[theroadnottaken]

ok well i'm new here and am also looking at buying a new bike, i'm not very happy with my cruiser and would like to try something new and have settled on the 98-01 vfr. i've heard bad things about the vtech and i was wondering how bad the trasition between 2 and 4 cyliders is. also i'm a tall guy 6'00 and i was wondering if this bike would fit me. i would be doing alot of touring and i'm not a hot rod so power isn't much of an issue, thanks for any replies in advance.~ Matt

i also posted pics of my bike for the heck of it so if you bored take a look. ~Matt

[UncleJesse954]

i havent heard of them having problems with vtech. ive heard that it's kind of a useless concept on the bike though because of how well they run and efficiently enough without it. it's more useful on the cars i guess. but all ive heard is that theyre great touring bikes. so go for it. they look pretty cool too in an almost superbike ducatish sort of way. almost

[theroadnottaken]

Originally Posted by UncleJesse954

i havent heard of them having problems with vtech. ive heard that it's kind of a useless concept on the bike though because of how well they run and efficiently enough without it. it's more useful on the cars i guess. but all ive heard is that theyre great touring bikes. so go for it. they look pretty cool too in an almost superbike ducatish sort of way. almost

well the problems that i had heard of is the sudden jump when it switches over. it seems like it would be kinda unnerving when in a corner.

[slickwill]

It switches from 2 to 4 valves not from 2 to 4 cylinders. However, either way there are a lot of complaints about it due to the sudden rush. Others though say that they just get used to it and always shift accordingly. They are good bikes.

[blickdander]

Matt, the '98-'01 VFRs are not VTEC engines. VTEC was introduced in the '02MY and beyond. I am close to 6 foot with a 32" inseam. The VFR fits me very well and is comfortable for many hours of riding. Mine's for sale in Ann Arbor.

[theroadnottaken]

Originally Posted by blickdander

Matt, the '98-'01 VFRs are not VTEC engines. VTEC was introduced in the '02MY and beyond.

sorry, thats why i was looking at the 98-o1 vfrs, because they don't have VTEC. sorry for the misunderstanding.

[theroadnottaken]

i ment to say that i looking at the 98-01 and was wondering about the VTEC in the 02 and later models. sorry

[UncleJesse954]

Originally Posted by slickwill

It switches from 2 to 4 valves not from 2 to 4 cylinders. However, either way there are a lot of complaints about it due to the sudden rush. Others though say that they just get used to it and always shift accordingly. They are good bikes.

its not 2 valves to 4 valves. vtec is a cam/lifter system with 2 DIFFERENT PROFILES ON THE CAM. when it is under a certain rpm. the rockers/lifters are actuated by the MILDER/NORMAL profile of the cam. when you hit vtech a pin goes in place to set the rockers/lifters to the MORE RADICAL profile (higher lift, longer duration) the engine is still using ALL of its 16valves ALL OF THE TIME. it like having NORMAL CAMs in your bike until you hit a certain rpm. then you are rewarded with MORE VALVE LIFT. not more valves

[Twincam]

Originally Posted by UncleJesse954

its not 2 valves to 4 valves. vtec is a cam/lifter system with 2 DIFFERENT PROFILES ON THE CAM. when it is under a certain rpm. the rockers/lifters are actuated by the MILDER/NORMAL profile of the cam. when you hit vtech a pin goes in place to set the rockers/lifters to the MORE RADICAL profile (higher lift, longer duration) the engine is still using ALL of its 16valves ALL OF THE TIME. it like having NORMAL CAMs in your bike until you hit a certain rpm. then you are rewarded with MORE VALVE LIFT. not more valves

Sorry if i sound dumb, but does that mean that when you pass over a certain RPM, you are then "awarded" with a high lift cam?

[-Z-]

Originally Posted by Twincam

Sorry if i sound dumb, but does that mean that when you pass over a certain RPM, you are then "awarded" with a high lift cam?

Exactly, except there's no ceremony to go with the award and your name doesn't get published in the paper or any of the usual niceties that go along with being awarded something.

[slickwill]

Originally Posted by UncleJesse954

its not 2 valves to 4 valves. vtec is a cam/lifter system with 2 DIFFERENT PROFILES ON THE CAM. when it is under a certain rpm. the rockers/lifters are actuated by the MILDER/NORMAL profile of the cam. when you hit vtech a pin goes in place to set the rockers/lifters to the MORE RADICAL profile (higher lift, longer duration) the engine is still using ALL of its 16valves ALL OF THE TIME. it like having NORMAL CAMs in your bike until you hit a certain rpm. then you are rewarded with MORE VALVE LIFT. not more valves

That's how it works in a VTEC car but my understanding is that on the bike it also includes a switch from 2 valves to 4. Here is a somewhat unclear quote from a review of the VTEC VFR that seems to allude to the same thing. It was the best I could find on short notic.

