by Jim Langley
aftermarket today for the Ford Windsor small block is absolutely
fantastic. No more does the Chevrolet crowd have the monopoly
on easy to find go-fast goodies. The advent of the fuel injected,
roller-cammed 5.0 V8 changed all that. True, the prices are
still slightly higher for the blue oval parts but nowhere
as high as they used to be, and the availability is now basically
equal. Take the aftermarket cylinder head arena, for example.
It is absolutely overrun with choices- aluminum, iron, ported,
and even some decent stock offerings. With prices ranging
from about $650 to well over $1500 for a good set of bolt-on
heads many of us can't swing that without seriously compromising
our credit ratings and good standing with our significant
other. We here at Fordmuscle have lived through that and tried
a cheaper alternative- porting stockers ourselves. The results
were pleasantly surprising. A set of '69 351 Windsor heads
actually flowed as well as box stock Edelbrock aluminum castings
once larger valves were installed. Even more impressive, was
that this was only the second set of heads this author had
ever ported. With such encouraging results we felt we should
pass on what we learned so those with plenty of time and little
cash can duplicate our efforts.
Why port stock heads?
The answer is plain and simple, stock small block Ford heads
SUCK! Actually they wheeze... like trying to breath through
a swizzle stick. From the factory, almost all of the heads
offered up to 1995 couldn't flow enough air to get much more
than 250hp out of a 302. Two noticeable exceptions are the
GT40's on the EFI 5.0 Cobra's and the recently released GT40P's
found in 5.0 Explorers. The Boss 302's worked well as long
as you stayed above 5000rpm (besides, they were Cleveland
Since the stock heads flow so poorly it is just about impossible
to screw them up... but it is possible. That's why we put
together this article. By understanding the fundamentals of
porting, you can pick up that die grinder or Dremel tool with
confidence, and come out with a set of heads that will rival
the brand name castings. By the way, if you already spent
money on aftermarket heads, or if you own an FE, Cleveland,
or and other Ford engine for that matter, you should still
study this article -while some of the details may be Windsor
specific, the principles apply to really any cylinder head
A simple cartridge roll clean up and smoothing of the ports,
runners, and bowls plus clearing out the smog injector bumps
(if present) can net you around 20 horsepower. Throw in some
basic gasket matching, valve guide boss work, combustion chamber
shaping, large valves, and you can see well over twice that.
Gains like this are definitely worth it if you can spare the
time but not the cash. Don't worry if some of these terms
are new to you, we'll define them for clarity before going
off the deep end.
A quality carbide cutting bit is
indispensable when it comes to porting iron heads. They
are not cheap, so get an assortment if you plan on porting
as a side job, other wise one or two bits will suffice.
The bits shown here are available through Mondello.
best tools for head porting are either an air operated die
grinder or high-speed electric grinder (Joe Mondello prefers
Makita electric.) Of course both of these can be expensive.
This author has used a 12 volt cordless drill for the carbide
work and then a Dremel tool with a flex-shaft for reaching
into the intakes. The high speed grinders are quite a bit
There are nice porting kits available today that come with
a variety of cartridge rolls and grinding stones in varying
grits. Most do not include a carbide bit, which is just about
mandatory if you are working on exhaust ports with smog bumps.
The Eastwood Company and Standard Abrasives does have them
at extra cost. Joe Mondello will soon be offering a complete
line of kits including carbide bits made to his specifications.
They have longer shanks (shafts) and special shapes for specific
porting requirements. Look to spend between $30 to $50 for
a good, quality carbide bit. A good shape for all around use
is a conical or football bit.
Working with a fifty-pound chunk of iron is not easy. You
dont want to be porting while trying to balance the head on
a flimsy work surface. Find yourself a sturdy work bench,
or fab one up with saw horses and 2x4's. The head itself should
be level, stable, and angled such that you can look directly
down the ports as you grind. A few pieces of 2x4 can make
for a very functional head stand.
Before starting, find a shop or friend that has aftermarket
heads, preferably in aluminum. Inspect the ports both visually
and with your fingers. Your sense of touch will be very useful
for checking your progress. I fondled a set of Edelbrock heads
about a dozen times before I started porting. Finally, I bought
a dial caliper so I could check my progress and try to keep
the port sizes equal.
Before you begin, decide if you are going to put in new valve
guides and have new valve seats cut. If you are going with
new pieces you don't have to be as careful with the bits skipping,
otherwise, a gentle touch will prevent damage to them. In
general it is good practice to plan on having a valve job
performed after you are done porting.
Finally, before taking your carbide bits to the ports, get
a feel for how they cut. Try your different bits on the casting
ridges on the ends of your heads,or on a spare junk head.
Your local machine shop probably has a junk head they are
willing to give you. You can even start working on grinding
down the Thermactor bumps in the exhaust ports. Keep the grinder
moving up and down, and in a circular motion. Don't let it
stay in one spot for any length of time. By constantly moving
the cutting bit and applying gentle pressure you can cut nice,
Remember, let the tool and it do the work, a lot of pressure
is not neccesary and only leads to quick wear of the bits
How Far Can you Go?
Stock small block Ford heads have pretty thick walls, and
there are really no critical thin areas. Nevertheless it is
indeed possible to make a wall too thin, or actually cut into
a water jacket. Professional porters work against these limits
all the time, but, for the home porter, if you stay within
the guidelines offered in this article, you won't be anywhere
close to damaging the head. An experiened porter will also
tell you that you can "hear" when you are cutting
close to a thin area -as the tone of the carbide cutter will
change to a higher pitch. Continue