Welcome to Club Hot Rod!  The premier site for everything to do with Hot Rod, Customs, Low Riders, Rat Rods, and more. 

  •  » Members from all over the US and the world!
  •  » Help from all over the world for your questions
  •  » Build logs for you and all members
  •  » Blogs
  •  » Image Gallery
  •  » Many thousands of members and hundreds of thousands of posts! 

YES! I want to register an account for free right now!  p.s.: For registered members this ad will NOT show

 
Like Tree1Likes
  • 1 Post By pat mccarthy

Thread: How much lift can stock Vortec heads handle?
          
   
   

Reply To Thread
Results 1 to 11 of 11
  1. #1
    micaiahbur14 is offline CHR Member Visit my Photo Gallery
    Join Date
    Sep 2014
    Location
    Howe
    Posts
    3

    How much lift can stock Vortec heads handle?

     



    I'm putting a set of Vortec heads on my sbc 400 my cam has a lift of .443/.465. i've heard a lot of different things about the highest lift vortecs can take without machining ive heard .420-.550. which seems a little high. I have matching springs, Competition Cams 742-16 Steel Retainers, with locks, do not have new valve stem seals yet. I'm wondering if with what i have if i can use this cam with theses heads without cutting the valve guides down. any help would be greatly appreciated.

  2. #2
    techinspector1's Avatar
    techinspector1 is offline CHR Member Visit my Photo Gallery
    Join Date
    May 2003
    Location
    Zephyrhills, Florida, USA
    Car Year, Make, Model: '32 Henway
    Posts
    12,423

    Quote Originally Posted by micaiahbur14 View Post
    I'm putting a set of Vortec heads on my sbc 400 my cam has a lift of .443/.465. i've heard a lot of different things about the highest lift vortecs can take without machining ive heard .420-.550. which seems a little high. I have matching springs, Competition Cams 742-16 Steel Retainers, with locks, do not have new valve stem seals yet. I'm wondering if with what i have if i can use this cam with theses heads without cutting the valve guides down. any help would be greatly appreciated.
    There is lots of bogus info concerning these heads. I think this tutorial sums it all up pretty nicely.
    http://www.crankshaftcoalition.com/w..._cylinder_head

    .
    PLANET EARTH, INSANE ASYLUM FOR THE UNIVERSE.

  3. #3
    glennsexton's Avatar
    glennsexton is offline CHR Member/Contributor Visit my Photo Gallery
    Join Date
    Mar 2005
    Location
    Tigard
    Car Year, Make, Model: 63 Nova SS
    Posts
    2,584

    Welcome to CHR!
    The article referenced by Tech is really spot on. The stock Vortec is limited to .420 lift. You will find people that claim to have the stock heads with more lift but one of three things exists with a claim of a stock head running with greater than .420 lift; a) damage is being done (or has already been done) to the head, b) the measurement was done incorrectly (actually .420 or less) or most likely, c) the individual doesn’t really know what the net lift is. The most a stock Vortec head with stock components will safely accommodate is .420. Anything more requires machining the valve guide boss and the valve guide as well as new seals.

    With proper machine work as outlined in the article, it is possible to have up to .600 lift on a Vortec head which is more than sufficient for all but the most radical valve train combinations. The pushrod holes should also be enlarged to 1/2" if you'll be using other than stock 1.5:1 rockers. As to the valve seals, see the pictures below.

    Best of luck and let us know what you're building.

    Again, welcome to CHR
    Glenn
    Attached Images
    "Where the people fear the government you have tyranny. Where the government fears the people you have liberty." John Basil Barnhil

  4. #4
    pat mccarthy's Avatar
    pat mccarthy is offline CHR Member/Contributor Visit my Photo Gallery
    Join Date
    Apr 2005
    Location
    bay city
    Posts
    10,546

    yep did a set long before the big net were guys said it could not be done .set them up on the seat and guide machine drop down on the spring pocket then clean up the guide with a seal cutter tool for a 531steel clad rigid chimney viton seal thin wall steel wall if need the od diameter or std 531 seal. i stop using them white PC seals long ago hate them things pure junk use to spilt before you could get then on . i still have them two small trays in my seal cabinet is till they started making the steel wall only viton seal for trip springs with a od of 500 it was them white bastards or NO seals at all or a sbc o ring on the EX valve and some RTV in the valve keeper lock gap to slow some of the oil down the new chevy casting there is no guild holes to open as its a self guided rocker there is no pushrod holes
    Last edited by pat mccarthy; 09-02-2014 at 07:57 PM.
    glennsexton likes this.

