24 replies to this topic

[Andrew Bishop]

Look at here if you' re interested in it

http://www.motocicli...0B?OpenDocument

[Powersteer]

The crank timing looks 360 degree... on a v5. Connecting rods looks liek they are H beams.

[desmo]

Nice find and great photos! Thanks, i've been wanting a peek inside the Honda V-5s for a while now.

It looks to me like the two outer crank journals carrying two rods are in phase with each other and the central journal carrying only one rod is 180 degrees from the outer two. Look at the flywheel mass compared to an F1 too! Also it appears that a wet sump- if you want to call that a wet sump, I would- is deemed fine for moto engines where getting the crank CL as low as possible isn't a concern.

Look at the size of the clutch compared to the engine!

[Powersteer]

Actually I was wrong about the 360 degree crank. After looking at it again I think that the central journal is 90 degree from the two wide ones because they both are on top of the main. The intake port looks huge.

[12.9:1]

The crank seems to be Oiled from both ends, and that clutch would not begin to fit under the "cover"? Also note the huge cooling pump and plumbing.

As that's the "Hayden" version, I might guess that the V4 would look about the same - less one jug.

[Hans Derbe]

here are some more....

http://www.crash.net...h_string=rc211v

the rods look massive. this little thing must have a crazy firing order. what's the angle between the two cylinder banks? 75°?

hans

[imaginesix]

Originally posted by Powersteer
The crank timing looks 360 degree... on a v5. Connecting rods looks liek they are H beams.

The con rods look like box section to me! I think you got that one wrong too.

Weird friggin engine, how was it born and how did it perform?

[Powersteer]

Originally posted by imaginesix
The con rods look like box section to me! I think you got that one wrong too.

Weird friggin engine, how was it born and how did it perform?

Not as powerful as the Ducati's ;) You were right about the con-rods

[desmo]

Those rods are quite different. I'm assuming they are either hollow box section or conventional I-section with stiffening plates added. I'd think either would have to be fabbed up, presumably welded up from pieces. Oil supply to the piston pins could be tricky too I reckon if they are hollow.

[Engineguy]

Originally posted by desmo
Those rods are quite different. I'm assuming they are either hollow box section or conventional I-section with stiffening plates added. I'd think either would have to be fabbed up, presumably welded up from pieces. Oil supply to the piston pins could be tricky too I reckon if they are hollow.

Nah, just simple titanium square beams. With a short titanium rod there is nothing to be gained by molesting the beam 'cause you have to put that metal back on at the corners to get back to the minimum cross sectional area needed to handle the tension forces. A long rod is a different issue.

I've been told, by a guy that talks tech with MotoGP mechanics on a regular basis, that there is nothing at all trick or exotic in the Honda V5s... nothing that would be out of place in a race-prepped superbike (although that is, of course, a pretty high standard of engine development) other than a slightly higher bore/stroke ratio.

[Engineguy]

By the way, this engine, leading the MotoGP standings with a couple races left in the season, designed for the two-wheel version of F1... where the engines are designed from scratch as a pure racing engine, not based on any production engine, uses bucket tappets, NOT finger followers. And it's not a turd (ref. GM IRL engineers' excuses and other assorted finger follower worshippers claims).

[hydra]

Not very surprising given the fact that this engine displaces a measly 200cc/cyl with an intake valve diameter around 32mm, meaning our valve lift requirements aren't as high as they would be in a larger engine. But you were right, it all depends on the overall package...

[DOHCPower]

I dont think the lift requirement is what engineguy was referring to. These engines are still revving to 16k plus correct? Any valvetrain design that can cope with those kinds of revolutions must be designed correctly.

[Halfwitt]

Originally posted by Engineguy
Nah, just simple titanium square beams. With a short titanium rod there is nothing to be gained by molesting the beam 'cause you have to put that metal back on at the corners to get back to the minimum cross sectional area needed to handle the tension forces. A long rod is a different issue.

I'm not so sure. If you examine the rods, there appears to be a dark patch on the lateral faces, in an identical place. I can't think of anything in the manufacture of the rod, or in use that would lead to this, unless something trick has been done.

I disagree with the idea of not molesting the beam section. In many cases stress in rods is fairly low in much of the beam, and it is at changes of section where failures occur (close to little or big ends). I've seen a lot of racing Ti rods, and never seen any that are simple plain section.

I agree that fingers are an additional complication and expense, but they are neccesary if you want ultimate performance from a fixed bore where tappet piston size is limited.

One interesting thing to note; only one gudgeon pin circlip.

Desmo, oil supply to the little end via the rod isn't always necessary, even in very high speed engines such as these.

[Powersteer]

Nice to see the technical vultures hovering the pictures.

