Help identifying carb setup?

[Chrisrich]

Does this look familiar to anyone? I can't find any reference to this setup in any of the workshop manuals. There's no balancing tube and no provision for a crossover pipe. I'm trying to sync these, but there's only one set of controls for both idle and choke.

Should I be on the trail of a new set, or are these a workable pair?

Thanks in advance....

Chris

[hatman]

Looks like a couple of SU's someone's cobbled on.

[types26/36]

Looks like a couple of SU's someone's cobbled on.

No not S.U.'s they are Stromburgs, probably off one of the Triumph cars, are they 150 CD's or 175 CD's ? think I have a book somewhere about Stromburgs......I'll see if I can find it.

[elan_fan]

No they are Strombergs and 175's however you will have to check the number on the needle which should be B2AR (that is not the end of the story but a good place to start). What you are missing is the intermediate part of the manifold which sits between the carbs and the cast portion of the inlet manifold. This would be the part that comprises of the High/Low level balance pipe and O ring seal assembly. Stick a wanted ad on the forum.

regards
Mark
S4 SE
+2S

[Chrisrich]

Thanks guys.

Ok, the story gets a little more interesting (sort of).
The needles are B1G, and they are fixed.
When I say fixed, I mean FIXED.
One has the correct 'holding' screw, the other does not.
Neither of them move.
Both of them are up pretty high, i.e., not level with the valve, but recessed somewhat. From looking at other adjustable (triumph) setups, I'd say they are as high as they can go.
I have a funny feeling I should be looking for a completely new intake arrangement, rather than fighting with these to the death, no?

As usual, thanks for the help (this forum has been a life-saver)

Chris

[pamitchell]

Is the small pipe running between the carbs next to plug wires acting as a balance tube? I would also recommend replacing the paper air filters with the factory air box and mounting the air filter (K&N cone) in the nose.
Rgds,
Phil

[elan_fan]

Chris, B1G is the correct needle for a federal set up and yours would have had the balance pipe and intermediate butterfly set up that sent the mixture over the exhaust manifold to pre heat it. In many cases the cross over pipes and cast manifold are removed. So what to do... you can obtain/fabricate a balance pipe assembly but your carbs will still need attending to.

You could have the stromberg inlets on the head machined off and a weber part welded on, I believe dave bean has all the bits. Also if you check the lists from a while back this was discussed and there was a race fabricator who had done several.

You could stick with what you've got, as when they are well set up they are perfectly ok. However you will have to fit a better pair of needles and I suggest the B2AR floating needle which is the needle in an Elan SE which has a higher compression head and 'D' profile cams. Fit new diaphrams and check out the Jag forums as the big V12 motors were fitted with a bunch of strombergs as standard and I believe they are a source of adjustable air valves (that is the bit that the needle fits into).

So the these are you options as I see them - fairly expensive head work and the price of a pair of webers or fuel injection. Or - rebuild you carbs and source the bits - gonna cost you but not as much as the other. If all else fails QED in the UK do a fuel injection kit for the stromberg cars.

Give me a p.m. if you want any info or pics.

regards
Mark

[1964 S1]

Chris, if you need the intermediate manifold piece, let me know. I'd sell you one for ten bucks plus shipping. I do not have the crossover pipes but they're not needed anyway. Eric

[bill308]

Chris,

I believe you absolutely need a balance pipe for a Stromberg setup. You will likely never achieve a good balance without one. The thing is, the firing order is 1-3-4-2. So what happens is the firing of 3 robs some of the fuel/air mixture from the 4 cylinder which fires next. Similarly, the firing of 2 robs some of the mixture from 1. This is because 3 and 4 and 1 and 2 are paired on single carb. Also, Strombergs are not designed to work on a pulse of air, but a more of a steady state air stream. Weber and Dellortos on the other hand are designed to operate on a pulse of air and that is why they are most effective when each throat feeds a single cylinder. If you look at any sports car to which Strombergs or SU's are fitted, you will likely see a balance tube. The balance tube provides an alternate mixture source, or path, or plenum for the cylinders to draw from.

Bill

[steveww]

Burlen fuel systems www.burlen.co.uk still make Stromberg carbs and all the bits.

You will need to source the balance pipe, take up that offer of one for $10

There is a common belief that the Stromberg carbs are no good and that only the manly Webers will do. Sure if you want to go racing and get max bhp then Webers are what you need. However for road use I believe the Strombergs are better as they give a fatter torque curve and more economy. They are also easier to set up.

The Constant Velocity type of carb (Stromberg/SU) was used on high performance motor bikes until fuel injection took over. The CV design is very good, some say better than the Weber type designs. Ideally you want one Stromberg per cylinder, the limitation is more in the cylinder head than the carb design. I have some notes and a needle guide on my web site www.steveww.org

[Chrisrich]

Thank you, everyone.
Steve, your site is KILLER. Lots of great info.
I'll pick up Eric's intermediate pipes and get my hand on some new airvalves and adjustable needles. I've got a more stock filter arrangement coming from Bean. I'd love to make the Strombergs work.

Thanks again-

chris

[ppnelan]

I'd love to make the Strombergs work.

When you do you won't be disappointed...

Matthew

[CBUEB1771]

Chris,
Thanks for posting the image. You certainly are missing important pieces. The image posted by elan_fan is of the non-federal Stromberg arrangement. This has a proper balance tube of something like 1/2 inch bore and no diverter valves for shunting incoming mixture over to the preheating section of the exhaust manifold. This is a superior solution to using the federal manifold with a blanking plate. The federal version with blanking plate works reasonably well but the bore of the balance "tube" isn't really adequate.

[Frank Howard]

Does this look familiar to anyone?

Chris,

I got curious one day and removed the balance tube part to see what would happen just as your car shows. The result was that the car ran terribly. Not only do you need the balance pipe, but you need the longer intake length to make the car run properly.

Are you sure you don't have the correct adjustable needles? Both of my cars came equipped with B1G needles and both cars run well. Take the air valve out and place it upside down on an open vice allowing the tube to hang down between the jaws. Take a short piece of brake pipe, maybe 5" long and place it over the needle. Now tap the brake pipe and the needle will come out on to the vise along with various other bits including a star washer that holds the whole thing in. Clean and lubricate the bits and reassemble. Take note that the top of the assembly has a provision for a 1/8" Allen wrench which is part of a fuel mixture adjusting tool. If you purchase the proper tool, you will be able to adjust the fuel mixture. Most British parts suppliers will have one. Mine was made in Taiwan and cost $10. Combined with the other $10 you are spending on a balance tube assembly, you should be able to fix your car for $20. Good luck.

[Chrisrich]

I'm actually very relieved to hear that, Frank. I have a feeling once I put the correct front-end on that motor, I'll be in pretty good shape. It's interesting that you tried to run the no-balance/no manifold route.

The needles I have are the non-adjustable ones. I have a triumph will the standard needles that use that adjuster wrench, so I'm a bit familiar with that setup.

Thanks again--- chris