Author Topic: Air intake Amal carb 350cc Douglas  (Read 1131 times)

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Offline douglas1947

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Air intake Amal carb 350cc Douglas
« on: 01 Mar 2021 at 14:23 »
I have a 1930 350cc Douglas with original Amal carburettor, but only with the small Amal air intake, not the Douglas air bow. It is in summer no problem to ride the bike, but a lower temperature I have trouble with ice at manofolds and carb.
Can some help with this Douglas intake?
Or has someone a drawing?
I would be very happy for help or ideas.

Michael

Offline Tazmantic

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Re: Air intake Amal carb 350cc Douglas
« Reply #1 on: 01 Mar 2021 at 19:30 »
Hi one of my 250s has the bow intake I can take a pic for you and also try get some measurements if that would help?

Offline douglas1947

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Re: Air intake Amal carb 350cc Douglas
« Reply #2 on: 02 Mar 2021 at 05:01 »
That would be fine!

Michael

Offline arturro

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Re: Air intake Amal carb 350cc Douglas
« Reply #3 on: 02 Mar 2021 at 11:06 »
Amazing bike .

Offline Tazmantic

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Re: Air intake Amal carb 350cc Douglas
« Reply #4 on: 09 Mar 2021 at 18:15 »
Sorry for the delay, the tube is approx 24mm OD

Nice looking bike

p.s for some reason the pics get distorted it is a 90 degree bend







« Last Edit: 09 Mar 2021 at 20:21 by Dave »

Offline Dave

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Re: Air intake Amal carb 350cc Douglas
« Reply #5 on: 09 Mar 2021 at 20:23 »
Hi Tazmantic,

Please see this topic regarding distortion when photos are taken with a mobile phone in vertical orientation.

cheers, Dave

Offline Tazmantic

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Re: Air intake Amal carb 350cc Douglas
« Reply #6 on: 09 Mar 2021 at 20:49 »
Thanks Dave, my mistake I will remember for next time  :)

Offline douglas1947

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Re: Air intake Amal carb 350cc Douglas
« Reply #7 on: 11 Mar 2021 at 14:46 »
Hi Tazmantic,

thanks for the useful photos. I will think about to make a repro, best from brass or copper.

Has anyone an idea for the nut?

Offline oily bloke

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Re: Air intake Amal carb 350cc Douglas
« Reply #8 on: 12 Mar 2021 at 16:51 »
I made mine from 22mm copper pipe and nickel plated it. The fastener I made from brass and plated that too. I made the fastener as a knurled ring as it only needs to be finger tight. A couple of thousand miles in and no issues. My EW has an AMAL274 fitted.

Offline Doug

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Re: Air intake Amal carb 350cc Douglas
« Reply #9 on: 12 Mar 2021 at 22:30 »
I thought that by the time of the EW there were using a knurled ring. At least that is what is shown for the 600EW. The 600EW was a little fancier as it did use a cast aluminum bell mouth rather than flaring the end of the tube as done on the lightweight models. It makes it much easier to separate things for cleaning and plating! I did make a small batch of the knurled rings in stainless steel.





-Doug

Offline douglas1947

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Re: Air intake Amal carb 350cc Douglas
« Reply #10 on: 13 Mar 2021 at 13:13 »
Hi Doug,

interesting knurled rings of your production!

May be the rings have a bigger dia than, because I think Amal has 2 different dia for intake bellmouths on their carbs.
I will check the H3 carb dia. I think it is the small type (like 274/275 - the special Amal carb for Douglas T35 carb has the unusual big dia).

Michael

Offline Doug

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Re: Air intake Amal carb 350cc Douglas
« Reply #11 on: 13 Mar 2021 at 14:37 »
Michael,

The rings I made fit the B&B 123-5 body; they have a 1-3/16 x 26 thread. They are a little bigger that the thread on the AMAL (I think 74) fitted to my 1936 Aero.

-Doug

Offline cardan

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Re: Air intake Amal carb 350cc Douglas
« Reply #12 on: 14 Mar 2021 at 01:14 »
Hi Michael,

The 4/007  - as in your photo - is the carb listed by AMAL for the 1930 350.

Leon

 

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