Is there any benefit to notching the top of the cylinder bore on the intake side to unshroud the valve? I noticed that my heads combustion chambers are opened up to the head gasket and the headgasket is not round. It appears that the cylinder wall is seriously obstructing things. I'm aware it would drop compression, but not much. I believe some Pontiac engines had this.
Any opinions?
Scott

 

What kind of engine are you talking about? On an LT1 I don't think that it would be needed, but on a BBC it is pretty common practice because of the huge valves and relatively small bores.

 

Maybe on a 305 especially if you went to larger valves.

 

There is a thread on this that isn't a month old, in this forum. Please search

 

Already performed a search to avoid just this type of "constructive" post.

 

If ya notch an LT1 like a big block it will unshroud the valve. It has to be done correctly or cyl's won't be balanced.
It will add some HP but have never dynoed the change. It is pretty pricey to get done to where all notches match, so make sure ya want that last 5HP.

It's a bitch getting the rings to go in without the proper squeezer.

 

http://web.camaross.com/forums/showt...nshroud+valves

Hope you got all the info you could out of this thread then

 

I had actually read that when it was originally posted but it pertains to a BBC where some blocks allegedly came that way from the factory. Figured the theory applies to a SBC, but was just getting the opinions of those that may know better. Thanks though.

 

I understand, just checking. I'd hate to think that a thread got wasted on here (there seems to be so many that do).

Best of luck to you,

Jeremy