So I recently got myself a 1953 harley. Trying to get started on restoring it. from what i know it is a flatty that's been converted to OHV and has old ironhead top end on it. i would like to rebuild the engine but i dont even know where to start as far as getting parts. The top end has 16561-57 the bottom has 53 kr m1752. Any info i can get would be great. No pictures yet but if you go on youtube and look up 53 harley bobber you can see a video of the person i got it from kicking it and riding it.

Thanks,
Steven

 

The K Model was first made in 1952. This was a 45 cubic inch flathead (or side valve is the official name type).

The KR was a similar engine being 45 cubic inches but the difference of a KR compared to a K Model is the KR has a lot of roller bearings and needle bearings where the K Model has bushings.
The KR was the racing engine used on the dirt tracks and road races back in the day. First made in 1953.

So it sounds like some has taken a KR and put a Sportster top end on it having overhead valves.
This has been done before by others but is a hybrid for sure.

Some of the questions I have are as follows:
Since the KR is 45 inches (750cc) and the Sportster is 55 cu inches (900cc)......
What connecting rods were used?
What pistons were used?
What was used for push rods?
What was used for pushrod tubes?

I am thinking it must be Sportster rods, pushrods and cams, with a KR lower end and cases?
But I am not sure.
You basically are going to be using parts for a K Model for the bottom and parts for a Sportster for the top end.
The middle parts are going to be what ever it takes to connect the two areas together. So you are kinda on your own here.
Post a pic of the bike if you can.
Videos do not interest me like a photo would.
Here is a pic of my old 1955 KR dirt tracker. Your bike once looked just like this if it is a KR and was a dirt track machine.
If it was a TT or a road race machine, then it would have a swing arm frame, not the rigid frame of a dirt tracker......



pg

 

thanks. i will have some pictures shortly. I am very excited about this project.

 

When you take some pictures......
If possible, show a shot of.............

The pushrod covers and lifter bases.
The cast part numbers of the cylinders ( on the cyl bases on left side)
The right and left side view of the engine
The engine serial number on the left side of the cases just below the cylinder bases.
pg

 

http://www.flickr.com/photos/73465501@N07/ but thats where you can find them

 

It appears that the suffix on the cylinder part numbers ends with -59?
If so, then the cylinders are 1959 Sportster, or later and are 900cc in size. That will mean the the connecting rod assembly is also Sportster.

I could not see what your pushrod covers and lifter bases look like but I have to assume they are the chromed tubes for a Sportster also.
So, you have a K Model lower end matched to a Sportster upper end. Nice combination.
pg

 

So if i wanted to start doing an overhaul where do you think i should start looking for parts and how hard is it gonna be to find them. and is the lower end a krm?

 

This book, if you can find a copy, has some interesting reading about the old krm. Even the free available pgs in google are good to get you started. A bit of a shame the bike was changed over to the OHV.

http://books.google.ca/books?id=7KfX...%20KRM&f=false

Parts are available online ebay, J&P Cycle and others...google will help with that or search build threads and read what others have done. Buy quality name brand parts not cheapest available. Many parts are made in Asia. They are cheap, generally poor quality and are even sold in HD dealerships. Look for names like Kibblewhite Precision, S&S, colony...to name a few that are made in North America....you get what you pay for.

A quick glance through the J&P cat. turned up parts listed for the K models. Your bike has been modified, though, so it is anyones guess what else has been changed besides the obvious....won't know until you start looking. The big difference between the K and early 900s is the top end and yours has been changed. (Don't start thinking the bottoms are the same, though...as you may find out if it starts dropping out of gear. Sometime in the mid 50's a trap door was added for ease of access....but 53 sounds a bit early for that)

I'll be following this build. post lots of pics as you go. love the old stuff. nice find

 

I'd be watching ebay for an old K frontend, rear fender, shocks and top end and collect this stuff together to rebuild it as a K again someday.

 

http://www.flickr.com/photos/73465501@N07/6638698477/
The lower end is 53kr m1572
http://www.flickr.com/photos/73465501@N07/6638705551/
http://www.flickr.com/photos/73465501@N07/6638706881/

Thanks for all the help so far,
Steven