Get a 1945 Harley running again

  • Auto/Motor
  • Thread starter Mark44
  • Start date
  • #1
34,885
6,626
Summary:
I bought a 1945 HD basket case, and am working on putting it back together
My current DIY project is the 1945 Harley-Davidson UL. The engine is a "side valve" AKA flathead, similar to the ones in older lawnmowers. Pretty low-tech, with manual advance points ignition. Not shown in the pictures are the engine, which is missing a lot of parts, but does include a bunch of parts that are too far gone to use or aren't for this bike.
The transmission appears to be in good shape, but I have it all apart for cleaning and replacement of any parts that should be swapped out. The bike came with both wheels and new tires, but was missing the brakes and associated linkages, as well as the clutch, primary chain and drive chain, generator, all of the wiring and control cables, fuel lines, oil lines, and many more parts.
IMG_1955.JPG

The front wheel and fender aren't shown, but I have them. The fender has the same paint scheme.
IMG_1956.JPG

The engine isn't shown. A friend of mine who just retired from a machinist job and who also has a similar bike of slightly older vintage is helping me get the engine back together. I'm hoping that this thing will be running in 6 months, but it could possibly take a fair amount longer. Although the bike is missing a lot of parts, repop parts are relatively easy to find -- all you need is $.
 
Last edited:
  • Like
  • Love
Likes Astronuc, PhDeezNutz, dlgoff and 6 others

Answers and Replies

  • #2
berkeman
Mentor
59,444
9,554
Wow, do you end up having to fabricate some of your own parts though? Fun project.
 
  • #3
Averagesupernova
Science Advisor
Gold Member
3,834
763
Very interesting. Was that originally an army bike? I assume a suicide clutch and the shifter up on the side of the tank? Did it have crash bars on it? Keep the pix coming!
 
  • #4
34,885
6,626
Wow, do you end up having to fabricate some of your own parts though?
Not really, although I'm going to make a small bracket that the horn attaches to.
Very interesting. Was that originally an army bike?
I don't believe so, but I suppose it could have been. Most of the Harleys that were used by the Army and other services were WLA models, with a 45 cu. in. flathead engine.
I assume a suicide clutch and the shifter up on the side of the tank?
I'll be running a foot clutch and hand shift. There's a common misconception about foot clutches, that they're all "suicide clutches." Not so. A suicide clutch is one that works like a car clutch - press in to disengage, let out to engage. What came on this bike, and what I'll be using is a rocker clutch that will stay in either position, unlike a so-called "suicide clutch." My other old bike, a '48 Panhead, came with a suicide clutch, but I swapped it out for a rocker clutch.
Did it have crash bars on it? Keep the pix coming!
No crash bars, but my other old bike has engine crash bars, and the WL I just sold had crash bars front and rear. I will definitely keep the pix coming!

In the meantime, here's my '48. You can see the rocker clutch with its two pedals, and you can also see the shifter on the side of the tank. Once I get the '45 UL running I'll take this one apart and refresh the engine and transmission.
3.11.18d.JPG


My '46 WL, which I just sold. The '45 UL of this thread will look a lot like this one, but with a 74 cu. in. engine instead of 45 cu. in., and with a 4-speed trans instead of a 3-speed.
IMG_1495b.jpg
 
  • Like
  • Love
Likes PhDeezNutz, Oldman too, DaveE and 3 others
  • #5
berkeman
Mentor
59,444
9,554
Wow, nice work Mark! :smile:
 
  • #6
34,885
6,626
I've been working on this bike daily, but not anything interesting enough to show in pictures. When I get the transmission back together and in place, I'll post some more pictures. And when we get the engine bottom end buttoned up, I'll post some of that, as well.
 
  • #7
Averagesupernova
Science Advisor
Gold Member
3,834
763
Heck I wanna see guts!
 
  • Like
Likes Tom.G and dlgoff
  • #9
34,885
6,626
By popular demand (i.e., @Averagesupernova), here are a couple pix of the "guts."
Bottom left: left engine case
Bottom right: right engine case, showing the empty cam chest. This engine has four cams, one for each valve.
Rear: cam chest cover
My machinist friend is fitting new races into the case halves and is working on truing the flywheels in preparation for installing the flywheel assembly into the cases.
IMG_1963.JPG


Most of the transmission, with the case on the left. The stack of gears to the right is the countershaft. The mainshaft is elsewhere but some of its gears are shown here and there. The transmission is a four-speed with what is called a jockey top (not shown). The gear shift is on the left side of the tank (you shift with your hand, not your foot -- the clutch is operated by a foot pedal).
IMG_1964.JPG
 
  • Like
Likes Spinnor, berkeman and Averagesupernova
  • #10
1,123
307
Be prepared to have many babes!
 
