Downdraft SUs

For now, I lumped all the pre-war cars together, I would LOVE for there to be enough demand to split it into groups (hint...hint, post here about your pre-war Singer)
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darcy
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Joined: Sat Jul 23, 2011 11:17 am
First Name: Darcy

Downdraft SUs

Post by darcy »

A 1933 Singer Roadster I have just purchased (see separate thread) came with a pair of downdraft SUs just like these without the top ornamentation-
As it should look?
As it should look?
Has anyone come across these on Singers before? My brother has 1940's Singer Utility with a Single one of these. I also have the attached photo on what appears to be a LM.
On a LM
On a LM
The two piston domes may not be correct on mine, the oil filler cup shown on the right hand dome is missing. The domes are conventional side draft SU style. This maybe correct I am told by the local SU expert (Midel).

Any comment or iput appreciated plus if anyones has parts for these units they don't need please contact me.
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mothy
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Re: Downdraft SUs

Post by mothy »

My SLM engine has this carburettor setup as well, and I have been wondering what the engine is.
It is not the original engine for the car, as my car is 1934, and the block has 1935 casting mark on it.
The log book says 1074cc rather than the 970cc.
As my car has had a 1098 A series engine in it for 30 odd years, I don't suppose I will find out where this engine came from, and even if it is a Le Mans engine. It was sourced or built up when the existing engine snapped the crankshaft.

Image

Image

Roly
-----------------------------------------------
Used to own a 1934 Singer Le Mans

Beer: So much more than just a breakfast drink.
darcy
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First Name: Darcy

Re: Downdraft SUs

Post by darcy »

The motor is an Inger LM - the 35 stamp on the side means it the block was made in 1935. I have two cars (or parts thereof ) see separate lsiting - both have morors that may or may not be original and have different years - I am told this was often the case with imported cars were parts were swapped. So it may / or may not be the original motor. But is an original 35 block, the head may be different - you need to find the stamp.

But if you want to sell the SUs let me know.

Darcy
darcy
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Re: Downdraft SUs

Post by darcy »

I have now found out they are a D2 (there was also a D3 and a D4 - larger bore)- and they were fitted to Singers (Wolsleys, Rovers and Bristols). They suffered from wear on the bottom of the piston chamber ( as you would expect) and not returnng to idle - at least that is what I have been told.

Darcy
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Phillip
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Re: Downdraft SUs

Post by Phillip »

Hi Darcy,

Downdraught SU's were used on the pre-war R-series Roadster and the post-war A-series Roadster. In these cases, only a single carb was fitted and the engine was the 1074cc 3 bearing unit.

The engine shown in the photos has a 972cc Bantam-based 1936 style block with the oil ways cast into the block, rather than using the separate pipes and unions as on earlier engines. The manifolds shown would be fitted with down-draught Solex carbs originally and were used on both the Nine Sports and 'standard' Le Mans ( as opposed to the Speed Special, which used side-draught SU's ) The very early manifold used on the early '33 Sports lacks the carb linkage pivots cast onto it and used Zenith carbs.

Hope that helps!
Your Friendly Canadian Pre-War Singer Specialist, Collector & Historian,
Editor & Pre-War Registrar & Canadian Contact -NASOC
Singer Enthusiast for over 40 Years.
'28 Senior, '33 & '34 Sports, '36 Le Mans SS & Bantam
darcy
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First Name: Darcy

Re: Downdraft SUs

Post by darcy »

On that basis I would appear to have one Bantam engine which would explain the '35 stamp on the side with a '33 chassis. I will post some photos to get confirmation.

Regarding the SUs - I have several photos of these D2 downdrafts on LMs etc as twins. My brother has a single on postwar Singer ute. Were these twin D2s added after market? The chassis's that I have came as rolling chassis from UK and when delivered could have had any number of modifications. I wonder if this is when the D2's were added?

Darcy
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Phillip
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Re: Downdraft SUs

Post by Phillip »

Hi Darcy,

Just reviewed your 'Two into One' thread. A very interesting project given the special locally-constructed bodies. Take a look at my July Bytes & Pieces Editorial on this site under 'eNEWS'. I discuss one of your cars, the second and less complete one rescued in 2009 by Simon Agar of West Pimble, NSW, a few years ago. There is also a great photo of a car with very similar bodywork to both yours taken in 1937. I'd be interested to hear your comments comparing the car in the photo to yours.

Any down-draught SU's fitted to a 972cc engine would have been fitted as aftermarket items. That said, though, I assume if you asked the factory to fit them and were prepared to pay, I am sure they would probably have indulged.

Note that the casting date on the block would have been roughly six months or so before the build date of the car as blocks were left to 'season' before being machined. Singers didn't worry about matching numbers but all the major components should be in the same range. It's not uncommon to find replacement blocks and heads fitted from different years or models, given the likelihood of the castings cracking.

Hope that helps!
Your Friendly Canadian Pre-War Singer Specialist, Collector & Historian,
Editor & Pre-War Registrar & Canadian Contact -NASOC
Singer Enthusiast for over 40 Years.
'28 Senior, '33 & '34 Sports, '36 Le Mans SS & Bantam
darcy
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First Name: Darcy

Re: Downdraft SUs

Post by darcy »

Hi Phil, I think we have got off the subject of SUs and maybe should put/copy this discussion under another heading.

This is the first time I have seen the Hamilton photo and I will see what else I can get through the local Clubs.

I now have Simon's car - it had the Bantam engine. Below is a composite from another car from the same factory (we think) then there is a side view of my first '34 and finally there are 3 photos of Simon's car when it was "restored" in 1969 I believe. It had been out in the open ever since until Simon bought it.

In each case the cars today have very little body work and the Hamilton photo is the best I have so far seen. It does appear to have the same windscreen that all 3 cars had i ie not an LM style. In each case the cowling if different in shape and style. In the case of my two it appears the cowling is wider and the bonnet (at least on mine) shortened by 2 inches.

From what was left of the two cars I have - they were not well made and the remains did not seen to have the more graceful lines of the English cars - your Hamilton car makes a lie of this view - it certaily looks good. I am now inspired to try and get more photos of this car.

Darcy
Attachments
Another from same factory?????
Another from same factory?????
My first - ignore measurements
My first - ignore measurements
Simon's car Cir 69
Simon's car Cir 69
Simon's car Cir 69
Simon's car Cir 69
Simon's car Cir 69
Simon's car Cir 69
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