Carburetor Detective Work 175 CD and 175 CD2

[Hegg]

Greetings, friends!

I have a 1980 model year (mfg in 1979) TR7 that I *think* is pretty much stock-ish. I have obtained an additional intake manifold and carb assembly that was claimed to be a 1980. However, I'm not exactly sure what I have right now.

I have taken several pictures and posted them at
https://unabled.com/show/cars/tr7/carbs/. The ones on the car are the "original_" ones and the new intakes are the "new_" ones.

First of all, The new set doesn't seem to have a choke system that I can readily see. Secondly, the breather rail assembly seems to match the 1975-1976 layout -- according to my parts book. Thirdly, the new one doesn't have the EGR valve thingy on it, and the intake casting seems to be slightly different. The underside of the new set also has a removable valve of some sort.

All of these things make me think "hmm... this is probably an older carb set up than my 1980 is". However, if you take a look at the "closeup" pictures, you'll see that my stock system has the Stromberg 175CD, while the new one I have is the Stromberg 175CD2. One would assume that the CD2 came after the CD.

Anyway, does anyone recognize either set up and can tell me anything about them? Which set is better? What do I do about the choke system in the event that the CD2 is a nicer carb setup to use?

Seems like kind of a detective story to me, but probably not as humerous as the fellow that lost the bolt from underneath his Triumph.

 

[Mark Beiser]

The new manafold and carb setup you got is Canadian spec with manual choke. The EGR valve is there, but the round part with the vaccume diaphragm is broken off.

You can use it, but you would have to get your hands on a double choke cable from an early model, or later Canadian spec car, and mount it under the dash. You would also need to do some rerouting of heater hoses and possibly change throtle cables.

There is no functional difference between a 175CD and 175CD-2 carburetor as far as your engine performance is concerned. IMO, your better off sticking with your stock setup and purchasing one of the nice manual choke conversion kits sold by just about every British parts supplier.

[ 01-30-2004: Message edited by: Mark Beiser ]</p>

 

[Hegg]

AAaaaah, so it's a Canadian one!

My stock setup already has a manual choke all hooked up and working just dandy (I like it), so I'll just keep with that.

Now I just hafta wait for my rebuilt kit to get here!

Thanks for the info,

Hegg

 

[steve99]

Hegg,

I also have a 1980 (Mfg 6/79) TR7. My existing setup appears to be same as yours, my auto choke still works. I rebuilt carbs last summer, pretty straight forward. I would recommend purchasing the Weber carb manual that has a fairly extensive section on the ZS carbs.