Not Ranked
> Engine lost about 800 RPM's on the big end and the power band was totally
> straight from idle to about 6200 rpm's. Cam was a .65 lift roller with
> about 11 to 1 slugs and 392 cubes. Putting back a worked over set of 4
> barrel heads the engine came alive and and gained over 150 horses I'd bet,
> and that's with a one point in compression loss.
Thanks for the info. I've suspected those heads wouldn't make any more
power than a decent set of pushrod heads. DeTomaso actually had a couple
of cylinder heads prototyped. One was a 2 valve OHC head for the 351C.
I suspect that it didn't make as much power as the 4V heads too. The other
looked a lot like a Gurney-Weslake but I think it was meant to go on the
289 and 302 engines in Mangustas.
> It also ran very slightly better yet with a set of slightly worked over
> Aussie heads, over the four barrel heads.
That's surprising on a 392 cube engine. The Aussies do have better port
velocity than the 4V's but they give up a lot of flow on the intake side
to 4V's. I've got a set of Aussie 2V's on the 351C in the Pantera but
for larger cubes, I usually jump to the closed chamber 4V's or, better
yet, a set of aluminum Ford Motorsport high ports (A3's, B351's, C302's).
The high ports are really hard to beat. As much or more velocity than
Aussie 2Vs with 50% more flow.
> He's looking at a set of the new Blue Thunder heads now. Time will tell.
Dennis at the Pantera Performance Center has used those but was kind of
disappointed. Apparently they took a lot of chamber work. I talked to
Art Francis at Blue Thunder about the heads and he was pretty insistent
that they wouldn't make a good street head due to the large bowls. He
said they need lots of RPM or cubes to work properly. I'm using a set
of C302's on my new engine (Fontana block, 3.85" 4340 forged crank,
4.1" bore, 11:1 compression). Even with the relatively small ports, they
flow over 330 CFM intake and 230 CFM exhaust at 0.600" lift with very good
low lift flow. The velocity is excellent.
The new D3 Ford Motorsport heads are very much like a raised (again) port
C302B. The canted valve angle is back.
Dan Jones
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