[DeTomaso] 4V cc iron heads

Daniel C Jones daniel.c.jones2 at gmail.com
Tue Jan 10 16:06:48 EST 2012


> 403, or 408?

403.  It's a 4.005" bore by 4" stroke.  Basically just needed to
clean up a standard bore 4 bolt main 351C block.  Have several sets
of Ford Motorsport high port heads (A3 and C302B, ported and unported)
and matching intake manifolds to test.  Just came up with a set from
Alan Kulwicki's shop with a matching Roush B351 intake that has had
very nice port work.

> Tricks?  Do tell?

1. Beehive vs conventional valve springs.  Might also test higher seat
pressure (160 lbs seat, 400 lbs open) conventional springs.

2. Intake manifold modification (port divider extensions in the plenum)
to Edelbrock A331 single plane.  If it works, may try it in Roush A331.

3. Ultra Pro Machine hydraulic roller lifter oil (altered leak down rate)
in conjunction with minimal pre-load.  Vizard has tested this oil (he
shares shop space with UPM) and says it extends the rev range.

4. Single inlet, dual outlet Magnaflow mufflers (that fit the Pantera).

5. Have Mad Dog's old high port 180 degree headers along with Byars
4-into-1 bank separated high port headers.  Also have a set of high
port headers that may be altered into a true tri-y design (not just
a tri-y collector like the GTS headers).  I still have to do some
mock up work but it appears a tri-y header can be designed with an
optimal length and still fit the Pantera chassis.  At the pinch point
where the collector is on a standard short Pantera header, the tri-y
would have two smaller pipes side-by-side which merge farther back.
I've run the design through PipeMax and the lengths look good I just
need to see if there will be any clearance issues.  Well designed
tri-y headers may make slightly less peak but a better overall average,
especially when less than optimal mufflers are used.

6. I've verified Scott Cook's dual plane intake will work with the A3
high port heads and have obtained one of his intakes.  However, it's
an early version and he has since spent considerable effort re-designing
the intake.  I've tried contacting Scott to see if they are available
yet but have not heard anything back.  Scott's intake would be a nice
option for A3 heads as it would fit under the stock engine screen and
possibly increase torque with the large port high port heads.

Dan Jones



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