1920 Harley Model F

[T. Cotten]

Hello Cotten, thanks very much for the reply and information.

The build report from 1988 stated:

"After cleaning out, found to be worn on butterfly spindle, also distorted & worn butterfly valve. Replacement spindle fabricated & carb body re-bored to suit, replacement butterfly made up. Spindle is now modified to take a screw retained butterfly (rather than old soldered in type)."

I am not sure if this is a common mod or not but judging by your comments I guess not?

You ask "Cutting to the chase: What's the wear groove into the body from the throttledisc/friction washer look like, when you yank that all out?".

The answer is I have not been able to yank it out yet as it moves about a quarter inch and stops with a clunk so I didn't want to damage anything until I had satisfied myself how it all goes together and comes apart.

Its 22:00 here in the UK now so it will be tomorrow after work when I get chance to investigate further. I have a lathe chuck so will proceed as per your suggestion and I will report back tomorrow.

John

John!

Just having the rebuilder's notes is unusually comforting! But now you will do better than he.

Tommo once posted that he used screwed discs for convenience, but he didn't explain how to use the same top of the shaft.

(When I was productive,..)
I cut blank shafts that would then be trimmed for all the different varieties, and then splice them into either the severed tower of the original (since they vary greatly also), or a common replacement I produced, when necessary.

The failure of your assembly is illustrated by the gap beneath the throttlecam in the last carb pic.
The purpose of the friction washer is to prevent this upward movement, so it must be feared that the assembly has worn itself further into the bore (And weird wear upon the cam itself).

But fear not, it all should 'come out in the wash'!

...Cotten
PS: Your disassembly should be a helluva lot easier than blowing out a soldered assembly..

[TechNoir]

I have now had chance to study both the Service Station manual and also another Schebler manual that I have and I now know what I was doing wrong to remove the spindle and butterfly. I will take it all apart tomorrow and post an update and devise a plan.

John

[TechNoir]

Hello Cotten, thanks very much for the reply and information.

The build report from 1988 stated:

"After cleaning out, found to be worn on butterfly spindle, also distorted & worn butterfly valve. Replacement spindle fabricated & carb body re-bored to suit, replacement butterfly made up. Spindle is now modified to take a screw retained butterfly (rather than old soldered in type)."

I am not sure if this is a common mod or not but judging by your comments I guess not?

You ask "Cutting to the chase: What's the wear groove into the body from the throttledisc/friction washer look like, when you yank that all out?".

The answer is I have not been able to yank it out yet as it moves about a quarter inch and stops with a clunk so I didn't want to damage anything until I had satisfied myself how it all goes together and comes apart.

Its 22:00 here in the UK now so it will be tomorrow after work when I get chance to investigate further. I have a lathe chuck so will proceed as per your suggestion and I will report back tomorrow.

John

[T. Cotten]

Golly John,...

The only mystery to me is a disc screw-fitted shaft assembled with a proper tower on top.
Pinned like I do?
(I don't screw with disc-screw shafts, though.)

They are all tortured.
Please don't torture it, or yourself, more by trying to save wrong stuff.

Cutting to the chase: What's the wear groove into the body from the throttledisc/friction washer look like, when you yank that all out?

....Cotten
PS: Please dress the upset 'head' off of each end of the throttlecam retaining pin, and then with a decent anvil, carefully use a precision pin drift to remove the 1/16" pin.
I do it in the lathe chuck. Its already taken a beating.

PPS: I lied.
EVERYTHING about evil HXs is a mystery to me.

[TechNoir]

As per my comments above, I will skip a couple of jobs (but I will return to them in due course) and write about my current issue.

Carburettor fitting. I knew the carb was sticking a little bit when the butterfly was fully closed so I want to address this before fitting it. It felt like the edge of the butterfly was sticking on the bore of the carb. As if the butterfly was a tiny fraction too big.



The butterfly had been modified to add screws during the 1988 engine build (see earlier in this thread for details). I loosened the screws slightly and the butterfly stopped sticking although that might have just been because the butterfly wasn't fully closing with loose screws. However one of the screws wouldn't tighten up, it just kept on turning. Great. I went to remove them completely and having previously seen that they had been split on the back, presumably to lock them. When I squeezed the splits back up to remove the screws one of the "tangs" broke off.





The screws are No 6 x 40 which I didn't have any spares of so I ordered some which turned up today. However new screws didn't fix it, one still wouldn't tighten up. So I think I need to re-tap the hole slightly bigger, probably 3 BA. I will Loctite the new ones rather than splitting them. However I need to remove the butterfly and spindle to both re-tap the thread and also adjust the butterfly. I haven't looked at the Schebler manual yet to see if I am missing something obvious but the spindle will withdraw about 0.250" and then stops abruptly (rather than just getting tight).

Does anyone have any tips on removing the spindle and butterfly?


First two pictures are with the spindle in place, the second two with the spindle withdrawn as far as it will go.









