Ran the 446

Yamaha Raptor 350 & Warrior Forum

Help Support Yamaha Raptor 350 & Warrior Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
They arent junk... they are just mild. You cant install heavy duty valve springs with them either for some reason. Or at least it says not to.

There a waste of money. IMO, they are junk for what they did to other raptor owners and there cam profiles.
 
The cam specs on the Hotcam stage 2 are .393 lift, 262 in dur. 254 ex dur. So they barely machine any lift over stock therefor lobe intensity isn't so harsh, hense the stock springs.
 
I got the megacycle cam comming, Mickey told me I won't ba able to take much advantage of Powrolls race cam as the duration is way to long and really needs higher rpms. Since the 446s stroke is 75mm, maximum rpm should only be about 8500 RPM which puts the piston speed at 4,232 FPM, although since this motor has such a lite weight piston and of a good forging it could probably tolorate 4,500 FPM, but that speed starts to stress the side wall loading of the piston. I wish I could set the rev limiter on this rev box. By Dynatek setting it at 15,000 RPM ain't doing me no good.
 
Stock is like .332 lift or 8.44mm, so hotcam is def an improvment, they just don't cross the .400 lift barrier to stay within the stock spring specs.
 
I got the megacycle cam comming, Mickey told me I won't ba able to take much advantage of Powrolls race cam as the duration is way to long and really needs higher rpms. Since the 446s stroke is 75mm, maximum rpm should only be about 8500 RPM which puts the piston speed at 4,232 FPM, although since this motor has such a lite weight piston and of a good forging it could probably tolorate 4,500 FPM, but that speed starts to stress the side wall loading of the piston. I wish I could set the rev limiter on this rev box. By Dynatek setting it at 15,000 RPM ain't doing me no good.

I know I can't wait to try this same cam in my setup (252x-1). I guess from what I've read you want to have about 5 degrees of cam advance and that will help give you a broader power range and help the low end power. I think it will be a little big for what I want to do but hey I'll give it a shot. I was hoping to sell it to you if I didn't like it but you already bought one! :) I think even with powrolls spec's (+9.5mm stroke) it's rather large of a camshaft to be turning a stroker that hard.
 
[quote:eek:y42u206]I got the megacycle cam comming, Mickey told me I won't ba able to take much advantage of Powrolls race cam as the duration is way to long and really needs higher rpms. Since the 446s stroke is 75mm, maximum rpm should only be about 8500 RPM which puts the piston speed at 4,232 FPM, although since this motor has such a lite weight piston and of a good forging it could probably tolorate 4,500 FPM, but that speed starts to stress the side wall loading of the piston. I wish I could set the rev limiter on this rev box. By Dynatek setting it at 15,000 RPM ain't doing me no good.

I know I can't wait to try this same cam in my setup (252x-1). I guess from what I've read you want to have about 5 degrees of cam advance and that will help give you a broader power range and help the low end power. I think it will be a little big for what I want to do but hey I'll give it a shot. I was hoping to sell it to you if I didn't like it but you already bought one! :) I think even with powrolls spec's (+9.5mm stroke) it's rather large of a camshaft to be turning a stroker that hard. [/quote:eek:y42u206]
Yeah I remember a while back we were talking about pistons speeds, and you were saying 4200FPM being the utmost extreme
you want to rev the motor, now since I have 10.5 mm stroke over stock, I came up with 8500 RPM being the most I should rev if I want the motor to live. I'm gonna call Dynatek tomarrow since I'm off of work a few days and see If I can send the box back and have the rev limiter set at 9000.
 
what do adjustable timing sprockets do? If thats what your talking about
They allow you to be able to advance or retard the cam timing by moving the sproket clockwise or counter clockwise, advancing the cam gives you a slight bit better torque at a lower RPM but at a lose of some upper RPM, retarding the cam moves the RPM band more to the upper range, thus losing a bit on the low end. This works perfect for tayloring your riding style, especially if your racing, you'll be able to taylor to different tracks.
 
Yup, all altering cam timing is doing for you is moving the power band around to better suit your needs. It only like a few hunderd RPM, but it makes a big difference.
4500 fps max on piston speed. With light weight and forged piston it should be able to hold together. But to be safe I would say around that 4000 to 4200 fps.
 
Well it's been a while so I'll update, after installing the Megacycle 252X1, the motor now has the insane torque I was raving about back in March. The torque hits from idle to the top, but now I have the Dynatek and the mid range pulls way faster then before. For such a long stroke motor it def likes to rev. Using the 38 tooth in the rear tones it down a bit, but top end is blindingly fast, the 40 tooth dose the same just alot faster, plus it wheelies in the first three gears even leaning over the bars.
 
Back
Top