What does the stock market
have to do with small block Ford cylinder heads? Not
much unless you ask Tony Mamo, the principal port designer
of Air Flow Research cylinder heads. The former Wall
Street stock broker by day and cylinder head porter
by night told us, "Rather than researching investment
opportunities for my clients I was spending my free
time building my ten-second Monte Carlo.” Knowing
cylinder heads are the key to building huge power Tony
decided to build his own flowbench to quantify and guide
him in the search for more airflow. “I became obsessed
with airflow and working on the flowbench.” Burnt
out on the high anxiety broker lifestyle, and coming
to terms with the fact his talents and passion weren’t
located on Wall St., Mamo made a final trade, exchanging
a career on the trading floor for one on the shop floor.
AFR's Tony Mamo
still uses the flow bench he made in 1996 to test
his designs. |
The self taught cylinder head
porter took a job at New York’s famed Shafiroff
Race Engines. In short time his cylinder head work was
helping to push their Chevy motors to new power levels.
Fast forward to 2000. Air Flow Research heads are quickly
becoming the aluminum head of choice for Chevy and Ford
enthusiasts. The AFR plant in Pacoima, CA runs 22 hours
a day, six days week, churning out 700 pairs of heads
per month. They still cannot keep up with demand. New
Haas CNC machines are filling up the once modestly sized
Pacoima, CA facility. To keep on top the Sperlings look
to bring on someone who can help with their Sales and
R&D efforts. At a PRI show Sperlings meet up with
Mamo, whom they'd already been familiar with through
their dealings with Schafiroff. The Sperlings indicate
their interest in developing a big-block Chevy head,
and Mamo offers to sell them his designs. AFR goes one
further and offers Mamo a full time job. As they say,
the rest is history and a relationship was born. Mamo,
who wears several hats in any given day as Sales Manager
and R&D manager in charge of port design, wastes
no time putting his real world experience to good. He
looks to improve on the already efficient and powerful
AFR port designs. One day while analyzing a cut away
of AFR's small block Ford 165cc head Mamo notices potential
areas for better flow. He approaches the Sperlings with
the idea of an improved Ford head, and Rick tells him
to run with it.
Improving a Great Design
The success of AFR's 165cc Ford head, now a top over
three thousand engines, has been in the conservative
intake runner volume and 1.90" valve diameter.
Moving more air without increasing cross sectional area
is an often overlooked recipe for good power while retaining
impressive torque. This has been a hallmark of the 165cc
head, especially amongst the 5.0L Mustang crowd. Hitting
the 300 rearwheel horsepower mark from the small displacement
Ford, a feat once only accomplishable by over-cammed
NMRA motors, has recently become run-of-the mill thanks
to the advance in aluminum aftermarket cylinder heads
like the AFR 165.
With the bar already set high Mamo works to give Ford
enthusiasts yet another reason to rave about AFR. He
starts with the existing 165cc head and makes seemingly
trivial changes with a die grinder. Each time the port
is reshaped, a flow test follows to measure the effect.
Even more important than removing material in the right
places is being able to add material and pick
up flow. Tony calls this concept "shrink porting".
Improving the current 165cc head incorporated exactly
that; adding material in areas he felt were "dead"
or slow moving and not conducive to flow. At least one-hundred
trips to the flowbench later and what we are left with
is a new port design with the same volume of the original.
Flow is picked up all across the lift range due to a
better shaped and more efficient port design that will
allow higher airspeeds before ultimately stalling. Of
course the AFR heads are
not hand ported but precision cut by CNC (computerized
numerical control)
machines. Everything Mamo does with the finesse of a
die grinder needs to be translated, and consistently
reproducible by the CNC software. What may yield great
results by hand is useless if the machine can't reproduce
the results. Enter Guy Trip, an AFR twenty year veteran,
and part owner, who heads up the Engineering department.
Trip, a self taught CNC programmer, and the AFR engineering
team have made huge advancements over the years in their
ability to digitize and reproduce the airflow results
of a port design that Mamo might have worked months
on.
Making new molds in an
expensive proposition. However, revising the CNC
program is much more economical. |
Another constraint, and perhaps
the most difficult to grasp for the outsider
looking, is there can be no changes to the mold. All
improvements need to occur in the CNC process. It's
is much more cost effective to change around a CNC cutting
pattern than to developing new molds. The former can
be done infinitely, with the only expense being the
time it takes to make the inputs into the software program.
On the other hand making a new mold and casting heads
from it is a $75,000 proposition, if you go with inferior
tooling. AFR typically funds $250,000 into R&D and
tooling for a brand new cylinder head mold and tooling.
Working the CNC end of the process makes sense as the
heads really do not take shape until they get on the
automated cutting machines. As raw aluminum castings
they are akin to uncut
diamonds - striking little resemblance to their respective
finished products.
Once a new port design has been digitized, Engineering
works hand in hand with R&D, flow testing and evaluating
prototype cylinder heads until the end result yields
airflow and volume figures within 1-2 percent of the
hand-ported original it was copied from. This is no
task for the impatient. Port size, locations, valve
job profiles, CNC feed rates, and many other parameters
all effect the finished product. The cycle of making
design tweaks, engineering the CNC cuts, producing the
head and testing it on the flow bench is typically a
4-8 week long process without a defined finishing line.
It is a very tedious and time consuming process that
must be done if you absolutely must deliver a production
piece that flows at or close to a hand-ported piece
that might have been “romanced” for months.
Anyone with reasonable talent and access to a CNC machine
can port aluminum cylinder heads, to be able to mass
produce a CNC production head that truly flows big numbers
across the board takes a lot of dedication and experience.
One of the bigger challenges in the entire “fine
tuning” process is trying to find all the airflow
without increasing the runner volume. After all this
still needs to be a 165cc head.
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(AFR 165cc Comp Flow bench results) |
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A Haas CNC machine performs the "First
operation" whereby reference points
are drilled onto the "wings".
All further machining is based on these
references.
Once the reference points are machined into
the wings the raw castings go to a Mazack
machine where the various holes are drilled
and tapped and valve guides cut in.
The heads then sit in a Haas machine for
the main program where the CNC porting occurs.
This process is 2 hours for a standard AFR
165cc head, and 3.5 for heads with the new
Competition porting package.
Once ported, the heads go on to receive
a valve job, pressure testing and final
assembly and packaging.