There was a big dip in the torque curve at 6,500 that slowly recovers to the expected curve a further 500rpm after the four valve change over at 7,200. The chasm is incredible, I’d have sent it back for investigation but for my knowledge of homologation legislation and Honda’s enthusiasm for being leaps ahead of the rule makers. They’ve strangled the motor, hanging onto two-valve mode even after the point where all drive-by noise and emission tests are conducted and then let the motor have it’s full quota of valve surface at 7,200rpm.

[UncleJesse954]

i did not know that. interesting.

[UncleJesse954]

somewhat unclear though like you said. not quite sure what that guy is talking about

[Twincam]

VTEC in motorcycles

Apart from the Japanese market-only Honda CBR400F Super Four HYPER VTEC, introduced in 1983, the first worldwide implementation of VTEC technology in a motorcycle occurred with the introduction of Honda's VFR800 sport bike in 2002.

Similar to the SOHC VTEC-E style, one intake valve remains closed until a threshold of 7000 rpm is reached, and then the second valve is opened by an oil-pressure actuated pin. The dwell of the valves remains unchanged, as in the automobile VTEC-E, and little extra power is produced but with a smoothing-out of the torque curve.

Critics maintain that VTEC adds little to the VFR experience while increasing the engine's complexity. Drivability is a concern for some who are wary of the fact that the VTEC may activate in the middle of an aggressive corner, potentially upsetting the stability and throttle response of the bike.

This is a definition i found on the internet - it may help.

[UncleJesse954]

ahh so it's just one intake valve that is not running. the bike is a 12 valve below vtech.

[Maholli]

Direct-actuated type HYPER VTEC Reconciling High Revolution and High Power and Environmental Performance

It can be said that VTEC, the original Honda variable valve control system originated from REV, revolution responding type valve pausing mechanism, announced in 1983. Receiving the demand for high power for sports bike engines at that time, prior study was started to reconcile high power in high revolution range and excellent drivability and high efficiency from idling throughout all ranges. An epoch-making variable valve system came into being, which enables to switch over from two valves to four valves. This technology later developed into the variable valve timing mechanism, VTEC (variable valve timing and lift electronic control system), which forms the nucleus of automobile engines. With the growth of interest in global environmental protection, measures are being actively taken also in the development of motorcycles, such as the improvement of fuel consumption rate, cleaning exhaust gas and the reduction of driving noise. The reconciliation of the measures for environmental protection and engine output is a technically difficult problem.
Honda has developed a "direct-actuated" type valve control system, "HYPER VTEC" (Variable valve timing and lift electronic control system), which will reconcile engine output and environmental protection measures for sports type motorcycle engines, for which high rotation and high power are required.

Honda has thus far developed variable valve control systems, such as the REV mechanism developed for motorcycles in 1983, VTEC mechanism having further developed the REV mechanism and recognized worldwide for application to automobiles and various VTEC mechanisms controlling variable valves by incorporating hydraulic circuit in locker-arms.
For sports type motorcycle engines, however, the mainstream is a "direct-push dynamic" valve system, in which cams directly drive valves, from the need of pursuing high revolution and high power. Sports type motorcycle engines requiring a high revolution zone of over 10,000rpm is commonly used at times. To reconcile such high revolution and high power with environmental protection measures, an entirely new and compact "direct-actuated" valve type variable valve control system with built-in hydraulic mechanism in valve lifters, HYPER VTEC, was developed. The HYPER VTEC is at present the only VTEC system without passage through the locker arms, including those used for automobiles. Not sure if this helped but Honda Worldwide has good explanation of VTEC of there website.. Honda Worldwide | Technology Close-up

[slickwill]

Originally Posted by UncleJesse954

ahh so it's just one intake valve that is not running. the bike is a 12 valve below vtech.

Yeah, one intake valve, PER cylinder, is idle until the 7000 rpm mark. Then at 7000 rpm's a second valve PER cylinder becomes active giving two valves per cylinder so you now have 8 intake valves in action. The same thing happens on the exhaust side so you also go from it being 8 active valves to 16 active valves.

I think that's the idea. All I know is that it goes from two per cylinder to four per cylinder.

