[ihc] Re: How to port and polish web sites, tool info (long)

[Colin M Rush <salmineo@xxxxxxxx>]

Visit these sites here:
http://www.sa-motorsports.com/diyport.htm
here:
http://www.fordmuscle.com/archives/2000/07/homeporting/index.shtml
and here:
http://www.grapeaperacing.com/GrapeApeRacing/tech/nitrousheads.cfm

The last link pertains to head mods based on nitrous.  I put that in
mainly because I do not know what your program is.  What you do with a
head really depends on what kind of head you use.  For example, most of
the porting info you will find out there uses the Chev small block as the
reference, (or Ford in the case of the second link).  However, if you
just jump into an AMC V8 head without talking to the folks who know AMC,
you will not know to avoid the roof of the exhaust port, which has this
curve that sure looks like it should be smoothed flat, and you will get
happy with the grinder, and will grind right through the very thin roof
into the water jacket, and then will then throw your heads away and get a
Chevy and malign the (now) poor construction of the AMC motor.  Talk to
some people who have been there before you and know what to look out for.
 If you are indeed working on a head for an IHC SV motor, chances are you
will have no problems as they are pretty thick, but there are other
things you can do to those heads that you may or may not want to do. 
Some of those things consist of changing valve sizes or materials,
plugging the AIR ports, installing hardened seats on the intake, bushing
or sleeving the valve guides, and so on.  Do your research before you
start grinding, cutting, or machining.  Spend the money on carbide burrs,
and skip the stones; they cut faster, and can be resharpened.  The stones
cost less, but take a lot longer, get fouled up easily (especially with
aluminum or plastic) and are throwaway items when they are fouled or
broken.  If they get chipped, they also get imbalanced, which is hard to
control and bad for the grinder.

FYI, if anyone is looking for a great Christmas present, or needs a hint
to drop their spouse for a gift idea, that Makita die grinder shown on
the second link is what I have, and it is the most useful tool in my
arsenal, hands down.  It cannot be used for drilling, but it has so many
applications on other jobs, it makes me wonder how I got by without it. 
Much better than a Dremel because it has some torque, but better than a
regular air-powered die grinder because you can use it other places than
just your garage, assuming you even have an air compressor (I do not). 
It is relatively cheap (I think ours cost about $120 five years ago.)  My
brother has used it on his boat.  I used it all the time to massage holes
in all types of metal that may be just a little bit off-center or
slightly too small.  My roommate uses it to grind the heads off of very
small screws when he rebuilds carburetors.  And we have ported many sets
of heads.  I have used it to install a furnace, and a friend used it to
work on his RC car.  I have used it to deburr pipe and plate steel and
engine blocks.  I have used it as a cutoff wheel.  In situations where a
drill will not work, this tool is extremely handy.  Case in point, I sold
some adaptors to a fellow that had the 4 bolt holes slightly off-center. 
He spent an hour putting it on a drill press and using the drill to
nibble away at the sides of the hole until the hole was in the right
location.  I took one of the adaptors, held it in my hand, and fixed the
problem with this tool in 5 minutes with a small carbide burr.  This die
grinder also uses 1/4" shaft burrs and stones and sand roll arbors, but
there is a collet sleeve you can put in it that also allows you to use
all of the little bits that are made to fit the Dremel tool, which
doubles the available tooling for it.  If I am in a bind, and cannot get
a new burr, I can go to the local Home Depot and use Dremel bits to get
me by until the weekday.

You will need to get a speed controller or else the die grinder spins too
fast (25000 RPM) and the tool skips over the work.  Most of the time, we
operate in the 3000 or less RPM range.  What you need to get is something
called a router speed control.  The unit I have is a model RSC-15, shown
here: 
http://www.mlcswoodworking.com/shopsite_sc/store/html/smarthtml/pages/spe
edcon.html
Do not just use a soldering iron voltage control, as it works
differently.  The soldering iron voltage control varies the voltage, but
at low speeds where you will use the die grinder, there is just no torque
available, and the tool stops on the work.  Using the router speed
control modulates the speed, but the torque is still there.  (I assume it
varies the amperage available to the tool, but do not know exactly.) 
Most of the time, you will be operating the die grinder with the knob set
to the 1/4 to 1/2 position, or even less if you need to do precise work.

-Colin Rush


[ihc] How to port and polish web sites
 
Anybody know of any good sites that go into detail about how to do a good
port and polsih job?  I am fairly new to it and want to learn as much as
I can so I can make my engine a screamer when I rebuild it this summer.
Jack

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