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MG TD TF 1500 - Catalytic converter

When searching for exhaust parts for my 51TD, I noticed someone selling what they called "universal" catalytic converters (one for 49 states, one for CA). They claimed reduced emissions and improved performance.
Just wondered if anyone had ever strapped one onto their TD?
Geoffrey M Baker

P.T.Barnum is looking for him. Bud
Bud Krueger

There's this bridge in Brooklyn - - - -
James Neel

T-series cars are flammable enough as they are, plus the rich mixture and oil burning would kill it in minutes. George
George Butz

I have one on my car - I pipe the excess heat into the car to assist with the car heater. Around the same time I installed the converter I also added a "Fish" carburetor and the little magnetic things around the fuel line to improve fuel economy. I also have a J. C. Whitney toilet-paper-element oil filter - saves me a ton of money.

Oh, and thanks for the tip on the copper bracelets, guys - my arthritis has completely disappeared.








(Yes, I'm kidding... about all of this.)
Kevin McLemore

Kevin,
Great sense of humor!!!!! Acording to the old JC Whitney adds, all of your mods must have increased your HP at least 27%

Can you imagine how fast a TD would "flame up" with a Cat located under the plywood floor !!!!!!!!!!!

Steve
Steve Wincze

The bizarre thing is that those toilet paper oil filters are *still available*! They are still made by Frantz. Who will be the next to add one to their TD?

Check it out...

http://www.frantzoil.com/TOILETPAPER.html





Kevin McLemore

Wonder what brand of toilet paper they recommend? The hard crispy stuff or the super soft? LOL.
Paul S Jennings

Now (OT) talking about tollet paper, I came across a neat invention on our recent holiday to Bolivia. They advertise toilet rolls where a smaller roll with a handful of sheets is contained in the middle of the big roll. You take that out and with you when you´re on the road. So no need for the big roll behind the rear seats with a knit cover ;-)

Mike
Mike Fritsch

Equally OT, I recently saw an ad for toilet paper that discussed that the millions of cardboard toilet paper rolls are trashed each year, and that THEIRS is eco-friendly by NOT having a roll in the center!

Tom Lange
t lange

A universal cat will do all those things -if it goes on a car originally set up for a cat, and the existing cat is in bad shape. But I never heard of anyone promoting them for use on cars not originally equipped. Since the cat goes downstream of all the power-producing stuff, and can only add more back pressure to the exhuast, hard to see how it could improve output.

TP filters are another thing altogether. They work, TP filters are depth filters. They trickle a little of the oil though a deep bed of filter media, which has been proven to clean the oil more thoroughly than a single pass filter. Nothing magic about TP, its just a cheap, good readily available material for a depth filter. You cold just as well use newspaper, rags, or diatomatious earth. The ideal would be run both, a full flow to keep out all the big stuff and a depth to superclean the oil. Used to be quite a debate as to which was best. GMC favored single pass, and Ford depth. But do you realy need cleaner oil? Damn few engines wear out these days from dirty oil, even with stock filtraton.
kylemorley

I know continuing this thread will just make the 'ribbing' worse, but I think it's an interesting idea.
A catalytic convertor is a simple device that passes the exhaust over a 'bed' of materials that cause a catalytic reaction which causes the exhaust to burn hotter and cleaner. There are no moving parts or pieces to obstruct the flow of the gases.
As long as the converter is sized correctly, it will cause no significant back pressure. With no obstructions, the only possible back pressure comes from the expansion of the gases themselves, and if sized correctly, this problem is avoided.
There are three types of converters, early models (till 1981) which assisted in burning two (CO and HC) of the gases more cleanly, and later 'three-way' models which also reduce NOx emissions. Only the later models require oxygen sensors.
Earlier models are still available for 'lean burn' engines and I see no reason why one could not be adapted for ANY engine that uses modern fuels (leaded fuels destroy catalytic converters quickly).
The fundamental problems with a catalytic converter on a car like ours are available space and heat dissipation. Heat shields are commonly used on modern cars to make sure you don't set fire to vegetation when parking; and as someone pointed out, our wooden floorboards would be a problem.
However, if it were possible to mount a converter in the engine bay directly below the exhaust manifold, I think it could be safely done.
I have no plans to do so; I just believe it could be safely done.
And before anyone asks why? the simple answer is I like the idea of our little cars not being the worst offenders when it comes to emissions.
Laugh all you want, guys...
Geoffrey M Baker

Geoffrey, a noble cause. Regards, Tom
tm peterson

I'm sorry, Geoffrey - didn't mean to offend - was just having a wee bit of fun.

