9A-ABF comparison

Discussion in '16-valve' started by Golfsburg88, Apr 25, 2010.

  1. Golfsburg88 New Member

    Joined:
    Feb 7, 2010
    Likes Received:
    0
    Location:
    Cairo, Egypt
    I'm building a strong 16V that can rev to 8, 000 rpm

    The ABF and the 9A have the same bore and stroke, but different rod lengths?

    Which would be better for high revs, and which would produce more power the 9A short block, or the ABF tall Block

    Professor Nate Romero used the tall block in his NASP setup project 20/20, please help me to sort out which is better and why? Thank you
     
  2. Golfsburg88 New Member

    Joined:
    Feb 7, 2010
    Likes Received:
    0
    Location:
    Cairo, Egypt
    9A:

    Capacity: 1984cc, Bore: 82.5, Stroke: 92.8, Output: 134hp@5800rpm,

    Torque:186NM@4400rpm, CR: 10.8, Compression Height: 30.2, Rod length: 144mm



    ABF

    Capacity: 1984cc, Bore: 82.5, Stroke: 92.8, Output: 150hp@6000rpm,

    Torque:180NM@4800rpm, CR: 10.5, Compression height: Unknown, Rod length: Unknown

    Please provide me with the words in red, and please help me to choose which block is better
    for a revy NASP setup

    Thank you and my reference is a German website called:
    http://www.doppel-wobber.de/wbb2/jgs_portal.php?id=119
     
  3. danster Forum Addict

    Joined:
    Apr 2, 2008
    Likes Received:
    7
    The ABF is a taller block than the 9A.
    The ABF uses longer rods (159mm) compared to the 9A (144mm).
    This means the ABF conrod has less angular movement during a crank revolution and reduces the thrust on the side of the piston and makes for a freer revving engine.
    The 9A engine is still very able and has a shorter block height making installation in some cars slightly easier.
    ABF has an internal crank trigger wheel and the 9A does not. This could be considered a bonus or not, depending on if it is required.

    The compression height of the ABF piston is different by 1mm or so from the 9A (cannot remember exactly off hand)
     
  4. Brian.G

    Brian.G Forum Member

    Joined:
    Feb 3, 2008
    Likes Received:
    446
    Location:
    West of Ireland
    The longer rod also means that the piston passes over tdc slower than with the shorter 144 rod, it gives the port a better chance to breath from say tdc-10degrees. Which iirc is where the abf gets some of its extra low down torque from.
     
  5. danster Forum Addict

    Joined:
    Apr 2, 2008
    Likes Received:
    7
    This may well be the case, but the two engines run different heads, valve size (exhaust in ABF is 27mm instead of 9As 28mm), cams and engine management control, so it not really possible to tell exactly what it is that is making the difference.

    As this lad is going to be tuning the engine and not to a race spec, all the above is pretty much going out of the window anyway so either engine will probably be usable.

    EDIT :
    Bold bit is not entirely accurate. The later 9A (and 6A) engines do use the improved 051 103 373 D head.
    Both 9A and 6A engines with the later head do use their own respective inlet cams too.
     
    Last edited: Nov 10, 2011
  6. Golfsburg88 New Member

    Joined:
    Feb 7, 2010
    Likes Received:
    0
    Location:
    Cairo, Egypt

    There is a myth in my mind, and its about the shorter movement of a shorter rod, always makes a better revving motor, and its based on how the BMW M10, S14 blocks are made, also F1 motors use to have a very short stroke and a very big bore, thats what i miss in my VW ABF block, please advise

    since you prefer or you advise with a higher rod length, then i guess a big bore, less stroke, higher rod length will make a reving monster???
    Then I would prefer a bore/stroke ratio of an oversquare motor like the BMW block M10 used in the e21 with bore 87.5mm and stroke of 79mm

    To be noted:
    I use in my setup an ported and polished 027 KR head+ ABF cams+ ABF Block+ABF AE ECU
    Please advise

    (((Extreme examples of oversquare engine designs are found in Formula One race cars, whose rules tightly limit displacement and thereby require that power be achieved through high engine speeds. Stroke ratios of 2.5:1 are typical, with engines capable of 19,000 RPM. my reference is: http://en.wikipedia.org/wiki/Stroke_ratio)))
     
    Last edited: Apr 27, 2010
  7. SkyRocketeer

    SkyRocketeer Forum Member

    Joined:
    Oct 22, 2003
    Likes Received:
    13
    Location:
    Here be dragns
    Unless you play around with the crank, I think you'll find the stroke of the abf and the 9a are the same.

