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what carbs are best

Discussion in 'Performance' started by dakdak, Dec 16, 2015.

  1. applez

    applez Member

    Messages:
    58
    Location:
    Wollongong, NSW
    I've just done this dance and it resulted in a few headaches because of the endless amount of engine combinations i discovered. I found that talking with Stan Pobjoy (he will burn your ear off with info), Rod Penrose and others was very valuable and also sorting through SSVC, SAMBA, Kombiclub forum discussions yielded good information.

    Note: I'm not an engine builder. Just opening this up to further discussion. Please correct me if i'm wrong. This is what has been advised to me and I would appreciate feedback from experienced folks

    I'm currently running a 1641 with dual 36 IDF webbers jetted to suit and a beetle AC coded 1500 swing box in my 11 window bus. Not sure of cam but i'm fairly confident its not stock just by the way it drives. With a full load of people bus sits on the highway at 100km/hr to 110km/hr no worries, rev's hard in second to get it up Bulli Pass but that's all good. I have driven a fairly stock (crank and cam) 1915 with dual kadron carbs and the engines simply don't compare but that's what you would expect. No replacement for displacement, or so they say.

    So that's what i have. So what am i building.

    I've just priced a full 1915 build using a good quality second hand brazilian 1600 DP case which i pulled out of a 1975 LBug. Motor was sitting for like 20 years. New battery and spark plugs got it going. Compression was pretty good and no oil leaks observed from case. I've since split the case, degreased it and it all looks the goods. I'll be using this case.

    So why 1915. Mainly because its the largest size you can go without having to stroke your cam and still keep the 94mm wall thickness; see here http://johnmaherracing.com/2013/01/project-2110-part-2-bore-stroke/. I've been warned 92mm is a little too thin for reliability. I mentioned to Stan Pobjoy on the phone that i had read reliabilty is compromised with the 94mm wall thickness and he told me that is an old wives tale created by a certain engine builder back in the day to push his cylinder product or something. Stan has built hundreds of 1915's with Kadron carbs and stock cranks and say's it will be fine with the right cooling set up, but to be safe just monitor your oil temp. and cylinder head temps if you can be bothered setting it up.

    So for parts the prices vary between about $2500 and $4000. I basically had two options for the build noting that reliability and engine longevity are my two primary concerns. Originally i was going to keep my stock crank, keep the stock cam or C25 or Engle 100, use new un-ported 40mm intake/35.5mm exhaust heads and run a second hand set of 40mm Kadron carbs with an aftermarket CSP linkage. According to Rod and others the Kadrons work best with a fuel pressure regulator fitted. So i'm told, this set up will have torque at lower revs and using the stock crank it's best to not rev the pants off it racing style all the time (like keep it under 5k RPM) just drive normally.

    I can't help myself though and am going to save for a little longer and then go with a counterweighted 8 dowel crank, Engle 110 or C35 cam, ported heads and dual webers. The choice of cam basically has shifted the power curve to a higher rev range. So hence why i've gone with a counter weighted crank as it should spin smoother at higher revs. Also, Webers produce quite a bit more power than the Kadrons and the difference in price is a few hundred dollars. I will need help to set them up right though as they are apparently tough to tune correctly for a novice. As i see it Webers are in higher demand, and should hold their value better than Kadrons if you needed to sell later on or can use on another set up.

    Obviously i could stroke the crank but then i may have to trim the inside of the case for clearance and i'm not so sure my stock flywheel, clutch and gearbox would take the extra torque that a larger stroked motor would provide. So more money again.

    Anyway, good luck with the build.
    -
     
  2. Barry

    Barry Well-Known Member

    Messages:
    5,708
    Location:
    Abbotsford NSW
    For what its worth (not much) here are my comments

    best thing since the VW was invented (besides a flange kit on your exhaust)

    just make sure its a good one. Not cast. DPR

    Consider Dells - with the Jet Doctor kit. Webers have the idle jet on the side and it is a pain in the arse.
    Dels also run a larger idle jet and less chance of blockages
    Seriously consider buying your carbs off Alfa1750.
    You can buy them prejetted and vented.
    If you buy "new" Chinese / Spanish Webers they come with dumb jetting / venting and it will cost you $200+ to set up properly
    http://www.ebay.com.au/itm/VW-DELLORTO-DRLA-40-CARBURETORS-/262056215564?hash=item3d03c4840c
    or
    http://www.ebay.com.au/itm/PORSCHE-912-WEBER-40-IDF-CARBURETORS-/291637064832?hash=item43e6ec7480
    Whatever - a set of Italian Dells / Webers is streets ahead of the new stuff.
    They wil hold their value - even increase.
    Dont ask me my opinion on HPMXamotosis or other knock off carbs

    Consider the Los Banditos or Los Panchito heads.
    They are CNC and while they are not as good as ported heads are a damn lot cheaper.
    I "believe" they are still available

    Whatever ;)
     
  3. applez

    applez Member

    Messages:
    58
    Location:
    Wollongong, NSW
    Haha, don't under sell yourself Barry, Your comments are worth their weight in gold!

    Yes I'm aware the cast cranks are more brittle than the forged cranks. See the sh1t hot comment here from Ed Brewer http://www.shoptalkforums.com/viewtopic.php?t=23600
     
    Last edited by a moderator: Feb 28, 2016
  4. applez

    applez Member

    Messages:
    58
    Location:
    Wollongong, NSW
    I am wondering whether ported heads really make that much difference though?
     
