>What choices are available for a true "bolt-on" aluminum street head
>for a 351C.
That depends upon what you mean by a true "bolt-on". If you mean,
remove your iron 2V or 4V heads and bolt up your existing intake
and exhaust manifolds with no modifications, then the short answer
is there are none at the present time. There are a variety of
aluminum cylinder heads that will bolt to the 9.2" deck Cleveland
block but they may require a specific intake or custom headers
or have some other fitment issue. The list of players include:
Ford Experimental Trans Am aluminum 4V cylinder heads
Ford Motorsport High Port family (A3, B351, C302, etc.)
Ford Motorsport Yates family (C3L, C3, C3H, etc.)
Ford Motorsport SCI
Blue Thunder
Brodix-Neal BF200
Brodix BF300
Cylinder Head Innovations 3V
Edelbrock Victor
Bennet canted valve cylinder head
I'm working on the aluminum head section of the 351C web page but it's
not finished. Here are my working notes which should give you an idea
of what's available. The bulletin board software will probably screw
up the formatting...
Ford Experimental Trans Am Aluminum 4V Cylinder Heads
-----------------------------------------------------
Back in the days before SVO, Ford had a batch of 351 Boss heads and
blocks cast up in aluminum, supposedly for Trans Am competition though
some were used for drag racing. These are very rare and are essentially
aluminum duplicates of the standard 4V quench head.
Ford Motorsport High Port Family
--------------------------------
These were Ford's racing cylinder heads before the Yates cylinder heads
were introduced. The high port canted valve aluminum heads included
three basic designs: the A3, B351, and C302. The A3 was the earliest
of this family of heads. They were basically an aluminum evolution of
the Pro Stock high ported iron 4V's. Back in the '70's, when 351C's
were campaigned in the Pro Stock drag class, it was standard practive
to cut off the exhaust ports of iron 4V Boss 351 heads and bolt on an
aluminum plate that had a raised exhaust port location. Some racers also
filled in the bottom 1/3 or so of the intake port with epoxy or aluminum
port stuffers. The A3 is basically an improved aluminum version of a
Pro Stock high ported 4V head. The intake port is the same width as
an iron 4V (and is in the same location) but the lower portion is filled
in. The exhaust ports are circular in cross section and radically
raised compared to a 4V exhaust port so custom headers are required.
For an intake manifold, you can use a 4V with the ports filled or
a Ford Motorsport A331 (by Edelbrock). Any of the other (non-Yates)
Ford Motorsport high port intakes will also work but will have narrower
ports. The A3's have the largest ports of the lot (241 cc intake and
134 cc exhaust) and were optimized for 355 cid and larger engines used
in drag and circle track racing. The B351's came on the scene next.
They had smaller 223 cc intake and 106 cc exhaust ports and were
optimized for NASCAR 355's. The C302's were the final version of these
heads and had the the smallest ports (212 cc intake and 95 cc exhaust,
optimized for 320 cid and under Trans Am engines). They were also
designed to permit (require) custom porting for larger displacement
applications.
Since this family of heads was originally based upon iron 4V heads, they
are compatible with Boss 302, Boss 351, and 351 SVO valvetrain components
and pistons. Except for the intake and exhaust manifold differences
that are required by the port location and shape differences, these heads
were designed to be 1-for-1 replacements for Boss 351 cylinder heads.
They use a Cleveland style quench chamber and standard 302 Boss/351
Boss/351C/351 SVO valve train parts (will accept 2.19"/1.71" valves).
They have cast iron seats and guides (titanium valve compatible) and are
set up for studs and guide plates. They are also cast with combustion
face and front and rear coolant outlets to allow use on Windsor, Cleveland,
and SVO blocks. Pipe plugs are provided to seal the threaded openings as
required. The fact that they are basically bolt-ons, unlike the Yates,
makes them very desirable heads, particularly for applications like Panteras
where off-the-shelf headers exist.
