Vintage J-Model Whizzer

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All I can say is WOW, that cylinder got new life. hey, can a guy get one of those valve spring compressor, maybe? can't hurt to ask can it. Thanks.

Ray
 
Paula,
Just amazing workmanship! To the reader, it all looks so easy, but like a skilled surgeon, that detailed work comes from years of working at your craft. It's fair to say that the original whizzer motors when first made did not recieve the level of care that you lavish on your engine. The rest of the bike is going to be a stunner if this engine rebuild is any indication!
Take Care,
Mike
 
All I can say is WOW, that cylinder got new life. hey, can a guy get one of those valve spring compressor, maybe? can't hurt to ask can it. Thanks.

Ray

Hi Ray, you know it wouldn't be a bad little sideline project at that -- making Whizzer valve spring compressors -- seems like they would sell pretty well if they could be produced reasonably enough. Unfortunately, I've got more projects lined up now than I can shake a stick at. But fortunately it's not all that difficult to remove/install the valve keepers without the tool.

Paula
 
Very good, will look forward to the next project!! Thanks

Ray
 
Paula,
Just amazing workmanship! To the reader, it all looks so easy, but like a skilled surgeon, that detailed work comes from years of working at your craft. It's fair to say that the original whizzer motors when first made did not recieve the level of care that you lavish on your engine. The rest of the bike is going to be a stunner if this engine rebuild is any indication!
Take Care,
Mike

Thanks, Mike, it's always nice to hear positive feedback! I just hope I can stay on track with this project. I have a tendency to get into one project, and then see something else that I'd like to take on, and I'll go running off in another direction. I do manage to finish things, but it sometimes involves numerous stoppings and startings.
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Paula
 
Needle Bearing Crankshaft

Hi again,

On first disassembling this engine, I was rather surprised to find that it was equipped with one of the optional needle bearing-type crankshafts. I don't think that the previous owner was aware that his engine contained one of these rare upgrade items, otherwise he would have been asking a higher price (The needle crank seems to be a desirable item among Whizzer enthusiasts.)

In the early fifties, Whizzer contracted with a German manufacturer to produce a multi-piece crankshaft incorporating a captive needle or roller-type bearing for the crank journal. Presumably, the optional crank offered increased performance potential over the standard one-piece, insert-type crank (and perhaps a measure of cachet. :cool:) The needle crank required the use of a special connecting rod, designed to clamp around the needle bearing's outer race. Metric cap screws are used (M6 x 20MM long,) the heads being cross-drilled for a retaining wire.

Removing the crank from my engine, I found it to be in good shape visually, but the needle bearing race seemed to have an excessive amount of clearance, indicating a good deal of wear. Checking it with a dial indicator showed a clearance of about .005", which I deemed as excessive for re-using in an engine that was being rebuilt. In order to return this crank to factory specs, I would need to acquire the tools and expertise needed, or hire the work out to someone else. What to do...

As I was trying to make up my mind, fortune intervened: An original Whizzer needle-crank service tool came up for sale on eBay. This was more than a tool-lover like myself could resist! Even though I could have had someone else rebuild my crank for much less than the cost of the service tool, my hunger for the experience of doing it myself carried the day. I know enough about myself to realize that this is a major driving force in why I do this kind of work. It's not just the prospect of achieving an end result, but the joy in mastering the challenges of the experience itself.

Anyway, I did wind up purchasing the Whizzer needle crank service tool. It was not in the best of shape, but looked to be mostly intact. There were some parts missing that would have to be replaced or re-made. The pressing screw turned out to be seized up. Missing parts included the indicator bracket assembly (and of course, the indicator itself), the "tommy bar" (the long sliding handle for tightening the screw), the centering pin, and the spreading wedge. Here's a "before" picture of the tool:

TOOLB4.jpg


As I pondered possible approaches for restoring the tool to usable condition, fortune intervened once again. As it turns out, I had already purchased numerous parts for this project from a gentleman by the name of Chuck Gatto. It seems that he noticed that I was the one who had bought the crank service tool on eBay, recognized my user name from our parts transactions, and contacted me to offer information and advice (the story is actually a little more complicated than that, but not really worth going into here.) Chuck has a lot of experience with the Whizzer in general, and with needle crank servicing in particular. In addition, he has a helpful nature, and offered to provide any information I would need to reproduce the missing crank service tool parts, as he owned one himself.

