Tuesday, December 25, 2018

Norton / Amal carburetor spacers project

I've been working on this project for a good long time now, and it's finally starting to pick up the pace. My goal, was actually to find some original longer carburetor spacers like the Norton Works Dept, used on the Domiracer and the Daytona race bikes, but they simply aren't available. I've been lucky enough to see some in person, but they were mounted to an original machine. All others, have only been seen in photos. So I've decided to make some of my own, and with the help of my good friend Chris Wire, the crew at Real Art were able to take the flat digital template that I designed, and extrude it, in order to make this 3D printed positive. I've taken a lot of time to clean up the lines on the shape, and matched it up to an Amal monobloc carburetor flange.



I've designed them with my Solo Motorcycle Works logo to be inset into just one side of the casting. That way, they can be turned in and faced down, should I not want to see the logo. That would give a traditional look, but still allow all the benefits of the longer inlet tract.

Here's a photo of my prototype spacer, along with actual original spacers that can sometimes be found. This will give a comparison to the difference in length.


At the forefront of the photo, the thinnest spacer, with the balance pipe, is a stock Norton piece. Behind that, is another stock Norton piece, normally found on Atlas and Dominator machines. The finned spacer, is a Dunstall item, and to the right of that, is an original Devimead spacer, which was a popular aftermarket item for BSAs. In the very back, is my 3D printed prototype.

I'll produce them to be a straight fit, with stud holes at 2" apart on center. The center bore will be 1 1/8" and the thickness of the spacer overall is 2 1/8". 

For additional reference, here's a detail photo of the original spacers on the 1962 Daytona Dominator.


And the Domiracer.



My plan is to source studs at the correct length, and sell the spacers, longer studs and nuts, as a complete bolt on kit. I'll likely offer them for sale in bare cast finish, as per original, as well as polished, and polished with the inlay painted.

Another nice bonus is that once finished, they can be milled down should they be slightly longer than needed. Anyone interested, should consider the spacing on their particular machine. For instance, a featherbed machine, with the stock battery box and oil tank, will not allow enough room to make use of these longer inlet tract spacers. You'd need a central oil tank, or some other modified set up. They should work great on a Commando, Triumph and BSA.

Finished cost for a set of the spacers, is unclear at this point, and will basically depend on the mold cost and tooling, plus the cost of the studs. I'm not exactly taking orders yet, but if you're interested, please send me an email, as it'll help me to gauge overall interest, and guesstimate quantities with the foundry. I'll only make a small batch of these, and selling them is intended to allow other enthusiasts a chance to get them and offset part of my cost. I'll be having these produced by a foundry and professionally machined, so it's not some sort of back yard operation. Also worth noting is that these will be produced in the USA. With the extent that I'm taking this project, my final goal is to have them made properly. So if you've got any interest, please email me at works.moto@gmail.com