EKHKHK56 wrote:Yours appear to be shaved, see the deck broaching is not perfect smooth factory looking to me. With no head gasket the surface should be perfect.Erik
How in the world can you make a comment about being shaved and the quality of a machined finish from a crappy photo that provides no clue as to the gasket surface height or finish? The gasket surface is in fact perfect and looks no different than if someone just fly-cut the raw casting today.
- LR NOS KHK head seal machining.jpg (100.07 KiB) Viewed 1867 times
Likewise, the head is not shaved and the sealing surface is a full 1/8” proud of the bottom fin everywhere.
- NOS KHK gasket surface.jpg (34.46 KiB) Viewed 1867 times
If one considers the condition of the spotted head being shown here, it is easy to envision how a skilled worker with a die grinder fit with a burr, a sanding roll, and a polishing roll could make the spotted head combustion chamber into a fully polished KHK head in about 5 minutes. And of course, the polishing provides no functional improvement, but does allow a marketing claim about "polished ports and heads" to be made in the sales literature.
I have never contended the spotted heads were K, KH, or KHK, just that I was aware of 2 different machining operations (spotting and full machined) that were employed to create valve clearance in K model heads, and that I had NOS heads that had polished exteriors, which suggests to me they were KHK heads. Like we all know only too well, at Harley changes occurred continuously, some documented, some undocumented, and I still suspect the spot machining was the intermediary version of machining employed to deepen the IN pocket and that the fully machined chambers were the final machining iteration, along with polishing to finish the part, and this variant was employed by the time of the later KHK models.
I dug out another few spotted heads and found 1 had polished fins and the other 2 were unpolished fins. As suggested above, the difference between polished and unpolished is a few minutes of time leaning on a buffing wheel. The wild card in all of it is "when did the polishing occur?", in the factory or after the fact?
- LR Spot machined heads.jpg (53.62 KiB) Viewed 1867 times
Lacking a time machine, we don't know exactly what machining operation or head variant went on what bike. For example….
What bikes were the tall window heads used on?
What bikes were the short window heads used on?
Which of the foregoing 2 heads were spotted and which were fully machined, or could either be machined either way?
When did the fin pattern change from the coarse variant, to the finer variant, to the discontinuous fins around the sparkplug hole to fins fully encircling the spark plug hole?
Were there high window and low window head versions where fins fully encircled the sparkplug hole?
What chronological order did all of the foregoing changes occur in?
Looking through the "Gallery" here in the website there is certainly no shortage of mismatched cylinder heads out there on the bikes shown.
I’m happy to leave it at that, and say we know some answers, but we'll never know all the answers.
