DESCRIPTION:

When MBE set out to replace it’s 11 degree Big Chief style cylinder head, the advancements it made were so significant that the result had to be classified as a brand new head. Meet MBE’s Big 9 - a true game changer for anyone racing a Chevrolet big block.

The Big 9 is all about moving the most air and fuel possible into the combustion chambers. Improved parts not only flow more air, but they also rotate the valve location inside the combustion chambers. This makes it possible to stuff the largest intake valves ever into a Big Chief-style cylinder head. The intake valves are 2.550 inches in diameter with a 55 degree valve seat. Another big change is the 9 degree valve angle (compared with the Big Chief’s usual 11 degree angle) that helps move air and allows for a shallower combustion chamber. To make the most of the 9 degree valve angle, MBE raised the intake ports to help move air more efficiently past the short turn. All these changes add up to intake ports that flow an astounding 600+ cfm. And remember, MBE is the only cylinder head manufacturer that guarantees their advertised flow numbers with your money back if you don’t see the same results.

The exhaust ports, meanwhile, are equally improved to keep up with the intakes and flow in excess of 355 cfm. But they still keep the traditional exhaust flange location, so if you are upgrading from an older set of 11 degree BC cylinder heads, you can keep your headers and exhaust layout.

But those max flow numbers aren't the only significant competitive advantage the MBE’s Big 9 holds over every other Big Chief head out there. A rocker arm layout modeled after MBE’s Pro Stock systems creates the most rigid, efficient Big Chief style valve train available. It does this with an extra wide, one-piece rocker bar that uses 23 fasteners to absolutely lock each rocker arm base in place. This significantly stabilizes the valve train, allowing for more valve lift, better valve control and valve spring life extended by as much as 30 percent.

MBE’s Big 9 is dyno proven to be 40 to 50 horsepower better than MBE’s 11 degree Big Chief - and that’s a cylinder head that is still competitive and winning races. In fact, with a single carburetor, engine builders have seen 1,350 to 1,410 horsepower. So if you've ever looked for an absolutely unfair advantage on the competition, here you go.

MBE also offers its state of the art “Billet 4500 Dominator Intake Manifold”. This provides increased horse power, improved fuel distribution and a major weight savings over the current cast versions. Also this is accompanied by a  MBE Billet valley tray that is not only functionable but is needed eye candy for a serious race engine.