Stromberg specifications

[yvesmontreal]

My S4 Elan has been fitted with a pair of SU carbs some time in the past.

There is no clearance between the passenger's footwell and the petrol lines coonecting the carbs to the float chambers. Impending disaster IMO.

I would like to go back to a pair of Strombergs. I cannot find the specs of the needles and springs used in non-emission, Stromberg equipped Elans. Does anybody have this info?

Thanks

[snowyelan]

Hi Yves,
I've sent a PM to you about the strombergs. If it doesn't work out feel free to contact me as I have the non emissions setup on my 69 s4. I have a pair of SU's that I may try in the future, so I'd be interested to hear how yours are working.

Scott

[yvesmontreal]

Here is what the SU carbs (HS6 - ex Healey 3000 or MGC) look like on an Elan:

Note there is no balance pipe.

There is zero clearance between the float bowl and fuel line vs the passenger footwell. Adding the manifold blocks for a balance pipe would make things worse.

There are other versions of SU carbs such as the HIF; their body is even deeper than the HS.

[The Veg]

Hi Yves,
I've sent a PM to you about the strombergs. If it doesn't work out feel free to contact me as I have the non emissions setup on my 69 s4. I have a pair of SU's that I may try in the future, so I'd be interested to hear how yours are working.

What's the difference between emissions and non-emissions? Having a federal car, I'm guessing that I've got the emissions version.

[CBUEB1771]

]There is no clearance between the passenger's footwell and the petrol lines coonecting the carbs to the float chambers. Impending disaster IMO.

Which engine mount are you using on the carburetor side? Are you already using the type that elevates the carburetor side of the engine to provide clearance under the bodies of Weber carburetors in Elans? If not you might solve your problem by changing engine mounts. Of course this will reduce the clearance of the dash pots to the underside of the bonnet.

[yvesmontreal]

Emission vs non-emission: the carbs themselves probably only have different needles and perhaps other minor parts; the main difference is the crossover EGR assembly which replaces the simple balance pipe of the non-emission version with a complicated arrangement adding another pair of butterflies.

Engine mounts: no idea which are on the car, the SU carbs were fitted by a shop who rebuilt the engine and seems to have installed it with whatever was lying around the shop. I've just checked this thread quickly lotus-twincam-f39/engine-mounts-tilting-twink-t14152.html
and the intake side mount seems to be the lower one - there is about 1/4 in clearance between the top of the vertical plate and upper surface, with the engine weight. This I believe is what is normally fitted with Strombergs.

I will check the clearance between the carbs and bulge... who knows.

[RogerFrench]

You're right about one thing, the emission carbs can easily be converted to non-emission. The emission system isn't EGR, it's a means of heating some intake air and returning it to eliminate wet fuel deposits.
You can replace the non-adjustable needles with adjustable. Standard emission needles are B1G, Big valve sprint are B2AR.
Spares are available from Burlen in England, as is good advice, by the way.

[CBUEB1771]

Regarding a return to your Stromberg CD175 carburetors, Burlen Fuel Services should have everything you need:
http://zenithcarb.co.uk/cf/vehicle/list ... hicle=Elan
At this link you will find specifications for several CD175 variants used on the Elan. The latest non-emission application lists the B2AR needle which I recall everyone changing to on Federal +2 models in the 1970s. I believe the B2ARs have adjustable height in the piston unlike the fixed-position B1G needles used in Federal Elans. So you will also need the special tools for adjusting the needles. This is a pair of tools, one a long allen key that engages the needle adjuster and the second a tool that keeps the piston from rotating during adjustment by engaging the slots in the top of the piston damper tube. The piston has to be kept from rotating during adjustment to prevent damage to the diaphragm.

Your description of the "EGR" system on the Federal cars is reasonable except that there is no exhaust gas recirculation, the cross over tubes and secondary "throttles" direct the inlet mixture over to the exhaust manifold for preheating when the engine is cold, no mixing with exhaust gas.

If the shop that installed the SUs reused the old engine mounts then you will have the same mount on both sides of the block. I was just thinking that the inlet side mount for Weber-carbureted Elans might help your clearance problem which I agree is a disaster waiting to happen. Going back to the Strombergs many be the better option.

I see my post crossed with Roger's in the ether, at least we both gave you the same information!

[yvesmontreal]

Thank you for the info.

They installed new mounts when they rebuilt the engine and installed the SUs, but bear in mind the car had been driven into the shop with a Weber head, wild cams and 45 DCOEs. (They claimed the head was cracked and the car was over carburetted, hence the "suggestion" to use a Stromberg head and SUs. The Weber head, carbs and cams were nowhere to be seen when the owner collected the car.)

I just dug out the old mounts which the PO had kept and they look very much like the one on the left, except in better shape. The current one on the carb side looks like the one on the right. Obviously the replacement was an attempt at gaining clearance.