1971 302 PCV hose question

[abrogate932]

I recently replaced the intake and carburetor on my 1971 302. Somehow along it’s journey, someone installed an 1978 EGR intake, omitted the EGR system and installed a 1.23” 2100. The 2100 has the aluminum carb spacer with the PCV inlet. I found a correct 1971 2 barrel intake, along with a 1.08” 2100. So far, things run much better. While replacing the parts, I decided to freshen up the PCV system. This PCV system is closed, with the fresh air coming from the air filter into the passenger valve cover and the crankcase air exiting through the oil cap on the drivers side. The oil cap has the PCV valve in it and there is a hose that routes to the 2100 base plate. The system has worked ok, but the hose between the PCV valve and the base plate has seen better days and has started to develop small cracks in it. I have been looking for a replacement and found the reproduction hose that Dennis Carpenter sells. I ordered it thinking this would be a simple swap out, but the hose is significantly shorter than the original hose that I had.

The original PCV hose I have has Autolite printed on it, but no part number. The hose was routed in front of the 2100, around the passenger side of it and then to the back of the carb spacer. It has a formed 90 on both ends and is approximately 25” long between the 90’s. The Dennis Carpenter part is about 16” long. My PCV valve was a Motorcraft EV-50, which had a 1/2” nipple. The replacement I used is a Standard V156, also with a 1/2” nipple. My 2100 spacer is aluminum and the 1/2” inlet faces the firewall.

For now I have bought some PCV hose from the parts store but it is not formed and is cheap and collapsing under idle vacuum. Yes, it is labeled as PCV hose and rated up to 3.4 Bar ~ 100 inHg. I have approximately 19 inHg at idle, so this hose is clearly not holding up to its claims.

Does anyone have suggestions for the correct hose for my application? I could order another hose from Dennis Carpenter and rig something up that will work, but I would prefer to find the right hose if possible.

 

[f2502011]

You're better off getting some heater hose that's what I had to do and looks fairly correct. Dennis Carpenter used to make the correct hose but my last communication with them they had discontinued it and will make no more. The PCV hose you got from them is for a different application can't remember what but it's not for the 71s and 2s. The original ones are unobtanium. I guess you could order another hose from them and put a connector in the middle to join them together at least that way you would have the molded 90s.

 

[abrogate932]

You're better off getting some heater hose that's what I had to do and looks fairly correct. Dennis Carpenter used to make the correct hose but my last communication with them they had discontinued it and will make no more. The PCV hose you got from them is for a different application can't remember what but it's not for the 71s and 2s. The original ones are unobtanium. I guess you could order another hose from them and put a connector in the middle to join them together at least that way you would have the molded 90s.

Your idea of making two into one is what I was thing as well. I could join them with a barbed 90 and follow the drivers valve cover and make it super simple. I’ve seen other 302’s with the PCV port on the carb spacer facing forward, but the one I have definitely should point backwards. The shape of it matches the 2100 base.
I was kind of hoping there would be a different application that I could search for. The DC hose is listed as working for 71 cars with a 302 and I was hopeful it would work. They do list 71 truck hose option, it may be the one you are referring to. I don’t how it would even hook up.

 

[DirtDonk]

My ‘71 was more like the short one.
It ran from the PCV valve in the fill cap to the rear (still on driver’s side) and over to the rear facing port on the spacer.
Any chance you can make yours work with that configuration?
I have seen other setups of various years with the hose routing like yours, but that always seemed crazy to me. What with the choke, heater hose, and various other fixtures in the way, the short path always seemed better.

But this is also why I always make my own PCV setups out of steel tubing with rubber just at the ends.
Bending 3/8ths steel lines is pretty fun and calming for me. And the end result is usually very satisfying and appealing to the eye.

 

[DirtDonk]

Oh, forgot to mention that the original on mine had two 90’s to make it work.
Since the valve was vertical it was necessary.
I prefer the valve that has a 90 already on it so that the hose can be straight.

 

[abrogate932]

My ‘71 was more like the short one.
It ran from the PCV valve in the fill cap to the rear (still on driver’s side) and over to the rear facing port on the spacer.
Any chance you can make yours work with that configuration?
I have seen other setups of various years with the hose routing like yours, but that always seemed crazy to me. What with the choke, heater hose, and various other fixtures in the way, the short path always seemed better.

But this is also why I always make my own PCV setups out of steel tubing with rubber just at the ends.
Bending 3/8ths steel lines is pretty fun and calming for me. And the end result is usually very satisfying and appealing to the eye.

