ALL things related to the Ford 351C
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PostPosted: Wed Oct 31, 2012 12:58 pm 

Joined: Tue Oct 30, 2012 8:27 am
Posts: 61
Location: St. Louis, Missouri USA
I was out of town on business but Dave McLain had the 403C for my white Pantera
on the dyno. The block is the 4 bolt main block out of my red Pantera. While
it had seen only 25K miles, it needed a slight clean up due to some surface
rust so we decided to go to a 4.005" bore using off-the-shelf Diamond 351C
stroker pistons. The parts list looks like:

Ford 351C block 4 bolt main block, 0.005" over (4.005" bore), not zero-decked
Diamond forged Cleveland stroker pistons (4.005" bore for 4" stroke and 6"
rods, 14.5 cc's dished, plasma moly rings)
403 cubic inch displacement (4.005" bore by 4" stroke)
SCAT 4340 steel forged 4" stroke SVO (Windsor design with Cleveland mains,
requires snout spacer) crankshaft
SCAT 4340 forged steel I-Beam rods (6" long with 7/16" ARP bolts)
Romac 351C SFI spec harmonic damper, zero balance
Clevite H-Series rod bearings (for SBC dimension rods)
Stroker kit internally balanced
Schiefer neutral balance aluminum flywheel
Crane link bar retrofit hydraulic roller lifters (p/n 36532-16)
Mallory Unilite vacuum advance distributor (small cap for Pantera firewall
and rear window clearance)
Crane steel distributor gear (p/n 52971-1 for 351C with 0.531" shaft dia.)
Pioneer brass freeze plug set (p/n 830005)
J.P. Performance double roller timing chain (German Iwis chain)
Ford Motorsport M-6005-A351 heavy duty chrome moly oil pump driveshaft
Blueprinted Melling M84A standard volume oil pump
Ultra Pro Machining hydraulic roller oil
Armondo Pantera gated and baffled road race oil pan
Ford Motorsport high port head gaskets for 351C block
Edelbrock aluminum 351C water pump (p/n 8844)
Trend custom length 0.080" wall push rods (for the taller roller lifters)
Fuel pump block off plate (dyno providing the fuel flow)
Bullet custom hydraulic roller cam (see specs below)
Competition Cams beehive springs (p/n 26095, 150 lbs @ 2", 375 lbs @ 1.25")
QFT SS-830 carb (claimed flow 900 CFM @ 1.5" Hg)
MagnaFlow single 2.5" inlet, dual 2.5" outlet mufflers, polished stainless
steel (p/n 14218, 5" thick, 8" wide, 14" case length, 20" overall)
ARP head bolt kit (with hardened washers)
Crane gold race aluminum 1.73:1 351C 7/16" stud mount roller rockers

A picture of the some of the engine parts:


I had some of the parts in my stash and Brent Lykins supplied the internally
balanced stroker kit, while Alex Denysenko supplied the rest of the bits.
This engine will initially go into my white 1974 DeTomaso Pantera L but
may eventually end up in my 1956 F100 project truck (whenever I get around
to it). The white Pantera is strictly a street car which I plan to use as
a nice weather daily driver. The goal is to peak around 6000 RPM with excellent
street manners and reasonable fuel economy. We did a similar engine with CHI-4V
heads and ported Blue Thunder for Mike Drew and it made 526 HP and 500 ft-lbs
through the dyno mufflers and he reports 18 MPG tearing through the mountains
at 80+ MPH so we think it could do 20 MPG during a level terrain cruise. Anyway,
that's the benchmark to beat.

I designed the hydraulic roller cam using Dynomation and crossed it against
the Bullet lobe catalog. Specs are:

293/298 degrees advertised duration
238/242 degrees duration @ 0.050" lift
0.640"/0.574" lift (with 1.73:1 rocker ratio)
110 lobe separation angle
Bullet CRA type intake lobe HR293/370
Bullet CRS type exhaust lobe HR298/332

Type CRA which means a grind with a conventional nose (as opposed to a nose
designed for a lift-rule race class), a lobe shape good for RPM and/or high
lift rockers (applies to 351C's 1.73:1 rocker ratio) and asymmetrical
opening/closing (helps with valve bounce). CRS is the same but with a
symmetric lobe. The flow numbers used for the cam design were gathered
without a pipe extension which biases the design for more exhaust duration
than if they were flowed with a pipe (adds approximately 30 CFM). If I had
it to do over, I'd probably shorten the exhaust duration a bit.