John

[TechNoir]

Hi Eric, thanks so much for the great comments

"I love your motorcycle and so grateful that you have shared what you have learned from your endeavor. I really like that your 1920 looks so much like my 1916, but the patina of your '20 has been less monkeyed with than my '16"

I don't want this to turn into a mutual appreciation thread. But. I really love your '16 too. The finish on mine is mainly rust with just a few original bits. I have the original tanks and I would love to use them but they have literally hundreds of holes in them and so I have to use the replacements that came with the bike which don't look as good. The left original one looks better than the right, the right looks like someone has attempted soldering up some of the holes. For now they can live on my garage wall.



The mill is a reasonably ordinary horizontal mill. I needed a mill with a small footprint due to limited space, I really wanted either a Bridgeport type or a Deckel but they would be too big. It is half refurbed, I need to re-do all the switchgear and refurb and fit a vertical head that I have for it. For now it works OK as a stub mill or horizontal mill. For boring the gudgeon pin holes it was actually perfect as a stub mill. The indicator that you commented on was just stuck to the overarm support which was partially retracted.



I totally agree with you about the satisfaction of solving problems and I had missed the two part numbers for the brackets but it makses sense for using compression plates.

I will post some more updates that I have. However I will skip forward a bit first to a current (hopefully small) issue.

John

[exeric]

You are a man of many talents, John. You have taken the challenge of fitting piston to cylinder to a level I have not seen, and I have tremendous respect for your quest to get that right. Your milling machine puzzles me as it looks like a horizontal mill, but I see that your dial indicator is on a ram, like a vertical mill. Regardless of the equipment, I love to see how good machinists fixture, and set-up the parts they want to machine. I think the process you show is what I love the most about antique motorcycle restoration. I believe it is the journey of solving problems, and noodling out the solutions that make this hobby so rewarding. Obviously, you wind up with a running motorcycle but getting it there is the real challenge.

Regarding the rear cylinder clamp bracket; the parts book shows 2 bkts. 1912-21 (for 30.50" singles and 61" twins). They don't go into any detail but I can only believe that it refers to with, or without compression plates. I recall having the same dilemma when I got to that point on my '16J because the bracket didn't line up, and my motor had compression plates.

I love your motorcycle and so grateful that you have shared what you have learned from your endeavor. I really like that your 1920 looks so much like my 1916, but the patina of your '20 has been less monkeyed with than my '16

[TechNoir]

Next job, gap the points and time the mag. I used a 2 inch travel 0.001" indicator to establish the piston position.





At that point I realised that I had put the inlet manifold on the wrong way round and paused to swap it round. Doh!


With that sorted out it was, I thought, a simple matter to put the motor in the frame. When I put it in the frame the top of the cylinders were short of the frame mounts. Strange, they were exactly right previously. I had a think and realised that I have removed the compression plates from under the cylinders.



This meant that with the engine in the frame the top mounts were now about 0.160" lower than before so they didn't fit. I can only assume that Harley did different length cylinder plugs depending on what thickness compression plates were fitted. I made a spacer for the front cylinder to raise the plug to the right height and made a new bracket for the rear cylinder. However I am toying with the option of making a couple of new plugs with a hex that is 0.160" thicker.







With the engine secured in the frame it should be just a simple matter of just bolting the last few parts back on.

John

[TechNoir]

Hi Steve, thanks for the comments. Here is a bit more.


I couldn't get enough clearance on one of the exhaust valves so needed to remove 0.020" from the stem. To avoid having to remove the cylinder again I modified a valve spring compressor that I have had in my pile of "useful stuff that I am keeping but not sure when I will need it" (we all have one of those piles don't we?). There was just enough room to remove the keeper with the shroud at its highest. (BTW, note the inlet manifold fitted the wrong way round, doh!)







I don't have a toolpost grinder (yet) so had to lash up a dremel type tool with cable ties. It worked but could only handle very gentle cuts. Tool post grinder on shopping list.



I will add some more progress in a day or so.


John

[Steve Swan]

John, it's great to see you back and that you've now some time aside from life's other demands. i will thoroughly enjoy following your thread. I'm glad you have the shop space with necessary equipment to carry out what needs to be done.

[TechNoir]

..........hopefully things will get back on track in the not too distant future.

Hmmm. I am not sure if this counts as "not too distant?



Hello to all my friends in the AMCA. It has been over a year since I did any updates on this thread (or any updates on the bike) but I have now unlocked the impasse (I hope).

First a recap so folks dont have to go back through the entire thread to bring themselves up to speed and remind themselves of how we got here. Bear with me while I do the recap, the progress update will follow.

I bought this bike in pieces in late 2015 and managed to put it together with the help of the folks on here and CAIMAG. It had been disassembled in 1988 after having stood in a shed since 1936. The engine had been rebuilt in 1989 before I got it but it turned out that the cylinder bores were in need of attention but hadn't received any so I needed to address this.

