[DeTomaso] A3 heads Jack Roush intake
Daniel C Jones
daniel.c.jones2 at gmail.com
Tue Nov 25 14:11:22 EST 2014
The right rear runner would normally carry the Ford Motorsport part number
(e.g. M-9424-A331) in smaller script but sometimes those are ground off.
Roush made several similar part number intakes for the high port heads
including M-9424-A331, M-9424-A351 and M-9424-B351. The A331 was for a
9.2" deck Cleveland block only. The A351 and B351 were the same basic
casting but finish machined for 9.5" and 9.2" deck engines. The featured
dual end seal rails so could work on either Cleveland or Windsor blocks.
These intakes were generally cast with narrower C3/C302/C302B port
openings. When ported to match the wider A3 heads, the runners will be
relatively thin (assuming the are ported all the way to the plenum and not
just port matched at the gasket opening). There were also several similar
looking Yates intakes. Note there were two different intakes that carried
the M-9424-A331 part number. One was made by Roush, the other by
Edelbrock. It was the Edelbrock A331 that had the wide ports that match
the A3 heads, though there were a few Edelbrock A331 intakes cast with
narrow ports. The Edlebrock A331 looks much like a Torker: Some pictures
of various high port intakes can be found here:
http://www.bacomatic.org/gallery2/v/hidden/dan/dan-cars/album04/album17/
The original intake gaskets for A3 heads were Ford Motorsport M-9439-A341
which are no longer available. Fel Pro makes two intake gasket sets for
the Motorsport high port heads. 1229 is listed for A3 heads but the port
opening measures the close to C302B heads (1.35" x 2.20"). 1265 is listed
for B351 and C302B heads but the port size is listed as 1.35" x 2.22".
Both as "trim to fit" for the A3 heads. I know that p/n 1229 has round
holes on both ends in case you run coolant through the intake. I'm not
sure about f the 1265 have the same holes. Both 1229 and 1265 of those are
0.060" thick. Fel Pro makes similar intake gaskets in thinner (12531 is
0.030", FEL-12532 and 1253S2 are 0.045") and thicker (12535 is 0.120")
sizes for Yates heads that could probably be adapted if you need to
compensate for head or intake milling.
Also, high port heads had two different exhaust flange bolt patterns. The
later version had one row of bolts moved about a bolt diameter to make more
room for porting (raising the port roof while still maintaining enough
material above the port to seal a header gasket). Here's a picture of the
an A3 high port head with late exhaust bolt pattern:
http://www.bacomatic.org/gallery2/v/hidden/dan/dan-cars/album04/A3_late_exhaust.jpg.html
The later pattern has a center-to-center bolt hole distance of 2.94" when
measured diagonally across the exhaust port. The early pattern has the
upper bolt hole lowered by about 1/2 the bolt hole diameter. Measured
diagonally across the exhaust port, the early version center-to-center bolt
hole distance is 2.77" and the external casting is flat across the top of
exhaust port. Here's a picture of an A3 high port head with early exhaust
bolt pattern:
http://www.bacomatic.org/gallery2/v/hidden/dan/dan-cars/album04/A3_early_exhaust.jpg.html
Notice the flange does not have material for later bolt pattern. There was
a third variation that had the late casting but was drilled with the early
bolt hole spacing. Here's a picture of a Ford Motorsport B351 high port
head drilled for early exhaust bolt pattern but has flange that supports
the later pattern:
http://www.bacomatic.org/gallery2/v/hidden/dan/dan-cars/album04/B351_exhaust.jpg.html
Fel Pro makes two different header gaskets for high port heads. P/N 1417
is for the early pattern and has a 1.94" diameter round port size. P/N
1431 is for the later pattern and has a 1.81" diameter round port size.
Dan Jones
On Tue, Nov 25, 2014 at 9:41 AM, Bill Allen via DeTomaso <detomaso at poca.com>
wrote:
> Hello, I have a recently purchased set of A3 heads and a Jack Roush eng
> Ford Motorsport intake. The intake has Jack Roush eng on the right front
> runner and Ford Motorsport on the left front runner and both are cast into
> the runners. I can not find a A331 or A351 anywhere on the intake. The only
> other marking is stamped not cast on the rear of the carb mounting area of
> B345. I purchased the heads and intake together and was told they were both
> on the same engine at one time and the lower end let go. I have had no luck
> finding info on this intake (even after talking to a Jack Roush factory
> rep). Hoping for some insight !