There are some issues to be aware of when running a hydraulic roller cam in
a 351C block. It varies from block-to-block and depends upon the size of the
chamfer at the top of the lifter bore but, on many blocks, the oil feed is
exposed at maximum lobe lift. Here's a shot of the lifter bore chamfer:


Some manufacturers (like Comp) will reduce the base circle of the cam so the
OEM type lifters can be used. As a rule, irregardless of how much lift that
a camshaft has, the lifters generally all stop in approximately the same
location at the top unless the base circle is deliberately reduced which can
cause problems at the other end of the lifter bores. With a reduced base circle
cam, the OEM lifters will usually be safe at maximum lift but some blocks will
have interference problems with the dog-bones. A local shop has a fixture to
machine the block for clearance but it can also be done by hand. Comps link bar
lifters have the oil feed (and associated band on the lifter) in the same place
as the OEM lifters so can have problems at max lobe lift when used with a
standard base circle cam. The Crane link bar retrofit hydraulic roller lifters:


have the oil feed placed lower on the lifter body and do not have the max lift problem.
The Lunati hydraulic roller lifters (made by Morel) cost about half what the
Cranes do. Tim Meyer sent me a pair and I verified the oil feed hole is in
the same place as the Crane so they should work but they are heavier and may
not turn quite as much RPM. Gaterman also makes a clone of the Crane lifters
which cost about half as much. I think Erson's street SBF hydraulic roller
link bars are the Morels and should also work. Be aware there are some Chinese
knock-offs of the Cranes that should be avoided.

We have several sets of Ford Motorsport A3/C3/C302/C302B high port aluminum
Cleveland heads available for testing, along with with matching intake
manifolds and exhaust headers. Some of the heads have stock chambers
(Cleveland quench chambers) while others have been clearanced for domed
pistons so the compression ratio will vary but should be in the 10:1 range.
Which parts we end up testing will depend upon how much free time there is
on the dyno.

Mufflers are 2.5" single inlet/dual outlet Magnaflow mufflers and all dyno
runs will be through mufflers unless otherwise noted.

I went with internal balancing as I already had a neutral balance aluminum
flywheel (a NOS Scheifer unit I got cheap because it was Ford 300 truck
inline six part). Since we were internally balancing, we chose SCAT's
I-Beam rods over the heavier H-beam rods as the light rods require less
Mallory metal in the bob-weights. Diamond had an off-the-shelf piston for
the combo to round out the stroker kit.

The oil is a special blend for hydraulic rollers that reduces the leakage
rate and meant to be used with pre-load set to zero lash. Out-of-the-box,
the carburetor was really rich with poor idle and part throttle but ran fine
at wide open throttle. The QFT SS series carbs have replaceable idle feed
restrictions so Dave reduced them to cure the problem.

Ford Motorsport used to offer the M-6065-A351 head bolt kit (1/2" diameter
bolts that are 1" longer than production 351C bolts, with hardened washers)
for installing SVO high port aluminum heads on 351C iron blocks but they are
no longer available. I ordered what was supposed to ARP's equivalent kit
but only half of its bolts were the correct length so Dave sourced replacements
for the other bolts. I've since found an original M-6065-A351 bolt kit.

Also obsolete is the FRPP snout spacer part number M-19009-A341C which
is required with 351 SVO crankshafts used in iron 351C blocks. Dave had
one he measured:

0.400" thick
1.830" OD
1.360" ID
45 degree chamfer about 0.125" wide on one end of the ID

and makes spares as he needs. They only need to be a slip fit. After
he made mine, I found several spares at a local machine shop.


The first set of heads tested are the unported but cleaned up A3's which were
mated to the Pantera shorty headers and an A331 intake manifold. Here's a
picture of the first top end set up to be tested (A3 heads, Edelbrock A331


Dave did some plenum work and added runner extensions to the intake to try to
get it to tune to a lower rpm. Dave's dyno is known to be 4% to 5% conservative
compared to the calibrated Engine Masters dyno (verified on Dave's 351C and 460
based EMC entries). Adjusting for that fact, equipped with the A3 and A331 heads
and intake, the engine made 560 HP @ 6300 RPM and 512 lbs-ft @ 4900 RPM through
the 2 1/2" single inlet/dual outlet Magnaflow mufflers. HP hung in until 6500 RPM
and then started to drop off and it liked approximately 36 degrees total timing
and a 1 inch open spacer under the carburetor. Removing the mufflers was worth
about 10 lbs-ft and 5 horsepower so not too bad but it could probably benefit
from a cross-over.

A promising start, given that Dynomation predicts the smaller ported heads to be
better by 20 to 35 HP. Info on the first set of heads tested:

A3 Ford Motorsport High Port Heads minor clean up, 2.19 intake, 1.71" exhaust,
2.74 square inches minimum intake port area, 1.88 square inches minimum exhaust
port area, intake port 2.125" H by 1.725" wide (3.665 square inches), exhaust
port 1.65" H by 1.725" wide (2.27 square inches), tested on Dave McLain's
SuperFlow flow bench at 10" and converted to 28". Clayed intake radius but no
exhaust pipe. As with most of the Cleveland heads we've tested, they generate
little to no swirl motion.

Lift Int Exh
Inches CFM CFM
0.025 15.7 11.7
0.050 34.6 28.1
0.100 65.5 56.7
0.150 95.2 87.5
0.200 129.2 109.8
0.300 188.8 142.4
0.400 242.8 167.0
0.500 287.7 186.7
0.600 321.4 204.4
0.700 337.7 216.3

Note: Dave's bench tends to be conservative compared to others I've tested the
same heads on (by 20 CFM or so) on but gives good results in Dynomation. These
numbers are very similar to what CHI-3V and CHI-4V heads produced on Dave's bench.

