Carb types?

[Tonyw]

As a newbie can anyone tell me what carbs fitted what models, I have an S3 S/E DHC which was completely dismantled and I mean completely! I think I have all of the parts (think) but I have two SU's and they did not get fitted to an Elan, so I am trying to find out what carbs I should be looking for and can I tell by the cylinder head what carbs were fitted. I have a 45/7665
Thanks in anticipation.

Tony

[ElliottN]

Tony,

Depends on the head. A Weber head has four individual inlet tracts while on a Stromberg head there are two (pairs of inlets are siamesed together).

An S3 should have had a Weber head originally (the Stromberg option was used with S4's) so you would be looking at DCOE40's - either Type 18 or 31 (not sure when they swapped over). An alternative would be Dellorto DHLA40's which were used for a time on Sprints.

However - if you've really got a pair of SU's and they were fitted to the head at one stage, it would suggest you may have a Stromberg head? The Stromberg carb's used were Type 175 CD2S.

If the car is completely dismantled I'd suggest you acquire a few books - Wokshop Manual, Parts List, "Lotus Twin Cam Engine" (Miles Wilkins) and the Robinshaw & Ross book "The Original Lotus Elan 1962-1973" or it's successor "Authentic Lotus Elan & Plus 2 1962-1974".

I should be in Perth next month - send me a PM if you'd like to catch up.

rgds,

[ppnelan]

I have a cylinder head somewhere that has been modified (welded) to take twin SUs.... It makes one wonder why anyone would bother when a Stromberg one is soooo gooooood !

Matthew

[Tonyw]

Thanks guy's for the replies. I only got this car a couple of weeks ago and have a lot of work in front of me.

I first saw these new when I was 18 and worked in a garage in Surrey, we put a couple together for some customers and I have lusted after one ever since, now I have one!!!!......... and the fun begins.

Tony

[steveww]

The 45/7665 number is quite late for a S3, may it is a S4? Perhaps you are looking at Stromberg carbs, they do look a bit like SU as they work on Constant Vacuum also. Can you post a picture?

[types26/36]

The way I read http://www.lotuselan.net/publish/car_type_by_vin.shtml S4's started at 45/7895 so 45/7665 should be a late S3. I don't think S3's had Stromberg's and think it is too early for Dellortos, I would guess it was originally on Webers.
It is also listed on this site http://www.sportscarworld-lotus.com/ as been built/invoiced on 11/28/1967

[Tonyw]

Guy's,
The number is correct I have the body plate sitting in front of me. The head is a dual Stromberg head though, I am (read was) a mechanic in my younger days so I am familiar with with SU's vs Strombergs the carbs are SU's.

I guess my question is should I try and get a Webber head or just use Stombergs? I remember from my youth that Webbers were problamatic to keep tuned, my current thinking is to use what I have.

I want to do this car up to be an everyday driver so originality is not an essential part of this, the starter and generator as well as the radiator will be modernised for reliability, I may even change the seats if I can find some that fit easiliy and look good.

This is a great site for information I am learning a lot about my car.

Thanks for your posts.

Tony

[types26/36]

Why not just try the S.U.'s if they fit, some people dont like S.U.'s for whatever reason but in my younger days I worked for a BMC dealer and all their cars of the time (Austin/Morris/Riley/Wolsley etc) had S.U.'s and they worked just fine.
I also dont believe Webers are more problematic then any other carbs and they are not difficult to keep in tune if the basic principles are understood.
If at a later stage the S.U.'s dont suit you then see what is available although I would go for a Weber/Delorto head and carbs as opposed to the Stromburg.(mainly because I am not too clued up on Stromburgs)

[steveww]

Go for it with SU

I have an S4 with Strombergs. The Stromberg was a copy of the SU, it even has the same mounting points which is how the previous owner fitted the SU to the Sromberg head. The Strombergs would have been CD175 i.e. 1.75" or SU HS6. As long as you get the right needle profile they should work a treat.

IMHO the SU/Stromberg are easier to set up and keep tuned than the Weber/Dells, they will also give more torque across the rev range and better mpg.