Any difference with the 450/451 and 479 grind????

[shamisc]

I have a 440 12.5:1, pipes, p&p head, hard welded rockers, hd spring Ti retainers, and the 450/451 WebCam. Will there be a noticeable difference if I get the 479 grind? Anyone else done this? I'm looking for more out of my engine and I'm thinking a cam swap will give me a little more all aorund.

[MIKE400EX]

I've got basically the same combo, just 1 point less comp. if your 12.5:1 is actual and not advertised. I had the 450/451 and swapped it out for the 479. IMO the bottom and mid was a big increase over the 450/451. Top end is just as good. Coming out of a corner on a MX track or shooting a big hill without a long run is way easier. If you also add a GT Thunder ignition box you'll be very happy, it does like to rev out.

[cletusEX]

My buddy ran both and the 479 is a lot better cam IMO. The 479 had more power everywhere. His 440 had the 479 grind cam, bigger valves, mild port, 13:1 compression, full exhaust and it ran real good. It would walk all over piped 450Rs that had a 13 tooth sprocket. I ran the 450/451 cam in my 416 and if I was gonna keep that bike I would have swapped cams to the 479.

[K_Fulk]

With my experiance betwwen the two. The 479 has more agressive power on the bottom, and revs out better.

The 450/451 seemed smoother on the bottom and didnt seem to rev as quick.

Granted, the 479 was on a 440 and the 450/451 was on a 416.

[shamisc]

Thanks guys!!:D One more thing, Webcam says you have to run shortened valve guides, any trouble putting those in?

[MIKE400EX]

Heating up the head to about 240 degF and a press helps. Just be careful since the head will be at an angle to the press piston (and HOT). You could probably bang them out/in with a stepped "punch". You'll have to ream or hone the guides to size after install, then do a valve job.
There are some aftermarket Honda/Acura automotive seals that work and are about .020" shorter installed than the OEM ATV seals. If you can find them at an automotive machine shop it'll save you changing the guides. Although IMO the Kibblewhite bronze guides are better than the OEM iron ones.