I have a 1981 350 with an RV cam and a high rise aluminum intake. On top is a 600cfm edelbrock with an electric choke. This setup runs great, but I have noticed that when the temperature outside is 40-50*F the car has much, much more power and runs smoother than when it is 70-80*F. It seems like the car runs rich at an idle on the warm day too. Could this difference be caused by having a small air filter? I am running something along the lines of 10" x 1.5". Would I need a larger air filter, or does this not affect it. (I was assuming that since air is more dense in cold weather that it is gettng more air to the engine on a cold day than on the warm day.) If it is not my air filter, what would cause the car to run like it does on a warm day. I tried retuning the idle mixture when it was warm, but did not seem to help any. Please help, because this really annoys me on warm days. (I live in Florida so it is normally 70-90*F)

Thanks alot

 

If you have an electric choke, and your carb is tuned too lean, in the cold weather the choke will richen it up a bit by limiting air flow. I would guess that the filter size has little to do with overall performance, but you can try running a larger filter if room allows. Another thing to try would be richening out the A/F mixture and see if that helps.

 

I am going to put a scoop on my hood soon so I can increase my filter size and then I'm gona put a K&N filter on there. Anyways, I do have an electric choke. On a warm day, I can smell extra gas when it is idling, which makes me think it is already running to rich on a warm day. Maybe it is supposed to smell to rich when idling?

 

Have the car tunned by a carb expert , or have them help you -- also a high rise intake and a RV cam is a mis match in the performace catigory-- to me a high rise = a victor Jr style intake 3500 to 7500 rpms stick with a performer or performer RPM, and last but not least an air-gap. anything rated from idle to 6000 rpms
GB

rk