JerrryR wrote:Hi All,
I've had some questions about K cams for a while now and was hoping to finally get some closure on the topic. What has prompted me to write about it now is a friends recent purchase. He bought a KRM motor (in parts). It came with two cams simply marked 1 & 4 and two marked 2KR & 3KR. Here are my questions or assumptions.
1. The KK cams were simply marked 1 through 4?
2. The KHKs starting in 54 used the KK cams?
3. The use of the KK cams marked 1 through 4 continued for the 55KHKs?
4. Probably for the 56KHK since it was a floor model Harley started marking the cams with KHK?
5. My assumption has always been that the KK and KHK cams were the same?
6. I couldn't notice a "slope on the #2KR cam I have?
7. Can my friend use the cam set that came with the KRM? Can you mix KR and what I assume are KK cams?
JerryR
Regarding your lobe measurements to determine cam lift, you must also measure the base circle as the maximum lift is the difference between base circle and lobe height. Without measuring you cannot assume the base circle of each cam is the same or was measured the same way. On the angle-ground K Model lobes it is necessary that the lobe height and base circle measurements are made on the same side of the lobe, i.e., the tapered lobe is larger on one side and smaller on the other, thus both height and base measurements have to be made on the same side of the lobe. The image below hopefully clarifies this where the red arrows indicate a satisfactory place to measure both the height and base, as do the black set of arrows. However, you cannot mix and match a red arrow data set with a black arrow data set.
- Measuring angle ground cam lobes.jpg (41.91 KiB) Viewed 15855 times
My ‘56 KHK has the 1,2,3,4 cam marked series in it – not KHK markings. Below are the lifts I get measuring the lobe base circle dia and height with a dial caliper at the largest end (red arrow side). Also in the table are the maximum lifts that were measured carefully in the engine for the same set of cams.
- Lift of KHK cams.jpg (19 KiB) Viewed 15855 times
For the sake of discussion the base circle size measured above was applied to the lobe heights you measured and the resulting lift values are in the table below. I find it curious that the EX lobes are all lower lift than the intakes, which if true makes me wonder if they might be KH lobes rather than KHK? But again, we don't know how or where the measurements on the lobe were made so the lift results in the table below could introduce information that may be more misleading than informative - therefore, proceed with caution.
- JerryR K Model Cam Lifts.jpg (26.68 KiB) Viewed 15855 times
I think your cam images posted above are sufficiently distorted that one should be hesitant to draw any conclusions regarding how any given lobe compares to another lobe. Perhaps you could retake the picture from several feet away and zoom in to minimize the distorted view?