The earliest versions of these heads went by a "Phase" designation and
were originally referred to as Phase 1 (A3), Phase 1 3/4 (B351), and Phase
III (C302, D302) heads. I also have a set of A3 heads that are Phase 1 1/2
that have intake ports that are narrower (look more like the B351 ports)
than other A3 heads. The exhaust side appears to be standard A3.
Apparently, these variations are not unusual as there were various versions
of these heads cast for specific applications and race teams. There were
also minor variations of the these heads. For instance, the D302 was an
unmachined version of the C302.
Roush and Edelbrock cast a variety of aluminum single plane race intakes
for the early high port heads. These heads are no longer in production,
though pop up on the used market from time-to-time. Specifications and
notes follow:
A3/B351/C302/D302 SVO High Port Canted Valve Aluminum Heads
-----------------------------------------------------------
Part CC's Int Exh Int Exh Description
Number Port Port Vlv Vlv
Vol Vol Dia Dia
CC's CC's In In
M-6049-A3 62 241 134 2.15 1.71 optimized for 355 cid
and larger, drag racing,
circle track, etc.
M-6049-B351 62 223 106 2.15 1.65 optimized for NASCAR
M-6049-C302 62 212 95 2.15 1.65 optimized for Trans Am,
320 cid and under
M-6049-C302B 62 212 95 2.15 1.65 designed to permit
custom porting, not
legal for Winston Cup
M-6049-D302 62 212 95 2.15 1.65 same as C302 w/o port
throat machining or
valve seats/guides
M-6049-D302B 62 212 95 2.15 1.65 same as C302B w/o port
throat machining or
valve seats/guides,
not legal for Winston
Cup
A3/B351/C302/D302 Head Notes:
----------------------------
1. The M-6049-A3 head has the largest intake port volume (241 cc's)
and exhaust port volume (134 cc's), intake flows 280 cfm @ 25 in Hg
as cast, doesn't respond to rpm transitions as well as B351 or C302,
has slight bend on intake port wall to accomodate pushrods, raised
floor increases port radius, straightening the turn for incoming
mixture and minimizing fuel separation, optimized for 355 and larger,
drag racing, circle track, etc.
2. The M-6049-B351 has intermediate port volumes (223 cc's intake,
106 cc's exhaust, flows 260 cfm @ 25 in Hg as cast, intake port
wall filled around pushrod area to straighten it, intake floor same
as A3, material added to exhaust port floor increasing radius for
flow, optimized for NASCAR.
3. The M-6049-C302 has the smallest port volumes (212 cc's intake,
95 cc's exhaust), at the radius the intake port floor has been
filled about 0.120" which forms a slight hump to lift incoming
mixture and drop it evenly around the valve, like B351 wall filled
around pushrod to ensure straightness, optimized for Trans Am 320
cubes and under, narrow ports for increased velocity.
4. B versions (M-6049-C302B, M-6049-D302B) were revised for durability
but not approved by NASCAR, advertised as "too hot for NASCAR" by
SVO, extra material in rocker pedestal area and at spring seats,
rocker cover raised 0.2", improved heat treat, shoulder added to end
plug for improved sealing, outer bolt boss height raised to provide
common head bolt length.
5. All versions are fully compatible with 302 Boss/351 Boss/351 SVO
valve train parts (will accept 2.19"/1.71" valves) and have cast
iron seats and guides (titanium valve compatible), rocker stud
pedestals are machined flat and holes are tapped for threaded studs
and guide plates.
6. Uses Motorcraft AG-series spark plug (14 mm, 3/4 inch reach) with
gasket.
7. Head is cast with combustion face and front and rear coolant outlets
to allow use on 351W and 351C blocks. Pipe plugs are provided to
seal openings as needed. On Clevelands, install pipe plug in holes
on end of heads.
8. Originally referred to as Phase 1, 1 3/4, and III heads.
9. Brodix has recently introduced a bolt-on replacement for the C302B head.
10. Nominal combustion chamber volume for the high port heads is
usually listed at 62 cc's, though Ford Motorsport sometimes
lists 65 cc's.
Ford Motorsport Yates family (C3L, C3, C3H, etc.)
