KH with KR heads

[Flathead fathead]

I was told that some early KHKs had KR heads from the factory due to a a shortage of KH heads (heads were not done for the early models or they just didn't make enough). Can anybody confirm this or is this just gossip. Also is this why production numbers were so low for the '55 KHKs. Any info would be helpful this is my first K Model and I'd like to be as educated as possible.

[kitabel]

Never heard that.
Not likely, the KR chamber volume is much smaller.

[Flathead fathead]

Do KHKs take a long reach or short reach plug? Do the casting numbers end with -52R on both heads?

[JoJo357]

Howdy, did you ever check out this site Flathead fathead?

www.harleykmodel.com

*M.A.D.*

[Rubone]

Never heard of or have seen anything to remotely suggest that. As far as production numbers there were actually quite a few 55KHK models relative to overall KH production. Same in '56. Several things to keep in mind. There was a worldwide recession going on in the mid '50s, even H-D big Twins sold as low numbers in those years. And the K series was not as big seller for H-D as they would have liked. My 55KHK is a relatively early production number and has normal KHK heads from the factory. I am the third owner and every bit of it pointed to no changes from original parts (other than the Indian Scout pistons in it!) and a blown out transmission case!!

[Flathead fathead]

I checked the K Model website no info but I did register and will ask there. As far as production numbers I found a couple sites that said there were only 449 KHKs made for 1955 compared to something like 1600 made in 1956. (Of coarse I can't seem to find those sites this morning) 1956 was the year of the famous Elvis photo, I'm sure that didn't hurt K Model sales. I don't know how many people owned this thing before I got it so who knows what's been changed, but all the numbers would indicate an original early production model.

[Bubbalowe]

Never heard of or have seen anything to remotely suggest that. As far as production numbers there were actually quite a few 55KHK models relative to overall KH production. Same in '56. Several things to keep in mind. There was a worldwide recession going on in the mid '50s, even H-D big Twins sold as low numbers in those years. And the K series was not as big seller for H-D as they would have liked. My 55KHK is a relatively early production number and has normal KHK heads from the factory. I am the third owner and every bit of it pointed to no changes from original parts (other than the Indian Scout pistons in it!) and a blown out transmission case!!

Scout pistons? Interesting.
I heard years ago that Gravely tractors used
a piston dimensionally the same as a K.

[kitabel]

The Sport Scout Bonneville piston's compression distance may be similar to the K (the standard Scout is to the 45) because of the pop-up design, but +.130" oversize at 2-7/8". The piston pin is of course smaller.

[Rubone]

The cylinders were so thin the spigots were like paper. Cylinders have been since replaced.

[Flathead fathead]

Production numbers for the KHK; 1955=449 and 1956=714

[Coolbreeze]

Do KHKs take a long reach or short reach plug? Do the casting numbers end with -52R on both heads?

Usually, short thread. A prior set of heads had plug inserts that were fairly long; so, it made sense to use long thread plugs with those heads.