Interesting engine numbers

[Crewchief47]

I got wondering tonight about a thread I read recently where the discussion went along the lines of the 80 hp engine seeming more like half a 4cylinder apex than twice the 250f(due to power levels). I had a look at Yamaha's spec sheets and came away surprised a couple times.

Model/Bore/Stroke (mm)
Phazer 77/53.6
Apex 74/58 (hmm closer than I thought)
YZ250F 77/53.6 (same as the Phazer)
YZ450F 95/63.4 (95-77=18mm wider per cylinder or 36 in a twin)(1.4")
Vector 79/66.2
R1 77/53.6 (biggest surprise, that's the same as the Phazer, 250F)

I realize the 450F twinned might need more room than 1.4" but does anyone think 1.4" more will shoehorn into the FX chassis?

Just some random musings....

 

[morrisond]

So if the R1 Bike Motor is 4 YZ250's and is what the future 1000 Apex Should be., as it looks like Yammy likes Modular Engines, How about a Quad YZ 450 Based 1800 Naturally Aspirated 4 stroke for the next SRX? Should be good for at least 220-230hp. It would be nice...

 

[Crewchief47]

Here's another thought that 'pimpedrage' had while we were in Muni. Three cylinder phazer using the YZ250F bore is 41mm(1.6") wider than 2cyl version.

In comparison, the twin 450F would need 36mm(1.4").

Those numbers don't include the material between the cylinders but should be a good rough guideline.

Also, everyone should keep in mind that the Venture lite is 15" wide tunnel, meaning the bulkhead should be 1" wider than the Phazer, making more room under the hood. If Yamaha has no intention of putting a higher HP motor in the current FZ chassis, I would be very surprised if there isn't a FZ II chassis in their prototype room.

 

[LazyBastard]

If you ask me, the most likely that they'll do (assuming that they want a bigger one) is cut it open to 600cc, which would get them roughly 96 hp. All it would take is widening the bore from 38.5 to 42.1. This translates into a total extra width of 7.2mm, which is less than 1/2", ASSUMING that there is not already enough space inside the engine to do this, which I guarantee THERE IS.

With this move, they would have sleds at 80, 100, 120, and 150 hp spots, one of which is a genuine 600, which would no doubt be a real hot seller. That kind of fills up the holes nicely, wouldn't you say?

 

[givemeaboost]

Where did you get your numbers from ? The apex , rx1 and r1 all take the same pistons according to Yamaha parts, 74mm. Ken.

 

[LazyBastard]

Check here: http://www.yamaha-motor.com/sport/produ ... specs.aspx

R1 piston: 5VY-11631-10-00
RX1 piston: 4XV-11631-00-00
R1 does indeed have different pistons from the sleds.

 

[givemeaboost]

OK, i just looked em all up . R1 1999- 2003 had the same pistons as the rx1 and apex. R1 04-06 has the different bore and stroke with dif. pistons so we're both right, Ken.

 

[LazyBastard]

I didn't think that was necessary to mention, since the RX1 is essentially an 03R1 engine without efi or gearcase.

 

[Yamahnator]

The interesting thing here is that superbike innovations have been fairly low in past years. Until the last couple years that is. They are really making strides and now is the time of the hp wars. The big push is Engine/chassis/weight. This can only be a good thing for the near future for 4 stroke sleds.

 

[PureBlue]

And the Vector has the same bore x stroke as the FJR 1300 ( 1,298cc. ), just less one cyl.. The FJR even has EFI.

 

[pro116]

the 05 has a different piston or rings compared to the 03-04 cant remember which one it was.