A VW 16v camshaft study.

Discussion in '16-valve' started by Toyotec, Feb 9, 2008.

  1. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

    Joined:
    Jul 26, 2006
    Likes Received:
    3,097
    Location:
    Creating Pfredstarke
    After working on a quite a few VW 16v engines and being able to quantify their character after optimizing them, the desire to find what makes these engine respond differently has arisen once again.
    Time and time after tuning up an ABF motor it can be observed that this engine does indeed respond quite well once the factory airpath, fuelling and spark advance has been fettled.
    We have discussed on here many times about heads and camshafts. About the long connecting rods and about piston dwell at TDC. But I convinced that as a package the character of the ABF engine is a hard one to beat. If only VW had the need to design a vtec cam system for this engine this would have left Honda owners quaking.

    We know from previous discussions that there are 3 common variations of 16v heads
    the 027 133 373 E , 051 133 373 and the 051 133 373D.
    The first two are fitted to early and later KR engines as well as post 94 9A and early 6A motors. The latter can be found on ACE, ABF and ADL motors.
    Having tested both types of KR engines it has been observed that the torque curve is more or less the same between 051 and 027 heads. The same happens but at a higher magnitude when the engine is a 9A or 6A with inlet cam 027109021AH fitted.
    This response changes somewhat when the engine is a Seat or VW ABF motor fitted with K jet, just to keep things equal. There seems to be more lower torque pre 3000 and even a bit more come 5500 then slowly the torque starts descending until it gets to near 6400 rpm before making a rapid crescendo.
    So whats responsible for this?
    Well if one was to remove the dress kit, i.e. the exhaust system , inlet manifold and intake tract and examine the head and block there many hidden improvements over older 16v motors.
    I was speaking to one of our german suppliers who was a VW enthusiast himself and after a bit of discussion of the above he gave a list of OEM camshafts for the VW 16v range.
    I will share them for all to see.

    16v camshaft (Nockenwelle) for ABF, 9A and PL and KR engines.
    All Measurements at 1mm valve lift
    IVO= inlet opens
    IVC= inlet closes
    EVO= exhaust opens
    EVC= exhaust closes
    PL= peak lift
    .

    KR
    Inlet # 027 109 021 AH
    IVO 3 ATDC
    IVC 35 ABDC
    Duration -3 +180 +35 = 212
    PL 9.6mm

    PL/9A pre 94
    inlet # 027 109 021 AL
    IVO 1 ATDC
    IVC 21 ABDC
    Duration -1 +180 + 21 = 200
    PL 8.8mm

    Exhaust cams for 027/051 103 373E/NC NC =* Not classified or No letter
    Exhaust # 027 109 022 G
    EVO 43 BBDC
    EVC 3 ATDC
    Duration 43+180+3 = 226
    PL 10.2mm


    ABF
    Inlet # 051 101 or 051 019 021B
    IVO 1 BTDC
    IVC 38 ABDC
    Duration 219
    PL 10.8mm

    ACE/ADL and late post 94 9A
    Inlet # 051 109 021 C superceeded by 051 109 021A as of 010304
    IVO ?
    IVC?
    Duration ?
    PL ?

    Exhaust cams for 051 103 373D heads found on ABF,ADL, ACE and post 94 9A
    Exhaust # 051 102 or 051 109 022B
    EVO 39 BBDC
    EVC 1 ATDC
    Duration 39+180+ 1= 220
    PL 10.8mm

    As the cylinder head is the mechanical brain of the engine, could it be that the 27mm exhaust valves and valve seats with subtly improved ports ( very small valve guide protrusion from factory), higher valves lifts an in the case of the inlet valve even more duration than older engines cause this ABF engine to respond quite well to tweaks. Is it that all of these interactions help to reduce pumping losses.
    ABFs cam sets seem to have a 1 of over lap vs 0 for KR camset.
    Let discuss to see if there is more learned.
    I will aslo add that I have seen a similar pattern on 1.8T engines where a series of engines with the same type of head have the inlet cam changed only.
     
