The Hodaka Club Forum

Hmmm. Strange happenings on Facebook but nothing unusual for the game. Troll infection partially. Subject control another factor. Should be about motorcycles for sure but does need a social factor. Think I just had my work removed from one of my favorite pages about carbs having to be on the front or back of a Hodaka cylinder which is not going to work. Probably the best idea was how it came from the factory, conventional being the word but other things have beed tried. Not to have wasted my time writing all this for my motorcycle friends, I’ll try this gang of friends and see if they find this interesting about 2-stroke motorcycles. Thought about it briefly once but quite impractical for an air cooled engine. Check this out so my efforts don’t get lost in the darkness of Facebook. Eek! Maxie
I said;
Subject recently brought up about reversing a Hodaka cylinder for some fit reason. Something I was always interested in when building racing engines but probably not a good idea on air-cooled engines I finally concluded but was fun to think about. Liquid cooling has several advantages, you can put things where you want. Seeing real GP two stroke engines was quite a treat on one of my adventures. Good example here using both concepts. Check this thing out! Maxie

OMG! Reminds me a little bit if the old Kawasaki triples, but with a twist (of 2 motors)! Where did you find that??? Victor

looks like a North Dakota bumble bee. Clarence.

Victor. Looking on the internet for something to show how you could reverse a Hodaka cylinder and ran across this engine that has it both ways. Probably would be be a cooling problem on air cooled cylinders but interesting none the less. check out this Honda NSR500 with carbs in front. These are so cool! Maxie

Clarence. Agree on the bumble bee! This four cylinder Honda thing made impressive noises both intake and exhaust!

Zoweeee, those are some fascinating engine layouts! They seem to have a few things in common. The most notable for me is that NONE of them have a need for Enduro/MX style air cleaner systems. Working out a truly "free breathing" (low restriction) air cleaner system which would be effective in muddy slop or fogging dust would be um, tough.

Relatively cool ambient air being pushed around by only ambient air pressure differences is WAYEEEEE more sensitive to restrictions which limit flow than relatively high temperature exhaust gases being pushed by relatively high pressures. That is at least part of the reason that enduro/mx machines have the air cleaner on the back side of the cylinder - which allows for short, large diameter "air feeding" to the carb.

Ed

OK, lotsa talk, I'll mock one up for fun. Maxie

First thing which comes to mind when I see this mock up, Maxie, is the cable would be very close to the cylinder fins. Heat, melting the outer casing comes to mind, even tho the air flow would probably keep it cooler while moving.

But what’s to stop trash from blowing into the carb? The force alone of the carb Venturi facing the on coming air would surely have some kind of turbo effect, compressing the air into the intake, especially while the piston blocks the intake. Probably would increase the air pressure inside the crank case causing an air fed agitation of the motor oil as well, don’t you think? I could see the oil blowing out of the crank case vent with this situation, no??? Just my brain rolling around in my head with this config… Victor

To stop trash from blowing the carburetor you could build some kinda strainer and call it air filter. There is no engine oil in a hodaka motor. with good seals in place the transmission is sealed.

What type filtration medium would be appropriate? I'm guessing a motor such as this would be prepped for paved track running only. This is interesting. Leave it to Maxie.

"Why?" Only a thought experiment, an entertaining puzzle. Nothing new in the world of two-strokes but someone did ask. We got some mileage on our thought processes, also fun! As Victor said about his brain rolling around in his head. Me too. I think I'll file this under "Not practical in this model" Maxie

so in stead of turning the cylinder around why not turn the whole engine around. get it running backwards, we are modifying right, switch the shifter and chain and rear wheel to the left side. air flow going front to back with pressure. and if your racing on an oval track your shifting on the left. win win.. ok im sorry i will go sit down now ...albert

That's a "grinner"! Yer gonna have to do something to get the chain runs past the magneto when the whole engine gets turned around - so there just might be a jack-shaft in this arrangement . . . and the engine could remain turning in the normal direction. (Ummm, there just might be some other details to wrestle with toooooo . . .)
Ed

ok HEAVILY Modified

Albert. The Win with turning the whole engine around is shifting would be on the right side. Would be OK for the guys who only make keft turns and keep their left foot down, but what a bout braking???? LOL!

Guess there would be pluses & minuses in just about any design change. But, it seems, if it were really viable, someone would have already figured it out and made the changes. After all, motorcycles have been around for over 100 years now! Victor

Actually the backwards configuration is in use today by Yamaha with their YZ models. They canted the cylinder toward the rear of the motorcycle in order to accommodate the fuel injection, the exhaust wraps around the engine, the fuel tank is moved rearward, and the air filter is where the fuel tank would usually be. Here is a picture of the 2021 YZ450F.

Some interesting stuff there. Leaning the cylinder toward the rear would really help out. I'm guessing one of the main goals with this YZ is moving significant weight (cylinder, tank and fuel) down and back to lower center of gravity.
Ed

The fact that this particular machine, in very capable hands, won both the most recent (2021 MX and 2022 Supercross) Championships in the premier division suggests that they may be on to something. It is interesting and is the production model. It is not, however, a Hodaka!