This problem of intake valve seats dropping has struck quite a few owners over the past few years. We first became aware of it with

Hoffman Automotive Machine (706)769-3783
Where's Your Head?
This problem of intake valve seats dropping has struck quite a few owners over the past few years. We first became aware of it with
Click here to see video of a 996 3.4 M96 head being pressure tested, revealing a microscopic crack that was not visible to the naked
This article explores and unravels the mysteries surrounding the sometimes controversial issue of venting Type 4 cranckases, for street and track cars.
M96/97 Valve Sizes, Chamber Volumes, Component details, Failure Types, Misc. Info.
We see an awful lot of busted exhaust bolts in these heads. And we see a lot of failed repairs. We also see a lot
Porsche 944s/968 Services This family of Porsche heads, including the 4 valve 928’s and 968’s, are simply magnificent. Nice port shapes with enough space to
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