Stromberg Geyser

[collins_dan]

Twice now, I had fuel pouring out the overflow hole in the rear stromberg. First time it really poured out, and wouldn't re-start. I tapped the base next to the inlet and it started back up. I drove it home and also on a couple of short trips with no problem. Drove it today and was almost home, when it had trouble holding idle and I could smell fuel. Sure enough when I got home it was wet from overflowing. At first I thought is was something stuck in the grouse jet, which I knocked clear when I tapped it the first time. Now, I'm thinking maybe I have a float issue that's randomly causing the grouse jet not to close fully. I will need to take the carbs off and look around. I was thinking I could take them off in one piece, drain them, take the float chamber off, check the grouse jet and the spindle. It was a little loose when I did the recent rebuild. I used a drift to tighten it down, but maybe it came loose? If it did, I'm wondering what people do to tighten it down. Drill a pilot hole and screw it down? Anything else I should look for? Thanks, Dan

[elanern]

When I rebuilt my Strombergs I did not replace the floats. Once I fired it up I had an intermittent geyser from the rear carb. Replaced floats, no further problems. They did not look bad, but evidently were.

[oldelanman]

Hi Dan,
If your float spindle bracket is loose I would say that is the most likely cause of your problem as it will alter the float height setting as it moves raising the fuel level as a consequence. Not sure how the bracket is fixed to the carb body - looks like blind rivets which are a drive fit. If so, rather than trying to drill a new hole I think I would be inclined to remove the bracket completely (if you can) then you could either put a couple of pin punch dimples into the shank of the rivets to tighten them up or alternatively carefully tap out the holes in the carb body to accept BA screws and then loctite them in.

Good luck.
Best regards,

[69S4]

When you rebuilt the carbs did you replace the grouse jet (I'm assuming that's what's known as the needle valve this side of the pond)? New ones came with my rebuild kits, but I've never had one jam open on me from wear, it's usually from dirt getting stuck in there and most commonly after a "clean" when something has gone down the fuel inlet pipe without me noticing.

What bit was it that you tightened with a drift? Stromberg floats do seem to be engineered on the "generous" side in that there is a lot of tolerance where the hinge spindle fits in the float, where the spindle goes into the fixing clip and movement in the rivets where the fixing clip is attached to the body. I tightened up the spindle fit into the fixing clip with pliers on my recent rebuild but left the others on the basis that I'd rather that the float was free to move and self centre rather than jam. You just have to take all of the free play into account when checking the float height - you have set the float height to between 16 and 17mm, right? If the fuel level is too high that on its own can lead to flooding.

[oldelanman]

Stromberg floats do seem to be engineered on the "generous" side in that there is a lot of tolerance where the hinge spindle fits in the float, where the spindle goes into the fixing clip and movement in the rivets where the fixing clip is attached to the body.

I would have thought that the generous clearance between the float and the spindle is desirable to ensure free movement in use but surely any other free play is due to wear or damage and is not right. Loosening of the spindle bracket securing rivets is likely to occur if you lever the spindle out against the body of the carb and not against the bracket itself and the fingers which hold the spindle may open up with repeated removal of the spindle over time. Personally I would correct both of these conditions otherwise the float height setting is likely to be unreliable.

Regards,

[collins_dan]

Thanks for the tips. To respond to some, no I did not replace the floats, but maybe I will now. I adjusted the float height. A grouse jet is a replacement for the needle valve, and I did replace my old grouse jets with new ones during the rebuild, so one could be bad. I didn't lever out the float spindle, but that's not to say that it wasn't done by a PO. I had no problems with the rear carb before the rebuild (I was trying to address a possible air leak, found lots), so the loose base clip had been that way and not caused problems. Maybe my tightening it down had somehow made things worse, and its actually looser now. Who knows? I have to take it apart, I just like to know what I am looking for and have parts on hand. Thanks. Dan

[david.g.chapman]

I have had a couple of instances of flooding carbs on my Stromberg engine. Each time fuel is pumped out of a hole in the air box flange.

I traced the problem to dirt in the inlet valve to the float chamber. Since then I have fitted an in-line fuel filter, and also a regulator to keep the fuel pressure down to 2psi or less.

Dave Chapman.

[collins_dan]

I have actually already done both, so not sure where it came from. I did just rebuild the carbs and added some new fuel lines between the carbs, something must have gotten in, or else I damaged a float, or else the grouse jet is faulty... who knows, but I'll be taking off the carbs this weekend. My plan is to try to take them off as one unit, so hopefully my short wrench with reach the bottom nut without too much trouble. If it does, I may add a small marine style access port underneath them to make this kind of operation easier for the future (I saw your other post about re-installing the engine with the webers already installed- ever consider an access port from the passenger footwell?).

Dan

[69S4]

My plan is to try to take them off as one unit, so hopefully my short wrench with reach the bottom nut without too much trouble. If it does, I may add a small marine style access port underneath them to make this kind of operation easier for the future
Dan

I've always taken my Strombergs off as a unit, which is why I hate the job so much. Actually, taking them off isn't the bit I dread, it's putting them back on. The bottom nut on the rear carb, aaargh!!! Last time I did put them back on individually and it was a bit easier but then didn't tighten the one of the screws on the flexible link spring thing tight enough so the carbs opened but the link then slipped and only one shut. The car then ended up doing a Toyota on me in the middle of London! A 4000rpm idle in a traffic jam doesn't make for a relaxing journey.

You've got your steering wheel on the wrong side so an access port would be in the passenger footwell and it might well work. Presumably it would have to be large enough to get your hand through. With UK right hand drive you'd have to work your hand around the handbrake, steering mechanism and the pedal box so not so easy. Even without that I've always been a bit sensitive about water leaks in that area as it drips straight onto my legs. Yours would only drip onto your passengers legs so no problem

[collins_dan]

My thoughts exactly and with a screw in marine access port, it should be very tight. I'm thinking about 2, one under the carbs and one to the differential and hand brake through the trunk. I haven't checked how things line up from the gearbox plug to the footwell, but was thinking about one there to make topping up easier. Dan

[billwill]

You probably can fit a port on a LH drive car, but it's pretty much a no-no over here, because the steering & the pedals would then make it even more difficullt to get at the carb nuts.


I recently cut a hole above the pedal area & then filled it in again with aluminium & fibreglass but about 1/3 to 1/2 inch lower than before to stop the carb/airbox edge rattling on the top of the driver footwell. That's the maximum drop I could achieve because of steering & pedal bits.

[69S4]

I recently cut a hole above the pedal area & then filled it in again with aluminium & fibreglass but about 1/3 to 1/2 inch lower than before to stop the carb/airbox edge rattling on the top of the driver footwell. That's the maximum drop I could achieve because of steering & pedal bits.

Doesn't it fill up with water when it rains / you wash the car?

The brass jet cover that sticks out the bottom of the float chamber is partially chamfered on my rear carb where it's been tapping on the footwell (P.O. put an ally plate there, presumably to stop the carb splintering the glass fibre). Even with the correct engine mounts the Strombergs are a tight fit between hitting the footwell and hitting the bonnet. I slotted the chassis side bolt holes on the carb side engine mount so as to "fine tune" the carb height. If it's tapping on the footwell, raise the engine a couple of mm, vici versa if it's tapping on the bonnet. Crude, but it's working at the moment.