel eens met zijn schrijven. For sheer power for money and driveability the best setup would comprise of. Twostroke oil is expensive, and you need about 4 ounces of it per gallon of gas. You dont need fancy expensive stuff to port two stroke cylinders, you can get by with cheap tools and a little creative engineering. Goplus bicycle motor kit, 80cc 2 stroke upgrade bike engine kit, gasoline motorized gas engine bike motor kit, speed up to 50kmh, 2000w 4.
It covers not only two stroke motorbike engines, but also car engines as well. Twostroke high performance engine design and tuning. The most common mistake is to choose the wrong combination of engine components, making the engine run. A taller port restored lost power but made the power band unacceptably narrow. So to me it came about two years ago, and that is the foekema symmetric twostroke fst. Ik kan mij toch niet voorstellen dat frits geen internet heeft. Pdf download two stroke performance tuning free unquote books. With this howto guide, you can win the battle with the temperamental twostroke engine. Bigger carburetors, higher compression ratios, altered port timings and expansion. One day later jan thiel called me to congratulate me, that. For instance, if an engine has been properly designed for medium output and a midrange power peak, raising the. Two stroke performance tuning book also available for read online, mobi, docx and mobile and kindle reading. Loads of equations, fairly modern information, and an easy enough read for the mechanics out there who just now how to make there engines run, rather then how to make them better then when they came out of the factory.
The two stroke engine its design and tuning 9780854291571 by draper, k. Jan 30, 2018 10 of the highest revving two stroke bikes ever duration. Facebook gives people the power to share and makes the. Ill try and get the ball rolling in here with a list of books i currently own on 2 stroke engines, and 2 stroke engine performance tuning. Nov 11, 2010 jennings book talks about port time area and porting the cylinder to have peak efficiency at a certain rpm.
This website and app will help you tune your moped or any two stroke engine. This book is limited to the treatment of scavenging, as skill in design of scavenging is considered the key to successful twostroke cycle engines. The difference between the twostroke cycle engine and the fourstroke cycle engine lies principally in the method of scavenging. Dec 14, 2016 kreidler rs 50 testrun 2 mikuni tm249 with an other setup and neuw inlet venturi duration. It covers early development work and since it was written in 1968, does not have any of the powerful twostrokes of the later period. The power listed on this guide is from experience not claims. Two stroke performance tuning back in europe two stroke engineers were battling excessive ring and cylinder wear, due to the exhaust port width being too great. 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. Many things in twostroke tuning has been made since the beginning of the two stroke. I would really like to see some new two stroke porting books. Two stroke performance tuning back in europe twostroke engineers were battling excessive ring and cylinder wear, due to the exhaust port width being too great. Carefully pull one strip of clay off the piston and then measure the thickness of the clay left on the piston.
Graham bell starts off by saying that he doesnt believe port time area and its all about the duration the ports are open. Till sofare i didnt want to spend time for this because there are many more important things to do when you wanted to be the fastest 50cc sprinter in the world on the 150 meter and the. Fully revised this book takes the reader through the various modifications that can be made to a twostroke engine and its components to give maximum useable. There are many ways to boost the power, one of which is by installing a tuned pipe. Get it if you want to squeeze peak performance out of your 2stroke engine. Most of my friends and i rode 2 stroke street bikes and welcomed the. The high performance two stroke engine by john dixon is also very good. Contents chapter 1 introduction 9 chapter 2 the cylinder. The great attraction of the two stroke is its enormous potential, contrasted with its appealing simplicity.
Armed with little in this well established book, now brought up to date in a second edition, the technical editor of performance bikes shows you how to evaluate your engine, how to assess what work you can undertake yourself, and what is. Remove the head and then cut the clay down the middle with a sharp, wet knife. Sep 10, 2014 squish band width calculation on head motor 2 stroke. 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 what you can get from reading the books. Blair 2 basic design of two stroke engines, gordon p. Basic 2 stroke tuning changing the power band of your dirt bike engine is simple when you know the basics. Jenning vs graham bell, 2 stroke tunning books motorcycle. That is how a twostroke engine completes a power cycle in only 360 degrees of. Balancing the crank dynamically, getting correct piston to bore clearance, using good rings with correct end gap, matching piston weights.
But these changes will increase thepower only if you know what you are doing. Nov 19, 2016 a twostroke works on the pulses of the exhaustpipe. Ftt calculations was the fastest way to get the highest possible power in every two stroke engine. Graham bells two stroke performance tuning is the book to have. Luc foekema age 65 wins in genemuiden 2008, read important. 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.
A twostroke works on the pulses of the exhaustpipe. Tips on how to port a two stroke cylinder, what to donot do and how to do it right. Enough to get you started and hopefully lead on to growing your own knowledge and skills. Decades have passed since i hung around with john and jim. When tuning is made high or very high the exhaustpulses becomes far more important. Tuning by aalt toersen using ftt ultrasap ignition, ftt exhaust calculation and. Twostroke carbs are usually found on leaf blowers, motorized bikes and mopeds. Most these forms can not change with the increasing of the number of revolutions. A tuned pipe has a set of cones divergent meaning the cone gets bigger and convergent meaning the cone gets smaller. If aprilla doesnt do it there must be good reason not too. Race replica bike builds specializing in engine frame transplant 2 stroke race reps eg. Performance engineering 2stroke tuning we specialise in honda 2strokes, covering the cr range of motorcross bikes, the nsr250 street bikes, and hrc grand prix 125, 250, and 500s. My porting setup affordable and functional 2 stroke tuning.
