Early set of carbs

[sujitroy]

I have in my collection of carbs and carb parts, a set without the vent valves. They are in bits, but I could steal parts from other carbs I have to get them working. It is worth going down this path? I'm under the impression they were added for meeting emissions, Are there other benefits of the valves?
Sujit

[trunt]

-The vent valve just diverts where it vents to so it should make no difference to the running. its just whether you want the emissions canister involved.

I would assume that the early cars that did not have the valve only vented to the floor, not the air filter. not sure if that was via the side outlet or the elbow outlet?

[marshman]

In my opinion the early carbs were OK and simpler than the later "emission" carbs. I had them on my MK1, no vent valves, no temperature compensators and no "poppet" valves in the butterflies. Never had any issues with them.

[richardthestag]

Rover v8 in the 1970s Range Rover never had any of those "cheat" complications for the Strommie carb sets. Chances are that the carbs you have are from another engine, I am no doubt wrong but I thought the stag was supplied for the fickle USA west coast emissions regs from day 1

Same regs strangled TR6, E-type etc etc etc. Trade tariffs used to be way more subtle, I think I prefer the 21c sledge hammer approach

[sujitroy]

Possible not from a Stag. I just this week saw one without the vent valve on a TR6.

[trunt]

The early 68-70? Ones had fixed needles..

[marshman]

Yes, fixed needles and adjustable jet.

[trunt]

Nope.. not on the federals, they cut the jet adjuster and blanked it off. I had to convert mine to make them adjustable.. 68 was the first year of the emissions changes, I think by 71 the CDSE came in..

[richardthestag]

Would be interested in more information on early Stromberg CD175 carbs fitted to the Triumph V8.

According to my manual and also conveniently replicated on the Burlen website, stag was only ever fitted with a pair of 175CD2S, 175CDSEV or 175CD2SEV carbs

The tag numbers from my manual suggest and also conveniently on Burlen website says;

Stag carb models from Burlen website.jpg

Now onto a few questions from them in the know, were any other carb sets other than 175CD2S, 175CDSEV or 175CD2SEV fitted to Stag.

From my brief research all stag carbs from the factory had the temp compensator, likewise with the fine tune screw on the side of the carb near the temp compensator.

Every carb set for the stag v8 was machined to take the seal and brass cup over 3 ends of the throttle butterfly shaft. the last end RH front is blanked off

I do not believe that the really early stag carbs had the float chamber vent pin, but only for the UK market.

The poppet on the throttle butterfly appears to have plagued them throughout production.

Every single stag carb set had adjustable meter needles and not adjustable jets.

Every stag carb adjuster used the hex key style and not the slot as used by carbs on Rover v8

Early carbs had a screw in bung for the now redundant hole in the float chamber for the adjuster, later had a push in plastic bung. None had the blanked off float chambers where the hole for the bung/adjuster was deleted.

Did any of the US stags get supplied with the hateful bypass valve bolted to the forward face over the end of the throttle shaft. I do not believe that any stags for the rest of the world had these fitted.

Just all helps me understand them better.

Saw a beautiful stag today with carb issues, no vent pins, 1973. but has vent pipes to side and air filter so suspect non original stag carbs, they will work fine with a brief refurb

[trunt]

Federals
Looking at the Parts list for Federals.. and my time with early TR's.. some theories.

The first few from 1971 may have not had the vent valve, there was a second charcoal canister that came in after that which was for that valve (Instead of dumping to the floor) also they seem to have had the 2 inlet air cleaner. ISTR that these cars were made early, in readiness for the USA release.

They would all have had some kind of bypass valve as it was already there in 1968 - side mounted. I think they all had them, my 73 has the hated side valve! Despite it being OK, I deleted it, when adjusted by the book it made the revs take a longer time to drop to idle, a PITA on a manual, maybe OK in an Auto?

The temp compensator was already used on Federals in 1968.

AFAIK the federal TR's dropped the adjustable (or not!) jets in 70. So all were adjustable needles by Stag times.

With the same carbs on the many TR's 68-76 I'm sure that some made it into Stags!



So a question Richard,
On cars without the vent valve were there still 2 outlets? or just one, if so which one?