Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

New Member - Emmissions Question

Discussion in 'The Garage' started by skink4president, Mar 5, 2005.

  1. skink4president

    skink4president Registered Member

    Joined:
    Mar 5, 2005
    Posts:
    79
    Likes Received:
    0
    Location:
    orlando
    I recently purchased a 1973 K-5 (350/350). I'm the third owner and the vehicle is, for the most part, in amazingly stock condition. The previous owner replaced the OEM intake and Q-jet with an Edlebrock square bore carb (#1405) and non-emissions Performer intake. In doing so much of the emmisions equipment was removed (no AIR system, no EGR). The EVAP is still intact but I question it's performance; which leads me to my questions:

    1) Can I or should I remove the EVAP?

    2) If the lines and canister are removed what mods need to be done to properly vent the gas tank?

    From what I can tell it's a fairly simple system: one line in from the fuel tank, one line out to the PCV/carb. No emmissions test here in Florida (yet)!

    Thanks!

    BTW - Anyone know how to fit tall valve covers under that damn AC compressor bracket?!?
     
  2. 1-ton

    1-ton 1/2 ton status Premium Member

    Joined:
    Apr 17, 2004
    Posts:
    2,890
    Likes Received:
    167
    Location:
    Las Vegas, Nevada
    When I removed an old cracked, dry rotted, and wore out EVAP system on a truck of mine once, I slipped a vacuum cap on the end of the fuel tank vent line, and then used vented gas caps (if you can find vented gas caps anymore). You need to replace the vacuum cap about once every couple of years (or so) because they will dry rot, crack, and then start leaking gas all over the top of your tank. Welcome to CK5!
     
  3. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,982
    Likes Received:
    191
    Location:
    Roy WA
    *IF* its working correctly, leave it alone. Venting the tank is a dangerous proposition IMO, and the EVAP system when working correctly is about the safest and least damaging to the truck.
     
  4. 1-ton

    1-ton 1/2 ton status Premium Member

    Joined:
    Apr 17, 2004
    Posts:
    2,890
    Likes Received:
    167
    Location:
    Las Vegas, Nevada
    I agree with this as well. The best thing to do is replace all the dry rotted vacuum hose (all the way back to the fuel tanks, which can be a b*tch), and the EVAP cannisters filter, which in located on the bottom of the cannister.
     
  5. dirtwarrior17

    dirtwarrior17 Banned

    Joined:
    May 14, 2004
    Posts:
    1,820
    Likes Received:
    0
    Location:
    Redding, CA
    hang on to all the emissions crap you can..... the laws are gonna change real soon...
     
  6. dirtwarrior17

    dirtwarrior17 Banned

    Joined:
    May 14, 2004
    Posts:
    1,820
    Likes Received:
    0
    Location:
    Redding, CA

    I don't know about 73 but for 88 i had to cut my ac bracket to get it to fit the holley manifold... it sounds like yours goes to the valve covers... you might want to call around to whoever made the covers. parts like valve covers, and manifolds come with instructions on how to modify brackets like ac to get them to fit.
     
  7. Fierospeeder

    Fierospeeder Banned

    Joined:
    Sep 17, 2001
    Posts:
    315
    Likes Received:
    0
    Location:
    Illinois
    gas evaporates. And when you leave your gas tank vented, you will be losing gasoline. That is why you see rednecks putting rags in their gas tank filler when they forget their gas cap at the gas station.
     
  8. skink4president

    skink4president Registered Member

    Joined:
    Mar 5, 2005
    Posts:
    79
    Likes Received:
    0
    Location:
    orlando
    Thanks Guys. I think I'll hang onto the EVAP system and just replace the lines and filter. In the mean time I've chosen to go with the "stock" height Edelbrock valve covers in place of the "talls".
     
  9. R72K5

    R72K5 Banned

    Joined:
    Mar 5, 2001
    Posts:
    8,905
    Likes Received:
    0
    Location:
    central IL
    yeh that gas does evaporate pretty quick, its crazy, whatever you do though dont create a situation where the tank cant relieve pressure when it expands and where it creates vacuum as gas is being pulled out by fuel pump

    its tricky,

    ive had a few vehicles that have done one or the other, when the latter happens it starts to deprive engien of fuel, when the first happens then the cap blows off the filler neck when you remove it(70 and older trucks for one before factory fuel vapors vent recovery system)

    be careful


    good luck
     

Share This Page