The new Hemi's have a valve seat problem. Probably because they don't heat them high enough before installing them to save time. The proper heat before the install of the seat the tighter the fit. Also freezing the seat.
When removing a seat you tig weld them and cool them with air. They fall out..
Gotta wonder if this is a systemic engineering or manufacturing process problem, and who makes these production heads..... 4.7's had a similar issue of the seats falling out.
More wondering out loud.... maybe there is a tooling difference that makes the different block material usable in the production shop but not good for an aftermarket shop? Based on my conversations with my brother-in-law who has worked at Landis Machine for 30+ years in application design, there are a lot of production tooling and technique differences between now and 20 years ago.
