Author Topic: 1906 motor bike engine (Read 124604 times)

AndyB · « **Reply #25 on:** January 29, 2013, 03:44:55 PM »

Hi Tom,

That is a real case of

I will be watching progress, especially as it looks similar to a bike that my great grandfather won a grass track race on at about the same time (he went on to build two racing Douglases, 'Otterzell' and then 'Otterstill' in the 1920's)

Eric and John, thank you so much for the books.

Andy

OKTomT · « **Reply #26 on:** February 03, 2013, 11:37:30 AM »

Hi guys.
I have been working on the cylinder head and the timing gears. This engine has a lot of crankcase presser on the down stroke and needs a case vent but the book said to just buy one. I would like to build a period correct one and am not sure where to put it. Have you got ideas on how to build this and where to install it. thanks Tom
Here you can see the bosses installed in the case.

The cylinder head still needs the fins cut and the intake and exhaust flanges installed.

John Stevenson · « **Reply #27 on:** February 03, 2013, 11:53:42 AM »

Tom,
Can you vent it into the timing case thru a hollow mainshaft and time it with a cross hole that opens into the timing side mainshaft bush on the down stroke.
Some early Brit engines vented into the Primary chaincase to lube the chain.

John S.

OKTomT · « **Reply #28 on:** February 03, 2013, 01:04:35 PM »

John it sounds like a good idea to vent it into the timing gear case to lube the gears but it is also a sealed compartment . I take it that the vent should be a one way valve only venting on the down stroke? thank Tom

John Stevenson · « **Reply #29 on:** February 03, 2013, 05:44:49 PM »

Tom, you time it by using a cross drilled hole in the main shaft that lines up with a groove in the bush so the hole only lines up with the groove on the down stroke.

You could always fit a labyrinth breather in the timing cover.

OKTomT · « **Reply #30 on:** February 09, 2013, 09:50:40 AM »

John thanks for the info.
I got some more done on the timing gears. Built a cam box and side plate.

John Stevenson · « **Reply #31 on:** February 09, 2013, 09:55:46 AM »

Looking the biz.
Do the cams go behind the gears ?

OKTomT · « **Reply #32 on:** February 09, 2013, 10:17:42 AM »

Yes John the cams go behind the gears it will keep the box narrower. The main shaft boss puts the drive gear out to far.
John I found this picture below on the net. I think its Norton. The lifters are not placed over the center of the cam shaft is this a good design ?

DavidA · « **Reply #33 on:** February 09, 2013, 11:00:49 AM »

I wonder if those lifters (cam followers) are original. Having the sharp edge of them contact with the cam doesn't look very professional. I would expect severe wear of the cam.

Dave.

John Stevenson · « **Reply #34 on:** February 09, 2013, 11:19:19 AM »

Tom.
That picture doesn't look right, all the followers I have seen have been top hatted at the bottom.
They are usual off set along the line of the crank where they sit on the cam so the cam first touches on one side and wipes the follower round. This is to equalise wear.

I'll see if I can find a picture.

EDIT Could be right, found this image

http://www.nsamotorcycles.co.uk/ekmps/shops/nsamotorcycles/images/norton-16h-tappet-rod-guide-assembley-complete-1125-p.jpg

RussellT · « **Reply #35 on:** February 09, 2013, 12:38:42 PM »

This may be a daft suggestion but could there be something missing from the picture - eg finger type followers pivoted at the corners of the case and lifting the rods.

Russell

John Stevenson · « **Reply #36 on:** February 09, 2013, 12:44:07 PM »

I think Russell might be correct as there are two unused bushes right where a finger or slipper would be needed

OKTomT · « **Reply #37 on:** February 09, 2013, 01:48:04 PM »

Thanks guys
I think Russell is right I missed that.

vtsteam · « **Reply #38 on:** February 09, 2013, 04:50:33 PM »

Wonderful work, and great subject!

(I saw the turkeys in the photo -- does the TomT relate to that?)

rowbare · « **Reply #39 on:** February 12, 2013, 03:48:14 PM »

Quote from: John Stevenson on February 03, 2013, 11:53:42 AM

Some early Brit engines vented into the Primary chaincase to lube the chain.

John S.

And later ones just lubricated the driveway...

bob

sdezego · « **Reply #40 on:** February 12, 2013, 06:24:37 PM »

Looking really nice.

Yes, as John mentioned, a lot of early motors had a Breather gear that was timed. Harley Davidson used the pretty much the same engine case setup and timed breather setup from 1936 all the way up to the 90's (if you can believe it). ...and almost all earlier models were pretty much the same too.

To give you an idea, the breather was a hollow cylinder about 3" long and 1" in dia and had a solid gear on the gear case side (driven by the cam) (Open end of breather cyl faced into crank case). It had a window on the side that lined up with a window in the gear case side when in time. The Breather slid into the case connecting to a pocket in the back of the crank case. When venting, the windows would align venting crank case pressure into the breather (inside the hollow cylinder) and out into the gear case. And then from a fitting/tube into the Primary chain side to mist oil the chain.

I am sure I made it sound more complicated than it is, but you could certainly dumb it down for your needs. I am sure I could come up with some pictures if you need.

Regards,
Shawn

sdezego · « **Reply #41 on:** February 12, 2013, 06:36:32 PM »

Most of my Harley pictures are pre digital camera

, but I quickly dug some up on the web to illustrate.

Notice the breather annulus? And the casting behind it on the left that serves the pocket in the crank case.

and the breather gear

Timed with cam

sdezego · « **Reply #42 on:** February 12, 2013, 07:21:16 PM »

After some thought, I realized that you are probably looking for something more period correct (which I am not sure if this is or not). This type of design "I know" was in some of the 20's era, but I have no experience on motorcycle engine dating prior to that.

Very interested in seeing what was used though...

tumutbound · « **Reply #43 on:** February 13, 2013, 09:12:52 AM »

I think this shows what RusselT was talking about

DavidA · « **Reply #44 on:** February 13, 2013, 02:35:52 PM »

Now that makes a lot more sense.
Dave.

John Stevenson · « **Reply #45 on:** February 13, 2013, 03:08:20 PM »

What engine is that please ?

Bluechip · « **Reply #46 on:** February 13, 2013, 04:59:28 PM »

Looks a bit like a Norton SV to me.

Big 4-ish ... ???

Although probably wrong, I usually am ...

Dave BC

tumutbound · « **Reply #47 on:** February 13, 2013, 06:05:20 PM »

Quote from: John Stevenson on February 13, 2013, 03:08:20 PM

What engine is that please ?

Not sure of the model. It's pre 1931 as it has exposed pushrods. More info at http://vintagenorton.com

OKTomT · « **Reply #48 on:** February 13, 2013, 06:27:27 PM »

Thanks for the info. guys.
The picture I posted was Guldner. Tom

OKTomT · « **Reply #49 on:** February 17, 2013, 03:25:37 PM »

Here is a before and after shot of the cylinder head. Tom

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Author Topic: 1906 motor bike engine (Read 124604 times)

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