Hardened Valve seats???

[mile2885]

Ok, so once again forgive me for my ignorance..............I bought a set of 049 heads that had a "fresh" rebuild on them for $150. Took them to the machine shop to have them looked over and the guy at the shop couldn't stop griping about having hardened seats on the intake and exhaust............is this bad should I take the heads somewhere else to have them checked out?? I was under the impression that when you have hardened seats installed it was on both the intake and exhaust but the guy at the machine shop seems to think its a bad idea. Any ideas?? :idea:

[Craig]

I was always under the impression that hardened valve seats were good :confused: They started using them when they were started phasing out the lead in the gas which is a lubricant.

[Wicked Performance Boats]

hardened seats are not bad depending on where and how you use them. O n a boat motor some engine-cylinder head builders will not use them because they are prone to fall out because the engine doesn't get as hot. Budlight

[Moneypitt]

I think that BBC valve seats are part of the head, and not removable. I may be wrong here, but I've never heard of replacing a valve seat on a BBC.......MP

[GofastRacer]

I think that BBC valve seats are part of the head, and not removable. I may be wrong here, but I've never heard of replacing a valve seat on a BBC.......MP
I've repalced them before, the trick is to find someone that knows WTF they're doing to make them not fall out!. I also have a brand new head from the factory with hardened seats!.. :smile:

[steelcomp]

I think that BBC valve seats are part of the head, and not removable. I may be wrong here, but I've never heard of replacing a valve seat on a BBC.......MP
Valve seats can be replaced on most any head, and seats don't "fall" out if they're done right, weather it's a boat or not. Makes no difference. Alum heads all have seat inserts and are way more in jeopardy of falling out due to the difference in the expansion coefficient of the two metals. Typically you only need hardened seats on the exhaust side. I'm wondering how he knows there are hardened seats on the intake side?? Replacement seats can be all kinds of different material, not necessarily hardened. It's not easy to tell by just looking. I'd want to know who did the job and how much experience they had...that's a lot of work replacing all the seats in a cast iron head. If they did a good job, it can be a good thing. If they didn't know what they were doing, or were in a hurry, that can be a bad thing. :coffeycup

[steelcomp]

I've repalced them before, the trick is to find someone that knows WTF they're doing to make them not fall out!. I also have a brand new head from the factory with hardened seats!.. :smile:
Most late model heads are induction hardened on the ex side, but valve job them once and by by hardening! :D

[Wicked Performance Boats]

Quote:
Originally Posted by Moneypitt
I think that BBC valve seats are part of the head, and not removable. I may be wrong here, but I've never heard of replacing a valve seat on a BBC.......MP
WRONG!!!!!!!! What do you think happens when a bbc or any other head for that matter, has valve seat ression, just throw the head away? Budlight

[steelcomp]

Quote:
Originally Posted by Moneypitt
I think that BBC valve seats are part of the head, and not removable. I may be wrong here, but I've never heard of replacing a valve seat on a BBC.......MP
WRONG!!!!!!!! What do you think happens when a bbc or any other head for that matter, has valve seat ression, just throw the head away? Budlight
Valve seat ression??? That's just not right, Bud. :confused: :D

[Wicked Performance Boats]

I flunked spelling along with attendance. Budlight

[GofastRacer]

Most late model heads are induction hardened on the ex side, but valve job them once and by by hardening! :D
Yep very true but this head I have is from the late 70's early 80's so I'm not sure what the seats are made of!.. :confused:

[steelcomp]

What kind of head?? Are they inserts?? Could be stellite, or ductile iron.

[steelcomp]

I flunked spelling along with attendance. Budlight :D :D You're a funny guy, Bud! LMAO!

[GofastRacer]

What kind of head?? Are they inserts?? Could be stellite, or ductile iron.
It's a factory large oval and they are inserts, I'd guess Stellite????, I'll dig it out and look at the numbers, I ain't looked at it in 15 years or so LOL..

[Stingray69]

I worked at a place that machined merc service parts; blocks and heads. Heads have no intake seat; just the casting.