I was advised to go to someone with experience of blind cylinders and found a guy who I was told was experienced with these old bikes. He had the cylinders bored out until the pitting was just gone and after some debate advised me to stick with cast iron pistons similar to the original ones. I had new, oversize pistons cast and the guy machined them for me. However it turned out that he didn't machine the gudgeon pin holes (wrist pin holes) in line with each other. The pin would go into one side of the piston but not through the other side. Needless to say I was not happy.

I pondered my options and things stalled for a bit and then I got some more castings made. Whilst my preference would have been to machine them myself I didn't have a mill so this time I gave them to a company that make Steam Engine parts to machine which they did. At this point things stalled again due to a desire to move house. This first entailed doing a million DIY jobs that curtailed any screwing around with old bikes. In any free time I did get I did a total rebuild from the ground up a new (to me) lathe. I had another reason for this which was the need to get rid of my old lathe so it would be one less lump of old iron to shift if we ever do move home. I also made a start on sorting out an old horizontal mill that I had acquired.

By the end of last year I had put most of the other stuff in order so my attention now turned back to the 20F. First the pistons and I noted that I had asked for a tight clearance between the rings and lands because I wasn't certain, when I asked for them to be machined, of the best figure so I wanted to leave room for adjustment. Since then I had decided on the correct figure and the adjustment is a simple job on a lathe. When I went to chuck the pistons to add the required clearance for the rings I noted that the crown sounded thin when I tapped it to seat it against the chuck. It turned out the crowns were only 0.030" thick (at most) compared to the original pistons which were 0.130". Back when I had them machined I had specified the key dimensions such as diameter and clearance for the rings but had just asked for the other features to be "similar to the original pistons" and provided one as a sample. I hadn't checked the crown thickness when I collected them.

Gutted!

In late January I commissioned some more castings. While they were being done I set to starting another bike project as the new castings were going to be 8 to 10 weeks away. They were ready at the end of March but then sat on a shelf for about 4 weeks as I was concentrating on the other project I mentioned. However, when that got to a suitable point I paused it and turned my attention back to the 20F.

Early May 2019.

Something that I have always known is that if you want something doing properly you need to do it yourself and this sorry tale proves the point. I don't have a fully functional mill (which was always the stumbling block) but I do now have enough functionality to sort out these pistons.

So I first chucked the casting in a 4 jaw taking time to get the best alignment. Being a casting, all surfaces are rough so it a matter of finding the best average. I did try to get the two pin bosses parallel to the cross slide so that when bored the pin would be parallel to the crown and through the centre of each boss.



Once the main dimensions were cut I left the crown thicker then needed (about 0.200") so that once all the holes were cut I would be able to match the weight of the pistons to the weight of the previous pistons to maintain balance.

I made what I will call "U" blocks to clamp the pistons in a vice to bore the holes.





One thing that I had thought about was how to align the the pin bosses along the axis of the mill. I had thought long and hard about this issue and made a tall thin vee block that fitted snugly inside the skirt. This transferred the alignment of the bosses to above the piston skirt. It was then a simple job to indicate the block.






It was then a simple matter of boring and reaming the holes.



This was another issue with the first guys work. The holes were off centre on the same side of the piston so even if aligned it would have natuarally imparted a turning moment on it. Here is a picture of the off centre screw-up



I then transferred the piston to a rotary table to do the other holes.



Back in the lathe I cut the ring grooves. Because I was holding an open cylinder in a chuck it was impossible to get the TIR better than 0.0003" to 0.0004" but that is good enough.



The last job was to take the crown down to thickness whilst also keeping an eye on weight to maintain balance.

Pistons now sorted out it was a simple matter to assemble the top end.

Stay tuned, more to follow.

John

[TechNoir]

You will be dancing in the street when you have concluded this restoration!

That will be two of us.

Thanks for the comments, hopefully things will get back on track in the not too distant future.

John

[AdvenJack]

You will be dancing in the street when you have concluded this restoration!
Thank you for sharing your progress!

John

[Peter Cooke]

John,

Don't be afraid to bang on the door and ask if you know of one that would suit your purposes. Just because it's not listed doesn't mean they won't consider selling.
I know of several people that have been successful doing this and, in the state I live in at least, you don't need an agent so it saves some fees as well.

The worst that can happen is you get a 'no thanks' but it also gets the word out there for you.

[TechNoir]

Thats certainly true eric, I am sure it is the same across the whole of the Western world. When we have been put on the Real Estate Agents mailing lists they only ever send out the stuff they cant sell easily (at least thats what it seems like). I do know that there are some people who go to the Estate Agents offices every day to see what has come to them in the last 24 hours. I bet its the same in your area too.

Good luck to you too in finding the right place for you and your family, I am sure that you will and that you wont regret moving to a quieter neighborhood, I know that I could never willingly move back to the city having lived in a rural area for quite a while now.

John