What could cause a broken valve guide?
Thread Starter
Teching In
Joined: Apr 2008
Posts: 21
Likes: 0
What could cause a broken valve guide? I installed a set of Patriot Stage II LS6 heads and a TR224 camshaft and from the get-go the car was smoking like crazy, burning more oil than gas. I suspected either the sealant on the rocker bolts or the valve seals. I started replacing the seals today and went to pull the seal off the #5 exhaust rocker and out it came with about 1 1/2'' of the bronze guide still attached to it. 
Pretty sure that solves why the car was smoking, but why the hell did this thing break? Car is a 2000 Z28 with 62k miles, automatic, used for some daily driving and autocross. Car has the above mods with LS7 lifters, Comp 7.4 rods, stock rocker arms, and bolt ons.
Also, since one is broken, what are the chances of finding another? I started on the driver's side and this was the only broken one. I haven't started the passenger's side yet...
How the hell do I get this fixed?
Need beer...
Thanks for reading.
-Aaron
Pretty sure that solves why the car was smoking, but why the hell did this thing break? Car is a 2000 Z28 with 62k miles, automatic, used for some daily driving and autocross. Car has the above mods with LS7 lifters, Comp 7.4 rods, stock rocker arms, and bolt ons.
Also, since one is broken, what are the chances of finding another? I started on the driver's side and this was the only broken one. I haven't started the passenger's side yet...
How the hell do I get this fixed?
Need beer...
Thanks for reading.
-Aaron
If i were you, i would pull the heads, and have ALL the guides replaced. It should cost too much to have a machine shop remove and install new guides. Ive remover quite a few at work, but dont normally put them back in.
Thread Starter
Teching In
Joined: Apr 2008
Posts: 21
Likes: 0
Update: After pulling the heads I discovered the guide was not broken, the whole guide had actually come loose of its press fit. I initially thought it was broken from the odd angles present on the bottom of the guide, but realized those had come from the CNC work to the head with the guide installed.
So I guess I should rename the thread, what could cause a valve guide to come loose?
The head were lightly used on a 1999 Z28 for about 2k miles. That car is owned by a friend who bought the heads new and at the time he ran the heads had an otherwise stock internal motor.
So I guess I should rename the thread, what could cause a valve guide to come loose?
The head were lightly used on a 1999 Z28 for about 2k miles. That car is owned by a friend who bought the heads new and at the time he ran the heads had an otherwise stock internal motor.
