Nissan valve seat technology

[PapaSmurf2k3]

https://www.msn.com/en-us/autos/news/ni ... 80f3&ei=51

Thoughts?
I think the bigger benefit here isn't part count reduction, but rather the ability to make the valve geometry however they want it.

[VStar650CL]

I think the bigger benefit here isn't part count reduction, but rather the ability to make the valve geometry however they want it.

Exactly right. Engines are often referred to as a glorified air pump, but from a purely induction standpoint it's a vacuum pump. Flow from vacuum is much harder to maintain than flow from pressure, because any loss of inertia in the air stream basically represents an unrecoverable energy loss (that's Newton, object in motion wants to remain in motion, including air). So the fewer bends and straighter path you can maintain between the throttle body and the piston crown, the more inertia you preserve for packing mixture into the cylinder before the intake valve closes. In efficiency terms, that's a huge deal.

[IanS]

Just a continuation of the market heading towards disposable cars. Can't replace a valve seat if it's machines into the head instead of a hardened seat pressed in. Just replace the whole head if the seats get worn or the damaged in any way. That's the same complaint I have with Nikasil. It's fine on a dirt bike jug, where you rebuild often and tossing a new jug on is easy. Making a car engine block single use because the Nikasil can't be honed or overbored isn't ideal.