1978 Evap System Removal

Hey guys,

So while doing my belts, I've been poking around the evacuation/vacuum system and seem to have a very interestingly pumb'd car. I've got a number of wide open switches, some hoses that go to nowhere and the like.

I think that I'd like to just remove the vacuum sphere and related hoses and leave the airbox evacuation pump, while disconnecting the flap mechanism (it was safety wired open anyways). I'm hoping to just simplify what's under the hood and put the vacuum stuff in a box.

I've included a couple of pictures of where it's at currently. If I disconnect the vacuum sphere at cylinder 8 and cap it, what do I do with the diverter valve? Also, it looks like there's a wide open, larger hose under my diverter. What role does that play and should it be hooked up as well?

Are there any other obvious, glaring, gonna-burn-down faults that I need to be aware of?

Thanks,

E
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On my '79 I don't have any of that stuff any more. The metal lines under the carbs (that went to the charcoal canister) have plastic caps on them. The air cleaner flap stuff is also gone and the holes plugged. (The crankcase breather is the only other thing going into the airbox.) Airpump also gone. So my answer would be, you're OK taking it all out.

 

Two points that I'd make:

1. If you don't have an operating air injection pump (and diverter valve, etc.) present = you should really remove the air injector nozzles and air injection manifolds (and put they oft-discussed custom plugs into the cyl head to replace the air injection nozzles - a search on the "108205" part number of the air injection nozzles should get you a ton of prior threads), and

2. On a euro 308, there is a vent tube connected to the fuel filler neck that runs down to near the ground. What this does is allow air to move in and out of the fuel tank, but, if the chassis goes upside-down, fuel will not run out just due to gravity. If you are going to completely remove the fuel evaporation control system, you need to provide a similar situation -- i.e., the single hose leaving the fuel vapor separator in the RH side C-pillar (that normally goes to the charcoal canister) should be extended down to the bottom of the chassis area so liquid fuel won't run out under gravity if upside-down. However, removing the airbox flap mechanism+sphere reservoir+small air pump+check valve does not mean that you have to remove the rest of the fuel evaporation control system (i.e., keeping the charcoal canister might not be such a bad thing - JMO).

See the technical figures in Section 3 of the 150/78 US '78-79 308 GTB/S OM for these systems -- they are quite good, and might help with your understanding.

PS Do save the bits -- they are already becoming valuable unobtanium...

 

Hey Steve,

Thanks for the detailed reply. I removed the vacuum sphere and airbox flap mechanism today and capped the openings that I have created. I was planning on leaving the small air pump and the connection to the canister. I figured even with the air box open, it could hurt to have a little suction heading the fuel canister's way.

As for the air injector nozzle and manifolds, were these on the '78 cars? I didn't really see anything around the exhaust ports on the back but might just be looking in the wrong place.

Would you happen to have any pictures of the item in situ? Is this the manifold I need to be on the lookout for:

New Factory Rear Air Injection Manifold for Early USA Ferrari 308 GTB Emission | eBay

Looking at the OM, I certainly don't have an air pump anymore and there a ~1" tube that's disconnected from everything on the rear of my diverter valve.

Thank you so much,

E

 

Yes, that's one of the air injection manifolds used on the '78-'79 US 308 that connects to the air injection nozzles -- although they usually look like this after some use :
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Well, all that stuff is still there, both front and rear. The rear piece looks easy enough to get to, but my god, how would you remove the front and then replace with the caps?

 

By going in thru the RH rear wheel well (with the alternator/AC removed) and from underneath -- I didn't say it was going to be "easy"

 

I remember back when I was a younger man (Tuesday) when I thought all I had left was removal of the vacuum sphere...

So I'm thinking the way to go here is to remove the air injector manifolds, plug with Verell's custom jobies, jet hot the headers, remove the heat shields, install the hyperflows, fire on a Nuvolari sport exhaust, hollow out the airbox, rejet the carbs, remove the check valve, remove the diverter valve...

What about the crankcase emissions stuff? Leave it be or is there a simpler setup?