So I ****ed my car up and it turns out that I broke 3 valve guides on the intake side but the valves dont look to be bent. Could this be from valve float? I was revving to 8100 on the stock valves which doesn't seem that extreme to me. Just wanted to see if anyone else has broken valve guides on the intake side, what caused it, and if this is a weak link in the evo head.

thanks,
Ryan

 

That is kind of high for the stock valvetrain, but I think the limit is much higher. I think it depends on what kinds of cams you're running. If you're running a high lift cam, then yes, the combo of high lift and high rev probably did it.

 

Did you have any lifter ticking prior to the episode?

I need to know

 

yeah, it was getting a little louder

 

if you have cams with 11.0 lift or higher on stock valve terrain is the limit unless you rev it to 7500 or less then yes bouncing off of 8k is not a good idea with 11.o lift or higher. we have brian crower valve terain instock pm me if your intrested

 

I think the OEM valve guides are cast iron...seems HIGHLY unlikely you've broken the valve guides. I've blown up probably over 6 4G63 engines in my lifetime, and all of them had valve damage. None of my valve guides ever suffered any damage. Are you sure the valve guides are damaged and not the valves? Do you have any pics? Is the cylinder head out of the car right now?

 

I dont know if you're familiar with the honda world but Tony Palo is the one working on the car and he is extremely knowledgeable not just in hondas but just in general. he pulled the head off today and he said that it was the valve guides. He told me to make a post about it because he thought it seemed odd also and wanted to see if it had happened to anyone else.