I got myself two factory air cleaners. First one came from an 85 F-350. The other one I just picked up is from a 78 F-250. Both from a 460 so that suite my needs. I want to take the snorkel from one and add it to the other for a dual snorkel intake. Which main dish is suggested?




The 85 (left) has a vacuum actuator on the back side that opens and closes a plate inside the main dish. It is missing the flapper on the snorkel however. The 78 (right) has the vacuum actuator on the snorkel and leaves the main dish clean looking. Both I know deal with letting warm air into the engine to help it warm up faster. Was there any kind of ducting for the 85 air cleaner's side inlet? Not sure if it will get as much warm air as the snorkels would being right above the exhaust manifolds.

 

Me the one on the left is junk as it does not have the flapper on the snorkel and what ever that thing is off the back?
I would use the one on the right and find another for a working snorkel.

BTW I thought Gary did this to one? It may of been on his site ???Gary's Garagemahal - Bullnose Forum
Dave ----

 

Yeah the gray one (from the 85) has the same type of vacuum diaphragm tucked in that "intake" out the back side that pulls that plate in to seal it off. I assumed it was a different type warm air intake feature like what you see on the snorkels. If it is, then I might run with that one and just wire brush and paint it up nice. Then remove the diaphragm and plug the holes on the snorkels.

What is a good way test diaphragms outside the engine?

 

Close, but not quite. The primary purpose is to maintain a relatively constant intake air temperature for better air/fuel ratio control. In the pre-injection Dark Ages, this was one of many small incremental improvements for cleaner emissions and better driveability with the lean mixtures of the day.

If the intake were to draw only unheated ambient air, the temperature would be all over the place. The thermostatic intake flapper thingy keeps the intake air temperature fairly constant, often well above ambient. The carb was calibrated for this fairly narrow temperature band. You might think cooler air is better, and it generally is, but since you don't always have an unlimited supply of cool air like in the winter, it was easier to just go with warm air all the time. This is one of those systems that often gets ripped out when "getting rid of all that pollution crap", typically swapped in favor of a non-snorkel chrome air cleaner that J.C.Whitney promises will give you more power.

Another benefit of the heated air intake is protection from carb icing. I had always thought this was the primary purpose of the heated air intake, but I have some Ford training manuals from the era that state otherwise. You live in prime carb icing territory, with winter temps in the 35-50F range and lots of moisture in the air. Definitely get the heated air intake working for this reason.

The heated air intake system has a temperature sensor/control valve in the air cleaner, inside the filter. This dealie senses the air temperature and modulates vacuum to the snorkel flapper valve to draw in heated air as necessary from the shroud around the exhaust manifold. The air cleaner on the left looks like it has the temp sensor/control valve. EDIT: I don't see any provisions for one on the right. If it's like my '84 351W, the sensor/control valve is in the air cleaner lid, not the base.

 

Two methods:

1) Get a hand-held vacuum pump such as a MityVac. I've had the older version of this one for years:



You can find other brands for less, too. I think that one is MityVac's top of the line model. I think they sell lower priced models.


2) Find a vacuum hose under the hood you can disconnect and use as a vacuum source. For example, the line to the speed control system is a good one to tap into. Run the engine at idle and you've got a 460ci vacuum pump.

 

What's with that shin catcher sticking out of the front of the bumper? If I was a personal injury lawyer, I'd be salivating, just waiting for some hapless pedestrian to get impaled on that big ol' protruding bolt. Sure, for a pedestrian to get hurt by your truck, he'd have to cross onto your property and run full speed into the front bumper, but it probably still wouldn't play out well in court for ya...

 

I will have to check the lids. I assume you are talking about that disc looking thing on the left one? I am going to end up with TBI with FiTech or Holley so not sure if those will be needed when a computer is controlling things.

That is a major eye sore for me! Seriously a "gotta do what you gotta do" moment from the PO. Your thoughts remind me of my dad in how he keeps is trailer hitch installed. If people walk to close, they get a bruise on their shins.

I need to get some carriage bolts for it and mount it proper. It's also related to figuring out what is not level with my truck. Someone asked if I had blown out body mounts on the passenger side. Crawled under but don't see anything. Have a thread I will update when I get some causes crossed off my list by doing some measurements.

