I need help with my 351w project's ventalation

MintyFresh

Member
Nov 2, 2019
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Denver
Hi everyone,

I recently picked up a new project car for my son and I to tackle in the form of a 68 Mustang coupe with a 351w (stroked to 387). We've been doing a lot of preliminary maintenance to fix some of the glaring issues before we remove the engine and transmission for the restoration. We want it running before we tear it apart. We've named it "Frankenstang" because of the numerous "creative" (shall we say) decisions a previous owner made.

In particular, I found a pair of oddities I could use help with. On the passenger side valve cover, the vent hose makes its way back to the manifold. You'll see on top of the manifold, what I'm assuming is just a fitting for the vacuum port. There's a small section of hose coming out with a bolt threaded into it. Obviously the bolt is supposed to stop vacuum air flow from outside, but I'd like to know what the correct setup would be here. Otherwise, it seems like it'd make sense to install a fitting without the extra vacuum hose attachment, but I'm not sure. More importantly, it seems like a PCV valve should be somewhere inline. I could use thoughts on that.

Second, on the front of the carb are similar hacks. There's a wheel stud inserted into a short section of hose with the other end attached to the carb. Next to it there's a a Phillip's head bolt in a smaller section of tubing. Both are just dangling there. The cap on the driver's side valve cover is not vented. In any case, I could really use some help understanding what one of the previous owners was up to, and how the engine should be properly set up.

It does run, and seems to run well. But I want to get this set up right, and wheel studs and random bolts just isn't what I'm going for.

Thanks for the help on getting this set up right!



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On a stock engine the pcv valve hose attaches to a carb plate under the carb, at the back of the carb. Your hose runs to the intake manifold which might cause a lean cylinder. Second it appears that you have an Edelbrock carb and intake manifold. The hose on the front of the carb that you are questioning is for a pcv hose! You could plug the hole in the back on the manifold and run a new pcv hose and attach it to the front port on the carb. Or find a rubber plug for the pcv hose on the front. The previous owner may have removed the carb pcv plate because the carb was to tall and had hood interference. Also it is sometimes hard to get a good seal between the carb and intake manifold. Pick up a good parts catalog from NPD, for your project (the paper one). I find it easier to naivigate than the online site. Edelbrock has online manuals for your carb. You and your son should have a lot of fun with your project. Any pictures of the car?
 
On a stock engine the pcv valve hose attaches to a carb plate under the carb, at the back of the carb. Your hose runs to the intake manifold which might cause a lean cylinder. Second it appears that you have an Edelbrock carb and intake manifold. The hose on the front of the carb that you are questioning is for a pcv hose! You could plug the hole in the back on the manifold and run a new pcv hose and attach it to the front port on the carb. Or find a rubber plug for the pcv hose on the front. The previous owner may have removed the carb pcv plate because the carb was to tall and had hood interference. Also it is sometimes hard to get a good seal between the carb and intake manifold. Pick up a good parts catalog from NPD, for your project (the paper one). I find it easier to naivigate than the online site. Edelbrock has online manuals for your carb. You and your son should have a lot of fun with your project. Any pictures of the car?

Funny - I came to a similar conclusion last night. I found that it's actually a Carter AFB 9636AS Performance carb, so basically the same as Edelbrock. I think the rebuild kits are almost identical. I fount yet another bold+hose hack under the air filter when I went looking for the carb's tag :rolleyes:. I've been traversing NPD and already had a bunch of sheet metal body parts I was about to order, so I'll add a few plugs and hoses to the order. I like the idea of routing to the front of the carb and capping off everything else. I might also consider possibly picking up a vented cap from Summit for the driver's side and running that hose over as well. In any case, thanks so much for the input. That's what I was looking for.

As for pictures, we picked it up in this state. It wasn't able to start without popping the clutch when we grabbed it. We've since got her up and running and we're working on getting the engine in good shape before we pull it for the restoration.
pony day.jpg
 
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Having PVC run to one cylinder runner will cause that cylinder to ping.
run PVC to carb base plate or carb PVC location.

That's my plan. I've ordered a plug for the intake and a hose to re-plumb to the carb. What I can't for the life of me answer is why someone set it up this way. Based on some of the other mods, I think he wanted to make a drag car out of it, so maybe he wanted it running lean. Seems like an unusual choice. He wasn't inexperienced by any means; just creative. For example, there's a schrader valve he mounted in the trunk floor just behind the rear seats. It looks like he wanted easy access to his gas shocks. "Creative" is being kind.
 
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For example, there's a schrader valve he mounted in the trunk floor just behind the rear seats. It looks like he wanted easy access to his gas shocks.


Ha Ha, I had a schrader valve filler in my trunk for air shocks for years after the air shocks were gone. It kept the hole plugged, right!?!