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Old August 12th 03, 05:14 PM
Corky Scott
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Default Ford V-6 engine work

I got a call from the Upper Valley Machine Shop Thursday of last week.
Will was headed for Watkins Glenn for the Bush Nothern tour and he
wanted me to come down and get my engine, it was ready to be picked
up.

Will has had the engine for about a year now. His business is a
single person operation and he doesn't lack for work. He made sure I
understood that right at the beginning that he would be unable to get
to it immediately. I told him I did not need it immediately, and he
was good as his word. ;-)

In my last talk with him, I explained that I did not want him to
install the pistons to the crank. I had to mount the drive cog for
the PSRU and it's best to do that with no drag from pistons sliding up
and down in the cylinders.

But I did want him to install the crank, and to use the ARP studs for
the main bearing caps rather than the old bearing bolts, or even
rather than buying new bearing bolts, which he did.

So he wheeled it out the door to my pickup, which I happened to be
driving that day, and together we lifted it into the bed. It was
wrapped with plastic to protect it from rusting in the monsoon like
weather we've been having lately.

In addition, I picked up the two spare heads I'd given him, the
pistons and the rest of the ARP studs for the cylinder heads.

So here's what my $860 has bought me in machine work on the engine.

The block was baked, then shot peened and then blasted clean. That
entire process takes about half an hour. Next, the block was rough
bored to .0028 over so we could see if that would take care of any
cylinder irregularities. It was obvious that the rough bore had
cleaned up the cylinders so we settled on pistons that were a standard
..0030 over. I got those from Wiseco, the company that makes pistons
for a huge number of vendors including many Detroit automakers.

The pistons turned out to be the ones that David Blanton developed
with Wiseco expertise. Basically Blanton explained what he needed and
Wiseco machined them. The design was tested by Blanton for a number
of years and the design was specified for use when converting a Ford
3.8L V-6. Wiseco has a number of these sitting on their shelf, but
they did not happen to have a .0030 over set, so mine got newly
machined.

Will's honing policy is to wait till he actually has the pistons in
hand before honing so that he can mike them to be positive about the
piston clearance. When I handed him the pistons, he was surprised to
see that the clearance was specified at .0060. That's a lot of
clearance, more than twice what you usually see for street cars, but
the engine isn't going in a street car, it will be operated at a
continuous 50% to 75% power setting, and at times will be at 100%
rated power during take off and climb. The clearance reflects racing
and testing experience and we did no second guessing.

In addition to the honing, the block was decked, the bearing surfaces
were trued, the cam bearings were installed and all the casting plugs
replaced.

The heads were bead blasted and degreased. All valves were inspected
and six new intake valves were ordered as none of the originals passed
inspection, they'd been damaged by water corrosion while the engine
sat in storage. The heads needed a bit of grinding and polishing, and
were also planed to make sure that they were completely flat.

Next, the connecting rods were inspected and trued, and the wrist pins
were installed attaching the pistons to the connecting rods. The
wrist pins were a story in themselves. Normally, when you buy
pistons, they come with wrist pins. But mine did not. When I called
Wiseco, they told me that Blanton had made them agree not to send
wrist pins because he believed that the Ford wrist pins were perfectly
adaquate for the job, and they have proven to be. So Wiseco agreed
not to send any wrist pins with Blanton pistons. The problem was I
didn't know this, and had tossed all twelve of them. Now I had to
find some and had a consideable amount of difficulty finding them.
Bruce Frank stepped in to the story here and found some at an auto
parts place near him and made the connection for me.

Within a week, they'd arrived and I handed them to Will. He said that
he had to hone the pistons slightly to get them to fit but they were
otherwise ok.

Finally, I asked Will to gap and fit the rings to the pistons as I did
not have the tools for that and he did. He also does this all day
long so I felt comfortable with his handling this part of the
assembly.

So that's what I offloaded at home, a bare block with all the
necessary machine work done and the crank installed, plus two machined
heads, the pistons and the ARP studs for the cylinder head
installation. In addition, I had the spare heads which I'll use by
mocking up the other engine so I can see how the cowl will work.

This past weekend I fitted the flywheel to the crank and then bolted
the drive cog of the PSRU to the flywheel to check for runnout. I had
bought a custom flywheel from Northwest Aero for the Ford V-6. The
flywheel is a shiny work of art. I cleaned up the cog, fit it to the
flywheel and aligned it to the crank. The crank bolt holes are offset
so that the flywheel can go only one way. In the recesses of my mind,
I'm sort of remembering that this is because the flywheel is part of
the crank balancing. The flywheel has two large holes machined in it
both on the same side so it's apparent that it's weighted to affect
balance.

Anyway, the flywheel includes the ring gear for the starter. The ring
gear sets against a flange machined in the flywheel, and is then held
to the flange with three round head machine screws. The center of the
flywheel has an insert that is bolted to the flywheel. The insert has
nubs on both sides, the one fitting into a hollow in the crankshaft,
the outer fitting into the drive cog.

All fits were tight, and I had to draw the cog and flywheel onto the
crank by starting the bolts, which where were allen head cap screws,
little by little, one at a time working around all six of them.

Eventually the cog and flywheel bottomed and I torqued them to 40 ft
lbs. When I bolt the flywheel on permanently, I'll torque them to the
requested 45 ft lbs.

All this was to check for runnout of the drive cog. You want the
minimum you can achieve. To check, I broke out the old dial guage set
I had which I had not used since I was an auto mechanic some 20 years
ago. It was the type that you clamped to something and then threaded
in an elbow rod and clamped the dial guage to the elbow and adjusted
it to the angle best suited for reading.

Initially I was stymied as the cog was some six inches above the
engine block and the elbow did not reach high enough or over far
enough to get the dial guage inside the cog. But I inserted a long
bolt into the block and clamped the arm to it and found I could now
get the head inside the cog.

It was the inside of the cog that I had to use for this reading as the
outside is ribbed to drive the huge Gates belt. After some initial
false starts, I was able to adjust the dial guage properly and gently
turn the crank using the flywheel and observe the dial guage. I'm
pleased to report that the cog ran pretty much dead true with hardly
any discernable reading. Can't ask for much more than that.

So now I removed the flywheel, the cog remained pressed to the
flywheel, I'll leave it like that for when I install it for good the
next time.

Corky Scott