Graham bell second edition this is the moped performance tuning bible as far as im concerned. There is quite a large section on changing the face of production racing and into the marlboro series and the lc era and through the kr1s and rgv eras. It was apparently released in 1968 in italian and 1972 in english. Lets journey back to 1973 and read the book that was the two stroke bible of that era. Two stroke high performance engine design tuning by cesare. Just in 1 calculation and a with a good execution, you get that result directly for every. Great book for those of us who like to really get nitty gritty with their engine tuning. The difference between the two stroke cycle engine and the four stroke cycle engine lies principally in the method of scavenging. 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. Detailing for any one interested in increasing the performance of their machines. Reading the above books, its important to keep in mind that both authors porting generalizations refer to comparisons among fullydeveloped oldschool racing engines, and shouldnt be taken out of context for modification purposes. The most common mistake is to choose the wrong combination of engine components, making the engine run worse than stock. When you use an afr in a 2 stroke you will work off the averages rather than the exact.
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. Twostroke performance tuning in theory and practice. I am very proud of the riders i helped and sponsored and there is an appendix. There is a huge interest in vintage snowmobiles and their simple two stroke power plants of yesteryear. How to made a 30hp kreidler 90cc dragrace cylinder, read. They are easy to work with and do not require excessive motor knowledge to achieve desired engine performance.
Information relates to engine to be found in formula junior cars, karts and outboard motor boats as well as scooters and motorcycles, detailed manual includes 290pages. Two stroke tuning paperback december 31, 1981 by roy bacon author see all 2 formats and editions hide other formats and editions. Two stroke moped tuning a tool to tune your two stroke. Generally, you will also need to rejet your carburetor to allow a greater volume of fuelair mixture to enter your. His port time equations dont even include rpm, you input the dime. Sep 02, 2008 ftt calculations was the fastest way to get the highest possible power in every two stroke engine. I do not profess to be an expert on two stroke tuning, but i can give you my experience with a efi two stroke project i have been involved with for quite a while. 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. This is because most parts of a 2 stroke engine has a solid form which is based on the purpose of the engine.
Anyone interested in doing their own engine porting, or taking the time to learn the intimate secrets of 2 stroke engines should take. It covers my early days in the motorcycle trade, on to starting my own mc business then forming my tuning business. Fit the head gasket and head and turn the crank to move the piston just past tdc. A tool to tune your two stroke engine, calculate duration, time areas, etc. Bells fourstroke performance tuning book, this book goes into extreme detail regarding performance tuning a twostroke engine. 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. Everyday low prices and free delivery on eligible orders.
Motorcycles, maintenance and repair, motors twostroke cycle, performance. Two stroke cylinder porting tips watch this before you. I started reading these about a year ago now and ive learned so much in just the short time already its mind boggling. A myriad of different aftermarket accessories is available for you to custom tune your bike to better suit your needs. Most of what i have read gives a full throttle mixture of around 0. That is why i thought that someone else already did the same in the past. This book is limited to the treatment of scavenging, as skill in design of scavenging is considered the key to successful two stroke cycle engines. A narrow port reduced power but improved reliability.
Motorcycle tuning twostroke 1994 edition open library. The way a two stroke motor works causes them to be fairly noisy and a bit inefficient. Twostroke carburetors are perfect practice for novice mechanics. These kits replace your cylinder and piston with a larger bore. The current way of scavenging exist almost from the beginnng of the 2stroke history and never changed, unless the many other systems which had been founded. Squish band width calculation on head motor 2 stroke motor. You would burn about a gallon of oil every 1,000 miles if you used a twostroke engine in a car. Twostroke, john robinson 5 the highperformance twostroke engine, john c.
We personally assess every books quality and offer rare, outofprint treasures. But thinking to get more power you automaticly come to new ideas. Moreover you can have advices for the development of the engine thanks to the help of tested formulas for intake, exhaust, blowdown and transfer. Building a 50hp two stroke shifter kart in 10 minutes full. Two stroke motors are more efficient that four strokes for a few reasons. The morbidelli 125 twin road racer is a rotary valve engine. First rule of 2 stroke or any tuning is to make it like it should be, i. There is a wealth of knowledge contained in this manual.
Other books to his credit are modern engine tuning, twostroke performance tuning and forced induction performance tuning. Download two stroke performance tuning in pdf and epub formats for free. This fully revised and updated edition is one of the most comprehensive references available to engine tuners and race engine builders. It is my hope that this book will assist the enthusiast involved in motocross, enduro, desert, road or gokart racing to develop and tune his twostroke engine for. Kreidler rs 50 testrun 2 mikuni tm249 with an other setup and neuw inlet venturi duration. An introduction to tuning 2 stroke motorcycles for those who want results straight out of the box. The piston crown opens and closes the exhaust and transfer ports. That is why the amount of fuel and its purity changed when the engine revs went higher. On a four stroke, you can rely 100% on the afr for tuning. But these changes will increase the power only if you know what you are doing. Get peak performance from twostroke engines do you spend more time trying to start your weed trimmer than you do enjoying your backyard.
Twostroke principles although a twostroke engine has less moving parts than a fourstroke engine, a twostroke is a complex engine because it relies on gas dynamics. Still not the highest level which would be possible with a 90cc twostroke of 40. Blair 3 twostroke performance tuning, graham bell 4 motorcycle tuning. There are different phases taking place in the crankcase and in the cylinder bore at the same time. Graham bell steers you through the various modifications that can be made to coax maximum useable power output. On a stroker things like matching the ports to the liner, crankcase to transfers etc.