harleyKmodel

Digit stamp on KR heads...

It refers to the various versions... 1 in 52 till 7 in about 67. Most variations are on the angled shelf...

And not all KR heads are stamped, so it's a real muddle...

So, nothing to do with compression ratios.

I seem to remember the last version, 8, is the special ""shelfless"" hear for the dome pistons.

As the shelf is a necessity on a side valve to reverse the flow properly, it is generally assumed that #8 is not the best set up despite the rise in CR.

Reiman's 149mph average qualifying run around the Daytona bowl in 1968 was done after his father swapped the dome engine for Roger's twin Tillies flat track engine with "7" heads and flat pistons

Patrick

So Patrick, is the 7 head the one with the most common angled shelf that most of us instantly recognize as a KR head?

Thanks

LDB

I don't have any KR heads, just a magical lonely NOS 55R cylinder and a few loose bits, 1/4 speed pump and the like, but seen a lot of head sets from photos via ebay or sites/blogs...

They all look the same to me and they all have a straight and angled shelf, never seen anything like the rounded one marked 60R in the previous photos...

So the differences from 1 to 7 are minimal...

But then, some people never believed the factory and the amount of data it was able to coherse/collect from all the factory dealership and their KRs, so these outsiders went their own way and thought they could design better than the factory!!!

Record books show they never won anything to show for their efforts...

By the way, if some of you are wondering where my KR site's gone, its server either went bust or has shut down...

A good friend is helping me setting up a new one...

Patrick

thefrenchowl wrote:By the way, if some of you are wondering where my KR site's gone, its server either went bust or has shut down...

A good friend is helping me setting up a new one...

Patrick

Thanks for that, was wondering what happened to the site.

Slightly off topic from the KR heads discussion, but can anyone tell me what the difference between the XLR cylinders and stock sportster cylinders is? I know XRs had fewer fins, and know the differences in the heads, but can't think how the cylinders may have differed...

I think the pistons are a bit more slack in them, that's it...

So cylinders that would let oil pass shortly after ran if used on street models.

Patrick

I was looking at the 69R heads and that relief style is used by the famous Navarro company in their Flathead Ford performance head.

Hi all, I bought this NOS valve marked as WR in the picture at the Sunshine Chapter meet in Florida. It was in an original Harley box marked 18070-41R but the box had been opened so not 100% sure if it is the valve that came in the box. I have reason to believe that it is the correct one but one never knows when you have an open box. These intake valves were used on the early KK's, WR, KR, KRTT and KHRTT. The diameter of the head measures 1.755". The top has been machined smooth making it pretty thin. The stem has a tapered end unlike the standard K or KH valves. Can anyone out there verify for me if this valve is in fact the 18070-41R valve? If this is the correct valve did they use a standard 45 valve and mill it down to make it lighter? Patrick, I looked on your website but couldn't find any diameter size for a WR intake valve but you must know what it is. Thanks for any help. Stan

No Stan,

I don't have a wr valve to check.

I know my KK had them in and the only note I made at the time (1996...) was that from KK to KHK, the exhaust valve got smaller by approx 1mm while the intake got bigger by about the same amount, 1mm.

I don't remember them WR valves being waisted... They also had the WR keepers, quite lightened...

Can you put a picture of the waisted stem?

All KRs after 1954 got these waisted stems as an option. Stem diam. goes from '399 to a proper fraction, 5/16 for a bit more than 1", in fact 29mm, 1"141.

Patrick

Patrick, The waisted stem as you call it is in fact 5/16" or .312 in diameter and roughly about 1 1/8" long. The main part of the stem however is .339" on both the WR and the K valve. Are you saying that KR's and WR's had a valve stem diameter of .399" ? By using the information you gave that the intake valve got bigger by 1mm from the early KK to the KHK it puts the diameter of the valve I have almost right on. 1mm = .0394. If you ad the .0394 to the 1.755 that the valve is that I have it comes out to 1.794 which is pretty close to the KH valve diameter that I have pictured 1.807. Only .013 off and could well be within the margin of error.