Externally, the Edelbrock A331 looks like a Torker:


but has smaller A3 ports and no cross-over:


You can see how much smaller the A3 port is here:


That's a 4V gasket on top of an A3 port. What's not obvious is the A3 roof is higher
(obscured behind the gasket).

You can clearly see the evolution of the high port heads here:


On the left is an iron 4V modified with an aluminum high port exhaust port plate like
they ran in Pro Stock. You can see the lower edge of the original exhaust port (painted blue).
In the middle is an A3 port which is slightly higher with a more uniform round shape, instead
of the weird area changes of the iron 4V port. At the right is a ported C302B. The C302B
ports start out much smaller as you can see from this scan from an old Ford Motorsport
catalog showing a comparison of C302, B351 and A3 high port heads:


The same heads as above on the intake side:


and the chambers:


High ports share the quench 4V chamber design. The C302B head on the right has been
clearanced for a domed piston. High ports were also designed to be run on both
Windsor and Cleveland blocks. Here are the instructions that came with the A3 heads:


After the A331 intake testing, we installed on one Scott Cook aluminum dual plane intake on the 403C
with A3 heads. I forgot to snap a picture before dropping it off at the dyno so these are so from


Scott's manifold looks much like a Ford cast iron DOAE-9424-L dual plane but is
cast in aluminum, slightly taller (around 10 mm or a bit more than 3/8") with
smaller ports that are sized more like a CHI 3V. Luckily the intake was also
designed to fit a 4V iron heads (port stuffed or not) so also fits the A3 high
port heads. Like the over-the-counter version of the Boss 351 intake, it has
two oval holes in the carb flange instead of the four circular holes of the
iron Ford intake. The one tested is one of Scott's first generation intakes
which he has since redesigned to work better on larger displacement engines
and to match his new Cleveland heads. Given that it's the earlier design, both
Dave and I thought it might be out of its element on my 403C but it surprised
us. The dyno fuel log wouldn't clear without a spacer so it was run with a
couple of different 1" spacers, making the best HP with HVH 4 hole spacer
hitting 569 HP @ 6350 RPM and 511 ft-lbs @ 4750 RPM. Switching to a 1" open
spacer increased peak torque to 514 ft-lbs @ 4700 RPM but HP wasn't quite as
good. Not too shabby for a hydraulic roller street motor with 1980's tech heads.
Paint the A3 heads and Cook intake Ford blue and no one would know it's not
a stocker.

Dan Jones

Dan Jones
St. Louis, Missouri USA

PostPosted: Wed Oct 31, 2012 1:27 pm 

Joined: Mon Oct 29, 2012 9:34 am
Posts: 222
Do you worry about the extra clearance on the crank gear?
You'll have about .003-.005" clearance, Windsor crank compared to Cleveland.

Timothy Meyer

PostPosted: Sat Nov 03, 2012 3:34 pm 

Joined: Mon Oct 29, 2012 1:57 pm
Posts: 6
Cool HiPort pics.
I was lucky enough to visit Jack Roush's shop in 1974, small place in Livonia, cut-up iron Cleveland heads everywhere, making their own HiPort heads.

PostPosted: Sun Nov 04, 2012 9:24 am 

Joined: Tue Oct 30, 2012 8:27 am
Posts: 61
Location: St. Louis, Missouri USA
> Do you worry about the extra clearance on the crank gear?
> You'll have about .003-.005" clearance, Windsor crank compared to Cleveland.

I've asked Dave McLain to comment on this as he put the engine together.
I know I've had the opposite problem where the Windsor crank gear was too
tight and broke a puller trying to remove it after a trial fit.

Dan Jones

Dan Jones
St. Louis, Missouri USA

PostPosted: Sun Nov 04, 2012 1:07 pm 

Joined: Mon Oct 29, 2012 9:34 am
Posts: 222
Windsor crank on top, Cleveland on the bottom.
The Cleveland cranks have about .003-.005"
The spacer makes up the difference in timing chain alignment, but if you put a Cleveland crank gear on a Windsor
fits very sloppy. I use the Rollmaster timing set. They are not cheap, but I have a hard time using a crankgear that loose.
Maye I am being to picky, take a crank gear and try it out.


Timothy Meyer

PostPosted: Sun Nov 04, 2012 4:45 pm 

Joined: Tue Oct 30, 2012 4:50 am
Posts: 53
Tim,which rollmaster timing set do you use?
The CS-3130?

PostPosted: Sun Nov 04, 2012 7:09 pm 

Joined: Mon Oct 29, 2012 9:34 am
Posts: 222
Yes, The CS3130 is the one we try to keep in stock..try
CS3110 is the same but does not have the heat treated gears, not a big savings in $$

Timothy Meyer

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