How come there is four rings/cylinder for such a small displacement per cylinder? Those rings must be awefully thin to keep within the race tuners threshold of minimum surface piston rings to be using four.

[shaun979]

Originally posted by Powersteer
Nice to see the technical vultures hovering the pictures.

How come there is four rings/cylinder for such a small displacement per cylinder? Those rings must be awefully thin to keep within the race tuners threshold of minimum surface piston rings to be using four.

Probably one compression ring and a traditional 3 piece oil ring, totalling 4.

A normal street engine has total of 5. 2 compression, and traditional 3 piece oil control package.

[Powersteer]

I always thought oil rings as one piece. I've been had.

[cosworth bdg]

Originally posted by Powersteer
I always thought oil rings as one piece. I've been had.

They can be 4 pieces , depending on the user[manufacturer] requirement specification...........

[zac510]

Originally posted by 12.9:1

As that's the "Hayden" version, I might guess that the V4 would look about the same - less one jug.

That raises the thought of what it might be like next year when the capacity rules change. They might just retain the bore/stroke and go with the V4 pattern?

I follow motogp but not so closely that I know whether Honda have tested a 2007 engine yet..

[Engineguy]

Originally posted by zac510


That raises the thought of what it might be like next year when the capacity rules change. They might just retain the bore/stroke and go with the V4 pattern?

I follow motogp but not so closely that I know whether Honda have tested a 2007 engine yet..

With the per-cylinder displacement remaining the same (ONLY for a V5 to V4 transition) it would be a safe bet not much has changed... big jump on everyone else who have to start fresh(er). Note the cylinder head peeking through by Pedrosa's knee... looks just like the detail and placement of the V5's rear (2 cyl) bank.


Honda Reveal V4 800cc MotoGP Machine at Motegi Test
Written by: Honda Racing
Motegi, Japan – 9/25/2006

Spaniard Pedrosa put in 30-laps of the 4.801km Japanese circuit to give the HRC race engineers valuable data as they prepare the machine to comply with the 800cc MotoGP regulations scheduled for the 2007 season.

The initial shake-down test was positive and after a few visits to the pits for adjustments to various areas of machine set up the youngster lapped the multi-purpose race track at 1m 48.210s – a time just over half a second slower than his best lap time set in Sundays Japanese grand prix.


“The first feeling is that the new bike runs well and this is very important - it works normally and everything feels fine. The engine character feels a little different and this is to be expected but the package feels quite similar to the RC211V. Some things about the bike fees smaller and the rear seat is much shorter which makes the whole bike look more compact. The bike has some characteristics which are a little more like a 250cc but it’s still a MotoGP bike. The lap time today is quite good for a first test – though it’s too early to say whether it will be faster than the 990 . The cornering speeds feel very similar to the RCV – though the corner speed at Motegi is very low because there are many hairpins, so it’s very difficult to say definitely whether it’ll be quicker. This was a good first test though.”

Dani Pedrosa at speed on the new V4 (Photo: Honda Pro Images):

[zac510]

Looks great in all black

[alexbiker]

Like the exhaust.

That's going to be loud.

[Powersteer]

I love loud bikes. When I was a teenage I use to ride my dads Suzuki GS1000S. It had a 4-1 exhaust system that a worker who my dad borrowed it to had mounted. When he returned it I notice the silencer was rusted so I kicked it until the whole thing came off. I started the thing and love commenced, of course, until the day I got caught up on a Police road block. Young and reckless.

[alexbiker]

What I don't understand is this:

Moto GP engines are not tuned for maximum power, as it's not deployable. So, what we'll do, right, is this: We'll make the engines smaller, because that'll lower speeds, right?

Moto GP constructors promptly tune up the engines to recoup the lost power.

And there's no change in lap times. Which is what happened.

Alex

[Ben]

Originally posted by alexbiker
What I don't understand is this:

Moto GP engines are not tuned for maximum power, as it's not deployable. So, what we'll do, right, is this: We'll make the engines smaller, because that'll lower speeds, right?

Moto GP constructors promptly tune up the engines to recoup the lost power.

And there's no change in lap times. Which is what happened.

Alex

Crazy isn't it...?

Or consider this. You are HRC, you've lost Rossi to Yamaha and haven't won the title since. You have a young rider who you feel is the most naturally talented rider since (including?) Rossi. However he's 5'2" tall and light as a feather. It's just possible that he might not be strong enough to handle a 990cc MotoGP bike.

To ensure that he can compete you force a rule change to make the bikes more compact (if not slower) to ensure he will be competitive.

Unfortunately it looks like Dani Pedrosa was strong enough and everyone's now spending a s***load of money because HRC hate losing to Rossi.

Ben