TR6 Removing the charcoal cannister considerations

[Ribbs]

For various reasons, I'm removing the carbon cannister and associated piping from my 1973 TR6. I've already gone with a vacuum advance distributor in place of the original vacuum retard. A few questions; (1) Do the fuel bowl vents on the Strombergs need to be maintained or can they simply be capped? (2) Is it a good idea to simply run the crankcase vent (from the rocker cover) straight to the original carburetor ports and capping the line that went to the carbon cannister, or could performance be enhanced by capping the carburetor ports and running the crankcase vent to something like a puke tank? I know the carburetors provided a slight vacuum to assist crankcase ventilation (hence the term PCV?) but is that really necessary?

 

[poolboy]

Do not cap or seal these nipples that I have colored 'red' unless you know how to disable the transition whereby all the float chamber ventilation is done thru the brass lined port in the carbs airbox mounting flange.
If you do eliminate the CC, I'd advise you to have the valve cover vent to the carbs evacuation ports.....It could be worth considering what's to become of the fuel tank vent line and the fumes it sometimes emits if you eliminate the CC.
I was able to eliminate a bunch of the emission stuff, but I didn't do it all at one time and I did experiment with alternatives

.

 

[Ribbs]

Thank you poolboy. It appears that your crankcase ventilation goes straight to the back carburetor only, and not the front carb, is that correct? Also, I'm not familiar with the modification to the float chamber vent. Is the addition of the brass port the modification? I'm not near the car at the moment to see if it has the brass port.

I was thinking about something similar for the fuel tank fumes. Thank you for the pictures!

 

[poolboy]

I was able to vent the valve cover to just one carb..but there was some mixture adjustments necessary to compensate...you may have to also unless you use both carbs
The brass line port is found on all post 72 carbs,,,,the hole is there on the other years just not brass lined as there is no transition valve on the pre 73 carbs..and no 'red nipple' vent.

 

[Ribbs]

Okay, my 73 does indeed have the brass ports and a matching hole in the filter box. So am I safe in capping the fuel bowl vent ports (the red nipple in your picture)? I'm not sure about what the transition valve is or if I even have one..

*EDIT* I just read the technical article on Buckeye Triumphs website and now understand the transition valve. So, it seems fuel is only vented out the red nipple (to the CC) when the engine is off or at idle. I believe you were suggesting disabling the valve so that the fuel chamber always vents to the air filter assembly. Is there a procedure for that?

 

[poolboy]

Of course yo have a float chamber vent transition valve if you have 73 and later carbs... although the 73 versions were unique to that year....I wouldn't cap the red nipples until or unless you disable the transition and have the float chamber venting thru the brass line hole under all conditions including when the engine is idling.

 

[poolboy]

There are a few ways to disable the 73 and have them vent like the 70, 71 and 72 carbs solely thru the vent hole in the carbs air box mounting flange.
On the carbs I service, I do a permanent mod, but what you can do is remove the activation arm that the green pointer indicates and make sure the spring loaded brass plunger is fully extended...pretty much as far out as you see in my picture.
Stick something into the brass lined hole and push on the plunger to make sure it is fully extended. Then remove whatever you used to push the plunger
As long as the spring loeaded plunger stays extended all the venting idle included will be thru the brass lined hole.

 

[Ribbs]

This weekend's project - thank you for the help poolboy!