This is
what we started with when it got to Bob's shop. I'm
showing before and after pictures
to show the types of cleaning that can be done to a block after
it is disassembled.
Next comes
a little trip through the hot tanks to remove the grease and
rust from the
inside of the coolant passages. Please note that all
expansion plugs are removed, as
well as all oil galley plugs and the two lead slugs that are
located on the block.
A lot better, but not nearly
where we need to be.
This is
what you get most of the time, but it's not quite good enough to
get the remaining
rust and potential crud that may be lurking in the oil galleys
or coolant passages.
Now for a
final dip through the hot acid tanks to remove everything else.
This is where the lead plugs must be out or the owner of the
acid dip will not be happy.
That looks much better and is
ready for a lot of cutting and boring.
Before any other machining
takes place, the block is squared and machined for
zero deck clearance. This will allow a perfectly flat and
squared block to be set
up on the line boring machine as well as for the cylinder boring
process.
Measurements are taken from
many points on the block and the stable deck surface
of the grinder until the exact amount is programmed in for the
surfacing process.
This is the head being done,
but the concept is the same for the engine block's deck.
After the program runs the
cutters over the deck, additional measurements are taken.
This process takes place over
and over to insure that everything is going correctly.
Finally, the deck is a zero
clearance and we can move forward with the rest of the
machining.
That was the final
confirmation that the last pass took it all the way down.
Line
boring for the crankshaft is next.
This is
done on the same machine as used for the cam bearings and one
follows the other.
This is a
much faster process that the line boring for the cam bearings,
since there is
very little material to be removed during this process. Or
at least that's what you hope for.
There's a
nice straight line for the main bearings and crankshaft to ride
on.
Speaking of
the crankshaft, the first cutting ahs been done to get these
journals to accept
.010" over size bearings, which really means that the crank is
cut to .010" under size.
Here is the
crankshaft after balancing, but before final polishing.
Next the
final polishing of the crank takes place (after balancing).
Note the circles on the crankshaft throws where material was
removed to balance
the assembly properly. Every rotating part, from the
damper, to the flywheel was
balanced this way. This process, along with the line
boring allows for a smoother
and higher revving engine without the worry of harmonic
vibrations causing issues.
There will
be a couple of passes with the boring process as
the cylinders are bored out to accept .030" over size pistons.
As the
cylinder boring take s place, the vacuum hose is pulling metal
shavings from
beneath the cutters and keeping that from floating around the
open air.
After the
.008" was removed from the deck surface, new cuts were made to
bring the
proper depth to the pocket that accepts the metal seal on the
cylinder head gasket.
The
cylinder boring came out really nice as you can see below.
As clean as
this is, several more washings will be needed to remove metal
particulate.
The block
is machined for zero deck clearance and all of the boring is
completed.
Each of the
cylinders is given a final cross hatch honing after the boring
is completed.
During all
of the above, the rods were being reconditioned. Each rod
was trued
weighed and balanced in order to match everything perfectly when
finally assembled
Those are
new ARP rod bolts that the caps were modified to accept.
New piston
pin bushings were installed after the rods were shot-peened
and made ready for reaming. All sharp edges are removed
during this process.
Just some
additional and necessary weighing in.
And the
final total weigh in for recording as part of the blueprinting
process.
These are
all polished and awaiting their respective assembly time.
What good
are rods without new pistons to fit them to? I did use AE
Hepolite
pistons that were .030" over size. These come fitted with
perfectly matching AE rings.
The same
process begins as above and every part will be weighed and
matched.
The cam is
now installed and the final assembly is drawing to a close.
All of this
is being setup to degree the cam in properly and to insure that
the settings are correct.
According
to the spec sheet for the TH5 camshaft, this is dead on the
money.
I added the
Vernier adjustable timing gear and German made chain and crank
gear.
It was probably over kill, but at this point, what's the
difference?
All new
brass expansion plugs and this engine is ready for final
assembly at Erik's.
A better
view of the new pistons and the sealing groove surrounding each
cylinder.
Nice view
of a finished deck and block assembly ready for the trip to
Erik's.
A special
thanks to Bob Mason for a terrific job and the highest standards
of
quality and workmanship throughout this entire machining
process.
Mason's Racing
Engines
53 Hartford Avenue
North Scituate, RI 02857
Toll Free 888-235-1622
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