Tips on how to port a two stroke cylinder, what to donot do and how to do it right. A two stroke cylinder consists of exhaust, transfer, and occasionally inlet ports true inlet ports are only found on piston or rotary valve controlled engines. For a 2 stroke engine the tuned pipe is the section of the exhaust system that begins at the exhaust port and ends at. Two stroke motors are more efficient that four strokes for a few reasons. Nov 11, 2010 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. Two stroke engines have lower velocity so the needle jet has a halfmoon shaped hood protruding into the venturi to produce a low pressure area that aids in drawing the fuel up through the needle jet. Basic twostroke tuning by eric gorr twostroke principles.
Two stroke performance engine tuning performance parts. Two stroke cylinder porting tips watch this before you. Carefully pull one strip of clay off the piston and then measure the thickness of the clay left on the piston. Buy twostroke performance tuning book online at low. Most of the errors is to choose a less appropriate combination of engine components so that the engine actually ran worse than standart, ever experienced. Two stroke moped tuning two stroke timing moped tuning.
Other books to his credit are modern engine tuning, two stroke performance tuning and forced induction performance tuning. Bigger carburetors, higher compression ratios, altered port timings and expansion. Mar 23, 2020 23 march 2020 we are currently open for business and trading normally, however we are not accepting visitors to the workshop without prior notice. Apr 28, 2010 open library is an initiative of the internet archive, a 501c3 nonprofit, building a digital library of internet sites and other cultural artifacts in digital form.
Those of us who have grown up in the japanese two stroke. Stan stephens tuning are the uks number 1 two stroke tuning firm. Jul 21, 2016 thank you so much for clicking through to this video animation of how a two stroke cycle carburetor works. Buy twostroke performance tuning book online at best prices in india on.
Detailing for any one interested in increasing the performance of their machines. The focus of such magazines is usually to highlight nudes of one specific gender in the pictorials, not both, and the perspective of one. In the model tuning tips chapters of this book, all the head specs quoted have msv ratings. The most common mistake is to choose the wrong combination of engine. 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. You basically want the ports to be as large as possible, without going too high on its duration. There is a huge interest in vintage snowmobiles and their simple two stroke power plants of yesteryear. Intake and exhaust are both integrated into the compression and combustion movement of the piston, eliminating the need for valves. The alexander bell book is the best there is out there. Very few other books on engine development and most of these are either devoted to car. Two stroke petrol engines are preferred when mechanical simplicity, light weight, and high powertoweight ratio are design priorities.
Pdf two stroke performance tuning download full pdf. Stan stephens column in cmm covers it, as does two stroke performance tuning by a. Twostroke engine repair and maintenance edition 1 by paul. Contact details two stroke performance engine tuning. Graham bell, 9781859606193, available at book depository with free delivery worldwide. Port matching, porting and trenching twostroke engine cases duration. Motor cycle tuning two stroke by robinson, john, 1994, newnes edition, in english 2nd ed. The squish band is the part of the head that goes from the edge of the barrel to the edge of the combustion chamber where the gases are squished into the combustion dome. Ask our shadetree mechanics 2 stroke wizard pipe builder. Macdizzy is ok, there is all the formulas on his site as well as some cool project bikes. Graham bell starts off by saying that he doesnt believe port time area and its all about the duration the ports are open. Mikuni tuning and jetting guide the vintage bike builder. Graham bell steers you through the various modifications that can be made to coax.
Bells four stroke performance tuning book, this book goes into extreme detail regarding performance tuning a two stroke 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. Lets journey back to 1973 and read the book that was the two stroke bible of that era. Yes i know about this book, a lot of stuff to learn and explained properly. Jennings book talks about port time area and porting the cylinder to have peak efficiency at a certain rpm. Also i dont know guys if u have a tutorial for a proper cvt tuning here, if u want when i have little more time i can make one with everything explained.
