Hi all from Tucson
 

Hi everybody!
In 2009 I built a biodiesel motorcycle which got over 100mpg. But I ended up selling that to a guy in Mexico teaching sustainability classes, and instead I've now inherited my dad's 1951 MG TD, a 1250 cc carbureted engine.
I've got it working pretty well and it will soon be completely roadworthy (just finishing up the gas tank) but my mind turns to making it cleaner and more efficient... so I'd like to get people's opinions on the following:
1) You can purchase "universal" catalytic converters. Is this worth doing? I'm not concerned with mpg as much as cleaner burning....
2) With an older primitive carbureted engine, what recommendations would you make for increasing efficiency, in terms of best-bang-for-the-buck?
I look forward to spending time on these forums!

Welcome! Keep your tires well inflated to start with.

There's some good reading material here:

100+ Hypermiling / ecodriving tips & tactics for better mpg - EcoModder.com
65+ Vehicle modifications for better fuel economy - EcoModder.com

Welcome to ecomodder.

Electronic ignition.
Fuel injection.

I would not put a cat on the original setup (too dirty) but that TD would be a MONSTER, with a Miata engine and tranny and you would have a cat as well.

You would probably have to upgrade the brakes.

regards
mech

Thanks mech! Electronic ignition is in the plans although I don't intend to switch to injection.
I experimented with water injection on my biodiesel bike (you have to be careful with hydrolock on a diesel you can blow the head) and might play with it a bit on the MG... I abandoned it on the bike because the extra equipment I needed (tank, injector, a whole extra carb to control the flow) ended up weighing more that it was worth, but on a car the weight is insignificant. Room is a problem with an MG though.
Mech, can you elaborate more on the reasons NOT to add a cat? Understanding that the original engine is dirtier than modern ones, I can still add positive crankcase ventilation to the engine as well as electronic ignition, and adding a cat (from my understanding) would under any circumstances burn the fuel better and the worst aspect would be heat dissipation....