    The only practical differences between the two are what's stated above. 9A's are getting a bit thinner on the ground now I guess, given the cars they appeared in stopped being made back in the 90's ABF is a bit younger, so you're likely to find more engines and of better condition/less miles.
     
  8. infinity

    infinity Forum Member

    Joined:
    Jan 20, 2004
    Likes Received:
    28
    Location:
    United Kingdom
    How much power are you hoping to make.??
     
  9. Golfsburg88 New Member

    Joined:
    Feb 7, 2010
    Likes Received:
    0
    Location:
    Cairo, Egypt
    All motor 250hp on the wheels
     
  10. A.N. Other Banned after significant club disruption Dec 5th 2

    Joined:
    Oct 23, 2003
    Likes Received:
    395
    This is a very high level of performance, possibly too high for a 16v. What is your budget?
     
  11. Mike_H Forum Addict

    Joined:
    Oct 16, 2004
    Likes Received:
    17
    Location:
    iQuit
    It's possible, but it's at the top end of the N/A engine's range. Hope you've got a spare 5 grand, just for the bits.
     
  12. A.N. Other Banned after significant club disruption Dec 5th 2

    Joined:
    Oct 23, 2003
    Likes Received:
    395
    Also relevant is the use which the engine is being put to.

    An engine with 250bhp at the wheels will have 1,000km service intervals, by which I mean head off, valve springs replaced, pistons inspected, bearings possibly changed etc.

    So this level of power is for a dedicated race car only really.

    If you are prepared to step down the power level, it becomes more practical.
     
  13. Golfsburg88 New Member

    Joined:
    Feb 7, 2010
    Likes Received:
    0
    Location:
    Cairo, Egypt
    Budget is about 5, 000$ for now

    I was choosing which bottom end can make me rev easily and safely to 7500 rpm, please advise I'm confused

    I've got a ported n polished KR 027103373E head

    Cams 252/264 duration with 10.9mm lift on 114 lobe centers

    And a 020 2Y gearbox with final drive 4.5

    I am building it to compete with Honda's NA motors here in Egypt
     
  14. danster Forum Addict

    Joined:
    Apr 2, 2008
    Likes Received:
    7
    You will get towards 200bhp with that sort of spec. Either engine will be fine for that.
     
  15. Golfsburg88 New Member

    Joined:
    Feb 7, 2010
    Likes Received:
    0
    Location:
    Cairo, Egypt
    Please advise 252/264 duration with 10.9mm with this cams can they support me for 8000 rpm???
     
  16. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

    Joined:
    Jul 26, 2006
    Likes Received:
    3,097
    Location:
    Creating Pfredstarke
    Why do you need to turn the engine to 8000rpm, what spec are those cams.
    Not sure on where 250WHP target comes from either.
    Why does the engine have to be a NSAP or even a 16v for the money you have to spend.
     
  17. Golfsburg88 New Member

    Joined:
    Feb 7, 2010
    Likes Received:
    0
    Location:
    Cairo, Egypt
    I want the hardest way of gaining power NASP, and I need rpm gains to increase the MPS, thats why a F1 motor with 19, 000rpm, 41mm stroke can produce 700hp NASP
     
  18. Golfsburg88 New Member

    Joined:
    Feb 7, 2010
    Likes Received:
    0
    Location:
    Cairo, Egypt
    Please also advise if i am going to use the SportTuned 2.1L Engine Kits for 2.0L Engines, stroked to 95.5, in an ABF tall bottom end, what rods shall i use???
     
  19. A.N. Other Banned after significant club disruption Dec 5th 2

    Joined:
    Oct 23, 2003
    Likes Received:
    395
    What is your capacity limit for the cars you are trying to beat?

    What bore are you going to run?

    With a 95.5mm crank you will be over 2 litres.
     
  20. Golfsburg88 New Member

    Joined:
    Feb 7, 2010
    Likes Received:
    0
    Location:
    Cairo, Egypt
    I will go for 83.5 bore
    and my capacity will be

    83.5x83.5x3.14/4= 5473.2, 5473.2x95.5= 522692.15, 522692.15/1000= 523 cc per cylinder
    523 cc/cyl x 4cyl= 2092cc

    Motor I want to beat is Honda F20C with capacity of 1997cc
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice