Installed new valves and need help!!!

[Stroker81]

Ok guys I got my head ported and polished, also got 1mm bigger valves. Put head back on and adjusted valves started it up and wow it made some bad noise. Any idea's what i did wrong? I got the valves at manual spec 4thousandths and 5thousanths like the clymer said. I have not tore it back apart yet to check to see if the valves are hitting piston. I have the wiseco 440 kit 11:1 piston. You guys think the valves are hitting the piston? Thanks for all help in advance.

[witech]

Did you put the piston in backwards? If you did and the valves were hitting order up a nother set .

[Stroker81]

Piston was never took out, only thing that was took off was the head.

[ryanhood1983]

say the valves hit the piston.. would it bend the valves? and could you tell without taking the valves out of the head?

[witech]

If the valves did smack the piston in the case of the timing being far of or soemthing you might be able to look down the spark plug hole and see mark in the carbon on top of the piston. i dont remember if it can be done on a 400ex.

[mcgrath]

when setting valves make sure its .004 inch, not mil big difference. Also were you on the compression stroke? seems alot of guys dont get this right the first try. If your timing is on and they are the right valves there is no reason it would be hitting the piston. Unless you have the vavles too tight they might not be shutting all the way and with a 11:1 piston it might hit them I guess? not sure on that though. You will be able to see marks on the piston if it hit the valves. Recheck your valve specs.