Help me choose a cylinder head!!

Discussion in 'Engines' started by xstwin, Nov 28, 2018.

  1. xstwin New Member

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    Building a race motor for open class (autocross and mid size track). Bottom end is a 3A bores out to 83.5mm and compression will be bumped to 12:1 or slightly higher for race gas only.

    Looking for cylinder head to rework. The usual stuff... P&P, solid lifters, large valves, etc. Work to be done by one of the reputable shops although recommendation would be appreciated. Haven’t decided on fuel delivery; would prefer carbs with ITB as second option.

    What’s your recommendation as a starting point? Cast code would really help.

    Thanks much.
    XsTwin
     
  2. Jon Olds Forum Junkie

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    1st decision is 8 or 16V. If 8V next would be packaging for me. How do you get a decent sized airbox in?
    Bought a 2L crossflow 8V lump a while back to get the head to build (another..) race motor for my mk1 as there literally is no space
    down the back of the motor for proper filtration/airbox.
    Just a thought
    Jon
     
  3. HPR

    HPR Administrator Admin

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    An airbox can be a pain, as cylinders influence eachother, fuel meant for say cyl 2 are not neccesarily burnt in that cyl, due spitback and air/fuel mixture being partly swallowed by another cylinder.
    An open induction or with a foam filter works best … unless its properly develloped

    16V - 2.0 head ABF /ACE / 9A … make good power/ torque at a reasonable cost ….
    and much off the shelf parts to choose from…

    No need to go crazy on cams and use of hydro profiles & followers are certainly not a limitation…. 7000 - 7500 rpm allow more than decent power
     
    Last edited: Nov 28, 2018
  4. xstwin New Member

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    Sorry, left that out. Was looking for 8V but I guess going 16v isn’t out of the question although trying to make a screamer (8k motor) might be more challenging.
     
    Last edited: Nov 28, 2018
  5. HPR

    HPR Administrator Admin

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    In that case i would go for the crossflow 2.0 head
    But 2E head ( not crossflow) is also a good choice
     
    Last edited: Nov 28, 2018
  6. Jon Olds Forum Junkie

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    Hydro followers make proper set up of cam timing 'difficult'. Heavy, sloppy, why would you make a high revving
    high budget motor with them? Yes, mech is a pain, but once over the (expensive) pain, no issue.
    Airbox comment was all to do with keeping the combustion air temp low with adequate volume
    Take note of HPR's comments
    Jon
     

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