The secrets of resonance tuning in 2 stroke expansion. Motorcycle tuning twostroke 1994 edition open library. If aprilla doesnt do it there must be good reason not too. If youre working on an old two stroke, clean out the exhaust system. Twostroke performance tuning in theory and practice. I made this video to help better explain the workings of the two cycle carburetor, and. Free 2 stroke books banshee repairs and mods banshee. The port heights, widths, areas, directions they flow, and relationships to one another all have a significant influence on how the engine will behave.
Two stroke stickers featuring millions of original designs created by independent artists. Any recommendations on a book i can go buy that covers 2 stroke basics, theory, repair, etc etc. The best 2stroke tuning articles ever written lectron carburetor info. I have the book, but its nice to have as a pdf as well and a good reference for those who dont know about it. Other than exact replacement oem carburetors, all mikuni aftermarket carburetors and tuning components are sold as is for off road racing use only and are not intended or approved for use on vehicles operated on public roads or in locations where applicable engine tampering and antipollution laws apply. Graham bell is an acknowledged expert on engine tuning, with many years experience in this field. Undoubtedly, the virtue which has most contributed to the widespread use and varied application of the two stroke engine is its mechanical simplicity. Graham bell second edition this is the moped performance tuning bible as far as im concerned. Although a two stroke engine has less moving parts than a four stroke engine, a two stroke is a complex engine because it relies on gas. For introductory material on 2 stroke engines please see the following links.
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. The hard copy is actually out of print at the moment. The crankcase ofa two stroke engine is sealed off from the rranny. Both the latest advances in two stroke tuning and old standbys are covered for all areas of operation, from ignition, carburetion, cylinders, and. Decades have passed since i hung around with john and jim. With this howto guide, you can win the battle with the temperamental two stroke engine. 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.
Fit the head gasket and head and turn the crank to move the piston just past tdc. A novel method of tuning a stratified scavenged two stroke engine 2006320055 environmental concerns demand more stringent emission legislations concerning new power sources for handheld equipment like chainsaws and trimmers. Two stroke performance tuning two stroke all of these detonation triggers are virtually unavoidable, with the exception of excessive spark lead. The two stroke engine its design and tuning 9780854291571 by draper, k. A bible for building a high speed and high power 2 stroke machines. Graham bell steers you through the various modifications that can be made to coax maximum useable power output.
I know theres probably lots of info on the internet, but i want a book i can carry around with me and randomly read a section or two when i get to the straighter sections of i5. Two stroke performance tuning available for download and read online in other formats. Differences in two stroke and four stroke carbs the difference between a two stroke and four stroke engine is intake velocity. Download pdf two stroke performance tuning book full free. Alexander bell has a couple other fantastic books out titles four stroke performance tuning and forced induction performance tuning.
There is a wealth of knowledge contained in this manual. Changing the power of 2stroke engine is really very simple when you know the basic techniques of 2 stroke engines. 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. We specialise in honda 2strokes, covering the cr range of motorcross bikes, the nsr250 street bikes, and hrc grand prix 125, 250, and 500s. Two stroke high performance engine design tuning by cesare. I started reading these about a year ago now and ive learned so much in just the short time already its mind boggling. The hardback binding and corners are in very good condition. Decorate your laptops, water bottles, notebooks and windows. For instance, if an engine has been properly designed for medium output and a midrange power peak, raising the. My porting setup affordable and functional 2 stroke tuning. Everyday low prices and free delivery on eligible orders.
The two stroke dirt bike engine building handbook diy. The two stroke dirt bike engine building handbook is the most comprehensive guide for dirt bike engine building available, whether you are working at home or as a professional in a shop. The official home page of the 2 stroke wizard tuned pipe 4t exhaust header wizard software. The first thing you need to do when tuning a two stroke is to determine its characteristics.
