Thought I would have gathered some info on this K head by now. My parts books don't provide any info on the casting number and my memory doesn't serve me well, not even from the two KHK's I owned in the past. Pa
Hi Pa, I believe these are just later model K/KH heads (maybe from 54 or so onwards once the casting had been finalised?), and standard castings. I wondered for a while whether this casting number indicated KK/KHK relieved heads as I have seen some NOS heads with non-standard relief work (and see in the parts books that heads were part of the performance package), but haven't seen enough close enough to substantiate this and doubt it. Harley casting numbers aren't always part numbers as we know and this number isn't in any book I've seen for K/KKs, KH/KHKs, or KRs. How do your heads look? I'm sure Patrick, Mike, Beachdog or the others who have seen more of these bikes might be able to shed more light on it for you when they have the chance!
Appreciate the reply Bro. I only have the one head. It really belongs to my Ole Lady and I haven't a clue what her plans are for it. The chamber is in mint condition with no cracks or signs of repair but someone ground some of the forward fin stock, between the fins, away. I assume they did this for better airflow. I post a pic of this head in the near future. Pa
Here are a few pics. All I really know about it is it's a rear. I did find an inperfection after closer observation in the chamber area. Between the valve areas, against the chamber wall, is, what looks to be a casting flaw. If it is a crack, the cylinder mating surface doesn't agree. It is super flat. Pa
Yes, std K/KH casting. As cast combustion chamber. KK and KHK heads were milled deeper for clearance needed due to the higher lift cams
The cracks were another well kept secret from the factory... Everybody knows ALL the K gearbox must've exploded at some stage, but nodoby ever had a bad word to say about the heads, which mistify me as their propency to crack is second to none...
Due to the sharp transition edges between vertical walls and top around the valve area. I blame the double deck fin as well which probably induced unsufferable stresses when the engine stops and cooling occurs...
You've never seen a KR head cracked cause these sharp edges were relieved for more flow and lots of race guys in the 60's milled away the double decker fin!!!