Chuck carefully measured the indicator bracket components from his crank service tool, and mailed me some dimensioned sketches -- at his own expense. He also included dimensions for the tommy bar, and... A COPY OF THE ORIGINAL WHIZZER SERVICE BULLETIN for the "Crankshaft Disassembly and Concentricity Checking Tool" (Bulletin #42, June 1, 1954). Talk about a helpful guy! (I should mention that Chuck gave me permission to use his name in relating this story.)

The major components of the Whizzer needle crank are held together by medium-to-heavy press fit joints. While assembly of these components can be readily handled with conventional pressing machinery, disassembly requires special provisions. The needle crank tool provides this capability, and in a fairly simple manner. One side of the tool is equipped with a slotted plate to support either of the crank webs whilst the pin is pressed out with the screw. An additional feature provides a means to for checking the alignment of the two crank halves.

The tool I purchased was well-packed for shipment, and arrived in good shape. Soon after, I set about disessembling the tool for refurbishment. As mentioned, the pressing screw was seized in the threaded body hole, and it took a good bit of effort to extract. The threads on the screw were ok, but some galling of the female thread was evident. Fortunately, the machine shop at the company where I work had a M16x1.5 tap, and I was generously allowed to borrow it for cleaning up the galled threads.

After receiving the dimensions from Chuck, I set about making the parts for the missing indicator bracket. I also ordered a new dial indicator. The indicator bracket is not a difficult or complicated assembly, but I wanted to reproduce it as close as possible to the original, to help preserve the value of the tool. Here is what the finished indicator bracket assembly looked like before black oxide:

TOOL1.jpg


The original tommy bar had a metric diameter, so I had to turn the replacement from a larger diameter piece of cold-rolled steel. The body casting itself was bead blasted to remove rust and old paint, as were some of the other parts. Some parts only required moderate wire brushing. The body was painted with several coats of a grey oil-based enamel, while some of the other parts would be sent out for black oxide treatment. The centering pin was made from a "G" size high-speed steel drill blank (.261" dia.), which just happens to be the right size for a close slip fit in the crank journal through-hole. All I had to do was grind a 60 degree point on one end -- same method as used earlier to reface valves. Here's a picture of the finished tool:

TOOL2.jpg


(to be continued...)
 
Needle Bearing Crankshaft (continued)

Okay, now that the crankshaft tool is finished, it's time to replace our needle bearing. It takes quite a bit of torque on the screw to press out the crank pin, so mounting the tool in some kind of sturdy vise is almost a necessity. A sizable "foot" protrudes from the bottom of the tool for exactly this purpose. I used the vise on my milling machine to hold the tool, and it worked out fine. Also, it's a good idea to make some kind of provision to catch the needles once they have been freed from captivity, and want migrate about the surrounding area. I elected to use a shallow plastic pan lined with a shop rag, placed in close proximity to the vise.

With the screw backed out a sufficient distance, place the crank in the tool with the flywheel (long) end sticking out. Run the screw in by hand until it contacts the crank pin. Then insert the tommy bar (handle) and begin driving out the pin. It took some unladylike grunting, but ultimately the crank pin surrendered. With one hand turning the screw the last few turns, use the other hand to catch the free end of the separated crank:

CRANK01.jpg


Back out the screw by hand a sufficient distance, and remove the remaining half of the crank from the tool, along with the outer bearing race (if it didn't fall out on its own). Now place the other half of the crank in the tool, with the crank pin facing out. Like before, run the screw up by hand until it contacts the crank pin, then insert the tommy bar and begin pressing out the pin. Use your free hand to catch it as it emerges from the crank:

CRANK03.jpg


Before proceeding further, a word about lubricating the crankshaft tool's pressing screw... The forces generated in pressing out the crank pin are substantial, and generate a high friction load on the screw. Given that the screw was galled and stuck in the body when I acquired this tool, I decided to reassemble using a high performance lubricant. I used "Saf-T-Eze Moly Grade Anti-Seize Lubricrant" maufactured by Saf-T-Lok. It is a NLGI grade 1 grease containing molybdenum-disulfide, lithium, and graphite. It is designed to withstand pressures of a half million PSI(!) Highly recommended.

