Double OHC quad valve L series head | The Z Club of Great Britain

Double OHC quad valve L series head

Discussion in 'S30 (240Z,260Z,280Z) Engine' started by smileyinside, Jul 14, 2017.

  1. smileyinside


    I can't remember if I shared or indeed anyone else shared this but I thought it may be of interest.

    Something exciting for those of us without OS Giken money to aspire to.

    Tim - don't worry, this link is "Mrs safe"! :p

  2. richiep

    Z Club Member

    It was discussed on the OS Giken thread a while back. A few of us are watching with interest the excellent thread about it over on A twin cam head kit that would actually be semi-affordable versus the unobtainium of the TC24-B1Z.
  3. franky

    franky Active Forum User

    has he had it on the dyno etc yet vs his standard head?
  4. Turn & Burn

    Turn & Burn
    Z Club Member

  5. smileyinside


    Wow!!! I must have that sound in my life!!!

    My left kidney is on notice.
  6. smileyinside


  7. franky

    franky Active Forum User

    It'd be interesting to see how it compares to a properly done head like SKiddell has on his(cnc done head).
  8. jonbills

    Z Club Member

    No one but skidell dare answer
  9. smileyinside


    OK I'll dare but cautiously - I'd hazard a guess that in some ways one beats the other and vice versa! The twin cam sounds like it "comes on" noticeable at a particular point. Listening to the video, it was reminiscent of my old S2K once the vtec cut in.

    I bet a "properly done" n47 or P90 head has a smoother more linear torque curve.
    Last edited by a moderator: Jul 14, 2017
  10. Moriarty

    Moriarty Forum User

    There is very little comparison
    The Datsun works head is a very cleverly (and skillfully) crafted Honda K series scale up, and Honda heads are renown for making very high BMEP figures due to excellent port and chamber design

    The P90 (in practical applications) can flow enough air to make figures over and above 300HP (350 with bigger valves, offset guides huge ports, big compression, over 3 litres and a well matched cam) where as the Datsun works head will EASILY flow figures that would dwarf that plus it has a very stable twin cam/lifter layout that will rev comfortably to 9-10K (HP = torque and rpms right)

    The downside is that its still a lot of money, £10K will buy you the head and induction system but its not going to bolt onto a cooking or even mildly built engine and make big numbers, the bottom end would need decent crank, rods, pistons etc to get the rpms and compression up plus it needs a custom exhaust manifold etc not for the faint hearted

    Budget circa £15K (ex labour) when its imported a decent L series short engine is built and set up.
    But in the right circumstances on say a 3.2 or a 3.3 litre 400 naturally aspired HP and a noise to wake the dead would be something to behold

    Conversly a crate V8 LS3 and T56 could be had for circa £7k and would make enough torque to put that new iceberg back in place.
  11. franky

    franky Active Forum User

    not an l6 though and wouldn't sound the same.
  12. Moriarty

    Moriarty Forum User

    No, it was just for a HP/£ comparison that's all

    Latest on the Datsunworks head (well last that I read) was that the original prototype that in Derick's car had dropped a valve seat after 4500 miles or so, and they were investigating as to the cause.
  13. zNathan

    Z Club Member

    I feel like as an update to the guys not following his thread for fairness to Derick - the valve seat issue points to an incorrect installation by the installer, not Derick's head design.

    Been following the thread for a long time and is amazing the design work gone into it. Love how he decided to extend a Honda K20 head!

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