66-67 Dodge Charger Source Guide
Heads Q & A
Q |
06/12/03 George Hupp: I’ve never built an engine using milled heads before. When I tried to install my new Edelbrock Performer RPM intake manifold I could not get the bolt holes to line up. My heads have been milled .040” (I was told!), how much will need to be cut from the intake? Any estimate on the cost? |
A |
06/12/03 Greg Rose: For every .010" removed from the heads, the intake should be milled .0123". If you're only removing .010 or .020 then the bolts will likely still line up. But at .040, there will be a noticable mismatch. .040" / .010" = 4, so 4 x .0123" = .049" from each bank of the intake. |
Q |
02/18/06 Terry Hoover: Can someone put together a paragraph or two (or more) about open vs closed chamber, Different styles and their number, what it all means for design, assembly, performance, interchange, etc. |
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A |
02/18/06 Greg Rose: Big Block Chrysler Heads
915 are the closed chamber version of the 906 head. These heads port well and are said to have the highest flow potential. 906 heads had about a 83cc combustion chamber with 915s about 74cc stock. Starting with the 346 heads in the early 70s, the seats were partially hardened (but only 452s had true induction hardened seats - earlier heads need inserts for unleaded fuels). 452 heads flow almost as well as 906/915s, have the advantage of hardened seats, but have a combustion chamber of about 90cc stock. They likely need to be milled to get the compression of 906/915s (or domed pistons). 1967 and up heads have 2.08" intake and 1.74" exhaust. Got most of this from Chuck Senatore at Muscle Motors in Lansing, MI. |
