Cracked valve guides

[cozinsky]

I got my heads back from the machine shop. He replaced two exhaust guides and said the rest were still tight. I didn't notice until after I had them torqued down, but looking through the spring coils I can see both of the old guides cracked when the new ones were pressed or driven in. It looks like there still should be at least 1 1/2" under the spring seat inside the head to hold the new guide. Its just the part above the head casting inside the spring that's cracked. This makes me nervous. Is it ok to run like this or should I pull the springs off and knock the pieces of the old guide bosses off with a chisel? Is there still enough to hold the new guide in place inside the head without the shell of the old guides?

 

[Randy Bush]

When the old guide , part of the head casting is drill out for a replacement there is a very thin part of it left , not enough to add any strength to the new guide. It is a very much a press it and will not come out.

 

[cozinsky]

Should I be concerned with the cracked guide bosses? I don't want it breaking off while the engine is running.

 

[Randy Bush]

Are these intake or Exhaust ones? How bad is the crack , just see the crack or loose and peeling from the replacement one. If a intake does the seal remain in place when the engine has been turned over. With out really seeing it it is hard to really say. If you are unsure and trusted the machine shop go and express your concerns to them.

 

[cozinsky]

They're both exhaust and I have the nylon umbrella seals on them. As far as I can tell the cracks run the length of the guide boss that sticks out above the head casting, but there is nothing loose or peeling.