53 KK performance specs?

[thefrenchowl]

Thanks Jerry, real good info and photos...

I did read it somewhere, but until you see it, it is hard to be 100 % sure if it is fact or bull!!!

The other big difference from K to KH right case is that the face of the crank cavity is all machined flat on the KH to give room for the crankpin right nut... K/KK cases have a cast protuberance there similar to the WL right case to give more length to the camshaft left shaft...

Patrick

[JerrryR]

Patrick pointed out:

The other big difference from K to KH right case is that the face of the crank cavity is all machined flat on the KH to give room for the crankpin right nut... K/KK cases have a cast protuberance there similar to the WL right case to give more length to the camshaft left shaft...

So here are the pictures showing what he described.
Take care,
JerryR

52k Showing Lack of Machining..JPG (87.97 KiB) Viewed 15876 times

55KH Showing Factory Machined Surface.JPG (86.5 KiB) Viewed 15876 times

53K Right Side Case with Machining to Mate with a KH Left Side Case..JPG (88.08 KiB) Viewed 15876 times

[Hammie13]

My first Kmodel was a '53 K,it had the bombsight carb and KH cams and I rode the snot out of it. It had great low end grunt and could run at 70 mph all day. I busted a clutch cable one night and had to ride it 28 miles bang shifting it until I got to the freeway for the last leg of the ride. I down shifted it,up shifted and never had any trouble the next 2 years until I traded it for a fugly Panhead that blew up a month after I got it.

[sportsterpaul]

...bang shifting it until I got to the freeway...

Oh man, shared experiences. I hear ya brother. I remember my first clutch cable break. Same thinking-- "hey its a Harley, with low-end torque, who needs a clutch?"

Paddle paddle paddle my fat feet, until bang, its in first. After that all the other shifts were pretty easy. Its amazing how many right turns you can make on the way home if you need to never stop. I did have to make one stop-- but paddle paddle stall, and then paddle paddle paddle thunk and I was off again. It was worse than when I had both brakes fail, then you can always turn the engine off, and those right-hand turns come in handy too.

So after the clutch cable break, I started carrying a Leatherman Crunch in my jacket. Its a vice-grip pliers. Its handy when the shift lever falls off, and the Phillips-head tightens the mirrors as does the pliers if you don't mind scarring up the nuts. But the big theory was to clamp it on the broken clutch cable end, and use it to pry out the cable to get the bike into gear. Next cable break I almost killed myself, since I was only hanging on with one hand while messing with the pliers in the other. I put the Leatherman away, and went back to paddle paddle paddle THUNK and got home. Now I just lube up the cable pull so it swivels right and does not break the cable.

If you've got the cohones to push the bike and jump on it sidesaddle like a flat-tracker, then the getting started with a broken clutch cable might not be so hard. The big question is whether you should try to bang it it gear while still sidesaddle, or swing a leg over and then bang it into gear. At least the engine is already running, so that is one less hassle. I keep meaning to try to bump start my 1962, and every time, I just kick it over and am happy for having a kickstarter.

[epinut]

"Zoom-packed"...

[Mayday53]

Thanks for sharing that...cool to look at the old flyers!

[EKHKHK56]

The 53KK would run much stronger than a std K once in the power band. The regular K is much more streetable, or manageable at low rpm and mid range. The KK would come on and run well more on the late mid to top end. For stroker applications, my .060" over 5" stroke BigK is 61.5" and bases on 56KHK cases. The 52 cases are much weaker to start with and use a different pinion shaft bearing. The KHK flywheels and cases use the same or can use the same shafts as Sportster. To use the Sportster gearshaft one must turn the shoulder off the KHK flywheel. It is a stronger shaft with built in shoulder and larger retaining nut. When building a basket KHK one should check the flywheels to be sure the shoulder is still there and not been removed by a Sportster drag racer. I would estimate the 53KK picked up about 4-5 hp over the 52K at the sacrifice of low end and mid range punch. The KHK stroker is a ball to ride. Gear it as tall as possible and enjoy the torque. I used to beat most vehicles across the intersection without trying. Fun fun! Erik K

[Malte]

Thanks Erik K, sounds reasonable what you`re saying. Malte.

[John R]

Nobody answered the first question! My comments are all about stock bikes, not hopped-up or racers. Harleys claimed "about 30hp" for the standard K (that means probably high 20's) at 5,200rpm. The KK perhaps went over 30hp at slightly higher revs. Both K and KK standard gearing was 15.9mph per '000 revs. That computes to 82 mph at 5,200rpm. I was the buyer of Patrick's KK, and the speedo did indeed say 95mph, but it was lying! SatNav said 85. To do 95 would need 6000rpm, and it would need a very well prepared road bike to hold that mile after mile. Still not a full answer but a bit more in the mix.

The KK and KHK are very different engines. The longer stroke and shorter rod-length to stroke ratio of the KHK gives much more low-down torque and nothing is to be gained by winding-up high through the gears. The KK you have to rev the nuts off it to make it accelarate. It's very tractable at low speeds but you can feel it come 'on-the-cam' at mid revs, and you can scream it to good effect!

I took my '56 KHK to the local airfield drag-strip and properly timed it did 16.6 / 78mph in the 1/4. To be honest I was disappointed, expected to be in the 15's. The bike felt strong and clean running but I wasn't doing 2nd gear max revs clutch-dumps. I was thinking of those early fragile cases! But I was pouring it on strong and the photo shows the rear wheel has broken loose at the start. There was a 15mph head-wind though, maybe on a still day...

I will have a word with Patrick about calling me a commuter!

John R

[EKHKHK56]

Awesome John. Yeah my 53KK was mighty fast on the top side. Had J cams in it and wasn't bad at all surprisingly. But we don't have traffic around here. Definitely no low end I prefer the KHK set up much better.