[DeTomaso] Brian Hill's 410 cubic inch cast iron Cleveland on the dyno

Fri Feb 7 21:41:20 EST 2014

EXCITING!!!    BRAVO!!!!!   EXCELLENT WORDS BRIAN!!!!    CONGRATS, AGAIN!!!    ----BILL L

Date: Thu, 6 Feb 2014 20:20:59 -0800
From: mazdastuff at yahoo.com
To: daniel.c.jones2 at gmail.com; detomaso at poca.com
Subject: Re: [DeTomaso] Brian Hill's 410 cubic inch cast iron Cleveland on	the dyno

That is a superb write up Dan.  It is really amazing the numbers you guys were able to make happen.  To bad about the weather, the testing of the other heads would have made for some wild reading.  Additional 70hp on top of these numbers would have been something to see.  That would be exciting.
Bravo!
Brian Hill

 From: Daniel C Jones <daniel.c.jones2 at gmail.com>
 To: POCA list <detomaso at poca.com>; Brian <mazdastuff at yahoo.com> 
 Sent: Thursday, February 6, 2014 11:22 AM
 Subject: Brian Hill's 410 cubic inch cast iron Cleveland on the dyno

The odometer on Brian Hill's 1971 Pantera showed 60K miles but its 351
Cleveland was burning some oil.  The history of the engine was unknown
and Brian wanted more power anyway so it was decided to build a
stroker Cleveland.  Dis-assembly revealed the block had already been
bored 0.030" but had a few thousandths of wear so was honed to a
4.040" bore.  A Scat stroker kit with Probe forged dished pistons, 6"
rods and a forged steel 4"
 stroke crank was used to provide 10:1
compression and a displacement of 410 cubic inches.  The distributor,
carb, water pump, alternator were new and the McLeod flywheel had been
recently resurfaced so those parts were re-used, along with the
Pantera 10 quart oil pan.

Most of the stroker Clevelands we've done have been with aluminum
heads (Ford Motorsport A3 high ports, Ford Motorsport C302B high
ports, Brodix BF300 high ports, CHI 3V and 4V, TFS 2V,  etc.) but this
one was the first in a long time that retained the 1970's era OEM cast
iron 4V heads.  The heads were rebuilt years ago with replaceable
bronze guides and had been milled and drilled for screw-in studs and
guide plates.  Dave McLain machined the spring pockets for double
springs, installed single groove valves, did a valve job and
resurfaced the heads.  They looked pretty good so no additional
porting work was done. 
 On the SuperFlow bench, they flowed:

 Lift    Intake  Exhaust
 Inch    CFM     CFM
 0.025   13.90   10.90
 0.050   33.10   26.50
 0.100   66.40   52.20
 0.200  140.20   97.90
 0.300  201.20  129.90
 0.400  251.40  152.30
 0.500  290.90  165.50
 0.600  313.90  172.70
 0.700  301.70  173.30
 0.800  303.20  174.70

I used Dynomation to design the cam, starting with the simulation and
dyno results of the 408C we did for Glen Hartog's Pantera.  That
engine also used cast iron closed chamber 4V heads but those had some
short-side radius work and flowed a bit better (322 CFM @ 0.6").
Compared to the dyno data from Glen's engine, the latest version of
Dynomation was under-predicting the RPM of the HP peak so I biased my
goal to make sure the cam would peak at
 6000 RPM, providing the best
average HP between 4000 and a 6500 RPM shift point.  That works well
for a street driven Pantera with stock gearing and still pulls strong
at lower RPM.  Rather than use the Bullet lobes we'd used in the past,
Dave worked with Steve Demos and Mike Ingram to design a couple new
hydraulic roller lobes.  The lobes are based upon the Ford base
circle, not the smaller Chevy base circle of the previous Bullet lobes
we've used. The resulting Demos hydraulic roller cam was checked using
Cam Analyzer v4.0 and proved to be very close to the requested specs:

Cam # DM238HR/DM242HR, Grind 0001
 279.3/282.8 advertised duration
 239.6/242.6 degrees duration @ 0.050"
 159.8/162.4 degrees duration @ 0.200"
 0.620"/0.621" intake/exhaust lift (with 1.73:1 rocker arms)
 109 degrees LSA
 108 degres ICL

Seat Timing
 Intake Open 28.8 BTDC
 Intake Close 70.5 ABDC

 Exhaust Close 33.8 ATDC
 Exhaust Open 69.7 BBDC

0.050" timing
 Intake Open 10.8 BTDC
 Intake Close 48.8 ABDC
 Exhaust Close 11.9 ATDC
 Exhaust Open 50.7 BBDC

PBM/Morel link bar hydraulic roller lifters were used and the roller
rockers from the original engine were retained.  Previously, we had
tested a bunch of intake manifolds on Mike Drew's 408C with CHI 4V
aluminum heads.  The best of the lot were the Edelbrock Scorpion,
Holley Strip Dominator and a ported Blue Thunder dual plane.  The
Edelbrock Scorpion is no longer in production but I found a good used
one so we went with it.  Looking much like an Edebrock Torker, the
Scorpion is taller with a level carb pad (nice to have in the Pantera
which has a level mounted engine and transaxle).  Dave did a lot of
work on the entry radius of the ports in Scorpion's plenum.  On the
dyno, best power was made with a 1" open
 spacer and best torque was
with a 1" HVH spacer it only dropped a few horsepower and a few lbs-ft
of torque without a spacer.   Brian supplied a Holley 750 carburetor
(p/n 80528) which I thought might be on the small side for the stroker
engine but watching the manifold vacuum during the pulls showed no
significant depression so it looks like it's adequate for the 6000 RPM
410C.  It seems snappy and idles clean.  The engine liked 30 degrees
for total timing.  Brian will be using a stainless Wilkinson Pantera
exhaust system which performed well in previous testing but the engine
was tested with the following exhaust on the dyno:

 Hooker 351C Competition headers (part number HOK-6920HKR)
 1 3/4" diameter by 27" long primaries
 3" diameter by 8" long collector
 12 inch long collector extensions
 3" inlet/outlet Magnaflow mufflers

Based upon the simulation results, I thought we'd hit
 500 HP at 6000
RPM but the engine really surprised us by making 560 horsepower at
6050 RPM and 526 lbs-ft at 4600 RPM through the dyno exhaust.  Not too
shabby for a street cam and factory iron Cleveland heads.  Seems the
big port heads really like the extra cubes.  Previous testing has
shown the 4V heads also respond to a shorter exhaust rocker ratio and
to exhaust port stuffers (MPG Stingers).  It would have been
interesting to see if we could squeeze out a few more ponies but I
think Brian will be pleased with the results.  He kindly offered to
let me use his engine to do back-to-back testing between his iron
closed chamber 4V heads and a set of my Ford Motorsport aluminum high
ports (ported C302Bs) but with the very cold weather this winter
Dave's running a bit behind on the dyno so that testing will have to
wait.  The dyno rolls outside the shop and hooks up to an
 external
water source so it needs to be above freezing weather which the latest
forecast says won't happen in the next week.  We'll pick back up with
testing the C302B heads on my 407 Fontana engine in the spring.  FWIW,
the Dynomation simulation predicts another 70 HP for my ported C302B
heads and intake.

Dan Jones

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