Help Strombergs

[mark030358]

I have asked the question before but got no real answers. My problem is....
how does the stromberg choke cable get from the front carb to the rear carb. I have managed to source the "special" bracket that holds the cable to the front carb. However, is there is supposed to be a second cable coming from the bottom of the front carb and connecting to the rear carb?? If so how, as surely this cable would foul the brake master cylinder??

A PHOTO or ten would be FANTASTIC...

thanks in advance
Mark

[collins_dan]

Not with the car, so no picture unfortunately, but my choke only goes to the front carb. Dan

[oldelanman]

The outer cable is in two pieces with a short piece running from the bottom of the bracket on the front carb to the top of the bracket/clip on the rear carb - an S shape when fitted. The inner cable is one piece passing through the nipple on the front carb choke lever and on to the nipple on the rear choke. I can't post a photo as I discarded the set-up long ago and made a mechanical linkage instead.

There is an illustration in the workshop manual - Section L page 34 - which shows the choke cable routing.

[mark030358]

Roger,
Thanks for the information. Now I've looked at the manual all is clear.

However,won't the smaller outer cable foul on the clutch master cylinder, it's an awfully tight bend, I cant really see how its going to fit.

Also how close is the bottom of rear carb float bowl to the body? I have less than 1/4" so I'm a bit worried the carb will hit the body as the engine moves. What I am thinking is that the engine mount is a little low, therefore I have less clearance.

cheers

Mark

[Jeff@Jae]

Pretty sure there were two arrangements on Sttrombergs. Federal cars were certainly a single attachment and relied on the intermediate manifold to enrich both carbs on cold start. I've seen RHD cars with a rather complex set up where the cable on one carb actuates a cable to the other.

[69S4]

Also how close is the bottom of rear carb float bowl to the body? I have less than 1/4" so I'm a bit worried the carb will hit the body as the engine moves. What I am thinking is that the engine mount is a little low, therefore I have less clearance.

cheers

Mark

Not the easiest thing to measure but based on using my fingers as feeler gauges I've got about half an inch gap between the float bowl and the body. The exact position is a bit of a compromise because if you raise the carb too much the top taps on the bonnet as the engine rocks.

[mark030358]

Thanks chaps, appreciate the replies. I might change the mount, but will wait till the engine is started for the first time in a very very long time. Hopefully that will be this coming Monday.

cheers

Mark

[rgh0]

less than 1/4 inch is probably to little.. It will be OK at idle probably but when the engine moves underload with the torque reaction it will hit the top of the foot well. I need to generally be able to get my fingers underneath for it not to hit.

cheers
Rohan

[RogerFrench]

Mark, unless you're having real starting problems or are seeking originality, I really wouldn't bother.
My Twin Cam Europa had the cable to one carb only, and I found or made all the bits for it to operate on both. Starting was only marginally improved, mainly because the first couple of minutes with enrichment on one carb only led to lumpy warm up. However, the effort required to pull the choke was considerable, even though I had nice free-running cables etc. I therefore ended up ditching the modification.
Now admittedly this was a Europa, and the cable run is more tortuous, but I just thought I'd let you know anyway.

[oldelanman]

Also how close is the bottom of rear carb float bowl to the body? I have less than 1/4" so I'm a bit worried the carb will hit the body as the engine moves. What I am thinking is that the engine mount is a little low, therefore I have less clearance.

cheers

Mark

Not the easiest thing to measure but based on using my fingers as feeler gauges I've got about half an inch gap between the float bowl and the body. The exact position is a bit of a compromise because if you raise the carb too much the top taps on the bonnet as the engine rocks.

The clearance under my rear carb is only about 5mm and it does tap on the footbox when pulling away, it's always been that way and the brass jet cover has a chamfer worn on it as a result but there is no damage to the fibreglass. The bottom flange of the airbox where the two halves are bonded together is also very close.
I did try a weber mount at one point but as Stuart says the dashpots then hit the bonnet. I could slot the engine mount bolt holes but there isn't that much room for manoeuvre - statically I have only 25mm clearance to play with - 5mm below and 20mm above the carb - so the best I could achieve is about 12mm above and below, not sure if that would be enough. On balance I think hitting the footbox is probably slightly better than hitting the bonnet which would likely result in visible cracks....I will probably leave it as it is

[billwill]

The problem is not unique to Strombergs; the bottom of the carbs tapping on the top of the foot box can happen with Webers and Dellortos too.

Last year (with the car off road waiting for me to save up enough to buy a new head) I decided to have a go at preventing it. I cut a large portion of the top of the footbox away. Then made an aluminium tray to fit over the pedals but about 1/2 lower that the former top. Then I glass-fibred it all in to regain the strength needed for pedal pressure, with a net result that the half of the top of the footbox nearest the engine was now about a 1/4 to 1/3 inch lower than it used to be.

Not much but enough to stop the annoying tapping noise.

[oldelanman]

Interesting solution Bill, I didn't realise there was still a problem with Webers and Dellortos - I thought the "special" raised RH engine mount was there to prevent it.

Gives me an idea though.....the contact point on the Strombergs is the brass jet cover (see photo above) so I could simply cut a circular hole below that and fit a rubber grommet. It would still make contact but without the noise. I already have a grommet on the side of the footbox directly in line with the fuel pump and I've often wondered why it's there. Maybe it's for the same reason - the original AC glass bowl pump is very close to the body.

[69S4]

My previous owner must have had a problem with the jet cover knocking a hole in the footbox (and presumably then leaking in wet weather) as he covered it with a sheet of aluminium - thus cutting down the clearance by the thickness of the sheet! The jet cover has, over the years, managed to chamfer itself on the aluminium to the point of regaining the original clearance. As the jet cover is mounted at an angle it's one side that makes contact and I've wondered if deliberately grinding away the brass might be the answer. If it went too far I could always solder up the hole but it looks pretty thick at that edge so you might be able to gain an extra few millimeters.

When I first got the car the tapping drove me to distraction and I cut slots in the carb side engine mount to see if I could gain a bit more of a gap. It's all very finely balanced - a millimeter here, a millimeter there, make sure the bonnet is correctly mounted and the catches are in alignment, the manifold gaps are all correct etc but as it stands with the engine running correctly I don't get any tapping either on the footbox or the bonnet (at the moment ). The bottom of the airbox moulding runs just as close as the jet cover to the footbox but it's never shown any contact marks. At least that would be resolvable in a few minutes with an angle grinder.

[billwill]

Roger,
sounds like a good idea, blind grommets are usually hollow, so if you fitted it smooth side down, there might be clearance.

On the other hand it would collect rain water, oil drippings and any fuel drippings.

~~~~

I suppose I might have the 'wrong' engine mount on the carb side, not a raised one.

I never double-checked the clearance between top of carbs and bonnet.

Maybe I will also now do a 'clay test' of that gap, just so that i have all the relevant information.