Stromberg float chamber Oring Mods

[tbsmith]

I'm replacing the leaking o-rings on the plastic plug that goes in the bottom of the float bowl. It seems to be a common item to go bad and since the rear carb has to be removed, I'm thinking of machining a press fit plug of aluminum so I won't have to go through this again. Has anyone ever tried this before?

I'm guessing they provide those drain plugs so you can drain the gas easily (i.e. during storage), but it can't be removed on the rear carb in situ. Is there any other reason for those plugs?

Tom

[oldelanman]

Plastic plug - Do you mean the jet cover ? Mine are brass and screw into body of the carb.

[tbsmith]

Yes, that's it. Is your carb a 175 CD? I googled the problem and other British car owners have similar problems and theirs all seem to be plastic also. Maybe yours is a later version? Anyway, I can't tell from the picture...does yours have anything special machined into it, other than the threads and maybe a recess for the jet, as well as openings for fuel to reach the bottom of the jet?

Here's a picture of what mine looks like.


Thanks,
Tom

[oldelanman]

Yes mine are 175CD-2 carbs but non-emission if that makes any difference I don't know. The car is 1971 registered but built somewhat earlier. Didn't realise some carbs had a plastic plug there I thought it was always brass. Not taken too much notice of the detail but as far as I recall it's just a tube threaded at one end to screw into the carb body, closed at the other end with a large screwdriver slot to unscrew it, with holes for fuel to reach the jet and a groove for the O ring. I've never had a leak from that seal but I think it's probably important to screw it in before you tighten the float chamber screws so that the seal can centre properly.
Burlen and Gower & Lee in the UK both do Stromberg spares....maybe you could contact them to checkout if what you have is an early design and if it could be replaced by the brass version which may be better ?

http://www.gowerlee.dircon.co.uk/spares.html#Stromberg

http://burlen.co.uk/?___store=default

[tbsmith]

Hey Roger,

Thanks for the info. Don't know if my car has the original carbs since the PO removed most or all of the emissions equipment The car is a '72 Sprint.

Sounds more and more like I could make up some plugs that would serve the same purpose and not rely on an oring for the seal. Thanks also for the links to the suppliers, I never would have found them on my own!

Best,
Tom

[Esprit2]

Zenith-Strombergs came in adjustable-Jet, adjustable-needle, and non-adjustable versions. This many years down the road, it's possible a few Elans are running around very happily with non-original types.

For the adjustable-jet carbs, the plastic cover and O-rings are there as a convenient jet access for tuning. If you never seem to have to tune your adjustable-jet carbs (?), then the convenience may not be a priority for you.

For an adjustable-needle or non-adjustable carb, they would serve little purpose.

The plastic cover isn't typically a problem short of breaking. The O-rings provide the real seal, and they tend to get hard over time... then they leak. Replacing the O-rings is not difficult or expensive, and usually takes care of any leak.

The one hit against the plastic part is that long-term exposure to gasoline will degrade the material and make it brittle and more prone to cracking. Even if the part is visually in good condition, it's wise to replace a really old cover when replacing the O-rings.

A well-make metal cover/ plug could sure fix any leak issue once and for all, if you don't mind completely removing the float bowl to adjust the jet.

Regards,
Tim Engel

[tbsmith]

Hi Tim,

My jets are not adjustable. And on my car at least, I'd have to remove the rear carb to get to the jet anyway. The plastic plug is in good shape, but the oring is old and has flattened out. I don't know exactly how old it is, but they both started leaking within 6 months of each other. Now that the second carb is leaking, I thought this would be a good time for a more permanent fix.

Tom

[tbsmith]

Just to bring this thread to conclusion, I made some plugs for the float chambers out of aluminum and they were a press fit (about .0005" oversize). Just to be sure I used Permatex hardening (gasoline resistant) sealer before pressing them in. They've been in place a week now with no leaks. This should be a permanent solution, but they could easily be removed in the future if necessary (though I don't see why).

Thanks for all the help.

Tom