Do I want replacement valve seats?

[Begle1]

So would I want press in valve streets to replace all my cracked exhaust valve seats? Or is that just asking for trouble?

[burnt_servo]

i've had it done on many gas engines .

any vehicle running long term on propane or natral gas has had it done ( the exhaust valves and seats don't last very long other wise )

any aluminum head has hardened press in seats .

cracks can create stress risers and can grow , machine the cracks out , and you stop them from growing bigger .

the question is , do you trust the guy doing the machining ?

[Begle1]

He quoted me $400 for a valve job including putting in new seats. If I get that done then I'd just have all the little cracks between each intake port and injector bore, and it'd be cheaper than getting another head shipped out here.

But I've also heard of the newer trucks that have press-in valve seats from the factory dropping them? Would an aftermarket press-in seat have the same tendency to drop, or is that a problem unique to the factory?

[BC847]

According to the FSM, the OEM integral seats can be machined once. Previously ground seats must be replaced.

If the head has been milled 0.010" or more from the combustion surface, service seats must be installed.

The grinding depth maximum limit on integral seats is 0.010".

[seeker1056]

doesnt sound like much - why is that?

Is the hardened surface that thin?

do they feel the seats need to be sunk more once a head has been surfaced?

I can guarrantee you my intake seats wont clean up with .010 cut
they are so badly whats the word - concaved - recession of the valve face

does that mean i am into seats too?

[BC847]

As part of the head's manufacture, the integral seats are induction hardened. As such, the hardened part isn't that thick. One can easily machine the hard part right off.