So I have decided to put some of the pollution control back on my car to get rid of the stink and hopefully quiet it down a little.
It is a carbureted 1980 with a swapped 302, no current smog equipment, vacuum valves or TAD/TAB solenoid valves. No computer to control them.
A BBK catted H-Pipe is replacing the MAC off road H-Pipe and I am re-installing the smog pump. I do not need to pass any emissions testing, I just do not want my cats to plug up.
For the thermactor air I planned to only run it to the pipe at the cats on the h-pipe.
I was not going to add the pipe at the back of the heads as they are plugged, is it really required on a car only driven in the summer?
I understand that I need a Thermactor bypass valve to block off the pump flow to he cats during deceleration or it will cause backfires.
This thermactor valve needs to be actuated by a high vacuum level when the motor is being over run.
This is where I am having issues.
The thermactor bypass valve I bought runs opposite to this, it normally bypasses to atmosphere and under vacuum it supplies air to the cats.
In the Haynes manual I have it talks of a bypass valve that functions like I need, but need to find its part number.
I was wondering if one of these would be the right valve, but I can not find description on how they function.
Does anyone have a part number of an old school thermactor bypass that is actuated by high manifold vacuum? Or have the valve?
Another solution is to use a vacuum differential valve that will dump the pilot signal to the atmosphere when there is a change in manifold vacuum - again I would need a part number.
Will any of this actually work? Am I wrong with needing to turn the thermactor air off during decel?
Again I am just trying to find a way to get air to my cats without causing other issues.
Connect With Us