350X Engine Rebuild

[thebutelr]

Ok guys I finally tore into my engine and found that one of my valves had the keeper come off and drop down into the combustion chamber and hit the piston. The valve is bent and junk now but the piston seems to only have very little damage. The only thing I can see on the piston is a couple slightly rounded corners on the dome of the wiseco. Does this need to be replaced? Also I was wondering if since the valve was bent, would the valve guide have to be replaced as well? I am replacing all the valve springs and valve seals while I'm inside the motor. Is there anything in particular I should look for other than what I've described that could be damaged? Thanks.

[Dirtcrasher]

Did ya get the keeper out of the engine? That happened to a stock motor? or had the head been tinkered with before?

The guide may be perfectly fine it probably just bent the valve but I'd make sure the valve seat is perfect. And I hope the connecting rod or other valves didn't get bent.... I'd yank all the valves and inspect everything.

If the piston is within spec I wouldn't sweat a small amount of corner rounding. But, if it has miles on it then it would probably need a whole top end anyhow.... If it's your new Wiseco, I'd just sand them smooth - your talking about little nicks it seems like...

[thebutelr]

Did ya get the keeper out of the engine? That happened to a stock motor? or had the head been tinkered with before?

The guide may be perfectly fine it probably just bent the valve but I'd make sure the valve seat is perfect. And I hope the connecting rod or other valves didn't get bent.... I'd yank all the valves and inspect everything.

If the piston is within spec I wouldn't sweat a small amount of corner rounding. But, if it has miles on it then it would probably need a whole top end anyhow.... If it's your new Wiseco, I'd just sand them smooth - your talking about little nicks it seems like...

No this motor isn't exactly stock has only very mild mods, the cam is a mild grind web cam & the wiseco is a 10.5:1. I'm almost positive that the intake valve was floating & finally gave way, pushing the keepers off the end and dropping the valve on the piston. The cause of this is leaning more towards the valves being adjusted way too tight and wearing out the springs, also could be they weren't strong enough to handle the cam after 20 years of use. So far I cannot find any damage at all to the valve seat and the other valves are just as they were before, no damage. I am still going to take it all down and inspect everything before it goes back together. Also to answer your question about the keeper, it was laying right next to the valve when I took the valve cover off. . When this happened the motor was running really weak and finally just died acting like I ran out of gas. So I'm lucky that they weren't sent through the bottom end of the motor.