only saves the expensive honing stones, but it also produces less
heat in the process and he has seen bores glaze and wrap when
only honed. He has 40 years under his belt and looked like he
could do the job with his eyes closed. Each bore was repeatedly
measured throughout the process to ensure it was being machined
straight. Thankfully our block was square and each bore true and
unwarped, so it wasn’t too much drama.
Next it was bolted into the honing machine where it underwent
a three stage hone process using 120, 240, and finally 400 grit
stones. If you were to look at the bores under a microscope you
could see the steel of the liner has been torn during the machining.
The honing removes this and leaves a cross hatch pattern on the
bores, for the ring to bed into. Dieter prefers a 35-40 degree hatch,
but the machine is adjustable.
Once all the machining had taken place, the block was
cleaned thoroughly to remove any swarf or cutting fluid. Cleaning
is a huge part of engine building and if not done properly it could
destroy a new engine in seconds.
In the next issue, we will cover off the final pieces of pre-
assembly, the head work, and the final bolt together of the long
block, so check back to see it all come together.
The first
step was
to machine
each bore
leaving 4-5
thousands
of an inch
for finish
honing