Milling down plenum divider
Thread Starter
Melting Slicks
Joined: Dec 2000
Posts: 2,635
Likes: 0
From: Union Ontario
Milling down plenum divider
In the intake manifold.
Are there any real benefits on a 400HP street engine? I have the engine apart and I am thinking of milling down the divider on my Edlebrock RPM intake. I am gasket matching the intake ports to a Felpro 1205 which is a good fit to the Sportsman heads I have and I started wondering if milling this down would be a benefit.
Also how far down shoudl I mill it if I do it?
Are there any real benefits on a 400HP street engine? I have the engine apart and I am thinking of milling down the divider on my Edlebrock RPM intake. I am gasket matching the intake ports to a Felpro 1205 which is a good fit to the Sportsman heads I have and I started wondering if milling this down would be a benefit.
Also how far down shoudl I mill it if I do it?
Race Director
Joined: Nov 2000
Posts: 11,872
Likes: 12
From: Waterloo ontario Canada
I milled down a old high rise LS6 intake just like they did on the L88 intakes. The center divider was milled down about an inch. That was a great intake and when I upgraded to a single plane Victor Junior I lost performance.
I liked my milled down intake.
I liked my milled down intake.
Race Director
Joined: Apr 2000
Posts: 17,672
Likes: 199
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Take a look at the RPM Air Gap, there is 2 inch section milled down 1/2 in. It must work because the Air Gap only gives up about 5 HP @ 6500 HP to a Vic Jr on a 500 HP small block 
Le Mans Master
Joined: Jul 2005
Posts: 5,752
Likes: 4
From: Austin Texas
I had to modify the center divider on a Performer rpm this way to fix a tricky fuel mixture distribution problem between cylinders. This was a popular mod. in the late 60's and thru the 70's. 
