Vortec Cylinder Heads: The Definitive Guide

Discussion in 'Engine Topic' started by MikeM79, Jul 4, 2006.

  1. zachisageek

    zachisageek Veteran Member

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    Thats what I wanted to know :D
     
  2. Mz28att

    Mz28att Veteran Member

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    I am now the proud owner of a set of small port Bowtie Vortecs. I have a few questions. Will the LT4 springs work with the Lunati 401A6? I have 1.6 rockers on the intakes. Next, they have been milled down to 60cc chambers. How does that effect pushrod length? Finally, if I attempt to put these on my 406 with the above cam, should the steam holes be drilled in them?

    Thanx,
    MaTt
     
  3. Charlie Brengun

    Charlie Brengun Veteran Member Lifetime Gold Member

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    i'm looking for an estimate of how much HP and Torque my engine will produce after putting on a set of vortecs.

    I have a stock goodwrench 350, 250 HP 350 ft lbs of torque and should be 8.5:1 comp.
    It will have headers, a Q-jet, a PP cyclone intake, change the cam into a isky 264/270 mega cam 214/[email protected] .450/.456 lift and a 112 Lobe seperation.
    The heads are vortecs, that have been Cleaned, valve job done, guides cut down, studs have been pinned, new Comp cam springs for a .550 lift cam, no port grinding done on the heads.
    I'm going to change the valve springs to the springs that came with the isky cam kit.
    I have a stock HEI dizzy that i used an upgrade kit on so i can change out springs and weights as needed.

    from an other post i gather that with .015" steel shim gaskets and 64 cc heads compression goes up to 9.87:1

    so what would your estimates be? thanks ;)
     
  4. wayfast84

    wayfast84 Veteran Member

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    Dirt I have a question about rocker arms, I purchased the summit cam version of yours and the springs that where recomended with it, But my machinist used springs that are a higher lift as mine where to short or something. Should I step up to 1.6 roller rockers? what are the factors to piston to valve clearence?
     
  5. Dirt Reynolds

    Dirt Reynolds Veteran Member Lifetime Gold Member

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    You should not have p-v clearance issues with the 234/244 .488"/.510" cam and stock ratio rocker arms. Even with a 1.6 rocker I'd say you should be okay *but* to be safe if you are concerned about it, get your machinist to mock-up a piston with clay and check. Going to a 1.6 rocker might mean your pushrod holes will need to be drilled-out ("ovaled") for added clearance as they are very small in the stock Vortec head.
     
  6. ORANGE77

    ORANGE77 Veteran Member

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    I picked up a set 062 Vortecs from a member of this site and will be looking foward installing soon. They are unassembled with the exhaust side cleaned up a little. I have some questions. They will need valve seals. What would be recomended here. The seller told me positive for the intakes and umbrellas for the exhaust. I was under the impression the positives need head machining done. The springs I have are LT-1 w/ the LT-4 retainers and clips. Would .490 be the lift limit? I have a GM .390/.410 cam in my cars 350 now. Just curious on what h.p. I could get w/ 1 5/8" headers, 2 1/2" exhaust w/ x-pipe. The intake is a GMPP and the carb a holley 600 single feed. I also have a Quick Fuel Pro-Vac 650, dual feed, vac secondary. I was looking at the GMPP 330 h.p. HO cam, a Isky Mega 264/270 or a Linati Voodoo 262/268 cam for a upgrade. I'm new to installing seals and springs. I'm thinking on getting a shop to do that (seals and springs) and was wondering what that would cost. Oh, back on valve seals, I found some Fel-Pro stem seals in Summit. They list these as umbrella, but also say they're positive and are for a 96 to 00 Tahoe w/ the 5.7 engine. Could use those and put them on myself with which tool without machining. Tell me what you think everyone. :)
     
    Last edited: Jun 20, 2007
  7. Dirt Reynolds

    Dirt Reynolds Veteran Member Lifetime Gold Member

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    I just used the stock GM seals for Vortec heads. For retainer to guide clearance, all I did was the "ghetto grind" on the stock retainers discussed early on in this topic. Took off about 3/16" or so and had plenty of clearnace for a .488"/.510" valve lift cam. To *really* know what you are safe to lift-wise, you have to check. Some guys have gotten away with .500" reportedly while others manage around .460". GMPP 330 HP Vortec cam is a great cam profile in my opinion for a street 350 with Vortec heads.
     
  8. ORANGE77

    ORANGE77 Veteran Member

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    Hi Dirt, I was sort of leaning towards the GM HO cam also. I allways liked that motor (the GMPP 330 HP Vortec). The only difference is that I have a LM-1 350 motor to work of still in good shape with only 40K. Didn't GMPP use the the LT-1/Z-28 springs and LT-4 retainers and locks, because that's what I have. As for as seals, Fel-Pro makes a viton seal as a replacement for a 96 to 00 Tahoe. Or theres VTO that makes a seal that could be bought too. :smokin:
     
  9. mudtrux

    mudtrux Veteran Member Lifetime Gold Member

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    Hey all sorry I haven't read this entire (or the majority of) this thread but I did search for some key words and didn't find my answer

    In a round about way this is Camaro related

    I want a different engine for my mud truck so I can put it's current engine in my Camaro and finally drive it

    I have a set of fresh stock 906's with the guides milled down waiting for a short block to put them under

    A friend offered me a fresh 406 with high domed pistons (they look like about 1/2 over the top of the piston)
    My question is will this combo work together and what cam and carb would I be looking for?

    I'm planing on using a hi rise dual plane and I have 104 and 110 fuel available to me

    I want low end torgue and don't plan on running over 6000 rpm.
    If this sounds like a useable combo I'll probably ask more questions later.
    Thanks, Ken
     
  10. Dirt Reynolds

    Dirt Reynolds Veteran Member Lifetime Gold Member

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    Nope. You cannot use a domed piston with the Vortecs due to the shallow kidney-shaped chamber. The chamber was designed for use with either a (preferably) flat-top or dished piston. You will have to either use different heads or change the pistons.
     

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