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  1. #1
    Join Date
    Jun 2010
    Location
    Hobart, Tasmania
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    2,038

    The "Mighty" A9L

    I was recently asked about the performance of my (highly modified) VL GPA which prompted some thoughts and memories of a unique time in Holden history

    Essentially, at the end of 85 when Holden had just finished its first season under the International Group A rules the VK had its reliability issues and HMC were charged with developing an engine package to fit the homologation rules that were governing engine (and aerodynamics) of competing brands ....
    This formed the basis of the engine development of all 4 Group A models and the engine prefix A9L was given to the Homologation engines ... over the next 4 years various upgrades to the A9L were made to facilitate both performance gains and regulatory changes allowed by FIA

    The VK A9L featured over the LV2 a number of improvements.... double row timing gear .... headers ... performance intake manifold (Holden had 2 versions in their armoury) ... big valve heads which were machined for screw in studs and fitted with guide plates for 5/16 pushrods and Crane 1:65 Roller Rockers and Holden had Crane supply a cam to meet the regs at the time and also pass emissions .... and with a developed (by Les Small) combo of that donk Grice took the VKGPA to a win at the mountain

    A year on the next A9L was developed with a few more tweaks inc ... 3/8 pushrods ... lighter flywheel ... stronger rods ... specially treated crank .... trick machined main bearing caps .... lighter flywheel ... and special headers to manipulate the rules around the first join ... Brock also had a special cooling fittings at the rear of the intake manifold/heads which formed part of the "Plus Pack" .... sadly with the introduction of unleaded fuel Holden had to lower the comp (from 8.8 to 8.5) on the road going GroupA and the governing body also relaxed the Cam specs to fit the emissions at the time which had massive governing changes on 1/1/86 ....

    These 2 A9L's certainly formed the basis for many tough street/track combos back in the day .... and in my case - today ... ��

    The A9L tradition continued on to the 88 and 90 Group As with a raft of improvements inc 4 bolt blocks .... with extra ribbing .... EFI ... ang of course the better heads

    Tell us your A9L stories ....
    Last edited by Sniper; 1 Week Ago at 01:32 PM.

  2. #2
    Join Date
    May 2016
    Location
    Auckland, New Zealand
    Posts
    1,107
    Very interesting, itís an era I donít know much about


    Sent from my iPhone using Tapatalk
    2014 Gen-F GTS
    2017 VF2 SS-V Redline Hackwagon

  3. #3
    Join Date
    Dec 2010
    Location
    SA
    Posts
    137
    No stories to share in particular other than having an 88....................but finally an interesting read and some history. Thanks Sniper.

  4. #4
    Join Date
    Mar 2008
    Posts
    2,414
    I can remember when the unleaded A9L was introduced in the VL Group A,...137KW I think it was.
    Tuning was a new world with unleaded, we all thought we'd never reach the heights of the old leaded engines....& there was a bit of uncertainty for a while, but eventually,......how wrong we were!
    Pickles

  5. #5
    Join Date
    Feb 2016
    Posts
    643
    Quote Originally Posted by Sniper View Post
    ...............

    Tell us your A9L stories ....
    interesting whats above .... but not 100% correct

    let me start with GMH Engineering ECS 90886
    for the VK model Bulletin No VK558

    raised by Chris Shattock on 29 Jan 1985
    and signed off by Joe Whitesell 22 Feb 1985

    The subject of this states (and I quote)
    This bulletin covers introduction of a special
    merchandising pack (on VK SL sedan) including
    new paint and suspension and A9L HP engine
    additional equipment with the engine to be
    painted red

    With the 'Nature of ECS change' listed as
    Introduce Production Option A9L for VK SL Sedan

    with (LOVE THIS) the reason given-
    MANAGEMENT DECISION

    The fine details start as -
    Engine section: This ECS/Bulletin covers new/revised parts only
    as the engine basis IS THE SAME (my emphasis) as V5H

    There are another 16 pages of of this...covering everything
    down to the door handles (!) but one thing is ....
    HMC had zero to do with the initial set up /specs of the
    engine in the what we now know as the 'Blue Meanie'

    There are THREE inlet manifolds listed ... 92010721
    9947175 and 92005955 (the last the most famous)

    and for the record ....
    the Les Small engine fitted to Grice's VK which not only
    won Bathurst but was also the first touring car to average
    a 100mph lap around Bathurst differed in a number of respects
    from the HDT engines built by Neil Burns (assisted by Tatey)

    and it was Larry Perkins who developed the special water
    recirculation kits fitted to VL (never VK) Grp A road cars
    as part of the VL Plus Pack, (as signed by Brock)


    My VK clubbie race car today... has lots of those mods
    .... race track proven some 30 years ago
    Smitty
    Member PIARC VICV8s Old Fart Racing
    GEN-F R8 340 Clubsport Tourer VK race car Kwaka ZX12R

  6. #6
    Join Date
    Jun 2010
    Location
    Hobart, Tasmania
    Posts
    2,038
    Great info Smitty .... I was hoping you and others would get into this topic a bit and enlighten us all ... I'll be checking the P/N of my intake in the morning!!! .... and I didn't realise that I said the rear water jacket thing was VK .... I was only referring to VL ....

  7. #7
    Join Date
    May 2009
    Posts
    56
    As a VL PP owner, I have always been interested in the finer details of the A9L. Please keep the info coming.
    VFII Clubsport
    VL SS Polorised Brock #379

  8. #8
    Join Date
    Feb 2016
    Posts
    643
    Quote Originally Posted by Sniper View Post

    Tell us your A9L stories ....
    Everyone remember this?



    yeah...well in 1985 a young Product Development manager
    at Lukey Mufflers (in Chesterville Rd Moorabbin) had 3 guys
    turn up un announced at the offices in front of the factory

    One he knew as his girlfriends father was (naaah... too long a story)
    but anyhow it was one LP with 2 GMH engineers (from Exp Eng)

    They came to talk 'performance' exhausts for a not yet announced
    new performance Commodore... could they make one? Could
    they do testing? Could they a minimum of 500? quickly?
    and
    could they work with another supplier who 'may' supply the headers?
    (this subject to engine tests)

    Yes .. was the answer and as well, could Lukey get a bit of publicity
    in relation to these special part supply request? No problem to
    that was the answer.

    The parts (Lukey exhaust system got the tick, HM got the tick for the headers )
    all got supplied as requested by GMH, and the young Lukey Product
    Development Manager got his moment in the sun... when he arranged
    the above very well known advertising pic and was at Sandown when the
    professional photographer did his stuff. Chuffed he was...




    The young Lukey Product Manager?.... is my youngest brother
    Smitty
    Member PIARC VICV8s Old Fart Racing
    GEN-F R8 340 Clubsport Tourer VK race car Kwaka ZX12R

  9. #9
    Join Date
    Mar 2013
    Location
    Melbourne
    Posts
    344
    What great stories! This is what a great forum needs more of.

    Thank you Sniper, and thank you Smitty.

  10. #10
    Join Date
    Apr 2011
    Location
    FNQLD
    Posts
    1,538
    2nd that cheers from a long way from home







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