2 stroke


is it possible to convert a 4 to a 2 stroke? if so how?


Uh… no. Two different methods of intake and exhaust there.


Not even close . . . two different engine makeups. Rocketman


thats what i said, but my cousin keeps telling me that he did it


I suppose it could be possible by adapting a 2-stroke top end and oil metering system, including the carb/exhaust system, and whatnot but that’s a lot of trouble and expense.
It could be done if someone wanted to devote the time to an exercise in engineering and is prepared to put up with working the bugs out.

Heck, years ago a guy built a 30s era Harley knucklehead to run on the salt flats. The air cooled engine had been converted to dual carbs and water cooling. I’ve seen pics, and yes it’s ugly as sin. Function over beauty though.


Well you might make a 2 stroke using some parts from a 4 but I would not call it converting it.


A lot of 2-stroke bikes don’t even have a central oil metering system. Like ok4450 said, I guess you could use the barrel, head, carb, intake, and exhaust off of a 2-stroke bike on a 4-stroke lower case, but… why, again?


I’ll bet he did a lot of other things too that nobody can verify. I stopped the cold war by working on military aircraft. The Russians knew that if I was allowed to even get near an airplane that we weren’t serious.


I look at this post! And just sit back and laugh!



Is your cousin Al Gore? Did he do it right after he invented the Internet?


Look for a website about old SAABs . . . their early cars were strokers and you can appreciate how they attempted to develop the two-stroke for automotive purposes, increasing size, oil injection, water cooling . . . but eventually their engineers scrapped the two-stroke design for a four-stroke/four cylinder engine (I believe that they bought Triumph motors for their early 99s, and then built their own later on). If those engineers couldn’t adapt their proven but somewhat inadequate two-stroke design, I don’t believe that it is all that feasible. Having said that . . . someone with enough time, money and the inclination to do so, could build a four stroke out of a two-stroke. Rocketman


I look at this post! And just sit back and laugh!

Me too. Converting a 4 to a 2 stroke would only be possible with a very well stocked machine shop and an indepth knowledge for how to use the equipment and for internal combustion engines themselves. Based on the question the OP is asking, I suspect he’s on the other end of the spectrum.


I don’t recall the Triumph engines, but I can tell you that Saab began using an excellent V-4 that they sourced from Ford of Germany, in the late '60s–early '70s.

Incidentally the original Saab 2-stroke engine was a 2 cylinder (!) design that was essentially copied from the German DKW automobile. In 1955, they converted to their better-known, 3-cylinder, 2 stroke engine.

Although they progressively increased its power output over the years, by the early 70s they realized that the 2-stroke design had reached its design limits. And even with the advent of oil injection for it, the limited number of people who were willing to constantly refill the oil tank as well as the gas tank made it necessary to use a 4-stroke engine–hence the adaptation of that Ford V-4, which was a 4-stroke design.


now hes telling me that he did it the other way around and im telling him thats impossible too, i need some backup here please


Why do you need backup? He’s lying or he’s clueless, or both. Either way it doesn’t matter. Get a book on engines and show him the difference. 4-stroke induction is through valves. 2-stroke induction is through the crankcase, no valves(with the exception of charged 2-stroke diesels).


When pigs fly…


Sure it’s possible, but I think it’d be easier to build one from scratch by machining it out of a fresh block of steel.