Guys like larry widmer, ak miller and smokey yunick where instrumental in pointing the way with 4 stroke engines. He did his own investigation, and turned a minor suggestion into a real tool. The inlet port opens 30 after bdc and closes 79 after tdc. Gordon jennings 2 stroke tuning pdf everything2stroke. The man who changed motorcycle magazines cycle news.
A twostroke or twocycle engine is a type of internal combustion engine which completes a. He has taken some research that was done and published by nagao to do with inlet tract delivery ratios and without emphasising it nagao introduced the idea of port. This manual may contain attachments and optional equipment that are not available in your area. That formula looked familiar so i checked my copy of gordon jennings twostroke tuners handbook. The other material in the book is good filler, but without port timearea diagrams i doubt that jennings would ever have written this book. One of the best resources available to the home mechanic. Sep 10, 2014 in the example in his book graham bell, the size of the squish 54 mm piston squish band means it is 8 mm or 50 % referred to the squish band whereas from book 2 stroke tuner s handbook by gordon jennings. Throughout this book it will be assumed, inconvenient though that assumption may occasionally be, that the reader has progressed to at least a superficial knowledge of the manner in which a pistontype internal combustion engine with particular reference to those operating on the twostroke cycle principleconverts quantities of fuel and air into useful power delivered at the end. Only reason im asking is because my bike ec300 is currently at. Contents chapter 1 introduction 9 chapter 2 the cylinder.
Can someone point me in the direction of a good book or books. This two stroke engine tuners document contains the formulas, theory, examples and illustrations to literally turn anyone into a professional two stroke engine guru. The formula tells us that at that speed, maximum piston acceleration will be with the answer rounded off by my slide rule. Two stroke tuners handbook jennings moped wiki moped army. All the information presented was taken from the book design and simulation of two stroke engines written by dr. Nov 23, 2015 only reason im asking is because my bike ec300 is currently at. In a two stroke engine, the exhaust gasses transfer less heat to the cooling system than a four stroke, which means more energy to drive the piston and, if present, a turbocharger. Check the porting of your cylinder and compare to the recommendations given by proff. John wrote a computer program one of the first for designing expansion chambers for 2 strokes which is in the appendix of the book, which is now obsolete as the bbc b type computer is now a collectors item.
Optimization of twostroke petrol engine ijesird international. How to enhance a 2 stroke engines ports with piston ramps transfer port enhancement with piston ramp on page 117 of two stroke tuners handbook gordon jennings wrote how one could grind transfer and exhaust port ramps into the piston crown to test porting ideas without grinding on the more expensive cylinder. I think this book is the best book for 2 stroke engine builders and tuners to start out with. Please consult your local distributor for those items you may require. The piston crown opens and closes the exhaust and transfer ports. Jennings explains in his book 6 that if properly managed, the addition of a muffler to your expansion chamber will have absolutely no effect. Here is a link to the two stroke performance handbook by gordon jennings. Here is a pdf of gordon jennings 2 stroke tuners handbook. Squish band width calculation on head motor 2 stroke.
Twostroke tuners handbook by gordon jennings twostroke tuners handbook by gordon jennings two stroke engine tuners handbook. Gordon jennings twostroke tuners handbook was written in the early heyday of twostroke, motorcycle roadracing, dragracing and motocross. Lets journey back to 1973 and read the book that was the two stroke bible of that. Two stroke tuners handbook jennings from moped wiki. Twostroke tuners handbook by gordon jennings pdf manual discussion in scooter guides started by teezer, may 3, 2012.
Depending on the length and size of the front cone, middle expansion section, rear cone, and stinger allows you to tune the power curve, similar to a camshaft in a 4stroke. Tractorsport flowbench forum archive view topic two. Squish band width calculation on head motor 2 stroke motor. Many years have passed since gordon jennings first published this manual. Crankcasecompression two stroke engines, such as common small gasolinepowered engines, are lubricated by a petroil mixture in a totalloss system.
And at one time an engineer of saws he is a renouned pioneer in 2 stroke performance and the good thing is that the physics his work is based on. Twostroke tuners handbook gordon jennings i heart stella. 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. Im too lazy to do it all with paper and pencil no less than 5,000 ftsec2. Gordon jennings two stroke tuners handbook is conisdered the two stroke engine tuners bible. Speed of sound in a gas sound pressure wave velocity. May 03, 2012 twostroke tuners handbook by gordon jennings pdf manual. 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. A rare technical guide to the fundamentals of the crank train, cylinder heads, expansion chambers, port timing, crankcase pumping, carburetion and ignition. The way a two stroke motor works causes them to be f. Twostroke tuners handbook by gordon jennings, paperback. Two stroke engine and exhaust design software north.