-------------------------------------------------
The Yates family of cylinder heads were originally introduced to contend
with restrictor plate rules. The valve angles were changed (to 7.5 and
8.0 degrees with no side cant) to reduce piston valve relief depths and
permit higher ring packaging. Also, the combustion chamber shape was
revised for very high compression levels. The resulting head requires a
custom aftermarket rockershaft system, different pistons, valves, and
pushrods. The ports were also made small to allow custom porting and
require extensive porting to produce the desired flow numbers.
When considering Yates heads, keep in mind the valve gear required to
finish the heads is *very* expensive. The custom Jessel rockershafts
and arms cost nearly as much as the bare heads. Out-the-door costs are
typically $4K+. The A3/B351/C302 heads are nicer in this regard since
they were designed to take standard, inexpensive, 4V parts.
Also, the small Yates combustion chambers (40 cc's) and are designed to
operate with custom pistons that are dished with a mirror image of the
combustion chamber. You can get Yates heads in a larger combustion
chamber size but the extra power they provide over the earlier
A3/B351/C302 heads is mainly in the chamber/piston design. Some racers
maintain the earlier SVO heads are still superior to the Yates (at least
the early versions) in non-restrictor plate applications.
Like the high port family, there are a variety of Yates heads (see
table below). The C3 and C3L will accept most Ford Motorsport Yates
intake manifolds and have the same raised exhaust port location.
The C3H Yates is has a higher intake port that requires a specific
intake manifold (available from FRPP and Edelbrock). Notes and variations
are listed below.
Yates SVO High Port Canted Valve Aluminum Cylinder Heads
--------------------------------------------------------
Part CC's Int Exh Int Exh Description
Number Port Port Vlv Vlv
Vol Vol Dia Dia
CC's CC's In In
M-6049-C3 40.0 210 119 2.1 1.6 high compression
M-6049-C3L 67.0 210 119 2.1 1.6 low compression
M-6049-C34 48.0 228 131 2.1 1.6 CNC ported and
Extrude-honed
M-6049-C34 48.0 221 131 2.1 1.6 same as C33 except
smaller intake port
M-6049-C35 67.0 210 119 2.1 1.6 Same as C3L but without
seats, guides, or
pushrod holes
M-6049-C3H 40.0 2.1 1.6 Allows for taller intake
intake port.
Yates Head Notes:
----------------
1. Require aftermarket shaft mounted rocker arm system
2. Staggered valves at 7.5 and 8.0 degree angles with no side cant
to reduce piston valve relief depths and permit higher ring package
3. Revised combustion chamber shape for higher compression
4. Phosporous bronze valve guides
5. Motorcraft AG-series spark plug
6. The C3H version is listed as a "High Port Yates" and has higher intake
ports requiring M-9424-W352 intake manifold and 5.45" long intake and
5.26" long exhaust valves. the intake manifold bolts perpendicular to
the cylinder head. Uses same rockershaft as C3L but requires longer
pushrods. Exhaust port is same as C3L.
Ford Motorsport SCI
-------------------
The M-6049-SCI head is the latest FRPP racing cylinder head. It is often
refered to as a Yates head but is actually a separate design. Ford lists
it as "High Port Head for All Out Performance" but don't confuse it with
either the pre-Yates high port heads or the C3H high port Yates heads.
The intake runners are raised 0.4" over the standard Yates C3 heads and
requires a M-9424-W352 intake manifold (available for 9.2" deck only) and
uses Motorcraft AGS series spark plugs. The heads come semi-finished
without valve seat bores and must be ported, though bronze guides and
seats are included. Intake valves up to 2.18" diameter by 5.685" long
and exhaust valves up to 1.625" diameter by 5.565" long can be used.
