Vortec Cylinder Heads: The Definitive Guide

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

  1. hardline_42

    hardline_42 Veteran Member Lifetime Gold Member

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    I really hope you mean 2.02" valves, otherwise you got gyp'd!:eek: If your Vortecs have had that much work done to them (I have a similar set with upgraded valves for sale in the Swap Meet section) including portwork and larger valves (I'm assuming the exhaust valves have been upgraded too) it might be worth it to have some flowbench testing done before selecting a cam. Extensive port work can change the intake to exhaust flow ratio, possibly making a split pattern cam less effective than a single pattern. Once you start getting into custom and modified applications, it's much harder to pick an off the shelf cam.
     
  2. stickles

    stickles Veteran Member

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    hardline yeah i guess i should have double checked where i put the decimal point. the guy i got them from ran a single pattern cam. i also got the torker 2 intake and carb that he was using with it
     
  3. sschevellefan

    sschevellefan Veteran Member

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    Hardline, I`ve heard that the chamber needs to be modded to unshroud the intake valves when you go to 2.02/1.6. Is this correct or will basic bowl porting be ok? someone told me to use the head gasket as a templete to open the chamber up but they are awful thin and I really don`t want to cut too much from them. I`m not sure I even need the bigger valves.
     
  4. Dirt Reynolds

    Dirt Reynolds Veteran Member Lifetime Gold Member

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    The Vortec does not require the chamber to be modified for the 2.02" valves. One of the several unique features of this head is the chamber does not shroud larger valves, unlike other GM 64cc iron production heads.
     
  5. hardline_42

    hardline_42 Veteran Member Lifetime Gold Member

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    Dirt beat me to the punch. If you take a look at the pics from my Swap Meet ad for Vortec 062's, you can see what the larger valves look like in the stock chambers and it's clear that no shrouding occurs.
     
  6. sschevellefan

    sschevellefan Veteran Member

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    Yeah I saw your heads over there. I hear it from a head porter which is why I was asking. I was just going to reuse the stock valves but I`m thinking of putting the 2.02/1.6 valves in there along with with some bowl porting and gasket match. I might have them flowed before and after too.
     
  7. Alex71RS

    Alex71RS Veteran Member

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    I've looked on-line for an explanation, but what do you guys suppose is the reason for the square cut-out on the wall of each of the intake ports? You can see the bottom of the rocker stud in each one of the cut-outs. All I can figure is that it is designed to swirl the intake charge and create a negative pressure behind it to speed up the flow. I looked through Gary Penn's explanation of the Vortec head and found no reference to this feature. His writeup explained how many hours went into the heads design, and I'm sure this wasn't a casting mistake.

    By the way, my heads are 906s. Dumb question, but do the 062s have the same thing?
     
  8. sschevellefan

    sschevellefan Veteran Member

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    I should probably start another post but since it`s vortec related I thougth I would ask here. What do you guys think about this combo?

    327 at about 9.8:1 compression
    vortec heads with bowl work and gasket match, unsure about valve size
    Comp Retro hyd. roller XR276HR-276/282 224/[email protected] .502/.510 110LSA
    performer RPM or equivilent
    3310 750 VS with proform main body and billet base,just because mines worn out

    This would go in my 67 elky with about a 2600-2800 stall and either 3.73 or 4.11 gears.
     
  9. Dirt Reynolds

    Dirt Reynolds Veteran Member Lifetime Gold Member

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    Alex -- I know the little cast-in square you refer to but I'm not sure why it is there. Your theory as to it's purpose might be correct. I've not come across any info on that aspect, and the fact Gary never talked about it probably means -- as an educated guess -- that its presence doesn't really help or hinder.
     
  10. Dirt Reynolds

    Dirt Reynolds Veteran Member Lifetime Gold Member

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    If you plan to drive it daily I'd look at the next step down in cam for more torque in the low and midrange, but otherwise it looks like a pretty good combo.
     

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