53 KK performance specs?

[Malte]

Hi. I´d like to know if anyone has seen any performance specs for 53 KK?
H-D listed 30 hp for the standard K, i have not seen listed at which rpm this was achived and what was max rpm for the K`s.
Ideally it would be great to know these specs for both these models in order to see what the KK`s hotter cams and lighter valvetrain did as compared to the K.

[duffeycycles]

Enough HP to win 4 National Championships with 52KKX8-Carol Reswebber-the Duck Bike

[thefrenchowl]

Hi Malte,

I'm quite ashamed to say I used to have a 53 KK as well as my 54 KHK some years back... At that time, my KHK was also on the road, so nice comparisons could be had

The KK was 90 % OEM and original, only been repainted twice and only 3 riding owners. It was OK, but acceleration was bloody slow despite the race cams which are the same as the KHK.



It would, with the std K bars, do 90/95 mph all day long and I was forever trying to start races with Evo owners, but you never saw such a bunch of wimps and saddos plodding along at 50mph and wetting their pants...

The KHK is nite and day really next to it, it just goes as well as any early Sportsters, so quite strange what a stroke change can do...

The KK still had the M53 carb, it was starting well and did not seem to have any flat spots, but it drank gas like no tomorrow.

The KHK was already on twin carb, either twin Spanish square Amals, ugly, or twin Tillotsons which, believe it or not, was a very good set up...

Morality, KHK is loads better.

Sold the KK to a friend of mine in London who's not a petrol head like me and he uses it as a commuter bike, quite happy with it, it is still faster than the usual/useless WLA or C flattie...

Duffey, that KK went through the hands of Ralph Berndt, so not much KK left in that one!!!

The main differences between K and KK are the cams' durations and a bit of work in the heads to give room for the higher lifts ( K cam lift is .275 thou (7mm), KK/KHK is .375 thou( 10mm)

Patrick

[Malte]

Thanks for the input Patrick!
That`s really a surprise to hear that acelleration was slow, but there you go.

[sportsterpaul]

So this brings up the question-- should I put the KH flywheels I have into the 1952-K-model engine I got in once piece off eBay? My first concern would be tranny gears-- that the KH wheels would disintegrate the gears if they are still 1952 versions.

I might use the KH wheels to make a Sportster stroker, I hear they are 74 cubic inches. Then again. S&S wheels are probably a lot better than factory flywheels.

[thefrenchowl]

Paul, don't even try, you need half the difference in stroke as stroker plates under the K cyl and I also know but can't say I've seen it, one bolt in the K case was allegedly moved to accomodate the longer stroke, so you'd be better off with a set of KH cases...

K and KH trapdoorless cases do not have the same part number and I read somewhere that's the difference, 1 bolt location...

Also, as soon as I saw the original untouched never updated gear box cluster in my KK, I swapped it for a Sportster one... Better safe than sorry... ; - )

It is so lightweight as being unbeleivable... Everything, selector forks, gears etc SO SKINNY... No wonder it took 2 or 3 years to sort out properly...

With std bore, you'll only get a bit over 61 ci out of a KH 60's Sportster strocker. 74 if you find Dytch cylinders for 3"3/16 bore or on post 71 Sporty...

And my KHK std cast iron crank saw 9 Bonneville 2 miles runs at well over 107mph and just short of 122mph before it twisted a touch, but it did not break, just vibrated a lot more... drive side crankpin taper/nut got a touch loose...

Patrick

[sean]

i just went thru a 52 tranny build,i went with the 52 gear set,flywheels and rods.,i did a hardness test and everything was in the 60 rockwell range.the problem they had was soft gears and most bikes were recalled for a gear swap.check the hardness to make sure you have the later replacement gears.i have a spare motor in pcs with 52 cases but 54 and later gear set and aftermarket flywheels with 52 rods...i did notice the different sizes in the sprocket shaft between 52 and 54 related the use of a 54 and later comp sprocket assy, and wasent sure the 52 primary cover would bolt down due to the longer sprocket assy so a 54 and later primary would need to be found. ..so take that into account when wanting to use 54 and later stuff in the 52 cases.it snowballs.

[hennesse]

Malte (from Norway) recently joined our group, and besides asking questions, he's already contributed some cool photographs of Dutch Police on KHs. One is of some policemen escorting Haile Selassie, Emperor of Ethiopia - on a 1954 Harley KH (the policeman, not the Emperor).

Check out the Literature page - down at the bottom.

Thanks, Malte!

[JerrryR]

Hi All,
Thanks to all of you for sharing so much information, I have been learning a ton. Patrick mentioned something in this string that I thought perhaps I could contribute a little bit to, the case bolt pattern change from the -52 cases to the 54s. A few years back I bought a basket case 56KHK that someone had matted up a 56KHK left side case to a 53K right side case. The following pictures show the rear case bolt hole moving back slightly on the right side case and also show how if this was to be done some machining of the "Taint" would have to take place to accommodate the greater rod travel of the KH.
Happy Holidays to one and All,
JerryR

Text-53K right side case machined to mate with 56KHK left side case..JPG (98.92 KiB) Viewed 17307 times

Text-55KH right side case..JPG (81.76 KiB) Viewed 17307 times

Text-52 right side case..JPG (87.2 KiB) Viewed 17307 times

[sportsterpaul]

Wow, thanks for the great advice and information. I think I would draw the line at hacking up 1952 cases for KH wheels, that is just too much of a tear-up. I like the idea of putting it together with -52 gears, if that is what is already in there-- as long as they Rockwell out hard enough. If I was going to ride the bike on the freeway I might slap in a set of Sportster gears, while keeping the originals in a box should I ever sell the bike.

Then again, maybe the gears are not as delicate as I fear, and as long as I keep original power, then that is not enough power to break anything. I do not burn out or abuse my machinery-- so it might last.

Then again again, I now realize I have to split the cases to work on the tranny, so maybe strong gears are a good idea. I will see what is in there, and let you folks know.