Two stroke tuning book pdf scooter shack scooter forum. Although he disagrees with jennings on the value of time area calculations, programs and computers to crunch the numbers were not available at the time the first edition was published 1983it is a good resource. Jenning vs graham bell, 2 stroke tunning books motorcycle. Graham bell takes readers through the various modifications that can be made to a two stroke and its components in order to derive maximum useable power and mechanical reliability. The process of building two strokes to race engine quality is explained indepth in this thoroughly illustrated handbook. A problem with anyone of these items can marginalize performance and create an unnecessary problems during the tuning process. I would really like to see some new two stroke porting books. Jun 25, 20 one of the most famous books on 2 stroke tuning. One side of the crankshaft uses a dry seal and the orher a wer seal. A textbook dealing with the principles of design and construction, with a special chapter on the two stroke engine paperback or softback by kean, francis john and a great selection of related books, art and collectibles available now at. Other books on the subject of two strokes that should be digested. Velosolex s 3800 2stroke tuning and engine design books. Researchers have found that it is the gases at the very outer limits of the combustion chamber, called the end gases, that selfignite to cause detonation.
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. 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. Two stroke engines abebooks abebooks shop for books. Someone who knows what they are doing, so you can ask questions. Other books to his credit are modern engine tuning, twostroke performance tuning and forced induction performance tuning. A build up of oil in the exhaust can restrict the flow of exhaust gasses.
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. You dont need fancy expensive stuff to port two stroke cylinders, you can get by with cheap tools and a little creative engineering. Motor cycle tuning two stroke will therefore guide you through the necessary stages which can enable a stock roadster engine can be turned into a machine capable of winning openclass races, for an outlay which is positively low by racing standards. 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. Contents chapter 1 introduction 9 chapter 2 the cylinder. The main difference between the two engines is that all four stages in the four stroke engine are integrated into only two phases, one downward stroke, and one upward stroke. Since modifying the 2 stroke engines require not only a big. Two stroke performance tuning in theory and practice a.
Graham bell steers you through the various modifications that can be made to coax maximum useable power output and mechanical reliability from your twostroke. How to easily understand a two stroke cycle carburettorhelp. There are a number of resonances that occur inside 2 stroke expansion chamber performance exhausts. Motorcycle tuning twostroke motorcycle tuning 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 best left to a specialist. Do you want it to be full range, still strong at low rpm or do you want it for higher power at rpm even if that means you will loose some low rpm. I have a pdf floating around called the two stroke tuners guide but it is by a. Squish band width calculation on head motor 2 stroke. The stroke in stroke book is the frequent use of such periodicals to achieve sexual fantasy, arousal, and usually solo sex, that is, manual stimulation or masturbation to orgasm on the readers part. These easy tricks can be applied to most two stroke engines.
But these changes will increase the power only if you know what you are doing. A novel method of tuning a stratified scavenged twostroke. Our specialist engine tuners will be able to help you with every aspect of your tuning and servicing. Engineering acousticssonic supercharging of 2 stroke. Increase focus, and maximize performancein just two weeks hardcover by. Again, as of right now i am just reading tuning books, but i have never heard of fresh air entering in the expansion chamber, nor any mention from professional tuners that tune bikes 2 and 4 strokes on dynos that a wideband 02 sensor wont work in a 2 stroke. As a warning these books can be highly technical and possibly a bit dry to read. Everything you need to know about the twostroke cylinder. Motorcycle tuning two stroke will therefore guide you through the necessary stages which can enable a stock roadster engine to be turned into a machine capable of winning openclass races, for an outlay which is positively low by racing standards.
Remove the head and then cut the clay down the middle with a sharp, wet knife. Traditional cooper george smithwick history and how to make a wooden bucket duration. Basic two stroke tuning by eric gorr changing the power band of your dirt bike engine is simple when you know the basics. Feb 16, 2014 tutorial video explains 2 stroke engine operation. A myriad of different aftermarket accessories is available for you to custom tune your bike to better suit your needs. It covers history, physics, engineering and practicum for the development and refinement of high performance two stroke engines. The information used in the programs calculations was taken from the books the basic design of the two stroke engine and the book design and simulation of two stroke engines.