40 DCOE Settings
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Thread: 40 DCOE Settings

  1. #1
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    Default 40 DCOE Settings

    Hi all,

    I am thinking of fitting a single 40 DCOE to my Caravelle S. Does anyone know a good place to start for configuring, ie choke size initially and jetting.

    The motor is a standard 1108cc, 8 port head - standard cam (10S cam?!? on a '67 Caravelle S I wonder)

    Thanks.

    G:-)

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  2. #2
    Fellow Frogger!
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    Wilson Carburettors in Airport West

    3/16-18 Marshall Rd
    Airport West

    0393303216

    Very good and thorough. Carby oriented, well versed in Weber, Solex etc. Have chassis dyno for tuning

    They do a lot of historic/oddball stuff and do know their stuff

    Best Wishes

    Andrew

  3. #3
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    yep standard cam for these was similar to 10S/8S etc. They already have a 2 barrel down draft Weber. I wonder will there be much improvement in performance?

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    Yes, I wonder that myself. The downdraft weber is sweet. I had another Caravelle with a R12 1.4 motor at the same time as I had my 'S', and thought the 1.4 had better low down torque but not a huge difference in top end power. The 'S' also seemed a little smoother.

    I have a longer term plan to re-build a 1.4 engine with a bit more compression and performance oriented cam, but thought this might be a simple upgrade in the interim.

  5. #5
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    I have an R10 with a 1289 cc motor 2 barrel down draft, and it has low down torque yes, but feels harsh on the road compared to my Floride S with 1108 cc and single barrel Solex. But there is a marked difference in performance. Just the same I prefer to drive the Floride on trips. But around town the 10 is much better. The 10 does have mag wheels and 175 X 13 tyres. Where as the Floride has stock Nankans. It is so many years since I drove a standard 10 but I always thought of them as smooth. I have a worn 10S motor and have often thought if it was rebuilt it might make a nicer drive than the 12 motor. I have dual Weber 45mm DCOE's on my R17 in place of the standard fuel injection and they were a fiddle to get right. As they run on progression holes until the main jet comes in at around 2000 rpm which in top is around 100 KPH. Luckily Renault 12 G and Alpine 310 had similar set up so ended up copying the 310 set up.

  6. #6
    1000+ Posts alan moore's Avatar
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    This is a starting point, and it will run with this, but I am tending toward starting a little rich. I fitted a single sidedraft to a 1.4 about 30 years ago, and I have no record of what worked, although this engine had higher compression etc. and was a fair way from standard, used in a motorkhana special. Driving at cruise was never tested as such, and fuel economy was not considered.

    32 or 34mm Main Venturi, 30 will work, but main jet would need to be smaller. 34 is more suited to the larger airflow associated with a bigger cam, valves and porting, but quite probably still work Ok on a less modded engine.

    4.5 Aux Venturi, 130 Main Jet, F16 or 15 Emulsion tube, although try whatever the carb has in it now. F2 tends to be better suiting bombed Minis with large main jets. F9 may be Ok. Air corrector 180. Idle jet 45 F8 or F9 with screws out 1.5 to 2 turns to start with. Accel Pump jet .45 or .50. A 2.00 needle valve would be fine, and may get away with a 1.75mm.

    Sidedrafts do not like much fuel pressure, so generally it is regulated down to 2.5 Psi.

    Have you got the carb already? What does it have in it?
    '56 Renault 750 (16TS Power)
    '62 Renault Dauphine Gordini
    '89 Renault Alpine GTA V6 Turbo
    ‘02 and ‘03 Renault Clios 1.4L
    '13 Renault Megane RS265 Trophee +

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    Quote Originally Posted by alan moore View Post
    Have you got the carb already? What does it have in it?
    No, I am looking to order a kit including a new weber and manifold from spain, so the first thing seems to be to spec the chokes (main Venturi?!?) and then the jets.

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    Alan what about progression holes on a 40mm on a Sierra engine? Any ideas?

  9. #9
    1000+ Posts alan moore's Avatar
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    Any DCOE seems to have better progression with 3 rather than 2 holes. Given a new carb is looking to be purchased I would hope it would have the newest incarnation of progression holes to make its use the best that it can be. I might be expecting too much perhaps. I have seen these engines fitted with twin DCOEs using modified Datsun 1200 manifolds I believe.
    '56 Renault 750 (16TS Power)
    '62 Renault Dauphine Gordini
    '89 Renault Alpine GTA V6 Turbo
    ‘02 and ‘03 Renault Clios 1.4L
    '13 Renault Megane RS265 Trophee +

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    1000+ Posts Shoji's Avatar
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    Hi Fireblade
    New carbs!!
    The DCOE 40 151 has three progression holes and they are far back from the plate.
    FYI: The DCOE 45 152G has four progression holes and chokes start at 30, 32... > 40
    “Listen very carefully, I shall say this only once.” Cheers. John

  11. #11
    1000+ Posts Frans's Avatar
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    Quote Originally Posted by alan moore View Post
    I might be expecting too much perhaps. I have seen these engines fitted with twin DCOEs using modified Datsun 1200 manifolds I believe.
    I have built 2 of these wedge engines with the Datsun manifolds and know of another that is very potent. However, these engines have to be balanced by using proper cams, compression ratios, extractors etc. I think that 2 Webers will flood a standard cam no extractor engine. If one goes for dual Webers, go max from the start.

    Frans.
    Shoji likes this.
    Old enough to know better
    Young enough to do it anyway.

  12. #12
    1000+ Posts alan moore's Avatar
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    As much as I like sidedrafts, I agree with Frans and others that on a standard engine it is unlikely you will see much performance increase with single or twin Webers over the standard twin barrel downdraft. The main venturi is probably better at 30mm on a standard 1108. The larger sizes I mentioned were considering future mods.
    Shoji likes this.
    '56 Renault 750 (16TS Power)
    '62 Renault Dauphine Gordini
    '89 Renault Alpine GTA V6 Turbo
    ‘02 and ‘03 Renault Clios 1.4L
    '13 Renault Megane RS265 Trophee +

  13. #13
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    I think you guys are right - on a stock engine, you would be mad to go past the downdraft webers. It is a very sweet set up. I will stick with my plan and go all out on a rebuild of 1300/1400 with some mild cam and head work and twin side drafts.

    Thanks for your thoughts!
    Shoji likes this.

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