[UncleJesse954]

Originally Posted by Maholli

Direct-actuated type HYPER VTEC Reconciling High Revolution and High Power and Environmental Performance

It can be said that VTEC, the original Honda variable valve control system originated from REV, revolution responding type valve pausing mechanism, announced in 1983. Receiving the demand for high power for sports bike engines at that time, prior study was started to reconcile high power in high revolution range and excellent drivability and high efficiency from idling throughout all ranges. An epoch-making variable valve system came into being, which enables to switch over from two valves to four valves. This technology LATER DEVELOPED INTO THE VARIABLE VALVE TIMING MECHANISM, VTEC (variable valve timing and lift electronic control system), which forms the nucleus of automobile engines. With the growth of interest in global environmental protection, measures are being actively taken also in the development of motorcycles, such as the improvement of fuel consumption rate, cleaning exhaust gas and the reduction of driving noise. The reconciliation of the measures for environmental protection and engine output is a technically difficult problem.
Honda has developed a "direct-actuated" type valve control system, "HYPER VTEC" (Variable valve timing and lift electronic control system), which will reconcile engine output and environmental protection measures for sports type motorcycle engines, for which high rotation and high power are required.

Honda has thus far developed variable valve control systems, such as the REV mechanism developed for motorcycles in 1983, VTEC mechanism having further developed the REV mechanism and recognized worldwide for application to automobiles and various VTEC mechanisms controlling variable valves by incorporating hydraulic circuit in locker-arms.
For sports type motorcycle engines, however, the mainstream is a "direct-push dynamic" valve system, in which cams directly drive valves, from the need of pursuing high revolution and high power. Sports type motorcycle engines requiring a high revolution zone of over 10,000rpm is commonly used at times. To reconcile such high revolution and high power with environmental protection measures, an entirely new and compact "direct-actuated" valve type variable valve control system with built-in hydraulic mechanism in valve lifters, HYPER VTEC, was developed. The HYPER VTEC is at present the only VTEC system without passage through the locker arms, including those used for automobiles. Not sure if this helped but Honda Worldwide has good explanation of VTEC of there website.. Honda Worldwide | Technology Close-up

this report seems to say that the 2 valve to 4 valve thing is the beginning of the idea for vtech back in 83. but has evolved into what vtech is widely known as today. i could be wrong. im still listening

[Maholli]

1999 SPEC 1 Hyper VTEC switch over was @ 6750RPM
2002 SPEC 2 Hyper VTEC switch over was lowered to 6300RPM
2003 SPEC 3 Hyper VTEC raised switch over back to 6750rpm..

HYPER VTEC is a valve pausing system, further advancing VTEC technology through hydraulic control unique of Honda, in pursuit of the improvement in the suction, exhaust efficiency and combustion efficiency of 4-cycle engines. A direct-actuated type is adopted, in which cams will directly push up the valves through lifters. The system enabled to switch over the number of valve operations per cylinder between low and medium speed revolution range and high speed revolution range, and by setting cam profiles to give optimum valve timing to the valves on working side and on paused side, power output characteristics were demonstrated in the low and medium speed revolution range and in the high speed revolution range for further improvement in fuel consumption rate.

In January 2002, HYPER VTEC evolved into Spec II aiming at letting everybody actually feel the power drive over the entire ranges. As one of the aims of Spec II development, it can be pointed out that the CB400 SUPER FOUR, the model on which the system was installed, is the one having a wide user class. There were voices to point out that beginners, in particular, were unable to fully utilize the four-valve stage from above the revolution range of 6,700. The development team then developed HYPER VTEC SPEC II anew to enable many more users to enjoy the four-valve stage of HYPER VTEC.
SPEC II achieved increasing torque in the middle speed range and smoother power by refining the valve timing, inteke and exhaust systems, and the valve switchover timing revolution from two to four valves was changed from 6,750rpm to 6,300rpm. It has resulted in powerful and sporty engines, enabling one to actually feel VTEC in all driving ranges from low to top. In December 2003, SPEC III was introduced. The switchover timing for a 6 speed only was changed from 6,300rpm to 6,750rpm to improve fuel consumption in cruising over high speed roads without spoiling the cheerful drive.

Click on the link in my earlier post.. Its got so much info on the principles of VTEC you will get lost.. I did...

[slickwill]

Originally Posted by UncleJesse954

this report seems to say that the 2 valve to 4 valve thing is the beginning of the idea for vtech back in 83. but has evolved into what vtech is widely known as today. i could be wrong. im still listening

Yeah, I think that is the idea. The system on the VFR's is pretty low tech compared to what is being run on the cars. On the cars the actual lift and duration is altered like you said in your original post. I still haven't figured out what the overall point of the motorcycle system is since it seems to be agreed that it doesn't add much performance and adds complexity.

[Twincam]

Originally Posted by slickwill

Yeah, I think that is the idea. The system on the VFR's is pretty low tech compared to what is being run on the cars. On the cars the actual lift and duration is altered like you said in your original post. I still haven't figured out what the overall point of the motorcycle system is since it seems to be agreed that it doesn't add much performance and adds complexity.

Well Honda does like to bring out new technology e.g. a twin braking system.. The company love to be that one step further.. pushing that extra boundary even if it has no use to us at all.

Shame we cant 'jam' something in there to keep the valve open 24/7.