Does anyone know the RPM range of G4 Cams

[RacingJake]

Does anyone know the RPM range of G4 Cams

Thanks

[cbxchris]

Jake from racing many GS`s you will probably not get a lot of usable HP after 11K unless you are running a lightened valve train(titanium valves/retainers/rockers)....etc. Your carbs will have a lot to do with it also. Rule of thumb is bigger carbs for more top end HP ...smaller for more torque and less rpm. The G4 is not a radical cam at all. I would probably say from 6K to at most 11k. Your lob center settings will greatly affect where you engine picks up. I ran mostly turbo`s when racing but did have many large GS based street bikes. 110 lob center is a very good starting point. Usually lower lob center will mean more cranking compression and more torque quickly(less rpm) ans higher lob center will move your power band up in the rpm range. I would never go over 114 lob center. Its amazing when the hayabusa came out I was trying GS based lob centers because no one knew what worked. Anyhting above 107 is a waste and more like 102-105. Also the hayabusa times off the intake came with its injection...above 112 and they won`t run. What those low lob centers tell you is how good the combustion chamber on the hayabusa is compared to the GS series which until then had still been the best for many years. Sorry I kinds got off target here I just like discussing performance engines.

[cbxchris]

Jake to tell you how quick G4 cams can be in the right chassis (kosman pro stock 10 inch car tire)I had a 1325 with 10 to ones with G4`s with a super head(expensive!) and lectrons it would run 5.50`s all day long in the 1/8 mile. The head and carbs are as important as the cams. That was my street bike engine.

[RacingJake]

Thanks for the info

On my stock setup I'd shift around 9K. With this new setup 1166, 13-1, G4, 38mm CV's and stock head the RPM is so quick from 5K up. I guess I'll just half to wait until the track open's to find out the best shifting point.

[skip]

Thanks for the info

On my stock setup I'd shift around 9K. With this new setup 1166, 13-1, G4, 38mm CV's and stock head the RPM is so quick from 5K up. I guess I'll just half to wait until the track open's to find out the best shifting point.

with the g-4's i raised my power band from the 8500 range and 127 mph to 10,000 to 10500 rpm and 134 mph, I also did the head at the same time. but it was only a mild street/strip port job and not expensive. shift at 10500 and go backwords 500 rpm at a time and see if your times improve . Or throw it on a dyno.

[RacingJake]

I'm still running OEM valve springs. Is the 9K redline for the springs or cams.

I do have a new set of APE springs waiting to go in and when I compared the APE springs to the OEM's the APE's were not as tall??

[skip]

I'm still running OEM valve springs. Is the 9K redline for the springs or cams.

I do have a new set of APE springs waiting to go in and when I compared the APE springs to the OEM's the APE's were not as tall??

I dont think the height is as important an the strenght and rebound rate of the spring. I would not pust the rdline too far with sock springs nine grand is ok. but if you install heavy duty springs and a rev limiter dont be afraid to bring it up another 1000 rpm. I found my best et ever was shifting at 9,750 (but by the time i actualy shifted i was up at 10000 to 10200) with the g-4s and with the stock cams i shifted at 8800 and it worked great.