  5. Barry

    Barry Well-Known Member

    Messages:
    5,708
    Location:
    Abbotsford NSW
    as the last piece of the puzzle - definitely'

    As a starting point, no, not really

    Compression probably plays a bigger piece
     
  6. tiger8shark

    tiger8shark New Member

    Messages:
    10
    Location:
    Newcastle
    Had a set of Dellortos on a 1776 Ben Durie built motor and would definitely recommend. Running Kadrons now a 1641 Pobjoy and really can't say anything bad about them especially as they were half the price of Dell or Webers when I bought them.
     
  7. carazeee

    carazeee Member

    Messages:
    485
    Location:
    Tasmania
    Has anyone had any experience with the Rod Penrose racing carb kits for the type 4 motor? Looking at a carb upgrade at the moment and thinking about these. $1k and he has said he's installed a lot of them to date with next to no issues. Just interested to hear any first hand experience with them?
     
  8. Barry

    Barry Well-Known Member

    Messages:
    5,708
    Location:
    Abbotsford NSW
    Are these the "Decades?"

    If so they are a Weber copy

    Guessing it is like any copy piece
    personally i would have original trim over TMI or an original case over one of the "new" cases

    Depends what you can afford and what you want
     
  9. oldman

    oldman Super Moderator Staff Member

    Messages:
    10,228
    Location:
    Avalon Beach NSW
    I think Rod's are "Cadence"……..
    Cheers,
    Mark
     
  10. DakDak67

    DakDak67 Well-Known Member

    Messages:
    482
    Location:
    Brisbane
    OP question, Dell's if you can find them/afford them, Genuine Webers if you can't. My big engine has run 44 idf's for over ten year without a problem. I'm tempted to run a 48 IDA on the fresh motor , either way , bulletproof, set and forget.
     
  11. john doherty

    john doherty Well-Known Member

    Messages:
    795
    Location:
    adelaide
    This is one of my most favourite threads!
    I don't understand anything in it….Or on it…… But all this technical talk makes me very emotionally aroused.
    Do I have a problem……
    And if so………
    Can anyone out there help me???
    I drive a 1976 Sopru resurrected camper..... Who goes by the gender confused identity of "Hercules"...... as pernicious a beast as ever was spawned by Wolfsburg.... And according to the gospel of "old man….Super moderator".... Is stock!!!!
    Save and except for the pilot...... If that helps?
    Can anyone help me?

    JD in Adelaide:cool:
     
  12. Grantus

    Grantus Well-Known Member

    Messages:
    18,092
    Location:
    Southern ACT
    Have you considered a "low carbs" diet? .....:rolleyes:
     
    Last edited: Feb 28, 2016
    jobell likes this.
  13. Mordred

    Mordred Super Moderator Staff Member

    Messages:
    2,979
    Location:
    Penna, Hobart
    I concur with Oldman for a stock bus. I just dont need the hassles of trying to get something else working properly.

    Adrian
     
  14. dakdak

    dakdak Member

    Messages:
    120
    Location:
    charmhaven
    well didnt i start a thread,i took the bus up to tuncurry for the weekend,sat on 85 kph saw lots and took in the scenery.my conclusion for me is 1800 box,1776 motor,small cam and wait for it ''kadrons''why?i spoke to peter otoole at tuggerah and he made more sense than the rest for what i needed.he didnt say much about the kadrons just said he thought they were ok.so thats it thanks all
     
  15. applez

    applez Member

    Messages:
    58
    Location:
    Wollongong, NSW
    Well how about we let you get intimate with your new motor and then let us all know what you think about it. Why the 1776 though?
     
  16. dakdak

    dakdak Member

    Messages:
    120
    Location:
    charmhaven
    why the 1776? well again after talking to peter and what i'd be up too that setup would suit what i need.ive had everything from leave it standard to 130hp and he was the only fella that said what do you use it for.even with the 1600 i find i keep up with the traffic or i catch up to them at the lights or round abouts.what do i use it for well its a weekend bus,i fly remote control planes and thats only 5 klm's away,the boss and i head to tuncurry twice a year.if i can sit on 100 kph and the pistons are not sounding like their going through the head i'll be happy.so that about it
    p.s i do admit i would sometimes love to overtake some of them d'[@kheads that pull out on you because they don't want to get stuck behind a kombi.but i'm the one driving class bus
     
  17. applez

    applez Member

    Messages:
    58
    Location:
    Wollongong, NSW
  18. Alpal

    Alpal Moderator Staff Member

    Messages:
    8,959
    Location:
    Melbourne Bend of Islands
    With a sludge box to boot!
     
  19. jobell

    jobell Active Member

    Messages:
    579
    Location:
    Walwa, Victoria
    I'm glad I'm not the only one struggling to follow this thread. I'm trying though. All I know is is that my camper has twin carbies and that that makes her harder to tune. I'm planning on simplifying the engine set up. As soon as I know what simple is. Is simple stock?
     
  20. Barry

    Barry Well-Known Member

    Messages:
    5,708
    Location:
    Abbotsford NSW
    Jobell
    I tried searching but i cant see what engine you have - can you fill us in. Type 1 or Type 4?
    Twin carbs can be a POP to tune
    All depends on the set up
    A single non progressive on a Type 1 can be a pig to tune
    On a type 4 would be near on impossible

    Yes-ish
    Twin carbs on a Type 4 is stock and are simple as well

    If you are really interested have a read here

    http://www.aircooled.net/vw-parts-cat/vw-carburetor-tech/
     

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