I was considering the steel tubing with short connector. The end result will definitely look better than the junk I got from the part store. Oreilly’s sold me a PCV valve that had a 3/8” nipple, so I could use that in place of the V156 (EV-50). I would have to figure out how to bump up to 1/2” at the carb spacer though.

I also thought the routing that I had was cramped. It didn’t really look right, but it worked fine for years.

 

[DirtDonk]

Might have been a smog thing?
Perhaps broncos with an air pump (thermactor” in ford-speak) needed some different routing.

 

[DirtDonk]

I always wondered how to adapt the hose to the fitting. But the point became moot when I changed to an aftermarket carburetor that already had a 3/8ths fitting.

But thinking about it now it seems like it would be more straightforward to adapt the fitting down to a three eights to match the hose.
Not sure exactly how, but I think that would work better.

 

[Ovalis]

73 & 74 Broncos were a similar setup but they used a steel hardline for the back section. When they introduced EGR in 73, the EGR valve took up the space of the PCV port on the carb adapter, so the port was moved to the back of the carburetor and they used a hard line from the back of the carb that came around and stopped roughly underneath the choke. From there they used a rubber line to the PCV valve. Curious how far the new hose you ordered reaches. Would it make it to the choke?

 

[MarsChariot]

For what it is worth, here is the 71 shop manual diagram for the PCV arrangement.

 

[DirtDonk]

Interesting. I wonder if there was a difference between CA and FED models.
That, or the original owners of mine had changed it very early on, to eliminate some clutter maybe?
Although I still kind of doubt that because of the hose on mine already being old and worn looking, but it’s hard to fault the diagrams!

 

[Broncobowsher]

PCV to carb base plate. What I do is make one out of 3/8 steel fuel line. Do a bulge on each end (start a double flare but stop way early). Then a short 2-3" piece of PCV rubber hose at each end.

You can make any length, curves, bends, clearance. While not stock, it has a stock look to it.

 

[DirtDonk]

Exactly. Makes it look like somebody took their time to do it right.
And a lot of Ford passenger cars did it that way already by the early to mid 70s. A friend’s 73 LTD had it.
Don’t remember when the trucks started doing it, but my 79 with a 400 had metal tube also.

 

[MarsChariot]

If that isn't confusing enough, at some point Ford had switched from having the PCV valve in the rear passenger side valve cover and the intake from the air clearer in the oil filler cap. Somewhere I read that they moved to the front pil filler cap since it was closer to the top of the vapor stack or some such.

 

[DirtDonk]

Between ‘70 and ‘71 is when it changed at least for the V8’s.

 

[MarsChariot]

That's what I was thinking. It may have changed half-way through the 71 model year which is why the factory manual, being written at the beginning of the model year, had the earlier arrangement. Probably scattered over the space of a few months as they used up older parts stacks. The reason I say that is because mine, which was built in January 71 had the old arrangement, but the rest of the vehicle has all the drive train upgrades that happened in the middle of the model year.

 

[DirtDonk]

But January 1971 was actually was almost halfway through the production year.
Remember for that year it started in approximately August/September of ‘70 and went through August of ‘71.
So yours is not far out of line. I think mine was built in December 1970 and still got the Dana 44 front end.
Now you’ve got me thinking. I’ll have to go and look again at the build date.

Also 70 and 71 went through an electrical change.
They completely re-vamped the wiring harness for 71, but 71 was included in the early diagrams.
Apparently, the change memo was late again!

 

[Broncobowsher]

Exactly. Makes it look like somebody took their time to do it right.
And a lot of Ford passenger cars did it that way already by the early to mid 70s. A friend’s 73 LTD had it.
Don’t remember when the trucks started doing it, but my 79 with a 400 had metal tube also.

Now that you reminded me, it was stock on my '77 F250 460. It was metal and I had to build a new one when I changed to EFI and a better intake.

 

[abrogate932]

For what it is worth, here is the 71 shop manual diagram for the PCV arrangement.

This is exactly how my hose was routed. My clean air hose coming from the intake is slight different in appearance though. It is almost straight and the elbows are almost 45 degrees. I think I have only seen 90 degree elbows aftermarket.

 

[abrogate932]

73 & 74 Broncos were a similar setup but they used a steel hardline for the back section. When they introduced EGR in 73, the EGR valve took up the space of the PCV port on the carb adapter, so the port was moved to the back of the carburetor and they used a hard line from the back of the carb that came around and stopped roughly underneath the choke. From there they used a rubber line to the PCV valve. Curious how far the new hose you ordered reaches. Would it make it to the choke?

The new hose barely make it past the throttle assembly. I am planning on the hard line option and connecting it with some short pieces of PCV hose. I’ll post pics when I get to it in the next week or so.