Timing cover ID

APRRSV · Mar 29, 2021

Can someone tell me which Norton model(s) used the timing cover in the attached photo? Note the shape of the tach drive boss.

Ed

Screen Shot 2021-03-29 at 5.18.46 PM.png

EstuaryBoy · Mar 29, 2021

There's a blue P11 in the: 'P11 Daily Rider' thread that looks as if it has the tacho bolt holes in a similar orientation, though how it's machined beneath who knows?
Plus, angles and perspective can be deceiving :-(

APRRSV · Mar 29, 2021

EstuaryBoy said:
There's a blue P11 in the: 'P11 Daily Rider' thread that looks as if it has the tacho bolt holes in a similar orientation, though how it's machined beneath who knows?
Plus, angles and perspective can be deceiving :-(

Thanks EB. I noted the bolt hole orientation. I believe that was used for the P11 and G15CSR. But the shape of the boss is not circular as it is on my CSR cover. The part # for the P11 and CSR covers is the same.

Ed.

dynodave · Mar 29, 2021

http://atlanticgreen.com/NHTtimcvr.htm

Look at T2004 and 25186WM which are only casting # not part #

APRRSV · Mar 29, 2021

dynodave said:
http://atlanticgreen.com/NHTtimcvr.htm

Look at T2004 and 25186WM which are only casting # not part #

Thank you Dave. The first photo shows a cover without a tach drive hole. The second photo shows a circular tach drive boss. My question relates to the ovoid boss with angled bolt holes.
Ed

texasSlick · Mar 29, 2021

My 1962 build Atlas has a tach drive boss that looks like that. Same orientation to the bolt holes, but I do not remember how the machined inside surface looked.

Slick

EDIT:

This is a pic of a spare tach gearbox for my Atlas. The drive end appears to be a match for the machining in the timing cover above.

and on the bike ....

APRRSV · Mar 30, 2021

texasSlick said:
My 1962 build Atlas has a tach drive boss that looks like that. Same orientation to the bolt holes, but I do not remember how the machined inside surface looked.

Slick

EDIT:

This is a pic of a spare tach gearbox for my Atlas. The drive end appears to be a match for the machining in the timing cover above.

View attachment 78905

and on the bike ....

View attachment 78909

That's it!! Thanks Slick. And a very pretty Atlas!

Ed

dynodave · Mar 30, 2021

Did you look at T2004A early 1950's no tach drive?
Or
T2004 _ with slanted tach drive? it is the 5th cover, not the first
And my note mentions some round tach mounts are sometimes drilled for angle tach drive like on my 68 dunstall atlas.
The majority are tapped cover are have drilled screws with safty wire inside
My 63 has the slanted mount.
My 66 and 68 are round.

Gilesy · Mar 30, 2021

My '62 Atlas had them sloping forward.

texasSlick · Mar 30, 2021

If you note the tach drive on my Atlas, it appears the angle of the holes is meant to point the drive cable in the direction where it has to go to meet up with the tach.

Slick