notching cylinders for intake valve

[Vega v-6]

Has anyone ever noticed that when head is mounted that the cylinder area around the intake valve presents an area that seems to be a area that would present a obstruction to intake flow. It may seem hard to discribe but if when you have your next motor apart without the pistons in mount one head, flip block over and reach into that intake valve area and you'll notice a sharp corner and a ledge for incoming gasses to smack right into.The cylinder wall extends into the combustion chamber area (sharp edge detonation?)talk about flow obstruction.Even when and if you bore .030 over or..that area will still overhang into the combustion area. should we be relieving the block in this area? open for discussion. check it out.

 

[Phoneguy]

There is a very in-depth article in the GN-1 sticky at the top of this page concerning this. Very nice pics in a link inside the sticky. HTH
Bryan

 

[gnxtc2]

It's called "eye-browing" the block.

Billy T.
gnxtc2@aol.com

 

[Vega v-6]

eye browing block

Thanks for the definition but i wanted to find out if anybody has seen fit to really do this to their block or has nobody noticed this feature.

 

[unboostedV6]

Never done it on a Buick, but it's very common practice on big block chevy's. Another trick serving the same purpose of unshrouding the intake valve on Stock class cars is to offset bore the cylinders toward the intake. GB

 

[JayC]

Thanks for the definition but i wanted to find out if anybody has seen fit to really do this to their block or has nobody noticed this feature.

This was done on our TSM motor.

 

[NCTURBOS]

We've been doing this to all our blocks that get ported heads with oversized intake valves for 10+ years. We just scribe the area using a headgasket, grind the area, and then send the block to the machine shop for the rest of the work needed to be done.


K.

 

[Vega v-6]

Thanks for cylinder notching info

Thanks for your reply, now I no its has been done before!