  • #11
34,885
6,626
Be prepared to have many babes!
My wife wouldn't like that!
At any rate, when I'm out on one of the old bikes and stop off for something, people will often come up to get a closer look or take a picture. Several people have told me that their dad had one like this.
 
  • #12
Averagesupernova
Science Advisor
Gold Member
3,834
763
Several people have told me that their dad had one like this.
I would be one of those.
 
  • #13
1,123
307
My wife wouldn't like that!
At any rate, when I'm out on one of the old bikes and stop off for something, people will often come up to get a closer look or take a picture. Several people have told me that their dad had one like this.
The flesh is weak!!!!!

Thats amazing that you are into bikes. my interest lies on the opposite side (cars). Specifically, Low Riders.
I never learned to ride a motorcycle, but I was thinking of taking it up when I move to the boonies in Texas.
 
  • #14
34,885
6,626
my interest lies on the opposite side (cars).
I've always liked cars, as well. Over my life I've had 29 of them, plus 8 motorcycles.
I wish I had even one of the old cars I had in the 60's and early 70's - '48 Ford Tudor, '49 Ford Tudor, '40 Ford Sedan Delivery, '41 Chev Sedan Delivery, '56 Ford Sedan Delivery, '60 Chev Bel Air. The most I paid for any of these was $200.
My most recent "hot rod" is an '02 Porsche 911 Carrera, way more hi tech than my old bikes.
 
  • #15
34,885
6,626
I would be one of those.
A guy and his son came up to me one time when I was on the '48 Panhead (1st picture in post #4), and had stopped off at a small store to get a cold drink. The guy asked, "Is that a Victory?"
I said, "No, man, you're off by about 50 years!"
Victory is a defunct motorcycle manufacturer, a subsidiary of Polaris Industries, that produced motorcycles between 1998 and 2017.
Another guy at the same place but a different day, nailed it though. He knew what he was looking at.
 
Last edited:
  • #16
berkeman
Mentor
59,444
9,554
I never learned to ride a motorcycle, but I was thinking of taking it up when I move to the boonies in Texas.
A good way to get an introduction to riding (and how to stay as safe as you can on the street) is by taking a Motorcycle Safety Foundation class. The Basic RiderCourse version does not require that you already have a license, and they provide the (small) learning bikes for you to ride. You can enter the zip code for where you are planning on going to see where the local classes are held.

https://www.msf-usa.org/

1613147848764.png
 
  • Like
  • Informative
Likes Lnewqban, dlgoff and sysprog
  • #17
34,885
6,626
I'm still working on this bike, but it's one step forward, and two steps back. I thought I would be able to use the flywheels that came with the bike, but it turns out that they've been apart too many times, causing the tapers that the pinion and sprocket shafts go it to be too large. As a result, the flywheels can't be trued. When I get further along in the project and start actually putting the motor back together, I'll post some more pix.
 
  • #18
dlgoff
Science Advisor
Gold Member
3,960
1,936
but it turns out that they've been apart too many times, causing the tapers that the pinion and sprocket shafts go it to be too large.
Is the shaft keyed. Just curious. If so, could a thicker/wider key be used?
 
  • #19
Tom.G
Science Advisor
3,821
2,514
And there is always plasma spraying to build up the male part . (:eek:)
 
  • #20
34,885
6,626
Is the shaft keyed. Just curious. If so, could a thicker/wider key be used?
Both shafts and the crankpin are keyed, but the problem is that the shafts won't sit in their tapers straight when torqued down.
And there is always plasma spraying to build up the male part . (:eek:)
That might be a possibiity, but after being built up, the tapers would have to be machined true, and it might be difficult to find a machinist with the ability and the tooling to do that. In any case, the wheels have not been treated kindly during their lives, and have been whacked on with steel hammers, not lead or brass hammers, which are the required tools. Flywheels like that are prone to cracking, or so I'm told.
 
