[DeTomaso] 4V cc iron heads

[Sean Korb]

I'd like to reminisce a bit.  The right combination and tuning will do
more than just the parts by themselves.  This is from earlier this
year: I'd like to thank everyone who participates in the Dyno project
especially Dan Jones.  You *can* make good power with unported cast
iron heads.  You can make better power with the CHI heads, but it's
not as dramatic an increase as I was expecting.

The CHI and unported cast iron heads results are reported below.  Some
donations Dan's way would be appreciated, but I'd like it if he could
get to sit in one place for more than 5 minutes these days ;) The
story continues...


On Tue, Jul 21, 2009 at 6:49 PM, Daniel C Jones
<daniel.c.jones2 at gmail.com> wrote:
> An update on the dyno testing.  We're currently testing the unported iron
> 4V heads.  As a quick re-cap, we previously tested the CHI 3V aluminum
> heads along with the Pro Comp copies.  Fitted with the Scott Cook dual
> plane intake, the CHI 3V heads made right at 400 HP and 400 ft-lbs
> of torque (420 HP and 420 ft-lbs when corrected for the dyno absorber)
> through the mufflers.  We had some trace detonation so backed off the
> timing a few degrees which dropped the uncorrected HP to 395 (415 HP
> corrected).  Switching to the single plane CHI 3V intake manifold picked
> up 20 HP (436 HP corrected).  The stock ANSA Pantera mufflers cost a
> whopping 50 HP compared to the 3" inlet/outlet Magnaflows.
>
> For the second round of testing, we replaced the CHI 3V aluminum cylinder
> heads from Australia to the Pro Comp knock-offs from China.  We tested
> the same intakes (Scott Cook dual plane and CHI 3V 4150 pattern single
> plane).  On the flow bench the Pro Comps were down considerably to the
> CHI heads and this was backed up on the dyno.  The best pull with the
> Pro Comps was 378 HP and 381 lbs-ft of torque (397 HP and 400 ft-lbs
> corrected).  What worked on the CHI as far as timing (32 degrees) and
> carburetor spacer (4 hole 1 inch) also worked the best on the Pro Comp
> heads.
>
> For our third round of testing we switched to unported iron 4V closed
> chamber heads.  Interestingly, the unported iron 4V's made better power
> than the Pro Comps.  Fitted with a Holley Strip Dominator single plane
> and a 1" HVH spacer, the 351C made 397 HP and around 380 ft-lbs (417 HP
> and 399 ft-lbs corrected).  The Parker Funnelweb was tested next.  It
> picked up around 10 ft-lbs in the mid-range but was down about 6 HP at
> the peak.  An Edelbrock Torker was tried next which performed about as
> well as the Parker for HP and the Strip Dominator for torque.  The Parker
> worked best with a 4 hole 1 inch spacer, while the Strip Dominator and
> Torker prefered the HVH.  The final test for the evening was with the
> Torker intake manifold but with the 1 3/4" diamter long tube headers and
> Magnaflow mufflers replaced by the OEM 351C-4V cast iron exhaust manifolds
> and a short elbow of pipe (no mufflers).  The result was 366 horsepower
> and 351 ft-lbs of torque (uncorrected), a nearly 30 HP/30 ft-lbs drop!
> The engine also sounded rather odd and the increased back pressure upset
> the idle quality noticeably.  Combine this test with the muffler test,
> and it's easy to see you can throw away a bunch of HP on a 351C with a
> poor exhaust.
>
> Dave noted the 3.5" stroke 351C with iron closed chamber 4V heads required
> more timing than the 4" stroke 408C strokers he's tested with the same type
> iron heads.
>
> Rather than mill and drill the unported iron heads for studs and guide
> plates, we used the bolt-down roller rockers from Randy Malik at R.M.
> Competition.  These are fully adjustable aluminum roller rockers
> manufactured by Harland Sharp to Randy's specs whichare dedicated Ford
> 351C/351M/400/429/460 rocker dimensions.  Randy says they will withstand
> spring pressures in excess of 475 pounds open and over 625 pounds open
> when using the option Jesel bolts.  These rockers are not the old style
> flat top Harland Sharp rockers and are shaped more like the Crane Gold
> units.
>
> We've got a bunch more intakes to test with the unported iron 4V heads
> but I thought it was time for a quick update.
>
> Thanks,
> Dan Jones

On Sat, Dec 17, 2011 at 3:52 PM, Corey Price <coreyjprice at gmail.com> wrote:
> Mike,
>
> The heads are already machined for screw in studs.  I haven't included the cost of valvetrain since I need all new stuff anyway.
>
> Corey
>
>



-- 
Sean Korb spkorb at spkorb.org http://www.spkorb.org
'65,'68 Mustangs,'68 Cougar,'78 R100/7,'60 Metro,'59 A35,'71 Pantera #1382
"The more you drive, the less intelligent you get" --Miller
"Computers are useless.  They can only give you answers." -P. Picasso