Blue Thunder 351C Head
----------------------
This is a hybrid cylinder head with 351C valve locations and Yates ports,
aimed at the budget racer. Two things that drive the out-the-door cost
on Yates heads are that they require etensive porting and an expensive
rockershaft system. To keep costs down, the Blue Thunder heads come
essentially pre-ported and retain compatibility with Boss 351 valve train
bits. Standard 351C guide plates, rocker arms, studs, and stud girdles
can be used, though a rockershaft system is also available. Longer than
stock valves are required and the seats will accept diameters from 2.02"
to 2.2" intake and 1.6" to 1.7" exhaust. Since valve locations are the
same as 351C's, 351C pistons can be used. 5Occ and 70cc combustion
chambers are available. The heads have a 0.400" thick port walls and
are partly machined for alcohol down nozzles that can be finished with
a hand held drill.
As near as I can tell, the intake ports are based upon a ported version
of a Ford Motorsport SCI head. A friend compared a set with his Chapman
ported SCI's and said they look very similar. One the exhaust side, the
buyer has a choice of ports. The standard exhaust port is a raised one
similar to a ported C3H or SCI. The optional exhaust port has a double
Cleveland bolt pattern. The lower pattern is stock Cleveland height with
a port that functions as a "stuffed Cleveland" port, in which the bottom
of the port is filled. The second pattern is .750" higher and aligns the
floor of the port with floor of the flange. The top of the port can then
be cut out to match the flange for increased exhaust flow. The only
intake manifolds that are compatible are the 9.2" deck height C3H/SCI
compatible intakes from FRPP and Edelbrock. Blue Thunder may make an
adapter plate for 9.5" applications.
Art Francis of Blue Thunder was insistent that these are race heads and
will not perform well on the street unless large displacement and/or
RPM are involved. With minor clean up, he claims the intake ports will
flow 350-360 cfm at 28", with a 2.20" valve. Professionally ported intakes
can flow 395 CFM at 0.800" lift. Claimed flow for the raised height
exhaust port is approx. 240 cfm at 28" with a 1.70" valve at .800 lift
with clean up work (approx. 10-15 minutes work per port) and 285+ CFM with
professional porting. Claimed flow for the lower Cleveland exhaust port
is 200 cfm to 220 cfm in the lower location. The higher Cleveland location
must be ported and should flow 250 cfm when properly worked. Valves larger
than 2.125" are not recommended on bores under 4.125" as cylinder wall valve
shrouding is a problem.
Brodix Neal BF200 Head
----------------------
The Brodix Neal heads are competitors to the Yates C3H and FRPP SCI.
Like the C3H and SCI, they have higher raised ports than the standard
C3 and C3L Yates heads and require custom fabricated intake manifolds
(may work with the W352). Aftermarket shaft mounted rocker arm system
is required.
Part CC's Int Exh Int Exh Description
Number Port Port Vlv Vlv
Vol Vol Dia Dia
CC's CC's In In
Brodix BF200 46.0 248 ??? 2.125 1.6 see notes
Brodix BF200 Head Notes:
-----------------------
1. The Brodix/Neal BF200 head is a competitor to the Yates C3H and SCI.
2. Like the C3H and SCI, they have higher raised ports than the standard
C3 and C3L Yates heads and require custom fabricated intake manifolds.
3. Require aftermarket shaft mounted rocker arm system
4. Phosporous bronze valve guides, ductile iron seats, A-356 aluminum,
drilled accessory bolt holes
5. 1.350" X 2.200" intake port dimensions, use Fel Pro FP 1265 or
FP 1229 (trim to fit), Fel Pro FP 1431 exhaust gasket
6. Spark plug starting points: Autolite 51 for alcohol, Autolite 52 for gas
7. 11 degrees intake valve angle, 8.5 degrees exhaust valve angle, no
side cant, 1.750" spring pockets
8. Brodix claims intake flow into the 380 cfm range
9. Standard Intake Valve Seat: P 2.151 5/16
10. Standard Exhaust Valve Seat: P 1.650 3/8
11. Standard Valve Guide: SH 545 11/32 PL
12. The above information from the Brodix web site:
http://www.brodix.com/Catalog/Heads/Smallford/BF_200/bf_200.html 13. Brodix Cylinder Heads
301 Maple Street
Mena, Arkansas 71953
Phone: 501-394-1075
Fax: 501-394-1996
E-mail: brodix@brodix.com
Brodix BF300 and BF301 Heads
----------------------------
The Brodix BF300 is a replacement head for the popular Ford Motorsport C302B
race head which is no longer produced. According to Brodix, the BF300 series
heads use "all existing hardware from previous canted valve Ford heads" and
should be a bolt on for those running C302, B351, or A3 heads. Brodix lists
two rockershaft systems for the BF300 series (Jesel KRA 02211 and T & D 7200
or 7201) so 351C rocker arms may not work. Cant angles are listed as 9.5
degrees x 4 degrees on the intake valve and 9.5 degrees x 3 degrees on the
exhaust valve. Standard valve sizes are 2.125" intake and 1.600" exhaust.
