On some of the high lift cams, they require hard faced rockers and bigger springs. WHat does the XR400 cam require? Is this a low, mid or upper range gain?

Also, I believe I am going with an 11:1 piston stock bore, any other suggestions?

I just broke a shifter fork in the tranny, so while it is down....

Any other suggestions?

Thanks for the help.

 

I spent an hour on the phone with Tom of TC Motors/Racing. Which is the main builder for those who win GNCC. Anyway he told me I could run up to 10.5 comp. on pump gas. Also his cam is ground especially for 400EX needs. The XR cam has less grunt and more top in it. His cam was only 169./ piston kit 120. cheaper than stock parts. He is the real deal! I have seen his race motors walk the track. His # is 814-723-3514. Rockers and springs are okay.

 

You dont need to do anything to your rocker arms with the xr cam. I called hond {twice} before I put the xr cam in my 400 and the assured me that the valve train specs in the 400ex and the xr400 are the same. Im running a je 10.8:1 piston {stock bore} as well and really enjoy gains, especially on top. I also have the higher rpm rev box, a must for what you are thinking about doing in my opinion. No problems with my setup, Ive had it for about a year this way. 400exr is right about losing a little on bottom with the xr cam, but it revs out nice, plus the boost in compression helps that bottom end from going away.

Utah
99 400ex, lots of mods
99 Banshee, lots of mods
96 300ex, stock