KLX350SF Cams
#1
08-02-2010, 04:46 PM
Join Date: Feb 2010
Location: Okinawa, Japan
Posts: 42
KLX350SF Cams
I'm in search for cams for my KLX350SF (D-Tracker). Bill's bore kit provides great torque, yet, in essence, the engine still feels like a KLX250. I just want more horsepower for rickety rocket ***-sliding corner burning apex blocking power... at the smartest price.
Before any get another bike post, here's why it needs to be a KLX350. It stays within the local track regulation that allows any modification as long as I use the stock crank case. There enters the search more power from the KLX350SF.
The current engine set-up is B&B 350 kit, FCR39 open carb with filter and split intake bell, ported head, older model KLX-SR CDI (for more advance), RSV headpipe, CRF dual exhaust, and AI blockoff.
The current chasis setup is supermotard with alloy rims, reworked suspension, 4 piston caliper, and Brembo radial brakemaster 18x16.
Considering the above, more HP up top is needed and within 11,500RPMS so I am leaning toward using Webcam grind #55 (for the KLX300). Webcams say I need stronger valve springs but the Yoshimura has more lift and everybody that use Yoshis say no valve adjustments or stiffer springs are needed.
I don't want to use stronger springs because the valves slap back harder and decrease their life... maybe blow the motor. Yoshimura says using stock springs with their cams is good-to-go.
Here are the cam specifics.
YOSHIMURA SP-1 Race cams: Installation is Drop-in Bolt-on, Valve Lift is IN8.80mm EX9.20mm, Duration at 0.05" is IN234 EX238
WEBCAMS grind #55 for KLX300R (interchangeble with KLX250)
Installation according to Webcams says stiffer springs required, Valve Lift is IN8.94mm EX8.94mm, Duration at 0.05" is IN243 EX243
Webcam grind 55 with the overlap looks so good for absolute top end while the Yoshimuras look so sophisticated and calculated with the different IN and EX cam dimensions for a balance of top end power and reliablity with stock springs...
The question is, what do you guys think about using the Webcam grind number 55 with stock springs? I just need some thoughts or hindsight to help me with my choice....
Before any get another bike post, here's why it needs to be a KLX350. It stays within the local track regulation that allows any modification as long as I use the stock crank case. There enters the search more power from the KLX350SF.
The current engine set-up is B&B 350 kit, FCR39 open carb with filter and split intake bell, ported head, older model KLX-SR CDI (for more advance), RSV headpipe, CRF dual exhaust, and AI blockoff.
The current chasis setup is supermotard with alloy rims, reworked suspension, 4 piston caliper, and Brembo radial brakemaster 18x16.
Considering the above, more HP up top is needed and within 11,500RPMS so I am leaning toward using Webcam grind #55 (for the KLX300). Webcams say I need stronger valve springs but the Yoshimura has more lift and everybody that use Yoshis say no valve adjustments or stiffer springs are needed.
I don't want to use stronger springs because the valves slap back harder and decrease their life... maybe blow the motor. Yoshimura says using stock springs with their cams is good-to-go.
Here are the cam specifics.
YOSHIMURA SP-1 Race cams: Installation is Drop-in Bolt-on, Valve Lift is IN8.80mm EX9.20mm, Duration at 0.05" is IN234 EX238
WEBCAMS grind #55 for KLX300R (interchangeble with KLX250)
Installation according to Webcams says stiffer springs required, Valve Lift is IN8.94mm EX8.94mm, Duration at 0.05" is IN243 EX243
Webcam grind 55 with the overlap looks so good for absolute top end while the Yoshimuras look so sophisticated and calculated with the different IN and EX cam dimensions for a balance of top end power and reliablity with stock springs...
The question is, what do you guys think about using the Webcam grind number 55 with stock springs? I just need some thoughts or hindsight to help me with my choice....
Last edited by japanbilly; 08-02-2010 at 04:50 PM. Reason: grammatical error
#2
08-02-2010, 09:37 PM
get in touch with Bill Blue again.
He is working on HEAD's now and has a ported head with bigger valves which allows the motor to really breathe. You might want to ask him what cam and give him your head while you're at it.
He is working on HEAD's now and has a ported head with bigger valves which allows the motor to really breathe. You might want to ask him what cam and give him your head while you're at it.
#3
08-02-2010, 09:39 PM
Put some pics of that sumb!tch up!! Sounds like a nice bike.
It also sounds like you know more than 95% of everybody on here already. I for one can't help you. I'd like to see it though.
Dan
It also sounds like you know more than 95% of everybody on here already. I for one can't help you. I'd like to see it though.
Dan
#4
08-02-2010, 10:01 PM
Join Date: Jan 2008
Location: SW Ontario, Canada
Posts: 869
I am in the custom camshaft business (no I don't do anything for the KLX). I would not hesitate to use the stock springs with the Web profile.
#5
08-02-2010, 11:36 PM
I've been wondering the same thing about some cams for my 351. Sorry I can't offer much help, but I'd love to see your findings.. Keep us updated for sure.
Good luck
Good luck
#6
08-03-2010, 12:06 AM
Join Date: Jan 2008
Location: SW Ontario, Canada
Posts: 869
I'll be doing cams before I go big bore.
The stockers are a wee bit on the mild side, and you'll definitely benefit from some more lift, and 10-20 degrees more duration.
If I recall, there's a pretty extensive cam thread on here, and there's some good info in there.
The stockers are a wee bit on the mild side, and you'll definitely benefit from some more lift, and 10-20 degrees more duration.
If I recall, there's a pretty extensive cam thread on here, and there's some good info in there.
#8
08-03-2010, 12:18 AM
Lets see the bling!
I can see a small shot in your avatar but it'd be great for a nice large photo. Future BOTM winner from here.
Is the exhaust a full custom set up or are the headers available off the shelf (in Japan I guess,) and do they mate to the stock CRF250 mufflers?
#9
08-03-2010, 12:41 AM
My two cents....For what you are describing I think you're better suited with the #55 grind. That cam is going to really like the rpm's so be prepared to keep the rev's up to keep it in its range. In a 250cc, or even a 300cc to an extent, that cam would be a dog down low, but hopefully your extra 50cc will help the cam act a bit smaller than it really is.
I think the stock springs will handle the lift & duration, but spinning the motor at 11,000 rpm with a long duration cam could be a recipe for disaster. I would go aftermarket just to ensure no valve float.
Ryan
I think the stock springs will handle the lift & duration, but spinning the motor at 11,000 rpm with a long duration cam could be a recipe for disaster. I would go aftermarket just to ensure no valve float.
Ryan
#10
08-03-2010, 02:28 AM
What's your track like? will you pick up more time on the straights or running quick off the corners? do you ride rolling on and off in 1 gear or do a lot of shifting?
Unless the cam company's tell you both the total and 1mm lift durations AND the open-close event times it's real hard to compare. I'd talk to them a little more, even if they don't give specifics try to find out what rpm the hp and torque peaks were in their testing. You want to shift well into the hp peak and fall back on the torque. A good grind matching your gear spacing can often outperform a higher hp cam.
Unless the cam company's tell you both the total and 1mm lift durations AND the open-close event times it's real hard to compare. I'd talk to them a little more, even if they don't give specifics try to find out what rpm the hp and torque peaks were in their testing. You want to shift well into the hp peak and fall back on the torque. A good grind matching your gear spacing can often outperform a higher hp cam.