Motorcycle Forums banner
1 - 5 of 131 Posts

· Registered
Joined
·
32 Posts
Since everybody else is commenting...



Yes, all 4 strokes should have an oil filer, besides grit from the incoming air, a minor problem becomes a major one if grit from, say a cam follower get into the crank bearings or pistons. The cam might work for another 20 laps, get bad things in the mains or damage a piston and you are a DNF.



Why different displacement in different cylinders? Look at the spacing of the rear bellmouths (large) and the front bellmouths (small) Since the rear rods are far apart why not use the space to run bigger pistons?



Why are the three cylinders in the front? Weight distribution. All V engines have problems getting weight on the front wheel, the put the heavy bank as close to the front wheel as possible.



What will it mean? I don't know, the RC45 made more power than the 916/955/996 but never had the handling to go with the power. A post above mentions Honda's problems building a total package, that is not entirely true (see the NSR500 during the Mic D. years) but it has been a Honda tendency. I would say that a well designed twin (or even a 500 CC two stroke) might just win the first few years. Power is only useful if you can use it.



Whatever, it will be fun to watch. Honda has been, since the sixties, been the best engine company in motorcycling, it will be fun to see what they can do without the restrictions in WSB.
 

· Registered
Joined
·
32 Posts
You seem to be hung up on displacement, that is not the only way to measure engines. How about HP/ per pound of fuel per hour? How about Brake Mean Exerted Pressure (BMEP)? The four stroke will win those categories most of the time.



This is engineering, not religion. Unless somebody can fix the noise and air pollution problems (many have tried, many have held news conferences, many have failed) the two stroke is going away. Get over it, worry about the important stuff.
 

· Registered
Joined
·
32 Posts
Now that 500 GP racing is perfect I guess we should lock every thing up and never change, won't that be fun.



Don't you think that racing engines that have less and less to do with the real world will be as bad as anything Honda could do? Two strokes are going away everywhere but the third world. If the rules allow the biggest spender to dominate they will be changed. One way or an other they will be racing 4-strokes, get used to it.



Even if Honda out spends everybody it will take a few seasons to work out the new bikes. If Honda follows their regular pattern it will be fun to watch bikes with less HP beat them while they sort the chassies.



Whatever happens I doubt GP racing could be any more dull than it was while Dohan was totally dominant.
 

· Registered
Joined
·
32 Posts
You could use the article. In the sprit of the late, great Gordon Jennings let me point out: The number of cylinders or bore/ stroke ratio has nothing to do with the shape of the power curve. The only thing that is effected is the maximum RPM the engine can turn, short stroke (from big bore or more cylinders) means the engine can turn more RPM. The Honda S2000 is, by motorcycle standards, very long stroke yet it is peaky and makes around 120 HP/ liter in EPA legal tune. That might not impress you compared to the GSXR1000 (also a long stroke design) at 140 HP/ liter but bikes have a much less restrictive emissions limits and they need to last much longer.



The bottom line is (to steal one of Gordon's great analogies) do you think the gasoline know if it is in a short, wide container (like a can of tuna) or a long, narrow containers (like a can of soup)? All the fuel/ air mixture does is burn, if there is lots of it and/ or it burns more often you get more power, if there is less or it burns less often you get less power.



I very much doubt the folks at MO have the resources to devote to a subject this complex. My favorite technical site, Wheelbase, is off line since Gordon died. Your best bet would be to find a good book (you can always start with by Kevin Cameron's Sportbike Performance Handbook) and read it.
 
1 - 5 of 131 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top