EW fuel tank cap production

[watchpaintdry]

does anyone out there know the correct style of tank cap for an ew 350, i have seen various types with 2 rivets on the top and 3 on the top. I have just made a batch of ten of them and with the 3 rivet style and would like to know which is correct before I rivet them together. I have copied the original one than a friend lent me and even went to the detail of getting the correct knurl on the side! Any help would be greatly appreciated.

[douglas1947]

On my 1930 350cc model H3 is the same cap with the 3 rivets.
Donīt forget the breathing hole in the middle (with split pin for a chain).

Michael

[watchpaintdry]

I found out that the breather hole on these ones exits out the side under the clip. I wonder if the bayonet height on the tank filler tube sit lower down on the later tanks which might be the difference on the caps, mine (1926 ew350) measures 2.9mm from the top of the bayonet bar to the top of the neck.

[watchpaintdry]

This is the other type, I have no idea where the pic came from. Can anyone shed any light on this?

[LENBOY]

Hi All
I have trolled through dozens of my modern EW photo's and the consensus is that the two rivet type were fitted to the early 1926 models. The three rivet type would seem to be from from 1927 onward. I hope this is of help. Len.

[EW-Ron]

The 3 rivet type is what the Austin 7 used on their caps.
Could replacements with these explain anything. ?
Don't forget that 1920s era parts would be nickelled, not chrome.

I'd be very interested in a pair of these, if available

[Ian]

On my 1926 OC I have the two rivet type.

[watchpaintdry]

 After a big of digging around on the cap I have I found some patent numbers which the first one (255168)relates to the earlier cap that the application was on 24/04/1925 and the second(291941), which was an improvement to the design on 23/05/1927. Thanks for the information received I think we can safely say that bikes built after May 1927 had the later cap. A fellow Douglas owner here in NZ has kindly offered for me to borrow an earlier cap so that I can copy that design too.
This is my first batch of 10 and if enough interest then I will make more to order.I have also made a chain case for my bike again copied off an original one

[cardan]

Interesting that the patents belong to the Westwood Rim and Patent Co of Birmingham - best known for things rim and tyre, but it seems that caps (and other similar fittings) was the primary interest of the company after WW1. They were still taking out patents relating to filler caps at the end of the 1950s. I wonder if Douglas used them all the way through? Is there a patent number on a Drangonfly tank cap?

Leon

[Ian]

I would be interested in a couple of the two rivet caps. I lost one on a rally a few years back so mine are not quite matching.

[Marcus]

Hi,

I'm in Auckland, do you also make the screw on caps for the earlier TS model ?

Thanks

Marcus

[watchpaintdry]

Thanks for the interest in the caps I will let you know once I have nickelled the brass and make the correct parts for the 2 rivet style.
I can make other caps too, I just need an original to copy off. Does anyone know what the lower front mounting clip bracket looks like for the primary chain guard? . A pic would great if possible, many thanks.