Harded valve seats?
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Freshman User
Joined: Aug 2004
Posts: 36
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From: KS
Harded valve seats?
I was wondering if valves seats on engines from the factory are actually inserts which are easy to replace or are the seats machined into the head material itself?
Question? If seats are factory inserts, how do you remove them?
Questions? If seats are inserts, can you drive them in or do you use a arbour press?
Thanks
farmerboy
Question? If seats are factory inserts, how do you remove them?
Questions? If seats are inserts, can you drive them in or do you use a arbour press?
Thanks
farmerboy
Hotshot
Joined: May 2004
Posts: 12,170
Likes: 5
From: The hills of No. Calif.
Most (if not all) seats on these engines were simply machined into the head, and any hardening was done to the seat area in the head itself. Several valve jobs over time, or installing oversize valves can cut into the softer iron beyond the original hardening and make for seats that don't last long if not re-hardened or seat inserts installed.
I'm not a machanist, but I believe the seat is cut for the insert and it is simply pressed in with an interfence fit. One technique I seem to recall is to heat the head so that it expands while chilling the seat, then simply dropping or tapping it into place and letting the temperatures equalize.
I'm not a machanist, but I believe the seat is cut for the insert and it is simply pressed in with an interfence fit. One technique I seem to recall is to heat the head so that it expands while chilling the seat, then simply dropping or tapping it into place and letting the temperatures equalize.
Postmaster
Joined: Jun 2005
Posts: 2,656
Likes: 1
Here is a pic of a E7 head I did with 1.54 exhaust valves. I had hardened seat install at the machine shop.
and here is a pic of a e7 head I did with 1.60 Exaust valves without hardened seats installed. It's in my truck (hemieater) and I've been beating it for 3 years now with no proplems. i just didn't want to spend the extra money and have told that it would be fine as long as I didn't lug the motor all the time and with 4.56 and 31" tires it don't lug at all. I have adjust the valves 3 or 4 times and the exhaust clearance is very stable, meaning I'm not loosing clearance with would indicate the vlaves sinking into the heads. All is good for now and I'll keep hammering it until I start loosing clearance..(I'm running a solid cam).
For me it's not a big deal to change heads on a sunday afternoon but if your building it for the long hual have seats installed if you are putting in larger valves, not needed if your just freachening up your stock heads as long as they have been factory hardened.
pic of my heads no hardened seats........
and here is a pic of a e7 head I did with 1.60 Exaust valves without hardened seats installed. It's in my truck (hemieater) and I've been beating it for 3 years now with no proplems. i just didn't want to spend the extra money and have told that it would be fine as long as I didn't lug the motor all the time and with 4.56 and 31" tires it don't lug at all. I have adjust the valves 3 or 4 times and the exhaust clearance is very stable, meaning I'm not loosing clearance with would indicate the vlaves sinking into the heads. All is good for now and I'll keep hammering it until I start loosing clearance..(I'm running a solid cam).
For me it's not a big deal to change heads on a sunday afternoon but if your building it for the long hual have seats installed if you are putting in larger valves, not needed if your just freachening up your stock heads as long as they have been factory hardened.
pic of my heads no hardened seats........
