[DeTomaso] Brian Hill's 410 cubic inch cast iron Cleveland on the dyno
Kirby Schrader
kirby.schrader at gmail.com
Thu Feb 6 12:47:03 EST 2014
That's good stuff, Dan.
I don't feel too bad... :-)
I got 544 with my stock 4V iron heads (that weren't ported) and 393ci.
I suppose I should qualify it further... Open GTS headers and EFI.
17 more cubic inches and 16 more HP for Brian.
Really good stuff!
Thanks for continuing this! I love these reports.
Regards,
Kirby
On Thu, Feb 6, 2014 at 11:22 AM, Daniel C Jones
<daniel.c.jones2 at gmail.com>wrote:
> 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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