Reply to "Cylinder head identification."

> I read a quote by "Dyno" Don Nickleson about the A3 heads. I think it was
> around the time he had the BB with the Motorsport aluminum 429 CJ head
> engine. It was kinda of a negative one in that he said he got more HP out
> of the iron "high port" race heads then the A3's are capable of.

Do you have that quote? I'd really like to know the context and time
frame. Was it referring to the A3's or XE aluminum heads? Was it engine
power or flow bench numbers. If he was comparing a set of worked, iron
high ported 4V heads, to a set of out-of-the-box A3's then maybe but if
he was referring to equally prepared heads I do not buy it. I have a set
of iron high ported 351C Pro Stock type heads and there is nothing in those
heads that you couldn't do to a set of A3's. Plus the iron 4V's have several
undesirable area transitions.

> I always thought they were more "trans-Am" heads.

No, the C302's were the Trans Am heads. I've got a nice build up article on
a 310 cube Trans Am engine with C302B's.

> I don't get it. How does a head with a smaller valve, a smaller port volume
> flow more and make more HP with the same cubic inches? That's contradictory
> isn't it? Not only should the peak be lower but the area under the curve
> should be less as well for the same cubic inches?

The bowl work on the ported C302B's is a whole bunch better than my A3's.
Also, the shape of the ports is better. With some bowl work, the A3's
would likely outflow my C302B's but with somewhat lower velocity. With
all-out porting, the C302B's will likely outflow the A3's because they have
more material to permit custom porting shapes.

Dan Jones