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. You might start with graham bells book, which appears to be much more affordable. Two stroke tuners handbook gordon jennings pdf download. The morbidelli 125 twin road racer is a rotary valve 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. Be aware that gordon jennings twostroke tuners handbook deals with old school thinking.
Blair, professor at queens university belfast, and published by the society of automotive engineers. Materials and specifications are subject to change without notice. Buy two stroke tuners handbook by jennings, gordon isbn. The newest info i have is the twostroke tuners handbook by gordon jennings. I bought gordon jennings book the twostroke tuners handbook in 1976 to apply to my 1974 cr250 elsinore. Twostroke tuners handbook by gordon jennings im interested in the book, i have no idea what their worth though.
There are many ways to boost the power, one of which is by installing a tuned pipe. Where can information, formulae, andor a good discussion of same. Throughout this book it will be assumed, inconvenient though that assumption may occasionally be, that the reader has progressed to at least a superficial. Velosolex s 3800 2stroke tuning and engine design books. Let me know if you can tell me a price youd take for it. Two stroke tuners handbook gordon jennings free download as pdf file. Two stroke tuners handbook by gordon jennings and a great selection of related books, art and collectibles available now at. Most of my friends and i rode 2 stroke street bikes and welcomed the knowledge that jennings put forth. Twostroke engine news newspapers books scholar jstor september 2010 learn how and when to. Twostroke tuners handbook by gordon jennings pdf manual.
Nov 23, 2016 perhaps the biggest coup for cycle world was the hiring of gordon jennings as technical editor. Throughout this book it will be assumed, inconvenient though that assumption may occasionally be, that the reader has progressed to at least a superficial knowledge of the manner in which a pistontype internal combustion engine with particular reference to those operating on the twostroke cycle principleconverts quantities of fuel and air into useful power delivered at the end of its. Two stroke tuners handbook by gordon jennings goodreads. Jennings wrote about the beginnings of cycle world in one of his last columns for motorcyclist. His tech articles were the first things we read on the way back from the mailbox. Twostroke tuners handbook paperback 1973 by gordon jennings author. Gordon jennings really was a genius for his time, compiling the 2 stroke secrets of the time into an easy to read book. Gordon jennings two stroke tuners handbook in pdf format. To illustrate how high these forces may sometimes be, lets use as an example the yamaha td2, using 11,000 rpm for n. But once you get through it, 2 stroke engines will be as familiar to you as your own hands. They are so simple and fun that ive always enjoyed tinkering with them. Twostroke tuners handbook by gordon jennings offroad. Following his advice i could run regular fuel in my cr250 and yet not have to eat anyones dust.
Although keeping this in mind, reading newer litterature also, it will make a good book for the beginner. Gordon jennings was a life long motorcycle enthusiast and writer who worked as an editor for cycle magazine and motorcyclist magazine. I felt i had to share the background and history of the quest. Hi, being formerly a motorcycle mechanic, and enjoying very much gordon jenning s two stroke tuners handbook, i cannot find a book or guidance about porting a crossflow engine. If i remember right, jennings was the editor of a great magazine, cycle. Gordon jennings and crossflow two strokes boat design net. Great book, but ill guess the world has moved past that info. The technology has developed a bit since the 60s and 70s. This 2 stroke engine animation, article and diagrams are courtesty of.
It seemed like rocket science back then, so many radical ideas that had been mostly secrets and rumours up until then. This book is about the single idea of how to use port timearea diagrams. I have used this formula since 1973 when i bought the book. Gordon jennings book, is as far as i know the definitive work. Gordon put figures and math to the theories, and made it possible for ordinary gearheads to improve the performance of. This book, now long out of print, was the bible of twostroke performance engine builders and racers and its a treasured addition to any mechanics library. Expansion chamber design according to blair introduction all the information presented was taken from the book design and simulation of two stroke engines written by dr. It perfectly describes details about 2 stroke motors and exhausts. However, formatting rules can vary widely between applications and fields of interest or study. Grahem bell and gordon jennings discussion in scooter guides started by sf rider, may 18, 20. Twostroke tuners handbook by gordon jennings and a great selection of related books, art and collectibles available now at. This is a highly saught after book by motorcycle enthusiests.
Perhaps it will help you enjoy this copy and in closing i would like to thank gordon jennings for the fine material and all the effort he put into the original publication. 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. Gordon jennings is the author of two stroke tuners handbook 4. Perhaps the biggest coup for cycle world was the hiring of gordon jennings as technical editor. Gordon jennings 2 stroke tuners handbook has been around for 40 some years gordon is an engineer. In the example in his book graham bell, the size of the squish 54 mm piston squish band means it is 8 mm or 50 % referred to the squish band whereas from book 2 stroke tuner s handbook by gordon jennings.