Factory Magnum Heads

Hey BJR!

You probably already know this info,but I thought I'd pass it on.

There was an article in a mag ( I know,their selling stuff) about maximizing the magnum. Dec/Jan 08 issue of Mopar enthusiast.

About a company called Tico racing. Talked about the flaws of the mags.

Major points were;

1) Dont go larger than 2.0 intake valve. Larger may compromise the casting and crack (suprize!) the seat. Exhaust use the 1.625.

2) Major limiting factors are the springs length,diameter and valve length. Using a longer valve (.450 )means a taller spring without machining too deep in the seat. These are 5/16 stem so ream the guides. Now you can use all kinds of retainers/locks. And run a much larger cam!

3) Modify/notch the chamber wall enough to get near stock volume once a 2.0 intake is in. You should end up at slightly more than 61 cc.

Massage the entire port from bowls to gasket surface.Spend most of your time from the seats to just past the guides.

The mag has 2 major advantages. One is the combustion chamber design. The other is flow balance and velocity. Tico got a best of 234 int/185 ex for a balance of 79%! Best an x ever got was about 64-68%. Thats not good if you cant get the burnt stuff out. Another side bonus is compression goes up quite a bit when swapping on an la. Plus better ports without porting.

So the mags are not about big flow #s. They can flow around 260 with lots of work and big valves,but the seats get thin and will crack.