Full Assembly of the Ram Air System

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Murdoc

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Hi Everyone!

First let me say thank you to all of you guys because digging through the forums on here has led me to get some very helpful answers to questions that have boggled my mind for a while. I'm currently trying to track down all the parts I need to get the Ram Air system for my '71 Mach 1 fully functional. The engine is a '72 351C 4V. I'm getting close to having all the parts I need, but I'm still missing a few. One piece in particular I'm having a hard time tracking down or getting any info on is the bolt or rivet that fastens the vacuum motor to the top of the air filter snorkel. Does anyone know what this piece is called or the part number? I figured maybe just a generic nut and bolt would work, but it seems like that might get in the way of the flap inside the snorkel. To clarify, the previous owner of this filter box removed this piece so he or she could repaint the filter box.

 
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Most of my pictures are locked up in a crashed computer. I do have a couple original RA systems and a one owner original 73. The fastener is a rivet not a pop rivet with center hole but a solid rivet. This is only pic you can see part of it. Can get better later. This is before the car was cleaned up. All of the flapper valves were attached the same RA or not. This is a 12,000 mile car just was sitting in barn a long time.





 
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The rivets were hollow and clinched from behind on a rivet press machine. Unless this is a concours, or you really want a concours look and you can't find the appropriate rivets, hollow pop will do. The originals as far as I remember were dichromate color. At Canadian Fram, where these inlets were made, there were two finishes for the vacuum motors, dichromate and zinc. I don't recall different rivets though as it's been 30 years since I worked there. Don't sweat it, not many will ever know if you used a different rivet, just aim to make it look correct if you are unable to find the correct type.

 
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Hello  Murdoc,

Ford never released a service part number for the rivet that retained the vacuum motor to the duct and valve (snorkel).  The vacuum motor was part of the service replacement duct and valve and I have seen some of those that appeared to have a different rivet from the assembly plant version. The shop techs used a standard hollow tube rivet such as Geoff mentioned. Those at least had the look of the OE style and should pass for the "Correct" look.

 
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Hello  Murdoc,

Ford never released a service part number for the rivet that retained the vacuum motor to the duct and valve (snorkel).  The vacuum motor was part of the service replacement duct and valve and I have seen some of those that appeared to have a different rivet from the assembly plant version. The shop techs used a standard hollow tube rivet such as Geoff mentioned. Those at least had the look of the OE style and should pass for the "Correct" look.
 Anything prior to 1973 when I started work at Fram, I can't be sure of, but as I remember, the Ford inlet tubes were shipped unpainted with vacuum motors separately to be assembled at Ford's plant. For some reason, Ford stamped their own lower shells. I can't be sure, but I think in Toledo, memory is fading. The inlet tubes are the same on Chrysler air cleaners, but of course welded on and painted either Chrysler Orange or black. Canadian Fram also supplied the temp sensors, again common to both Ford and Chrysler. The only difference might be the hot air temp settings, signified by a colored paint mark.

Again, I wish I'd scooped a box or two of those parts when the shift over to remote plastic air induction boxes took place and much of that stuff was just sent to the scrap yard. Oh, hind sight!!

 
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Geoff, the line " If I Knew Then What I Know Now" is one I seem to be crying over more often now. Lots of my friends pitched air cleaners over the years in an effort to "Clean-Up"  under the hood. The same ones that are now bringing the big bucks on the ram air cars!

The shop did replace a few of the vacuum motors on the air cleaner duct (snorkel), but since Ford did not service the rivet we got those from an outside vendor. (Kent Automotive). From what I can remember the service vacuum motors seemed to be a mix of both dichromate and zinc colors.    :)

 
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Geoff, the line " If I Knew Then What I Know Now" is one I seem to be crying over more often now. Lots of my friends pitched air cleaners over the years in an effort to "Clean-Up"  under the hood. The same ones that are now bringing the big bucks on the ram air cars!

