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Stromberg Carb Question

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JPSmit

JPSmit

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Hi there, I have twin Stromberg 175s CD-2 carbs on my Vauxhall Viva GT. The car came with rebuild kits. When I took the first carb apart, the shaft is pretty worn. Are oversized shafts available? if so, where?

thanks all
 
Many times replacing the shaft with standard size will get you back into spec.

I put new shafts of my TR4 strombergs and did not rebush the bodies and it now runs great.

You could also try Burlen fuel systems in the UK.
 
glemon said:
Many times replacing the shaft with standard size will get you back into spec.

I put new shafts of my TR4 strombergs and did not rebush the bodies and it now runs great.

You could also try Burlen fuel systems in the UK.
Click to expand...

+1. Is there anyone local you could borrow a shaft from to give that a try. Moss and others all carry over-sized shafts.
 
Good engineering designs allow for the cheaper or simplest intalled component to wear out first. Installing a larger diameter shaft is simple but may require new body sleeve or may need reboring existing bush for best/optimum clearance, if there is material to rebore. Shaft replacement is easy. Reboring in place but may be ok, but replacing bush is more work!. Too many ifs w/o inspecting, testing, etc.

Or, just to test, can't you use the shaft coupling the two carbs for the test; it is same diameter as the shaft thru the carb bush.

Robert
66'tr4a irs
CTC53788L
 
FWIW, I've found that a little bit of wear doesn't really hurt all that much anyway. In operation, the shaft gets sucked against the housing on the vacuum side, so the leak (if any) is on the low-vacuum intake side. Makes the idle mixture a bit leaner than it would be otherwise, but since the mixture gets adjusted at idle, you can correct for that. Then the only downside is that the cruise mixture is a bit richer than it needs to be. Fuel mileage will be off, but performance about the same.
 
Bushings and shafts are available. Look thru the vendors on this site and they can direct you to a vendor or repair shop. Sounds like the same carbs on GT6, TR6 and MG. More options!
 
Rrbbeerrttoo said:
Or, just to test, can't you use the shaft coupling the two carbs for the test; it is same diameter as the shaft thru the carb bush.

Robert
66'tr4a irs
CTC53788L
Click to expand...

great idea - thanks!
 
TR3driver said:
FWIW, I've found that a little bit of wear doesn't really hurt all that much anyway. In operation, the shaft gets sucked against the housing on the vacuum side, so the leak (if any) is on the low-vacuum intake side. Makes the idle mixture a bit leaner than it would be otherwise, but since the mixture gets adjusted at idle, you can correct for that. Then the only downside is that the cruise mixture is a bit richer than it needs to be. Fuel mileage will be off, but performance about the same.
Click to expand...

Good point, though it is pretty worn.
 
LarryK said:
Bushings and shafts are available. Look thru the vendors on this site and they can direct you to a vendor or repair shop. Sounds like the same carbs on GT6, TR6 and MG. More options!
Click to expand...

Got an email in to my Moss guy - thanks for this advice!
 
Hi John-Peter,

I have a Europa with twin Zenith CD's, and just replaced the shafts. Note that the ZS have steel bushings, unlike SU's and other carbs. Being steel they don't wear much if any, but the shaft will. I replaced only the shafts, and seals (if yours has them) and the car now idles great and the A/F ratio is right on (I installed a meter a few years ago).

I hope your rebuild goes well.....

Jerry Rude
73 Lotus Europa TCS
67 BJ8 Healey
67 S1 Europa
 
Thanks Jerry, shafts are on order, my "guy" also said I didn't need oversize. Tonight's question has to do with gaskets. When rebuilding a carb do you recommend installing the gaskets dry or with sealant?

thanks all. BTW - sure am glad already I have a couple extra carbs to scavange parts from - or figure out how it goes back together.

Cheers!
 
Oh, and one more question. The carbs have the little spring loaded pin that you press to check the idle & mixture. (hope that makes sense) On the carb I took apart tonight it seemed to have a small rubber washer on it - presumably to seal it in the carb, the first carb did not have this. Does this sound familiar? should it have an O-ring or the like?
 
That is the mixture testing pin. Did you check the schematics for the specific model you have John-Peter? I don't remember a gasket there or see on the Moss site. Could be wrong, so double check.
 
On carbs, always install dry. any sealant can get into jets or other parts clogging things up.

My boy had a 912 once, and a little RTV ball got into one of the air jets. It took a long time to diagnose, and boy, could that car backfire!!

On the piston lifting rod, mine do not have them so I can't comment. Which model ZS do you have? CD, CDSE, ??

jerry
 
Lotuswins said:
On carbs, always install dry. any sealant can get into jets or other parts clogging things up.

My boy had a 912 once, and a little RTV ball got into one of the air jets. It took a long time to diagnose, and boy, could that car backfire!!

On the piston lifting rod, mine do not have them so I can't comment. Which model ZS do you have? CD, CDSE, ??

jerry
Click to expand...

CD-2 (IIRC)
 
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