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1970 Gas Tank ... EEC vs non-EEC

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Old Jun 22, 2004 | 04:12 PM
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Default 1970 Gas Tank ... EEC vs non-EEC

OK - so here's the question:

EEC == Evaporative Emmisions Controls

My 70 chassis came with a non-EEC tank. I have a chance to pick up a
1970 tank w/EEC. It looks like the only difference is the vent tube on the top
of the drivers side.

So, can I just block off the EEC vent tube ... and that's the only difference ?

Also, I think it has a sealed cap. Shouldn't the cap be vented, if the tank is not ?

Thanks for your help !!!


[Modified by NHvette, 4:46 PM 6/22/2004]
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Old Jun 22, 2004 | 11:14 PM
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Default Re: 1970 Gas Tank ... EEC vs non-EEC (NHvette)

As far as I know they are the same except for the extra vent tube. Just block it off. Yes either the tank or the cap needs to be vented. On my 70 there are two fuel lines along the P/S rail.

Jim
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Old Jun 23, 2004 | 02:53 PM
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Default Re: 1970 Gas Tank ... EEC vs non-EEC (NHvette)

Dave you need a vent somewhere in the system. By '74 (my year) they used a non-vented cap but installed a vent at top of the tank through a liquid separator to a Evaporative Vapor Canistor (EVC) up front in the engine comp/drivers fender well. This liquid separator is needed to remove liquid from splash inside tank. This ECV (same line) is then connected to the carb primaries above the throttle plates (ported vacuum) and this allows the tank to vent throught the EVC as fresh purge air is drawn in through bottom of EVC through charcoal and into tank or carb.
Before this EVC sys the tanks where just vented through the caps and vented caps are still readly availible. BTW I just replaced my EVC for $55 from NAPA.
Hopes this helps. cardo0
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Old Jun 23, 2004 | 05:18 PM
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Default Re: 1970 Gas Tank ... EEC vs non-EEC (cardo0)

cardo0

Where can you get one of thos e liquid separators without taking out a 2nd mortgage? can I get something from a different car to use? Originality is not an issue it just needs to work.

Steve
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Old Jun 23, 2004 | 11:41 PM
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Default Re: 1970 Gas Tank ... EEC vs non-EEC (stpman)

cardo0
Where can you get one of thos e liquid separators without taking out a 2nd mortgage? can I get something from a different car to use? Originality is not an issue it just needs to work.
Steve
Steve someone recently asked me this when I posted how I repaired mine for return to service. I still think its just a matter of someone doing the research to find a cheap and adaptable replacement. All that was inside mine was a ball float that seated a valve and looked alot like a carb inlet needle & seat assembly - just bigger.
To start looking I would try calling/visiting more than one business that handles fuel tanks replacements and repair. Also a good NAPA store will have a cataloge with pictures of nearly every part they sell - catch them when thier bored on friday afternoon and talk'm into a search. Last, most pick-your-own boneyards set thier cars up high on old rims and you may get to see for your self whats on what tank. I'm guessing but I imagine theres planty of liquid separators on junked cars using EVCs.
Good luck. cardo0
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Old Jun 24, 2004 | 11:02 AM
  #6  
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Default Re: 1970 Gas Tank ... EEC vs non-EEC (cardo0)

Thanks for the discussion, guys.
I think - if I get the EEC tank, I will initially block off the vent and use a vented cap.
One thing to add there ... tip from Doc Rebuild ....
Make sure the boot and drain tube are clear. If the boot fills with rainwater,
a vented cap will leak water into the tank.


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