Last edited:
  • Like
Likes Tom.G and dlgoff
  • #21
34,885
6,626
Things are moving along, albeit slowly. The new flywheel assembly arrived about a week ago, and we're getting close to having the bottom end buttoned up. Once that is done, then I can move ahead with installing the pistons and cylinders and heads, and then it will be a nearly complete engine. I'll be posting more pictures shortly, as we start making more progress with the build.

Some of you might not ever have seen a flathead (AKA sidevalve) engine, so I've included a couple pictures. The valves are lapped and installed, and the valve covers are in place.

Here's a pic of the top of the rear cylinder. The front cylinder is more-or-less the mirror image of the rear cylinder. The intake port is at the bottom of the image, and the exhaust part is on the back side, out of view. After the cylinders are installed, the heads will go on. The heads are just chunks of aluminum, with no moving parts. The terminology "sidevalve" arose because the valves are to the side of the combustion chamber, as opposed to being above it, as in overhead valve (OHV) engines. Flatheads are very low-tech.
IMG_1981.JPG


This pic shows the exhaust port and the valve covers, the shiny tubes. The lower parts of the valve covers will be screwed into the tappet blocks that are attached to the right-side engine case. These valve covers are new and are cadmium plated.
IMG_1982.JPG
 
  • Like
Likes 256bits, Averagesupernova and berkeman
  • #22
256bits
Gold Member
3,380
1,413
Are you putting the same pistons in?
Any wear in the cylinders?
It looks like you honed them already.
what's the wear in time for these engines?
 
  • #23
34,885
6,626
Are you putting the same pistons in?
Any wear in the cylinders?
The cylinders showed some wear, but still had a lot of meat on them. The old pistons weren't worth saving, so they are new and .030" oversize. The cylinders were honed to accept the new pistons, with a bit of extra room to allow for expansion. The guy that worked on the cylinders said that they were a very hard ductile iron, and said he had to spend an entire day working on them.
256bits said:
It looks like you honed them already.
what's the wear in time for these engines?
About 300 miles or so, starting with a few short startups just to get the engine up to temperature. I'll retighten the cylinder nuts and head bolts a few times, and then after a few of these heat cycles, I'll take the bike out for short rides at no more than 30 - 35 mph. At about 300 miles I'll change the oil, and the engine should be fully broken in.
 
  • #24
34,885
6,626
Things are moving along with the bottom end nearly complete. Here's a pic of the cam chest with its four cams (gray gears), which are behind the cam gears (the four to the left). The cams and gears have to be installed in a certain position relative to each other and to the pinion gear, the small gear below the four cam gears.
---------------Rear exh. ------------Rear intake --------- Front intake ---Front exh.-----
IMG_1983.JPG


Here's a shot of the right side of the engine, with the cam chest cover in place. It's not on for good just yet -- I'm checking the endplay on the cam gears, which can be adjusted by adding or removing shims.
IMG_1984.JPG


Here's how the engine looks at the moment. The scavenge pump (at bottom of case) is installed and correctly timed. Its main function is to return oil from the engine sump back to the oil tank, but it also serves to let air in and out of the crankcase as the pistons go up and down. For this latter reason, it has to be installed with its gear drive in the proper relation to the pinion gear.
The tappet blocks and tappets are installed. They are just above the upper curve of the cam chest. The tappets ride on the cams, causing the intake and exhaust valves to open and close. When the generator is installed (it goes in the hole at the right, I can button up the cam chest, and install the motor in the bike frame. Then I'll be able to install the cylinders and pistons and heads, and put on the intake manifold and carb.
Tappet ---------Tappet -------------------------Tappet ---------Tappet
IMG_1986.JPG
 
Last edited:
  • Like
Likes Tom.G, Averagesupernova, berkeman and 1 other person
  • #25
70
83
My dear ol Dad was a bike enthusiast. And after he recovered from a terrible accident he went with *big* bikes. According to him that way he could reciprocate the favor if somebody hit him head on again.

The poster who mentioned riding in rural Texas, I have to warn you. If you're waaay out in the dingweeds on a good freeway system and you see an oncoming tractor-trailer rig coming the other direction you should immediately go over to the far right and start slowing down. If not, a big rig going 80 to 100 mph passing you close aboard in the opposite direction has enough air draw to make bikes the size of a KZ1000 spin 180 degrees, even at comparable speeds.

One best be a competent rider when you get a "think fast" moment like that.

Happen to my Dad on the Northern Route freeway systems. (Through Idaho and the Dakotas)
 

Related Threads on Get a 1945 Harley running again

Top