The Jalopy Journal
Discussion in 'The Hokey Ass Message Board' started by bgaro, Aug 25, 2013.
I`d like to see the whole stem of the valve bgaro if you could.
here ya go dave, got a better shot of the fracture too.
why didn't you just pull the head ?
Thanks its really hard to see in the pics. I am wondering if valve stuck in guide hit piston and then fractured? If you take another valve and try to slide iit up and down the guide does it do so smoothly no friction. Check the valve stem for signs of gauling. Call me if youd like # is below in sig.
Also under fingers in pic above is a part # or name on valve.
i did pull the head, after seeing the impact to the piston, my concern is what else is wrong. i wouldn't be able to sleep at night if i just replaced the valve (OCD maybe?)
part# 00400 10611 if this means anything
I would pay a visit to your engine builder. HRP
Look at the valve head seating area (machined face)in your third picture.
That valve was flying when it hit the seat to deform that much.
See your builder
thanks, mine are from Elgin...but they are all probably made in the same offshore factory
if they are new, call sealed power, for warranty,
I was looking at that too but can't be certain it isn't the picture. The valve would have to be pretty soft to deform so quickly.
I'm interested in this valve closing velocity problem. Does it take out all 16 valves?
I've always tried to get valves to close as fast as possible and have used some very strong double and triple springs to do it and stop them from bouncing off the seat at 8,000 rpm and higher with solid lifter cams. If the valve is closing too fast at 3,300, it should have been more of a problem at more than twice that speed in a GM 302 with the infamous Duntov camshaft with .030 lash. As I said above, I've had almost everything else in the valve train break but never a valve at the top of the stem. Guess I've just been lucky.
That valve stem seems to have a alot of wear for a new valve. I will havce to go back and read your Original post
Should be ok as long as the valve is seating on the ramp and not on the flank of the cam profile. The engines I was referring had cams and valvetrains designed for 4200 rpm no follow speeds and hydraulic roller lifters. The cams had some pretty high accelleration rates but ramps designed for reasonable seating velocities.
just heard back from the machine shop, he found another valve that was fractured. he seems to think there is some clearance issues going on. plan is to redo the heads, the piston looked worse than it is and can be saved. i figure while hes at it open up the intake side.......why not, then i can feel like i've made progress.
Separate names with a comma.