Air Cleaner functions

[derek]

When we got our truck, it had an aftermarket air cleaner, and after reading the forums and documentation here it seemed like this was not ideal so we've been on the lookout for one that would work for us.  We found one that we thought would work so we picked it up.  

It's not the correct one for our truck, but it fits (barely - the back of it almost touches the cowl, but we were able to get it on there and tightened down with a little trouble).

So now we want to figure out how to set it up as best we can for our engine - we are probably overthinking some things, but I have a few specific questions and would appreciate any other advice you guys can give as well.

1.  On the backside of the air cleaner, there's a vacuum controlled door that appears that it would connect to what I believe is a cold weather modulator on the side (green).  It appears to me that this would be pulling air from the engine compartment if the door was opened.  What I am not understanding is when this door should open and the benefit that would provide.

2.  It has the metal temperature sensor in the bottom which I understand controls when the door in the snorkel switches between heated and fresh air.  Is there supposed to be another sensor in line with this before hooking into the vacuum?

3.  What are the other holes on the sides of this air cleaner supposed to hook up to?

On one hand, I believe if we sealed up the door on the back, capped the extra holes, and hooked up the vacuum from the metal temp sensor to the engine vacuum that would most match the original air cleaner setup on our truck.  But if there is a benefit to using this door and the extra ports on the side, I'd like to understand that and use them for their intended purpose.

Photos attached of our aftermarket air cleaner the truck came with and the ford one we found.

[85lebaront2]

That appears to be a 460 air cleaner. The extra door is held closed by manifold vacuum, so at wide open throttle it allows extra air in to feed that 4180C Holley 4 barrel.

[derek]

85lebaront2 wrote

That appears to be a 460 air cleaner. The extra door is held closed by manifold vacuum, so at wide open throttle it allows extra air in to feed that 4180C Holley 4 barrel.

So am I correct in understanding that if it's hooked up to that cold weather modulator, it would prevent it from opening in certain temperatures?  Would a 2 barrel 2150 carb benefit from the extra air under these circumstances?

[85lebaront2]

Ok, here is the diagram from my 1986 F350 with a 460 engine:

The red vacuum lines come from a 4 tube vacuum tap on the intake manifold. The lower tube that points straught to the left connects to the air filter diverter (back side of housing) through the CWM which I believe is a delay valve. The diverter is open with the engine off, and closed by vacuum when running. but at WOT it opens up to provide more air, and you can definitely hear it! The inlet snorkel is temperature controlled by a thermal valve in the lower part of the air filter and is connected to the same vacuum source. It maintains warm air so the engine doesn't stumble at low speeds in cold weather.

There is a jacket on the right side exhaust manifold for heat, and the end of the inlet duct goes to a plastic elbow past the radiator so it gets ambient temperature air when driving. You can definitely hear the roar of that 460 and Holley 4 barrel.

[ArdWrknTrk]

The CWM is a metal disc in the floor of the housing.
The green/black plastic thing in the side, up by the coil is just a delay, to add hysteresis to the flap's motion.
If vacuum drops a lot for more than a few seconds the flap inside the plastic shroud opens providing more (if hotter) air than can get through the snorkel alone.

I can't say if a 400 really pulls as much CFM as a 460, (certainly not through a 2V)
TTBOMK only 460's came with this air cleaner housing.  (Thanks Again Bill!   )

[derek]

That’s not my understanding from the documentation section unless I’m reading it incorrectly.

It’s referring to the CWM as a cold weather module and then additionally it speaks of a bimetal sensor, which I understand to be the one in the bottom.

From the “operation” tab in the air cleaner section of documentation it sounds like the CWM is in line with the bimetal sensor, and that it overrides it when ambient temp is within a certain range.

I had assumed the green thing was the CWM but if that’s a delay valve then I’m guessing we don’t have a CWM and may need to find one of those, and that may go in one of the extra holes we have in the side of the air cleaner?

[derek]

Thanks Bill, I that diagram helps.  Do you still have this air cleaner on your engine?  If so, would it be possible for you to send a picture of what the holes in the sides are hooked to or filled with so I can better visualize what we are looking for?

[ArdWrknTrk]

Bill now has sequential port fuel injection from a '96 Cali or Massachusetts 460.

I have his air cleaner.
There were two plastic elbows attached there, those hoses fed the twin air pumps.

If you don't have air pumps, and want to plug the holes I can show you the rubber Dorman master cylinder seals I've used to block them off.

[derek]

ArdWrknTrk wrote

Bill now has sequential port fuel injection from a '96 Cali or Massachusetts 460.

I have his air cleaner.
There were two plastic elbows attached there, those hoses fed the twin air pumps.

If you don't have air pumps, and want to plug the holes I can show you the rubber Dorman master cylinder seals I've used to block them off.

oh okay yeah that would definitely be helpful.  On the other side we have an extra hole next to the green thing, is it just blocked off too on yours?

[ArdWrknTrk]

That is for the breather filter.
There is a (sorta) curved plastic tray that holds a piece of white Scotch Brite stuff.
A forked metal clip on the outside, and an elbow with a hose that goes to the breather where you fill the oil on the front of the valve cover.

Do you want pictures???

[derek]

ok I believe we got the hose for that one then too, gotta see where on my engine that goes to, but I believe Will is familiar with it, just wanted to make sure of what was over there.  Thanks Jim!

[dirtymac]

Do either of those holes go to the valve covers?

[ArdWrknTrk]

[mat in tn]

have you noticed any benefit from the flow adapter (I forget the brand and actual name) but I do remember using them years ago when doing a bit of hotrodding in my youth.

[ArdWrknTrk]

It's called a K&N Stub Stack.

You notice it at the track, and I figure anything that has a proven track record is worthwhile.
Besides, it was lurking in the bowels of my track box from when I had my Notch GT.

Why not put it to use?  🤷‍♂️

[mat in tn]

this is where I "face palm". stub stack! it has been a few years, but we used them.

[ArdWrknTrk]

Did you feel they helped?
Did you do any blind testing?

It certainly can't hurt, to smooth out the inlet radius.

Have you studied any Ricardo?
That's really getting back to basics!

[mat in tn]

all I know is when we were out front, we kept going. if not, we kept tweaking

[dirtymac]

I was pretty certain on that setup for their driver's side valve cover.

I'm unsure of the passenger's side.  Does one hole go to the other valve cover or to the PCV valve?  Our air cleaner has two large holes on that side as well.

Also, in your pictures, what is the black piece around the bottom of the air cleaner and top of the carburetor?

[mat in tn]

hahahaha