Hardened seats or Stainless valves?

[rang-a-stang]

Originally Posted by wiley-moeracing

... The hardest part is finding a good honest machine shop now. Kind of like finding a doctor, when you do stick with them no matter if it costs more.

I'm with you Wiley-Moe!!! I KNOW I am paying a lot for these heads to be done. ALOT. But I trust this guy. Almost every person I have talked to at car shows here in Ventura County either recommended a shop that has shut it's doors or Jim Grubbs Motorsports (the shop I am using). Those are folks with engines from all the Big 3. It's very rare to find an AMC engine at a car show here.

I am paying for the viton positive seals now because I figure either do it now, or do it later and it really isn't to much money.

[Ristow]

Originally Posted by levelhead

SC/397 Would you go with valve guide inserts the machine shops seem to be pushing these days or replace with new cast iron guides?

its gonna be inserts either way. apparently cast iron and stainless don't play well together.i seem to recall i had stainless valves in cast iron guides but my memory may be failing me on that one. in that case it may have to be manganese bronze.

[FSJunkie]

New guides come in different types.

There are the thin wall "guide liners" usually made of bronze. The guide is reamed out slightly oversize and the thin liner is installed. I am not a big fan of those. Bronze is good at resisting scuffing from lack of lubrication, but it wears out quickly and has a low melting temperature.

Then there are what I refer to as actual guides. Calling them an insert isn't really correct. They have an outer diameter of about .503". The existing guide in the head (which is just the iron of the head itself) is reamed out to .500" exactly and the guide is hammered into place then trimmed to length. The guides are already the correct inner diameter for proper clearance to the valve stem, but unfortunately hammering them into the head collapses them a little and they have to be reamed back out to proper size. These guides come in steel with a smooth inner bore or steel with a partial spiral groove at the top to let oil get into the guide except for the very tip near the valve head. I prefer the spiral groove guides. All my engines have them.