Edelbrock Aluminum Head Modification

[RickLee]

Has anyone else had to modify, perhaps use a die grinder to the runners inside the Edelbrock Aluminum heads? The squared off machining has left a sharp edge in the exhaust runners that I am sure would have an effect on air flow.

[Clois Harlan]

I just installed mine this last weekend on my 428 CJ and didn't find any sharp edges like you describe. Mine seemed to be very smooth (for a casting). Maybe I didn't examine mine as close as you did. I also bought mine fully assembled and then took them to my machinist for examination. He told me they were fine and all I needed to do was to install them using Fel-Pro 1020 gaskets.

[hound dog]

RickLee,
Don't have the 427, but the Victor Jr.'s for the 393 are going on just as they came from Edelbrock. The ports were machined just a little bit at the openings but I didn't notice any sharp edges anywhere. I'm kind of like Clois, looked pretty good for a casting. Now the intake manifold is another matter.
h dog

[Joe Prochazka]

I too noticed a small amount of uneven but not sharp material on the exhaust runners on a set of Edelbrock RPM heads that were just installed on my engine.

I thought that it was no big deal but my engine builder said that since the heads were going to the be ported (I believe the intake runner volumn is only 170cc) anyway we would get the exhaust cleaned up as well.

By the time that the heads were returned, they had been ported, surfaced, cc'd and stiffer springs.

I sure hope that all the expense was worth it.

[RickLee]

My engine builder said that he would have to smooth this out. I am using ferea MR valves with 10 degree keepers and a stronger set of springs as well

[RickLee]

Here is a Picture

[RickLee]

Another Picture

[Oafus]

I have some data on those head used on my 427. I had fully ported low riser Ford heads on the car initially. A vavle sunk in each head, so I trashed them and put on the Edelbrock heads, as assebled from Edlebrock. I didn't have time to have any work done. On the chassis dyno I got an additional 30 hp. There were no other changes. About 6 months later I pulled the head and had them ported and the larger 427 valves installed. The gain was about 10 hp. The bottom line is that the heads are pretty good right out of the box. If you want to squeeze out the last little bit, you start to get diminishing returns.

Craig