[DeTomaso] Dyno Testing Update - unported iron 4V head testing

[Charles Engles]

Dear Dan,


            Regarding the Funnelweb intake test: did you use the intake port 
stuffers with the Funnelweb intake???


                              Very curious,  Chuck Engles


----- Original Message ----- 
From: "Daniel C Jones" <daniel.c.jones2 at gmail.com>
To: "Pantera REALBIG forum" <detomaso at realbig.com>
Sent: Tuesday, July 21, 2009 5:49 PM
Subject: [DeTomaso] Dyno Testing Update - unported iron 4V head testing


> 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
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