For the drag racers

[djsilver]

http://www.youtube.com/watch?v=5y8qxIQnWLM&feature=related

:D

[Matt93SE]

daaaaamn

[KA240SX808]

Yep, Fastest KA-T to date, they topped out an 1000whp dyno ;)

[2Fass240us]

Sweet Baby Jeebus.

[Epstein]

Glad that the KA guys caught up. 2010 will be a real SR vs KA fight!

Mazworx is trapping that high but is running low 7's with a 2.2L VE/DE on Meth at a clamined 1400hp. This is the fastest S-chassis.
Kako Racing has a Datsun 1200 with an SR that ran a couple 7.2's at over 180mph. This is the fastest SR.

[KA240SX808]

Doesn't Maz Rev to 12-14k also?

VE head is Krazy...

[Cory]

Doesn't Maz Rev to 12-14k also?

VE head is Krazy...

Isn't that right around the limit of wire coil springs?

http://scarbsf1.com/valves.html

I wonder what bikes used. All I have seen is that MotoGP bikes started using pneumatic valve springs around 2002 and I know street bikes have spun past 15000rpm for quite some time...

[Tower240sx]

??? ducati doesn't use springs (or rev very high) Desmodromic valve actuation

the street bikes that "rev'd past 15k" got yamaha in alot of trouble as they were caught programming error into the tach's turns out they rev'd to about 14.5. tach indicated 16k IIRC

I can't imagine a spring cycling 7,500 times/minute and lasting very long but if you stay away from coil bind and can supply enough pressure to close the valve before it needs to open again material sciences have come along way especially in surface treatments of metal to improve fatigue.

[jr_ss]

Doesn't Maz Rev to 12-14k also?

VE head is Krazy...

I believe they only rev it to 11k, atleast that's what the Motec digi dash is setup too.

[KA240SX808]

ah yes, you are right, just watched the video again. but still thats pretty amazing.

[Longfellow]

??? ducati doesn't use springs (or rev very high) Desmodromic valve actuation

the street bikes that "rev'd past 15k" got yamaha in alot of trouble as they were caught programming error into the tach's turns out they rev'd to about 14.5. tach indicated 16k IIRC

I can't imagine a spring cycling 7,500 times/minute and lasting very long but if you stay away from coil bind and can supply enough pressure to close the valve before it needs to open again material sciences have come along way especially in surface treatments of metal to improve fatigue.

Most 600cc bikes redline anywhere from 15k-16.5k indicated.

[Colorado S14]

Anyone know the motor build specs?

[Tower240sx]

Most 600cc bikes redline anywhere from 15k-16.5k indicated.

Indicated being the operative word,

I won't doubt that the engine may see the far side of 15k on occasion, however you can't ride a bike at that RPM for more than a few Revolutions due to the rate of acceleration of the motors at those speeds, and they wouldn't hold up long at those speeds regardless.

Sportbike redlines are like HP numbers inflated to help sales,

can you imagine trying to drive a car with a 600CC sportbike's powerband? ESP if you add a turbo and make it even top heavier

[Longfellow]

Most guys I know who ride will sit on the limiter all the time and they hold up just fine, 1-2k rpms isnt that much of a difference up that high, if it was the vibrations alone would kill it. These motors have a stroke of less than 2 inches. I also dont think the tachometers are off by that much or you'd have trouble shifting at the correct time. Those motors will handle 15k revs for a sustained perioud of time stock and I know race preped 600cc bikes go to almost 18k. My stock CB500 will go to 11k and it was built in 71' and race prepped versions would go as high as 14k back almost 40 years ago.

The valves are also traveling a very very short distance. The entire valve on a 600cc bike is all of about 3" long

[Tower240sx]

Good luck with that and you're not allowed to ride my bike

look into it yamaha faced lawsuits and offered to buy bikes back,

I'm not saying it can't be done,

What exactly are you trying to say?

My 618cc ducati spins to 11,5 and it doesn't have valvesprings FWTW

[CodyAce]

Indicated being the operative word,

I won't doubt that the engine may see the far side of 15k on occasion, however you can't ride a bike at that RPM for more than a few Revolutions due to the rate of acceleration of the motors at those speeds, and they wouldn't hold up long at those speeds regardless.

Sportbike redlines are like HP numbers inflated to help sales,

can you imagine trying to drive a car with a 600CC sportbike's powerband? ESP if you add a turbo and make it even top heavier

Not 15k, but here's my buddy Matt doing 12K+ at top speed for like 5 minutes straight on a 636.


But you are correct...in regard to RPM and Top Speed, that's what moves bikes anymore...

[Longfellow]

Good luck with that and you're not allowed to ride my bike

look into it yamaha faced lawsuits and offered to buy bikes back,

I'm not saying it can't be done,

What exactly are you trying to say?

My 618cc ducati spins to 11,5 and it doesn't have valvesprings FWTW

AFAIK Yamaha isnt the only bike manufacture, so one companies recall does not mean the entire industry is the same. I'm saying that the smaller bore bikes are built to be able to handle the RPM's they spin. I'm pretty sure they wouldnt set the redline to 15k+ if the bike would come apart if it sat there to long. I dont know where you got the idea of holding a bike up near redline for any amount of time will destroy it, because its not going to bother it one bit unless you some how over heat it (doing a very long burn out?) or run it out of oil some how.

[charles]

Pretty much all 600cc sportbikes these days spin over 15k all day long. Change the oil, lube the chain and they last forever. It's been this way for at least 4-5 yrs now. Yamaha did face a legit issue of advertising a BS claim on the redline of their latest 600, but everyone else has not.

If these numbers are inaccurate as some have mentioned, Kawi, Honda, Suzuki etc are all in on it.

Heck, the 800cc V-4 in my Interceptor spins just shy of 12,000rpm

[Epstein]

Just another little bit: Mazworx also spun 10.5k at times on their normal DET head with rocker arms. You just need a lot of valve spring and solid lifters. I think I heard they had the heaviest Supertechs (126#) shimmed to 140#. Never heard if they had done anything to the rockers, although a couple Japanese shops sell cryo and WPC treated parts.

[Tower240sx]

Again Im not saying it can't be done...I have a 600cc twin that sees 11.5, with more stroke than most inline fours even up to the 1300cc hayabusa.

How long do you want your engine to last...choose your redline accordingly,
and realize the decreased life of a motorcycle engine compared to a street car engine 30k vs 225k miles to rebuild if the motorcycle engine lives to be rebuilt lol

Mike

[Longfellow]

I have 2 friends with 01' and 02' F4i's that used to stunt them and both motors had over 35k neither ever had problems with the bikes for the 2+ years they owned them. Like I said these motors are built to do what they do and be reliable, there is a reason the powerband on most 600cc bikes dosnt start untill above 10k.

Luckily those two friends wised up and got over that stage of motorcycle riding.

And yes it pretty much as everything to do with stroke, and small bore 4cyl bike motors have virtually no stroke at all. The rods in these things are shorter than your middle finger and the valves hardly travel.

I guess we can agree to disagree.

[Tower240sx]

I guess we can agree to disagree.

Agreed lol