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Posted by: rbj914 May 28 2023, 11:25 AM

The charcoal cannister on my 73 2.0 is disconnected. You can see the lines in the engine bay. I want to reconnect it, but the nipple is missing on the engine shroud. Where do I find a replacement for this?

Posted by: Superhawk996 May 28 2023, 01:03 PM

Concours answer is find a donor part and swap or have one machined.

The more practical answer is appropriately sized tube (steel, copper, PVC - you choose) and some JB weld.

Posted by: Dave_Darling May 28 2023, 03:57 PM

Engines which had this blocked off should have a fitting on the side of one piece of engine tin. The hose would go onto that fitting rather than onto the fitting in this part of the fan shroud.

I don't know why the one or the other was chosen, nor if it's a year/displacement thing or just random.

--DD

Posted by: rbj914 May 29 2023, 09:56 AM

Thanks Dave, This is a 73 2.0 in a 70 car and there isn't one on the tin. Might not be the original tin for this engine. Appreciate the response.

Posted by: rbj914 May 29 2023, 10:03 AM

Thanks Peter, definitely going with plan B. It's a 73 2.0 in a 70 car, so no concours.

Posted by: Superhawk996 May 29 2023, 05:09 PM

Hmmm . . . Based on Dave’s comment I went and looked at the shroud I have in storage from a 73’ 2.0L. Sure enough - no nipple sticking out of the fan shroud. Just the same hole as you have.

@‘dave darling’

Posted by: Dlee6205 May 29 2023, 05:27 PM

Are you looking on the driver's side engine tin for the nipple? For 2.0L cars, the plastic vent lines did not cross the the engine bay like they do on the early cars.






https://bowlsby.net/914/Classic/TechNotebook.htm

Posted by: rbj914 May 30 2023, 02:42 PM

Ok, I think I see the problem. I do have a nipple on the driver's side tin, but it's going to the flashback valve (shown in the photo). According to Dave's diagram the flashback valve should be attached somewhere under the air cleaner. I don't see anywhere under there to do that. If I attach the one in the engine tin to the charcoal cannister, what goes to the flashback valve? Should there be another nipple under there?

Full disclosure, I put this engine in around 1980 and I can't remember where the tin came from.

Posted by: GregAmy May 30 2023, 03:10 PM

Hell, I put an engine in three weeks ago and I'm lost on where things go...

Posted by: JeffBowlsby May 30 2023, 03:34 PM

Keep looking, there are two nipples in the area by Cyl 2.

Your flashback valve is incorrectly connected to the supply air nipple for the charcoal filter.

Look for the flashback valve nipple closer to the #2 intake port emanating from the head. Both heads should have this port - one at cyl #2, the other at cyl #3, both get connected to the antiflashback valve - to serve its purpose for safely venting the case. The way yours is set up you are directing fan supply air into the intake through the flashback valve. Sort of a turbo effect, but likely leaning out the mixture.

Study Dave D's diagrams, it shows the relative locations of the two ports at cyl 2.


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Posted by: 914werke May 30 2023, 04:00 PM

More interesting information.
Indeed I never connected the fact that on some impeller housings that boss was present but not drilled through, with the fact that there was an additional bung on/near the the #2 top tin.
In either case its purpose once connected is to provide positive air flow to the charcoal evap plumbing & aid those gases into the intact tract.

Posted by: rbj914 May 30 2023, 06:22 PM

Well, this can't be good. #3 has the nipple and the vacuum hose is routed to the flashback valve properly. #2 shown below seems to be plugged with something. It will not come out, but I haven't tried to force it. Funny thing is, the plug has little ridges in it like around the nipple in Jeff's picture. Is this what Rich meant by "not drilled through"?

You guys are a wealth of information.

Posted by: JeffBowlsby May 30 2023, 06:46 PM

I think you may have an earlier year head. They did not have those flashback valve ports.

Check the head part number under the valve cover?

Posted by: rbj914 May 31 2023, 06:25 AM

Thanks Jeff, I will be under the car this weekend and check it out. Assuming that is the case, will I cause any damage by just plugging that port on the flashback valve and running without it? Doesn't seem like I have much of an option.

Posted by: Dlee6205 May 31 2023, 06:40 AM

That's what I would do. It shouldn't hurt anything.

Posted by: rbj914 May 31 2023, 09:14 AM

Thanks Doug, I appreciate the feedback. Looks like you are up there in God's country. Great roads for these cars. Spent some of my best years in Boone (with this car) many years ago.

Had this car 53 years and it has been parked the last 26. It's running pretty good thanks to the help of a local mechanic, but still sorting things out. Maybe I can get up that way and get your help when I feel confident she'll get me there and back.

Posted by: rbj914 May 31 2023, 09:25 AM

To all that posted on this thread. I now know more about flashback valves and head vents than I could have imagined. I am very appreciative and honored that the gentlemen above took the time to help me out. What an awesome resource!

Posted by: Jim C Jun 5 2023, 11:59 AM

Was the engine from an A/C equipped car? If so your carbon canister nipple should have been on a special timing opening cover on top of the fan shroud.

Posted by: rbj914 Jun 7 2023, 09:09 AM

Thanks Jim, I don't think it was A/C equipped. At least no cutouts in the tin. That is an interesting fact though. I think Jeff nailed it when he said it must be an earlier head.