>
> Sent from my iPhone
> _______________________________________________
>
> Detomaso Forum Managed by POCA
>
> DeTomaso mailing list
> DeTomaso at poca.com
> http://poca.com/mailman/listinfo/detomaso_poca.com
>
-------------- next part --------------
The right rear runner would normally carry the Ford Motorsport part
number (e.g. M-9424-A331) in smaller script but sometimes those are
ground off.A Roush made several similar part number intakes for the
high port heads including M-9424-A331, M-9424-A351 and M-9424-B351.A
The A331 was for a 9.2" deck Cleveland block only.A The A351 and B351
were the same basic casting but finish machined for 9.5" and 9.2" deck
engines.A The featured dual end seal rails so could work on either
Cleveland or Windsor blocks.A These intakes were generally cast with
narrower C3/C302/C302B port openings.A When ported to match the wider
A3 heads, the runners will be relatively thin (assuming the are ported
all the way to theA plenum and not just port matched at the gasket
opening).A There were also several similar looking Yates intakes.A
Note there were two different intakes that carried the M-9424-A331 part
number.A One was made by Roush, the other by Edelbrock.A It was the
Edelbrock A331 that had the wide ports that match the A3 heads, though
there were a few Edelbrock A331 intakes cast with narrow ports.A The
Edlebrock A331 looks much like a Torker:A Some pictures of various
high port intakes can be found here:
A [1]http://www.bacomatic.org/gallery2/v/hidden/dan/dan-cars/album04/al
bum17/
A
The original intake gaskets for A3 heads were Ford Motorsport
M-9439-A341 which are no longer available.A Fel Pro makes two intake
gasket sets for the Motorsport high port heads.A 1229 is listed for A3
heads but the port opening measures the close to C302B heads (1.35" x
2.20").A 1265 is listed for B351 and C302B heads but the port size is
listed as 1.35" x 2.22".A Both as "trim to fit" for the A3 heads.A I
know that p/n 1229 has round holes on both ends in case you run coolant
through the intake.A I'm not sure about f the 1265 have the same
holes.A Both 1229 and 1265 of those are 0.060" thick.A Fel Pro makes
similar intake gaskets in thinner (12531 is 0.030", FEL-12532 and
1253S2 are 0.045") and thicker (12535 is 0.120") sizes for Yates heads
that could probably be adapted if you need to compensate for head or
intake milling.
Also, high port heads had two different exhaust flange bolt patterns.A
The later version had one row of bolts moved about a bolt diameter to
make more room for porting (raising the port roof while still
maintaining enough material above the port to seal a header gasket).A
Here's a picture of the an A3 high port head with late exhaust bolt
pattern:
A [2]http://www.bacomatic.org/gallery2/v/hidden/dan/dan-cars/album04/A3
_late_exhaust.jpg.html
The later pattern has a center-to-center bolt hole distance of 2.94"
when measured diagonally across the exhaust port.A The early pattern
has the upper bolt hole lowered by about 1/2 the bolt hole diameter.A
Measured diagonally across the exhaust port, the early version
center-to-center bolt hole distance is 2.77" and the external casting
is flat across the top of exhaust port.A Here's a picture of an A3
high port head with early exhaust bolt pattern:
A [3]http://www.bacomatic.org/gallery2/v/hidden/dan/dan-cars/album04/A3
_early_exhaust.jpg.html
Notice the flange does not have material for later bolt pattern.A
There was a third variation that had the late casting but was drilled
with the early bolt hole spacing.A Here's a picture of a Ford
Motorsport B351 high port head drilled for early exhaust bolt pattern
but has flange that supports the later pattern:
A [4]http://www.bacomatic.org/gallery2/v/hidden/dan/dan-cars/album04/B3
51_exhaust.jpg.html
Fel Pro makes two different header gaskets for high port heads.A P/N
1417 is for the early pattern and has a 1.94" diameter roundA port
size.A P/N 1431 is for the later pattern and has a 1.81" diameter
round port size.
A
Dan Jones
On Tue, Nov 25, 2014 at 9:41 AM, Bill Allen via DeTomaso
<[5]detomaso at poca.com> wrote:
Hello, I have a recently purchased set of A3 heads and a Jack Roush
eng Ford Motorsport intake. The intake has Jack Roush eng on the
right front runner and Ford Motorsport on the left front runner and
both are cast into the runners. I can not find a A331 or A351
anywhere on the intake. The only other marking is stamped not cast
on the rear of the carb mounting area of B345. I purchased the heads
and intake together and was told they were both on the same engine
at one time and the lower end let go. I have had no luck finding
info on this intake (even after talking to a Jack Roush factory
rep). Hoping for some insight !
Sent from my iPhone
_______________________________________________
Detomaso Forum Managed by POCA
DeTomaso mailing list
[6]DeTomaso at poca.com
[7]http://poca.com/mailman/listinfo/detomaso_poca.com
References
1. http://www.bacomatic.org/gallery2/v/hidden/dan/dan-cars/album04/album17/
2. http://www.bacomatic.org/gallery2/v/hidden/dan/dan-cars/album04/A3_late_exhaust.jpg.html
3. http://www.bacomatic.org/gallery2/v/hidden/dan/dan-cars/album04/A3_early_exhaust.jpg.html
4. http://www.bacomatic.org/gallery2/v/hidden/dan/dan-cars/album04/B351_exhaust.jpg.html
5. mailto:detomaso at poca.com
6. mailto:DeTomaso at poca.com
7. http://poca.com/mailman/listinfo/detomaso_poca.com
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