Reply With Quotedid u replace the cam recently?---sounds like what happens when the springs coilbind when a cam with a higher lift is put in with stock springs
Dropped #1 intake valve while cruising at 3200 RPM. On teardown found that the lock had broken. Also found bent valve on #7 intake. Pulled the other valve pan and found that the top half of #2 intake valve lock on one side had broken off. The valves on #1 head were not properly seated and some had to be lapped. Anybody have a clue as to what could be causing this?
did u replace the cam recently?---sounds like what happens when the springs coilbind when a cam with a higher lift is put in with stock springs
I agree with Blown Gas...locks don't break unless there's some other issue as...coil bind or even check to see if the rocker's were hitting the upper retainers. Heck even a small piece of hard dirt may stop a lock from seating properly.
I don't even want to think about the damage that was done! I once had a valve head break...it was ugly! That kind of stuff stay's with ya for some time.
[This message has been edited by HammerDown (edited June 26, 2002).]
Also check retainer to guide clearance. Retainers could be hitting top of valve guide. Find the problem, then throw all the retainers, springs, and locks away and replace only with name brand parts. Check the keeper grooves on the valves also and replace the valves if keeper groves are bad. Watch out for cheap valve train parts. Not much is generally saved from an engine that drops a valve.
Check all the valve keeper grooves, if there is ANY burr, nick, booger or whatever change the valve or if nothing else dress the flaw before reassembly. The upper edge should be smooth with no flaws and have a sharp 90deg. edge.
Thanks for the input, all the parts involved are stock GM. Everything looked good except for the one valve keeper. Installed all new springs and keepers, lapped the valves. Will put back together and see what happens.
Thanks
have you had any vlave guide work done on the heads... also if you have head temp rise from using a different fuel or water passage blockage u will have a change in valve guide clearance... this will cause the valves to bind & pop the locks out of the retainers & crack or break them & cause the valves to drop & hit a piston & bend..... u also could have the valve springs going off & have some valve bounce at revs.. you have lots to consider here... GOOD LUCK
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