Angle milling 906 vortec heads

[ozyfordman]

Hi,
I’m after some guidance on how to prepare the spark plug boss on 906 Votec heads after a .070” angle mill. The deck surface will take down the spark plug boss,dividing the combustion chamber with that much off,as its only .042” below the deck face now.
What is the correct way to deal with this issue of chamber configuration. I can do the matching myself. Thanks in advance.

[rebelyell]

Don't have an answer ... but do have a question:
seeing as how gen 1e 906 /062 Vortecs' intake flanges' clamping angles are entirely different from earlier sbc (45* v. 90*) ... question if angle milling vortecs' decks presents more of a challenge (than when correcting intake flange angles of earlier gen1) ?? Dunno? askin'

[ozyfordman]

Yes, there is a raised rocker cover mounting rail that’s not parallel to the gasket face. I’ll have to under cut that slightly.

[ozyfordman]

I’m left with a few options. Leave new quench pad there but radius edges. Reshape with a taper back from the chamber wall at around 7 degrees .Or grind and blend back to the plug threads. Given that I’m trying to gain compression, I wouldn’t do the later unless it was a proven HP gain. Looking for advice from those that have done this. There are plenty of posts on angle milling Vortec heads but this subject is never mentioned. Someone must be able to give sound advice, here’s hoping!

[mag2555]

My 2 cents worth would be to just radius those new sharpe edges from the plug boss and then just leave that added new quench pad there.

[F-BIRD'88]

I would just radius the new sharp edge. No need to get carried away. What is the finished chamber volume going to be? Just curious.

[BillK]

Knowing how thin and flimsy the decks are on the Chevy Vortec heads I simply cannot imagine cutting that much off them, even angle milling. Unless it is some type of class race engine that wont allow it by the time all is said and done it would probably be less expensive to buy a set of pistons that would accomplish what you want to do.

Just my opinion.

[1980RS]

Knowing how thin and flimsy the decks are on the Chevy Vortec heads I simply cannot imagine cutting that much off them, even angle milling. Unless it is some type of class race engine that wont allow it by the time all is said and done it would probably be less expensive to buy a set of pistons that would accomplish what you want to do.

Just my opinion.

Amen to that for sure.

[ozyfordman]

I will take that advice. I just ordered a set of 1.56” pin height pistons. One less thing to worry about and I’ve got too much time in the heads to ruin them Thanks to those members who contributed.