The shop did replace a few of the vacuum motors on the air cleaner duct (snorkel), but since Ford did not service the rivet we got those from an outside vendor. (Kent Automotive). From what I can remember the service vacuum motors seemed to be a mix of both dichromate and zinc colors.    :)
 Another thing most do not know and it's not just the orientation of the nipple in relation to the rivet tab, but the spring load on the diaphragm inside. I bet all repos are the same thing, one size fits all.

And yes, If Only!!!!

 

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Wow, thanks guys. Lots of helpful responses on here. It seems like a pop rivet might be the most accessible and easy to install. On a related note, how necessary is the flex tubing and adjoining lower duct that attach to the end of the snorkel? Does it make much of a difference in terms of engine performance? From a lot of the pictures I've seen online, it seems like a part that a lot of people either never had or have chosen to live without.



 
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Geoff, the line " If I Knew Then What I Know Now" is one I seem to be crying over more often now. Lots of my friends pitched air cleaners over the years in an effort to "Clean-Up"  under the hood. The same ones that are now bringing the big bucks on the ram air cars!

The shop did replace a few of the vacuum motors on the air cleaner duct (snorkel), but since Ford did not service the rivet we got those from an outside vendor. (Kent Automotive). From what I can remember the service vacuum motors seemed to be a mix of both dichromate and zinc colors.    :)
 Another thing most do not know and it's not just the orientation of the nipple in relation to the rivet tab, but the spring load on the diaphragm inside. I bet all repos are the same thing, one size fits all.

And yes, If Only!!!!
Geoff, thanks for the memory jog, I had all but forgotten about the spring rates. Starting in 73 the vacuum motors had been removed from the "9D612" standalone listing and moved to a calibration parts list. That is where all emissions-related components were listed and had to be located by the emissions level of the engine. I'm sure the repo and parts house offerings are One size fits all!   :)

 

Don C

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When operating properly and the flapper opens and closes when it's supposed to, the heat riser from the exhaust manifold improves cold weather driveability because it provides a source for warm air while the engine is warming up, improving fuel atomization and reducing fuel condensation on the insides of the intake manifold runners. The flexible hose connects to an air source that draws in cooler air, improving performance by providing a denser air/fuel charge to the cylinders than what it would get from the heated air under the hood.

 
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When operating properly and the flapper opens and closes when it's supposed to, the heat riser from the exhaust manifold improves cold weather driveability because it provides a source for warm air while the engine is warming up, improving fuel atomization and reducing fuel condensation on the insides of the intake manifold runners. The flexible hose connects to an air source that draws in cooler air, improving performance by providing a denser air/fuel charge to the cylinders than what it would get from the heated air under the hood.
 Don, good explanation on both warm and cool air intakes.

 
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Geoff, thanks for the memory jog, I had all but forgotten about the spring rates. Starting in 73 the vacuum motors had been removed from the "9D612" standalone listing and moved to a calibration parts list. That is where all emissions-related components were listed and had to be located by the emissions level of the engine. I'm sure the repo and parts house offerings are One size fits all!   :)
 Yep, quite the memory jog for me too. I really had to scratch the ol' noggin about the spring rates as well. Been nearly 40 year since I played around building prototype vacuum motors. Damn I wish I'd........

 

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Excuse my ignorance Don, but aren't you already getting the cold air intake from the hood plenum? So what's the purpose of a second source for cold air intake? I'm just trying to understand how this all works together.

 
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The ram air flaps are held closed by engine vacuum. So during cruise situations where there is engine vacuum, the engine is ingesting air through the snorkel. During warm up, the snorkel actuator is fed vacuum to close the flap to draw in heated air from the bottom. Once the engine temp increases, the vacuum to the snorkel actuator is removed and the flap opens.

During driving situations, only when engine vacuum drops far enough for the RA flaps to open can outside air can enter the filter housing through the hood scoops.

I'm pretty sure that I have it right, others can correct me if I have it wrong...

-Matt

 
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donkost

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I am amazed to see all of the cars with factory air cleaner assemblies now. In the late 70's and early 80's it was the first thing we pitched into the dumpster, if the previous owner hadn't already done so.

 
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