  5. #5
    jerry clayton's Avatar
    jerry clayton is offline CHR Member Visit my Photo Gallery
    Join Date
    Feb 2006
    Location
    Bartlett
    Posts
    6,831

    Yep---years ago cut spring pockets, guides for seals and shortened, also machined for screw in studs---if you think you need more lift than you can get with those mods, you use longer valves

  6. #6
    pat mccarthy's Avatar
    pat mccarthy is offline CHR Member/Contributor Visit my Photo Gallery
    Join Date
    Apr 2005
    Location
    bay city
    Posts
    10,546

    Quote Originally Posted by jerry clayton View Post
    Yep---years ago cut spring pockets, guides for seals and shortened, also machined for screw in studs---if you think you need more lift than you can get with those mods, you use longer valves
    i was cutting down studs and tapiing them on the mill with a tilt table on it for this small machine shop in town i told him i did not care if i did them or not i think they found a guy that was 10. bucks cheaper then me . boring out the push rod holes were fun i always was waiting for the drill to grab and take the pinch out of the intake port

  7. #7
    micaiahbur14 is offline CHR Member Visit my Photo Gallery
    Join Date
    Sep 2014
    Location
    Howe
    Posts
    3

    So question? I'm building a sbc 400 my cam has a lift of. 443/465 and duration of do you think that this cam with vortec heads would work good? and if al what intake would you recommend for this build? Any other suggestions would be greatly appreciated. I'm trying to keep this build kk.d of on the cheap side.

  8. #8
    jerry clayton's Avatar
    jerry clayton is offline CHR Member Visit my Photo Gallery
    Join Date
    Feb 2006
    Location
    Bartlett
    Posts
    6,831

    measure the space between your valve retainer and the seal!!!!!!!!!!!!!!!!!!!!!!

  9. #9
    micaiahbur14 is offline CHR Member Visit my Photo Gallery
    Join Date
    Sep 2014
    Location
    Howe
    Posts
    3

    How exactly do I measure the distance? this is my very first engine build so any help would be awesome.

  10. #10
    techinspector1's Avatar
    techinspector1 is offline CHR Member Visit my Photo Gallery
    Join Date
    May 2003
    Location
    Zephyrhills, Florida, USA
    Car Year, Make, Model: '32 Henway
    Posts
    12,423

    Quote Originally Posted by jerry clayton View Post
    measure the space between your valve retainer and the seal!!!!!!!!!!!!!!!!!!!!!!
    Yeah, and leave 0.060" safety margin added to the lift to counter valve float.

    .
    PLANET EARTH, INSANE ASYLUM FOR THE UNIVERSE.

  11. #11
    techinspector1's Avatar
    techinspector1 is offline CHR Member Visit my Photo Gallery
    Join Date
    May 2003
    Location
    Zephyrhills, Florida, USA
    Car Year, Make, Model: '32 Henway
    Posts
    12,423

    Quote Originally Posted by micaiahbur14 View Post
    How exactly do I measure the distance? this is my very first engine build so any help would be awesome.
    Here's a nice little tutorial for you. You use snap gauges to find the distance from the spring seat to the underside of the retainer....
    https://www.lunatipower.com/Tech/Val...pringTech.aspx
    and here's another one from the crankshaft coalition, showing the use of a snap gauge to find the distance.....
    http://www.crankshaftcoalition.com/w...ve_spring_tech

    You can also do this the low-tech way by cutting a piece of clothes-hanger-wire to the length you are seeking and holding it in there with needle-nose pliers.

    .
    PLANET EARTH, INSANE ASYLUM FOR THE UNIVERSE.

Reply To Thread

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
Links monetized by VigLink