A Carb Queation?

[Motor-Mouse]

This carburetor was also in the box of parts I recently acquired too. 

I like to take stock of what's what, I can hang some paper tags on them then, and one day they will be of use to me, or someone... 


Regards


Stewart.

[Chris KC]

Stewart,
The correct carburettor for a Nippy is a Zenith 30VE1, it looks very much like the 30VM-2 in your picture though I can't tell you what the differences are. I'd guess the previous owner hoped to set it up on the Nippy as 30VE1's are hard to come by (the same thought has occurred to me in the past).

Do you have a copy of Chris Gould's booklet 'A Guide to the Austin "65" and Nippy'? It's a very useful reference.

[Motor-Mouse]

Morning Chris KC, A copy of the book arrived yesterday... The car does have a downdraught Carb mounted on it, I'll check said number, thanks... it doesn't look to have the correct manifold though, nor in the box of spares, it's missing its sports engine too... ?


Thanks for looking at the post.

S.

   

[Jeff Taylor]

The 30VM - 2 was fitted to the following Austins:
1935 - 38 Light 12/4
1936 - 37 14hp Goodwood
1935 - 36 12/6 - 13.9hp
1935 12/6 - 15.9hp
Marine Tornado - 15.9hp

The 1933 - 36 Zenith 30VE1 Nippy had the following spec:
Choke - 21
Main - 85
Comp. - 55
S.R. - 60
Prog. - 90
Vent. - STD
C. Tube - 2
N. & S. - 1.5

[Motor-Mouse]

The 30VM - 2 was fitted to the following Austins:
1935 - 38 Light 12/4
1936 - 37 14hp Goodwood
1935 - 36 12/6 - 13.9hp
1935 12/6 - 15.9hp
Marine Tornado - 15.9hp

The 1933 - 36 Zenith 30VE1 Nippy had the following spec:
Choke - 21
Main - 85
Comp. - 55
S.R. - 60
Prog. - 90
Vent. - STD
C. Tube - 2
N. & S. - 1.5

Wow, thanks Jeff,

That's all very helpful indeed... I'll take a look under the bonnet of the car when I go collect it next week...


Regards


Stewart.

[Chris KC]

That looks like a side-valve Reliant exhaust manifold to me Stewart. A perfectly serviceable substitute for the Austin one. The integral inlet manifold is not large and can stand a bit of opening out with rotary files etc. I nonetheless ran one of these with an angle adaptor to take a 1 1/4" SU and it was never slow.

[Motor-Mouse]

That looks like a side-valve Reliant exhaust manifold to me Stewart. A perfectly serviceable substitute for the Austin one. The integral inlet manifold is not large and can stand a bit of opening out with rotary files etc. I nonetheless ran one of these with an angle adaptor to take a 1 1/4" SU and it was never slow.

That's interesting. I'd never even thought of the Reliant...
SU's too, all sounds fun and games..

S.

[JonE]

Jeff's good stuff means that although you know what it WAS for, the VM-2 is a bit over choked for a Nippy with standard engine.

sadly can't see it on here, but you can check out the individual cars in the list and see if you can identify the exact model.
http://www.oldengine.org/members/diesel/...thCarb.htm

Two of the applications show 23 and 25mm choke which would be Austin 7 Speedy spec, and the Nippy was 21 and then reduced to 19 for the last standard cars and the Zenith replacement carb for the 30VE1.

You need to try and find a VM5 c855 (I think - check the nippy archive for exact), a lovely carb, which was the Zenith replacement in the 1940s and 1950s. Or see if yours has a choke insert which can be changed!

[Bob Culver]

If anyone wants a good VM5 to play with suggest they contact the Jowett Club. Every Javelin had 2 with 23 mm venturi and were mounted remote from the exh so not heat distorted as most others. Parts for the cars have been extensively hoarded. (Note that all carbs of a model may not be identical internally. Emulsion blocks vary between 4 and 6 cyl versions, but for 4 or 2 probably same) The Big Seven had a quite large venturi. When comparing Zeniths, some had an additional restrictive cross piece in the venturi .

[Ian Williams]

I have a 30VM-5 fitted to my Nippy, it has an unmodified Speedy engine, 3/8 lift cam etc, when setting this engine up I tried a range of alternative 30VM carbs, the larger choked versions did not appear to improve performance. So from from my experience with this car I would be inclined to agree with Jon that a std engine would be best with a 19mm or less choke size.

PS as I posted this I saw Bob's comment about choke size on a VM5, I am talking about a 19mm C855 not a 23mm Jowett Carb, as I mentioned my experience is that even with a high lift cam these are to large.