Pre-Yates Ford Motorsport and Edelbrock high port intakes should work. Seats
are ductile iron (compatible with unleaded fuel) and guides are phosphorous.
The BF301 has Nascar part number 3941078.
Brodix BF300 and BF301
----------------------
Part CC's Int Exh Int Exh Description
Number Port Port Vlv Vlv
Vol Vol Dia Dia
CC's CC's In In
Brodix BF300 65.0 196 ??? 2.125 1.6 see notes
Brodix BF300 Head Notes:
-----------------------
1. Intake port dimensions are 1.350" x 2.200", compatible with Fel-Pro
FP1265 intake gaskets.
2. 2.125" diameter by 5.300" long valve gives 1.9" installed height (intake).
3. 1.600" diameter by 5.165" long valve gives 1.9" installed height (exhaust).
4. Recommended head gaskets are Fel-Pro FP1021.
5. Recommended head bolts are hardenend cap screws.
6. Recommended exhaust gaskets are Fel-Pro FP1431.
7. Accessory bolt holes are drilled.
8. Spark plug starting points are Autolite 51 alcohol and Autolite 52 for gas.
9. Spring pockets are 1.750" (out of the box)
10. Standard Intake Valve Seat: P 2.230 3/8
11. Standard Exhaust Valve Seat: P 1.800 3/8
12. Standard Valve Guide: SH 545 11/32 PWIL
13. Valve Angle: 9.5� x 4� intake AND 9.5� x 3� exhaust
14. Flat Milling Yields: .0055 PER cc
Cylinder Head Innovations 3V
----------------------------
This is a new aluminum Cleveland head out of Australia. It's produced
by CHI (Cylinder Head Innovations) and was designed in conjunction with
P.R.E. Racing Engines. It's designated as a "3V" to differentiate it
from either 2V or 4V heads since its ports are an intermediate size,
larger than a 2V but smaller than a 4V. Chambers are standard Boss 351
and the heads use 4V size valves and 351C rockers, studs, and guideplates.
Seats are "high nickel chrome inserts". The ports are unique though
they claim you can use 4V intake and exhaust manifolding. A standard
4V intake would not be a direct bolt on, however. The intake port floor
is filled relative to a 4V and may be narrower (forgot to measure it).
TFC and Terry Parker both make raised floor 4V versions of their single
plane intake manifolds that can be port-matched to the heads. The
exhaust is also raised but it's not clear by how much. I was told it
is raised by 1/4" but they sure look like they are raised more than
that. However, it may simply be an optical illusion since the lower
floor is filled in. In any event, even 1/4" would mean header and pipe
rework on both my Pantera and on my Mustang.
I held one of these heads in my hands at the Columbus All Ford swapmeet
and tried to get an imprint off the head to see how it would match my
2V/4V/high port intakes but Mike didn't want me to. He said the head
was a machining reject for display purposes only and had the bolts
drilled in the wrong place. It's not clear how well it will match high
port (A3/B351/C302) type intakes.
Edelbrock Victor
----------------
Edelbrock Victor series small block Ford race heads can be adapted to
fit on Cleveland blocks, using an 9.2" deck Edelbrock Victor intake
manifold. However, since they are an in-line valve Windsor design,
there is little compatibility. Figure custom pistons, custom headers,
etc. Also a rockershaft system is required.
Bennet canted valve cylinder head
---------------------------------
No information currently available.
Dan Jones
