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Honda Reveals Four-Stroke GP Motor!

69184 Views 130 Replies 55 Participants Last post by  CBR1kboy
Seth -

We were supposed to go to the drag strip last week, except there was this thing called "snow."

Be patient my son.
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I can't wait to hear what it sounds like!
After Honda's expensive and well publicised failure with the oval piston NR of the eighties, it is not surprising to see HRC come after the new GP rules with a vengeance. It is no secret that Soichiro Honda didn't like 2 strokes.

Given F1-class technology, these power numbers are acheivable. Bear in mind, however, F1-class financials. Such an effort would likely cost around $25-50 million per year for engines alone.
The valvetrain looks like it is still mechanically actuated (no hydraulic, electical or pneumatic systems... yet). The two small humps on the left side (as you look at the picture) of each valve cover looks like conventional (most likely) gear-actuated camshafts, a lot like the RC-51. However, it is possible, as another article pointed out, that due to the bulk of the cylinder head, that the V-TEC system may have been engineered into it. Something tricky is going on in there, that is for sure, but what? It looks a lot like a Honda CART or F-1 engine, so it's certain that they have drawn off of that knowledge building this engine. And if, that's a big if, the rumors are true about a CBR powered by a version of this engine, that could spawn a whole new breed of GP-rep streetbikes. A V-5 CBR-820RR anyone? Very cool.

Enter the dominance of the 4 stroke into GP's again!
Hey guys at MCN (motorcyclenews..the brit site), they mentioned

that the rear 2 pistons might be of a diffent bore and stroke than

the front 3. What would be the advantage of this? What could they

gain in performance from doing this? I WANNA V-5 SPORTBIKE WAAAAH!!!

How come just when I get settled on what bike I want...they throw up

some new stuff and I get all muddled again.

WHERE"S THE ZR-7/SV650/MONSTER SHOOTOUT?!?!?!? I Can't wait any longer!


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Is that an oil filter at the bottom left of engine? Do 4 strokes absolutely need oil filters? I would think with a dry clutch the oil should stay fairly clean. Anybody have some insight into this.


the SV will win anyway, you don't need a shoutout to know this.
Ummmm, yes it is a filter. It's there to make sure any little metal shavings left over from production and/or break-in don't get circulated around the engine. So, while it'll run without one, it's cheap insurance. Smokers don't need 'em because they don't pump lubricant through the engine, it's suspended in the fuel.
If you keep the dirt from getting in oil filters aren't needed. But since you still need air to run an engine you will still get dust.
Actually, here's a funny thing. I remember an article in one of the M/c mags some months ago where a company around N'Awlins' (New Orleans to the rest of us) put a small turbine (jet) engine in a frame they designed, and were selling them. This engine put out well over 200 hp, and over 300 ft-lbs. of torque. The tires actually lasted much better than expected because of the seamless (no power stroke) power delivery of the turbine. The found the power stroke of a piston engine torques the outside of the tire relative to the rim with every power stroke (acting like a torsional dampner), then twists back. This heats up the sidewalls and tread. The torque from the turbine is much greater, but constant. So, it seems like tire life willll depend on what the firing order is to an extent. We'll see. I think Honda will find, as with the NR500, that it's the PACKAGE that wins the races.
Is that sarcasm I detect in your voice?

haha. That had me thinking you were actually serious, until you said that last line! haha, thanks for the smile!

That's correct. Harley Davidson tried to make a GP motor. I do'nt know what happened, but HD decided to sell them to a farmer in Nebraska. I believe the farmer uses them in kiddie-carts.
Late breaking news....

The method Honda will use to aid in traction for the new power output takes advantage of the newly announced rule that GP bikes will now be allowed to have four wheels.
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.
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Dirty Oil

Oil quickly becomes filled with combustion particulates and metal shavings in a running motor, especially in a new engine. As has been previously articulated, your car has a dry clutch and an oil filter, doesn't it?
Four strokes=GOOD

Four strokes are great! I don't know where the guy that said they were dead is, but I said a while back that 2 strokes are nearing the end of their useful life for motorcycles, and I stick by that. The new Honda engine is one example of why this is, and why the new 4 strokes are going to dominate in 2002; can't wait to see what the other manufacturers are going to bring out. Wonder what MV Agusta has up their sleeves?
It would be easier to...

Interesting concept, but wouldn't it be easier to have the onboard computer simply modify the fuel and ignition maps to adjust power levels rather than cutting out cylinders? That could be a very rough transition, much like a nasty rev limiter. In fact, Mondial, an Italian bike company which uses RC-51 engines in their chassis and body, has been developing this type of system. Check it out:

It's a very good looking bike! Advanced technology, also.

So you have a good idea, but the Cadillac system was meant to improve fuel economy rather than modify power for traction. I think that there would be easier and more effective methods of accomplishing the same thing. Mondial could be on to something.
Get over it? Ever heard a late 50's - late 60's (Colombo or Lampredi) Ferrari V-12? Or a Honda RC-166? Or an Group B Audi Quattro Rally I-5? Get over it indeed.... What is it about wanting to hear it, that implies I care about it's performance & engineering any less?
LOL.. The company is Max Turbine. I spoke to thier Rep at Daytona (Mar. 1999) and this guy was wacked... he was ranting on and on about how their (something like 10 feet long) bike would dominate any other motorcycle on the planet.... get this in ALL AROUND performance.... Now correct me if I'm wrong, but doesn't "All Around" include stop, go, and cornering? The bike was neat to look at, and had something of a "Gee Whiz" factor, but it was longer than a Valkerie for God's Sake. I'd love to see what it would do at a place like the Streets of Willow. Of course at Black Rock or Bonneville I must conceed, he would have the superior machine.
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