    Last edited: Nov 26, 2009
  2. Vegard New Member

    Joined:
    Mar 21, 2005
    Likes Received:
    0
    Location:
    Norway
    Anyone who know the rest of 16v cams specs?

    Duration @ 0.1 mm (Total duration) or Lift @ TDC?

    Made this specsheet:

    [​IMG]
     
  3. Mike_H Forum Addict

    Joined:
    Oct 16, 2004
    Likes Received:
    17
    Location:
    iQuit
    Mods, can we make this a sticky or an FAQ, please!!
     
  4. infinity

    infinity Forum Member

    Joined:
    Jan 20, 2004
    Likes Received:
    28
    Location:
    United Kingdom
    could valve springs be responsible for the power drop at 6400? or is it the engines ability to pump air that causes it to suffer? What rpm do chipped ABF's produce their power?:)
     
  5. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

    Joined:
    Jul 26, 2006
    Likes Received:
    3,097
    Location:
    Creating Pfredstarke
    Air charge interactions in the head on stock cams cause peak filling at 5300-5800 and 85%filling at 6300-6700 rpm. With or without chip. Recalibrations would tend to optimise torque and cause increases overall. But should not change torque/power curves.
     
  6. Neal H Forum Member

    Joined:
    Oct 18, 2007
    Likes Received:
    3
    Good information source Toyo. From the cam specs above it is fairly obvious that the ABF cams are designed for more power having a. more lift, b. more duration, and c. a smidge of overlap.

    What we don't have is any definitive comparative flow figures from 027, 051 and 051D heads to see where the factory improvements come from regarding castings. This would tell us if there an increase in inlet port flow, exhaust port flow, both, or neither. By gathering this data together you can make an educated guess as to what would be the best combination of standard VW parts to use for most power and torque.

    As a question, have you tested an ABF head and cams on a 9A block to see the torque and power characteristics of the two different 2L bottom ends? That would be an interesting comparison.
     
  7. Hotgolf Paid Member Paid Member

    Joined:
    Apr 23, 2004
    Likes Received:
    344
    Location:
    Smelly Cornelly
    There's an 026 head too which is similar to the 027(no water jacket in the inlet dividers)
    P/N 026 103 265.

    I had very good results with one of these in the past fitted to an 1800. Only the head was ported, standard cams, everything else standard and pushed out the same bhp @wheels as a standard ABF, same day, same rollers.
     
  8. Neal H Forum Member

    Joined:
    Oct 18, 2007
    Likes Received:
    3
    Mart, do you know what engines were the 026 heads were on?
     
  9. davidwort Forum Member

    Joined:
    Feb 23, 2004
    Likes Received:
    1
    Location:
    United Kingdom
    Does anyone have a torque plot/curve for an ABF, k-jet or otherwise? I've found plenty of modified 2L 9A plots, KR cams or aftermarket, but never seen an ABF head/block/cams plot to compare.
    The description of torque curve above sounds very much like my 6A/9A with a flowed late KR head and KR cams, and this head+cams was much the same curve on the old 1.8 block, with and without the flowed head, just lower values.
    That is, good torque at just under 2,500 rpm, peak at around 5,600 rpm and finally dropping below 130lb/ft (from a peak of 153) at about 6,700rpm.
    KR inlet cams are often, it seems, easy to spot from a torque plot, there's a pronounced dip at about 3,500 rpm for a few hundred rpm??? - not seen with the flat 9A inlet.
     
