I need some opinions, along with pros and cons, concerning the thermactor installation on my 1969 GT 500. I usually prefer not to have smog restricting devices on any of my cars. I also plan to never show my car at a competitive level. I love to drive and enjoy my cars, but Shelby owners are a different breed (good) of people and enjoy the authenticity of their cars.
Question - Should I leave the termactor system off the car? And if so, what tweaks should I do to the engine for good operation and performance? If I install the thermactor, do I leave it operational or modify (gut) the pump? If I modify the pump, what does this entail? I am looking for your guidance with pros and cons, to help in my decision. Thank you all in advance.
If you are driving not showing bag the smog.You are fortunate to have both options,it will make the car more valuable if you ever decide to sell.
+1 bag and tag.
On my driver 69/70 GT500's that I have had over the years that I would occasionally show or didn't I would install the smog under the hood for a factory appearance. I had the screw in head fittings plugged on the bottom end (brazed)leaving a 3/4 hole from the top side.I had the smog tubes but with no fitting on the end so I could push the tube down along with some antisieze into the empty hole of the head fitting. If I was changing sparkplugs I could then take the smog tubes out easily by rocking back and forth while pulling up . I made the smog pump non functional and free wheeling by taking off the back and systematically breaking off the plastic internal vanes with a long pliers ,screw driver etc. and then emptying all the debris out and then thoroughly lubricate the moving internals. I typically sourced out a already seized up smog pump to make free wheeling. With all of the parts in place it looked like a working system even though it was non function and did not put any parasitic drag on the engine. I would go a step further and disconnect the vacuum advance on the distributor and make it a mechanical advance and put in a duel point plate . I would have the mechanical advance recurved for more performance in mind . You could feel the better acceleration compared to stock. I would plug the vacuum lines and leave them hooked up to the non functioning external dist advance pod for a normal untouched look. Of course all of these fixes could be reversed if necessary PLUS they could be left in place if showing concours with no one being the wiser. Under the hood it looked like it came from the factory but I knew better. ;) Just what I liked to do.
Like always Bob, I do appreciate your knowledge (to both of my post today). It appears that I have some more work to do. Gracias
To me the system is just plain ugly and clutters the engine compartment too much.
That would be my justification for storing it.
In reality, this air injection system doesn't hurt performance at all. It's an esthetic thing.
As with any parts removed from a vehicle of historical significance, store them in a safe place for future consideration IF you can.
I gave away parts I'd love to have back now simply because I was still living with my parents and my father wanted my crap out of his house. He was not known for his visionary talents or any sympathetic tendencies.
I ran the Pure Stock Muscle Car Drags for years with my 427 Cougar GT-E. Several years without thermactor. The last few years with thermactor. It made zero difference in my 1/4 mile times. My spark plug changing times it made longer. It now takes about 60 minutes to change plugs. Previously about 45 minutes.
@ShelbyDoug - Sounds familiar, almost déjà vu; perhaps we had the same dad.
Quote from: PrettyMuchAShelbyGuy on October 08, 2021, 09:43:31 PM
@ShelbyDoug - Sounds familiar, almost déjà vu; perhaps we had the same dad.
Well I remember the story of "Johnny Appleseed" traveling around the country so you really never know for sure what seed has been spread and where?
Want some DNA to test? I can send you some hair samples. It keeps falling out anyway.