You can run a leaner mixture with warmer air which helps emissions. It helps with fuel vaporization as well as does the exhaust crossover to warm the intake.
Its so the Carb wouldn't Ice up . I've seen it happen in 50 degree damp weather . Car running like crap . Take the air cleaner lid off and the venturi of the carb is ICED . . The cold air rushing down the venturi causes ice up . It doesn't have to be 32 degrees . It will ice up to 50 degrees
Yes, "Carburetor icing is caused by the temperature drop in the carburetor, as an effect of fuel vaporization, and the temperature drop associated with the pressure drop in the venturi. If the temperature drops below freezing, water vapor will freeze onto the throttle valve, and other internal surfaces of the carburetor. https://en.wikipedia.org/wiki/Carburetor_icing
Worst carb icing I ever dealt with was going up a mountain range somewhere north of Las Vegas New Mexico. WFO, wouldn't hold fifth gear. Downshift to fourth. Mile later, won't hold 4th gear, downshift to 3rd. Eventually, I needed first gear to move at all. Then the engine died. I thought I blew something up. Sat by the side of the road, wondering what the hell I was going to do. Ten, fifteen minutes later, I tried the engine again--it ran like a champ. (All the ice melted, the fuel could flow again, and it ran just like always) I figured out afterward that the WFO uphill left no vacuum to run the air cleaner snorkel. The car just didn't have the suds for the speed I was trying to go; I'd have been fine if I'd dropped a gear earlier, and let off the gas some, built vacuum, and been able to pull heated air. Carb icing is most prevalent around 40-ish degrees and raining or at least high-humidity. As said, it can still happen even when warmer, or with mild humidity if the operating conditions are right.
Exactly. I've seen it in the Philadelphia area known for its damp and high humidity . It was amazing to see all that ice .
Thanks guys, learn something new every day. The humidity is really low around here and I've never had to deal with that.
gsx455, I ordered this sensor from Rockauto and unfortunately the vac mounting posts are about 1/8 inch further apart than the original and not workable with my 71 quad air cleaner mounting holes. I was hoping it would work as it is a US made Standard product but at least I have another option with Larry's part no. It was worth a try!
I have one out in the garage . I'll get the part # on Monday . I think it was a Borg Warner part . I'll check
Even if you had to open up the holes a little yours only talking about 1/16 of an inch on each hole .
Thanks for ideas; I did consider drilling out but would prefer to get one that fits existing mounting holes if I can. All options will be considered!
Larry, thanks for the info on the ATS-1 temp sensor at Autosparepartsmart.com. I haven't used this supplier before and do not see much info about this company. Have you used them or anyone else in the forum? I am tempted to order this part as it is pretty reasonable cost with free shipping!
This is great! will see if there is anyone else (mfg) out there that will cross referenced to this number. I wasn't able to complete a transaction with the supplier Larry referenced: autosparepartsmart due to their credit card processing issues with Visa card.
This is just a follow up to let you know that I finally installed the rock auto temp sensor to give it a try in my GS air cleaner; it worked like a charm. I finally gave up on trying to find and make the original AC temp sensors work reliably. I can tell you the difference in these new style sensors is remarkable (work so much better). Now I have the best of both worlds with cold start help (air intake flaps closed ) and full open flaps within a couple of minutes allowing max air intake!! As you mentioned, I just had to widen the two sensor mounting holes in the air cleaner by approximately 1/16 inch using drill bit. Thanks again for you input on this thread.... Have a great 4th.