With that out of the way, we can proceed to reassemble the crankshaft with the new crank pin, needles and outer race. First step is to press the new crank pin into the flywheel side of the crankshaft using an arbor press (as I did), or alternatively, a bench vise with the jaws relieved to clear the ends of the crank pin when fully seated. I coated the end of the pin and the inside of the hole with a heavy oil prior to pressing. Press the pin into the crankshaft hole, firmly seating the pin's shoulder against the inside face of the crank half:

CRANK05.jpg


Assemble the (24) needles and outer race to the crank pin. I used a bit of teflon grease to help keep things from moving around too much (more important if using a vise to assemble the crank, since the crank pin is horizontal):

CRANK06.jpg


With the crank pin end and crank hole lubricated as before, place the assembly in the press. Align the other crank half over the hole, and insert the alignment pin through the hole in the crank so that it seats in the corresponding hole in the lower crank half. This provides a rough alignment of the crank ends prior to, and during, the pressing operation. The picture below shows the alignment pin, lifted slightly by me to show the pointed end:

CRANK07.jpg


As before, press the assembly together until the upper crank half is firmly seated against the shoulder of the crank pin. Afterwards, check to make sure that the outer bearing race rotates freely. I checked the radial bearing clearance on my crank after assembling with the new parts, and it was in the range of .0010-.0015", which seems about perfect to me. Yay!
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CRANK08.jpg


(to be continued...)
 
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Needle Bearing Crankshaft (continued)

Now it's time to use the "concentricity checking" feature of the crankshaft tool to precisely align the two halves of the crank. With the indicator bracket in place, but swung out of the way, insert the assembled crankshaft in the tool with the long end down. Adjust the indicator bracket such that the indicator tip rides against the the upper crank journal, and the indicator stem's centerline approximately intersects the center of the crank journal:

CRANK10.jpg


It's important to realize that there are two principal ways in which one side of the crank journal can be misaligned with the other. The first could be called "radial" misalignment, and is checked with the indicator set approximately as above, and 180 degrees therefrom. If we consider the crank journals to be the center of a clock, and the crank pin as the 12 o'clock position, then we are looking for readings at the 3 o'clock and 9 o'clock positions. The difference in indicator readings at these two positions gives the amount by which the centers of the two crank journals are "rotated" from true alignment. In my case the amount of misalignment was around .005". Correcting the misalignment involves a bit of trial-and-error.

By rotating the crankshaft back and forth between the two points mentioned, decide which direction the upper crank half needs to be rotated to achieve alignment. I found it helpful to draw an arrow in the upper half with a magic marker, indicating the required direction of rotation. Swing the indicator out of the way, remove the crankshaft from the tool, and, holding the long end of the crankshaft in one hand, use a soft-faced hammer (brass works great) to smack the side of the upper counterweight, such that it will be slightly rotated in the required direction.

One needs to develop a "feel" for this process; a muscular awareness of how hard to smack the counterweight to produce the desired amount of movement. It may take some time, and tedious back-and-forth movement, to develop this feel. But after a while, you should be able to get the alignment within .001", which is acceptable.

The second type of possible misalignment could be called "parallel" misalignment. It is when the two crank journals are at some slight angle to one another (even though they may be "radially" aligned). Check for this condition by noting indicator readings at the 12 o'clock and 6 o'clock positions:

CRANK09.jpg


If there is more than .001" parallel misalignment, determine in which direction the two crank halves need to move: either closer together, or farther apart. My assembled crank was already within the acceptable range, so I didn't need to adjust it. But the process would involve either bending the two crank halves together very slightly with a vise (or press), or driving a wedge between them to force them apart very slightly. I would say that there is much less chance of encountering this kind of misalignment, as the alignment is "built in". But no doubt there are cases, perhaps involving catastrophic engine failure, which could cause this kind of problem.

Well, now our needle crankshaft is fully assembled with its new bearing, and properly aligned. All done, right? Well, supposedly. But there are voices of experience that tell us that it is possible for the two halves of the crank to become misaligned under normal running conditions. I tend to agree, and there is an accepted method for preventing this kind of spurious movement. It consists of using a welder, preferrably heli-arc (TIG), to make a couple of small tack welds on each end of the crank, at the interface between the crank pin and its corresponding hole:

CRANK11.jpg


I don't have the facilities to do this at home, but was able to sweet-talk the welder where I work to do it for me. Note that these are TACK WELDS only, and a great deal of penetration is neither necessary, nor desirable. If/when the bearing needs to be replaced again, a small die grinder will remove the welds with little damage to the parts involved.

Paula
 
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Once again Very nice! Hey that thing isn't a stroker is it?

Ray
 
Thanks, Ray! Though I never really checked, I think the stroke is the same as the standard crank (2-1/8")
 
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