# Harley Davidson 7A (1911) long long term project



## adacyb (Jun 26, 2013)

Hi 
This is my first post.
I'm under way to build model Harley Davidson in 1:6 scale. I have done a few parts   
and now I have started to project engine. But I have big big problem - I can't find pictures or drawings of engine inside - I want to do engine like an original.


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## enfieldbullet (Jun 26, 2013)

nice little bike!

i can't help you with the engine though, never seen one of these. shouldn't it be a v twin though?

here's a video of a 1911 engine [ame]http://www.youtube.com/watch?v=W9kdT8li23E[/ame]

looking forward for more!


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## adacyb (Jun 26, 2013)

This is single engine model


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## Rivergypsy (Jun 26, 2013)

Very nice work - i'm looking forward to seeing how you get on with this!

For engine details, while it might not be 100% accurate, you might like to spend some time searching for the same era of Indian engine. I'd thought of building a full size replica of one of their singles, and found a lot of info and section drawings   Like I said, not 100%, but I'd imagine they shared a lot of techniques...


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## Rivergypsy (Jun 26, 2013)

Oh, and while I think about it, I may have some SW files on the project if you're interested?


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## adacyb (Jun 26, 2013)

I would be most grateful for files and help
The biggest problem I have - lubrication system and oil way in block


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## Rivergypsy (Jun 26, 2013)

I'd imagine pump feed to the mains and head, and then splash to the big end? I didn't get that far into my research, as more steam derailed the project...


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## BMyers (Jun 28, 2013)

Wouldn't a 1911 be a total loss oil system?


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## jkimberln (Jun 28, 2013)

Google  jon szalay  He has one and rode it in the Cannonball in 2010.  He restores these things and probably can give you anything you want on them.  May not have drawings, but might take pictures.

JerryK


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## Hopper (Jun 29, 2013)

Great project. Subscribed.
The 7A was basically one of the V-Twins with the front cylinder removed and the crankcase rotated about 40 degrees clockwise. So the internals would be the same as the twins, pretty much.
There is a wealth of material available on the J-Model and F-Model v-twins of that era. They were much the same right up to about 1930. Some refinements but basic principles the same.

So yes it would be total loss lubrication through a pump in the cam timing chest, into the crankcase and main bearings whence it splashes around until firing out a breather pipe on to the primary chain.
There is no oil feed to the overhead intake valve rocker arm. It has an oil cup on it.
The side-valve exhaust has no lubrication. (Cast iron valve guides.)
The cylinder and head are one piece, so will be quite tricky to machine. There is a screw in "cage" in the top of the head that holds the intake valve and seat.
Main bearings and big ends are all rollers. Mainshafts and crankpin all attach to a pair of flywheels with tapers and nuts. (Used on all Harleys up to 1998, and still is on the Sportster models.)
The drive to the magneto is a train of gears, which also drives the cams. They are a very simple engine, so other than the one-piece cylinder/head unit, fairly straight forward to model. The oil pump is a dead simple plunger arangement, more of a metering device than a pump. There is also a hand oil pump on top of the gas tank on most models of that era.

I will dig around in my old boooks later and see if I can find some pics to post for you a bit later today.


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## motmaluk (Jun 29, 2013)

Timeless Motorcycles in El Paso Texas make a full size replica which is a cross between an Excelsior and Harley Davidson of that year. They sell them in semi kit form,I have one but it is a bit of a hand full to get it to start and run. It has points and a total loss ignition system,the oil is drip feed total loss adjusted by a needle valve.


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## Hopper (Jun 29, 2013)

You can buy a 1911 illustrated parts list here: 
http://www.geloman.de/html/harley-davidson2.html

Also, try the Jockey Journal forum at www.jockeyjournal.com
Lot of helpful guys on there might know where you can get a workshop manual to go withe parts book.


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## Hopper (Jun 29, 2013)

Meanwhile, here is some stuff from an old 1923, out of copyright, book I have, showing the internals of the 1920s v-twin. Like I said, the single is very similar inside, they were a steady evolution over the years. 1911 single I think has the "automatic" inlet valve with a light spring and no cam or rocker. Also the earlier models had a different oil pump arrangement without the bulge and the sightglass in  the timing gear cover.

These will at least get you started in the right direction:
















PS, maybe a better Harley forum to get info on these really old models is www.caimag.com  A lot of the guys on there are real experts on the early stuff. The guy who runs it, Buzz Kanter has edited classic bike magazines etc for years and rode a 1920s Harley J model in the last Cannonball, so would know all the people in that vintage scene. 

I know theguys on that forum were in raptures over some guy who made a paper model of a 7A some time back. Somebody building a working model will blow their minds. I am sure they can get you in touch with the info you need.
Tell them Hopper sent you.


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## Hopper (Jun 30, 2013)

Set o' flywheels for ya, from Caimag.com forum. Looks like several members there have these old era singles so should be able to help out.




Slightly later cylinder and head


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## Putt-Rite (Jun 30, 2013)

Rivergypsy said:


> Oh, and while I think about it, I may have some SW files on the project if you're interested?




I have a similar project in mind. If you would be so kind, I would like to see any information on the subject of these old engines myself. :fan:


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## Putt-Rite (Jun 30, 2013)

Hopper said:


> Set o' flywheels for ya, from Caimag.com forum. Looks like several members there have these old era singles so should be able to help out.
> 
> 
> 
> ...



That's a pretty good trick casting a cyl. in iron in one piece like that. I could hazard a guess that because they didn't have oil scraper rings, there was enough oil in the exhaust to lubricate the exhaust valve guide.


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## Hopper (Jun 30, 2013)

Putt-Rite said:


> That's a pretty good trick casting a cyl. in iron in one piece like that. I could hazard a guess that because they didn't have oil scraper rings, there was enough oil in the exhaust to lubricate the exhaust valve guide.



Probably. Cast Iron guides, low rpm, low compression (4:1 or so) not much lube needed. The OHV intake valve  has no lube to the guide at all, later models have just an oil hole in the rocker arm to lube the spindle with an oil can before going for a ride.

Yes they are a trick casting, and prone to cracking as they get older. Hard to find anyone who will rebore these jugs because they never had to do a blind hole before.


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