  10. Hotgolf Paid Member Paid Member

    Joined:
    Apr 23, 2004
    Likes Received:
    344
    Location:
    Smelly Cornelly
    Early KR's from what I can see on Etka, but thats all I know tbh.
    I used to have one knocking around but it's long gone to the scrap heap nufourtuantly :(
     
  11. James_mk2 Forum Member

    Joined:
    Jan 11, 2008
    Likes Received:
    1
    Location:
    Farnham, Surrey
    Does a KR exhaust cam modded to fit the inlet side have the same lift, duration etc. as in the exhaust side? i was just looking for figures to compare this mod with say a 260 degree aftermarket inlet camshaft
    Cheers
    James
     
  12. Neal H Forum Member

    Joined:
    Oct 18, 2007
    Likes Received:
    3
    If you could find the Seat ABF details too we could come up with a rpair of reasonable cam maps. That would be a nice piece of information. :thumbup:
     
  13. Brian.G

    Brian.G Forum Member

    Joined:
    Feb 3, 2008
    Likes Received:
    446
    Location:
    West of Ireland
    great thread:thumbup:
     
  14. Brian.G

    Brian.G Forum Member

    Joined:
    Feb 3, 2008
    Likes Received:
    446
    Location:
    West of Ireland
    I too would like to know this:thumbup:
     
  15. Trev16v

    Trev16v Paid Member Paid Member

    Joined:
    Oct 22, 2003
    Likes Received:
    450
    Location:
    Oxfordshireland
    Just made this a sticky.
     
  16. Golfsburg88 New Member

    Joined:
    Feb 7, 2010
    Likes Received:
    0
    Location:
    Cairo, Egypt
    abd intake and kr exhaust cam?



    Hey all, thanks Toyo for this thread, please can anyone advise is an ABF intake cam with a KR exhaust, or an ABF intake and exhaust, pleasde advise which is better???
     
  17. chrismc Forum Junkie

    Joined:
    Oct 22, 2003
    Likes Received:
    0
    KR and ABF exhaust cams seem very similar, with the ABF intake having more lift and duration than the KR item.

    From that a pair of ABF cams seem the way to go on paper...

    Does anyone have the TOTAL durations for ABF cams?? All quoted figures earlier in the thread are at 1mm lift, so not easily comparable to aftermarket cams
     
  18. Nellis Forum Member

    Joined:
    Jun 24, 2010
    Likes Received:
    9
    Location:
    Cape Town, South Africa
    Maybe this will help. Keep in mind that these are actual measurements, hence the slight difference to the "advertised" or "published" specs.

    9A vs ABF

    [​IMG]

    KR/AAL vs ABF

    [​IMG]

    9A

    [​IMG]

    KR/AAL

    [​IMG]

    ABF

    [​IMG]
     
    Last edited by a moderator: Jan 29, 2018
  19. Ade.Mk1 Forum Member

    Joined:
    Oct 24, 2003
    Likes Received:
    1
    Location:
    Staffordshire
    Hi,

    On my 16V G60 I have used a set of KR cams.

    It was mapped at JabbaSport this week and produced 215bhp and 253Nm - it runs really well and pulls like a train.
    However Mike indicated that he thought it was down on boost and therefore missing about 30bhp - my boost gauge is showing 6psi and when it was an 8V it showed 10psi - it is running a 68mm pulley.
    I am not sure whether the G60 can actually boost to those levels through the 50mm Inlet manifold.

    Talking with Rajan on the MK1 owners club who has an original Limited he said that his has:-
    Inlet camshaft 027 109 021AH (standard KR)
    Exhaust camshaft 027 109 022F (standard 9A I believe)

    I am told that the 9A and KR exhaust camshafts are the same - can anyone confirm whether this is true ? For overlap, duration and lift ?

    One of the thoughts is that boost is being lost to cam overlap.

    Any help greatly appreciated.
     
  20. rubjonny

    rubjonny Administrator Admin

    Joined:
    Oct 31, 2003
    Likes Received:
    2,012
    Location:
    Bracknell
    early 9a zaust cam is same as the kr, later one uses an abf zaust cam. you may or may not know about the 'how to build a 16v G60 site' which went offline years ago?
    I saved this and looking thru it it says the exhaust cam you need is 027 109 022 AH, which is a VW motorsport part I'm afraid. the guide does go on to say that the oem ones will probably work ok, as you have found.

    edit: oh and the zaust valves are also different, but it doesnt say why. I assume sodium filled if they arnt as std, and/or bigger in size if they are
     
    beetie likes this.

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