 

Here is the very informative thread written by Gary Lewis: https://www.ford-trucks.com/forums/1...-cleaners.html

Here is another link: http://www.garysgaragemahal.com/air-cleaner.html

 

I did read upon threads dealing with dual snorkels and open air cleaners. Air temp is what I came away with and not necessarily more air flow.

Since I am going TBI with a computer and O2 sensor, I shouldn't have to really worry about air temp too much because my ARF should be adjusted for me. At least that is what I hope is the case. I am sure the factory diaphragms and temp valves will help with fuel consumption during warm up and acceleration during warm up. I have a question out to the two TBI vendors I am deciding between so I'll come back with what they have.

Should have added TBI to the thread title so we are not thinking in terms of a carburetor.

 

I have a 1977 Custom with 302 2V, 4 speed M/T. It has an EGR, but it's blocked off. I bought the truck last spring, and my uncle, an amazing mechanic, got it running like a dream. I did not have the OEM air cleaner; mine was from a '70s Ford car. I guess I kinda obsessed over wanting an air cleaner from a pickup even though I was having no issues. I have since gotten a pickup air cleaner from a junkyard. Today, I fabbed up another snorkel. I don't really know why. I think the dual snorkels look cool. Mostly I just like to tinker and we're snowless up North right now, so more time to putz in my outdoor shop. The mod was easy enough--cut rectangular hole in air cleaner and attach 2nd snorkel with 2 self-tapping screws. I went for a drive not expecting much difference. At first, I thought things felt "smoother." However, after getting out on the highway, my pickup all the sudden started chugging/hesitating. It had never done this before, so poor performance after adding the 2nd snorkel can't be coincidence. It only did this at highway speeds in 4th gear. So...my plan is to block off the 2nd snorkel but keep it just for looks.

 

I suspect ice is accumulating in the carb throat. Does the original snorkel have provisions to draw warm air from a shroud on the exhaust manifold?

If the second snorkel doesn't have this feature, it's increasing the amount of cold air and overwhelming any needed warm air via the first snorkel. See post #4 in this thread for more details.

 

Thanks! I was thinking (after reading a bunch) that the dual snorkel is only effective for the bigger engines??? Or at least one with a 4 barrel carb? I do have the shroud heater hooked up on the original snorkel. The 2nd snorkel does not. The 2nd snorkel isn't hooked up to a manifold heat shroud nor is it plumbed to holes in the radiator support like the original one is. So the 2nd snorkel was sucking engine compartment air. If it was an icing issue and I could solve it, would I see any benefit for running the 2nd snorkel? Would I have to mess with AFR/re-jet the carb? (It was in the 30s on my "test" drive.)

 

Sorry to necro on this but this one of those instances where you can't belive everything in the training manuals. The primary reason for the heat flapper/riser is to prevent carb icing even the CFI/TBI systems used them where fuel mixture was computer-controlled and not affected by ambient temps. These systems long predate any sort of emission controls or precise fuel metering. Sometimes some of these stuffs other benefits were overplayed in tech manuals to prevent techs from disabling or ignoring faulty systems that they felt were redundant. Otherwise, there would not be much incentive for techs or dealers in the south-west states to repair these systems. But giving them a semi line of bull they can then justify the expense to customers to repair them in somewhere like Phoenix.. Pretty tough to justify the expense to repair something to prevent carb icing where the average temp in the winter basically never gets below 50°F and is dry as a popcron fart. Without this backstop semi line of bull, it would kinda be like trying to sell snow tires in San Diego.

 

wow thanks for the info! So in my case, adding the 2nd snorkel with no heat riser MAY have contributed to the poor performance of my engine at highway speed? And no, adding a 2nd snorkel wouldn't require me to mess with AFR/rejet my carb?

 

For the rough running, block off the end of the second (unheated) snorkel and go for a test drive under similar weather conditions as before. If the engine runs well now, open up the snorkel and see if the problem returns. If so, ice was the likely culprit.

To further test, wait for a warm day (above 50F) or a cold day (below freezing). Ice accumulation is most likely in that temperature range, so test outside that band. If you can run both snorkels now, ice was definitely the problem.

For jetting, I wouldn't worry about it. Plenty of guys run open chrome air cleaners with no ill effects. Well, other than guys laughing behind their backs for having embraced the J.C.Whitney school of chrome performance enhancement...