Rover Carburation

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lancedavis
Posts: 9
Joined: Thu Jan 21, 2016 3:44 pm

Rover Carburation

Post by lancedavis » Tue Feb 14, 2017 4:46 pm

Dear All
I found on my 1934 Rover 10, between the carburettor and the inlet manifold, a spacer ( insulating spacer) of 1/4" thickness which also carried a machined but damaged diameter reduction venturi, reducing the diameter from 1.25" to 23m ( 0.905") at that point. The reduction diameter is stamped 23 mm. According to the parts lists there should only be a thin gasket in this early model.

I also see on the parts list for 1939 and 1940 cars have a steel liner for centerpot. I wonder if this has been retrofitted to my car.

I plan to revert to original thru bore all at 1.25", but keep the spacer to help insulate , as modern fuels burn at higher temperature, and revert to CP4 needle?
Any one have seen this situation.

rgds
lance Davis

TonyG
Posts: 288
Joined: Mon Sep 07, 2015 4:38 pm

Re: Rover Carburation

Post by TonyG » Thu Feb 23, 2017 2:32 pm

Lance,

Back in the 80s I got some parts from a 1940 10 that was being stripped for spares. This had the later type inlet manifold, which I still have, along with the carb more recently used on my Tourer. The inlet manifold had a reduction piece, as you have described. Clearly, this will impact the performance as it effectively reduces the carb size. My only thought as to why this may have been done was as an economy measure - perhaps introduced during the War? When I worked for the Post Office in the 70s a similar arrangement was to be found on the Government Contract Morris Minor vans, only this was a simple steel plate between carb and manifold. Obviously we filed these out to return the van to 'normal' performance! In short, I would do as you have and leave it out of your Rover. You can find the correct needle sizes on the Burlen Services web-site. Southern Carburettors also stock the recon kits, jets, springs etc.

TonyG.
Tony Gilbert

P1 12 Tourer
P2 12 6 Light Saloon
Discovery 3
Discovery Sport

lancedavis
Posts: 9
Joined: Thu Jan 21, 2016 3:44 pm

Re: Rover Carburation

Post by lancedavis » Thu Jun 08, 2017 3:07 pm

Tony
Thanks for your reply, and I apologise for not responding sooner.
The plate between carburettor and manifold was in fact a Mangoletsi manifold
(www.mangoletsimanifolds.com/history--In the ‘50s the experience gained from working with gas carburation led to the design and patenting of the GM Manifold Modifier. This simple device, fitted between the carburettor and the manifold, greatly improved the distribution by atomising the fuel more efficiently, and keeping the unmixed petrol from attaching to the walls of the manifold. The modifier gave much smoother running, more torque and better fuel consumption.) I could just make out the name under magnifier.
This simple ( not necessarily proven) device was probably fitted in the 50-s.
I have filed out the reduction, and kept the packing piece in place to insulate the carburettor.
Can still running only just ok.
rgds

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