As to your idea, yes, I agree with your goal that it would be great to reduce the emissions on our cars... as a long-time outdoorsman I'm in total agreement.

That being said, as you've noted the heat put off by these little cans is quite substantial. The under-bonnet heat for most LBC's is already quite high and there's not a lot of space to be had, either. We already have issues in the TD and TF with carburettor boil-over - I can only imagine how much more this would be a problem with a frying-hot 'cat' sitting under them. As we move down the pipe it only gets more difficult to squeeze in, as you correctly noted we have wooden floorboards which could be consumed by the heat. Further back there's the hump over the axle and that won't work and we certainly can't have it next to the petrol tank, either.

The only way I see to do this is to change out the floors for metal or another non-flammable product and then apply substantial shielding and insulation to the bottom of the floor to prevent cabin heat and carpet melting. This would keep the heat out of the engine bay and also allow road air movement to cool the 'cat'.
Kevin McLemore

Much of this discussion may be in fun, but may I point out that the reason modern oils have virtually eliminated zinc (ZDDP) is that it kills the active component in catalytic converters. Without ZDDP in the engine oil, the cam and tappets in the XPAG engine can suffer.

So which is worse, killing your camshaft and tappets, or putting a few more parts per million of pollutants into the atmosphere?
LD Palmer

Kevin, I was not offended :)
As far as issues, you correctly point to the heat issue. I think a full heat shield would probably be needed (many aftermarket cats appear to incorporate them on both sides). However, we use jet-hot coatings to help with heat issues on the exhaust manifold, I wonder whether an application of jet-hot or other ceramic coatings on the outside of a cat would help? Obviously other issues would be to make sure that the carb overflow fuel lines are routed well away (or removed and the ticker pins plugged, as many believe should be done for safety, anyway) and that heater hoses are similarly rerouted. Lastly, an electric fan instead of our mechanical units might be preferable to keep air moving through the engine bay.
Putting heat aside for the moment, the other major problem is keeping a lean carb mixture.
Modern systems use stoichiometric analysis using computers and fuel injection to rapidly cycle the fuel output between lean and rich to keep the burn efficient. That is not possible with our carbs.
A working catalytic converter on a MGTD would require a carburetor in optimal working condition running consistently lean to be truly effective. On startup, the choke would defeat the catalytic efficiency every time, but that is unavoidable; once running, so long as you keep the carb tuned carefully, you should be able to achieve efficient burn in the converter. One modern BMW now uses a heater to heat the catalytic converter at startup to solve this problem.
For those who have moved to positive crankcase ventilation, even more efficiency might be achieved with a pulsed air injection system; using the vacuum created by the engine to inject air into the converter when needed. These are actually not complex systems.
At any rate, it's all food for thought and an interesting engineering problem.
Geoffrey M Baker

Lew, ZDDP contains both zinc and phosphorus, which are low-level catalytic contaminants, unlike lead which is a high level contaminant. Low level contaminants reduce the lifespan of converters, they do not quickly destroy them, as does lead. So if you want to continue using ZDDP, you can still use a catalytic converter... you will just replace the unit more often than an engine without ZDDP.
ZDDP has been phased out of engine oils since 2006. I don't use additives in my engine (but use synthetic oil). One can always install "hardened" valves and seats as well, I believe. I have read many pro and con postings (here and elsewhere) about ZDDP with many people claiming it makes no difference and others claiming it is a miracle product. I don't know. However I also read that OVERuse of ZDDP can damage your engine, and that "low amounts" of ZDDP won't significantly affect catalytic converters.
So I guess based on the fact that I can't find enough hard evidence on either side, I don't find the ZDDP argument to be a good enough reason NOT to use a catalytic converter... my answer would be that the worst case would be that you would replace a converter more often if you use ZDDP. That's all.
Geoffrey M Baker

This thread was discussed between 07/01/2015 and 12/01/2015

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