Engine: 3.6l SC -> K-Jet...

  • Hi there,

    I had engine damage and the engine had to be completely dismantled anyway. As I still had a set of cylinders from the 964 "lying around", this was now installed.

    So: SC block, 964 cylinder, dual ignition :pfeil: 3.0l to 3.6l

    The idea would be to continue running the engine with the K-Jet and keep it visually as an "SC"

    Probably won't be that easy...

    Does anyone here have experience with such a conversion?

    What tips do you have for the K-Jet? Flow divider? WLR? ZLS?

    What should you go for first with the K-Jet components...?

    Are there any specialized companies for tuning?

    I would be grateful for any hints and tips

    Regards

    fokke

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    911 SC, MJ 78, USA, 930/04
    944 S2, MJ 91
    Honda Zoomer Tokio Style

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  • 3.6 liters need to be filled.

    The K-Jet will be the bottleneck here, but that doesn't even have that much to do with the amount of fuel to be delivered, because the flow divider delivers more than some people think - it's rather the insufficient amount of air available for the 3.6 liters. And no large (so much praised) larger intake ducts, or retrofitted larger valves in other headers or the like, are enough ... In the end, it is simply the manifold and the diameter of the throttle valve, which is far too small. Therefore, individual throttles would be more likely to help here, or at least the mixture formation/intake architecture of the 3.2 on top. Only everything you change in the mixture formation from the factory state will then become a problem if you want to continue to drive the car on the road - the subject here is approval of the exhaust gas report.

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    Alles über den 3.0 US SC Motor 930.16 und viel mehr unter:

    https://nineelevenheaven.wordpress.com/


    - 911 SC 3.0, USA Bj 82, unischwarz, SSIs, eigens entwickelte digitale Lambdaregelung sowie elektronische Kennfeld-gesteuerte Zündung
    - VW Oval-Käfer Export, Bj 1955, 30PS, Stratosilber
    - VW Brezel-Käfer, Bj 1950, 24,5 PS, Grau, orig. Philips Elomar Radio

  • Yes Andrew, that's exactly how it is. In the end, however, the engine is technically and visually completely different from what Fokke thinks. Only cubic capacity hardly brings more power. Intake tuning only works with a lot of effort and money, otherwise you might as well leave it as original.

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    Gruß

    Rainer

    3.2 Carrera Cabrio, Bj. 11/83, Sportauspuff und KAT-100Zeller von DANSK, späte DME, ca. 230PS, 7"+8" Maxilite.

  • I agree with AndrewCologne and Norden-911. But I admit that I find the project interesting. However, I won't be able to contribute much.

    But if I look at it from a purely technical point of view, I see 20% more displacement compared to the 3.0 l and therefore, as a naturally aspirated engine, a correspondingly higher air volume. That's not even and will require a generally new and individual setup for precisely this engine and the K-Jetronic.

    On the other hand, there are the 930 turbos with 3&3.3l displacement that also run with a K-Jetronic, and in some cases still very rich, in order to keep the knocking and temperatures in check. It's perfectly clear that the air volume is increased or raised to a new level by the supercharger and the pressure. You would have to calculate whether the required air volume of the intake manifold, including the inlet pipes and the throttle body, can even get through the K-Jetronic.

    Since the K-Jetronic was also used by Mercedes, for example, in the large 8-cylinder engines with a displacement of 4.5 liters, it might be necessary to see if it could be used there. However, the air flow meters are constructed in reverse, i.e. the baffle plate swings downwards instead of upwards as on the 911...

    All in all, this will be very time-consuming and, in my opinion, esx needs a test bench on which you can check after each change whether and what effect the last changes have had. However, it is probably quicker to convert to a single throttle with a flat slide and freely programmable control unit, as already mentioned. Then the performance limits are pushed way upwards...

    If you can stay with the K-Jetronic, then a programmable 123ignition would be a good idea and you could easily trigger two HKZ's in parallel at its output, because it is now a twin ignition...

    I see WLR and ZLS as the least of the problems, they could still be fiddled with where they are needed...

    Greetings Thomas

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    81er ex-US 911 SC Coupé, platinmet., eSSD, K-Leder sw., Turboheckflügel & -frontspoiler, NSW, Maxilite 7/8J, Bilstein Fw("SpoStra" - noch...), 915/61, 930/16 o.Kat, WebCam 20/21 NW, hydr.KS, Dansk 92.502SD, 123 Ignition, orig. Porsche SWV, Seine Systems Gate Shift Kit, Momo Prototipo m.Nabenerhöhung


    „Nicht das Auto verdirbt den Charakter, aber wer keinen Charakter hat, sollte nicht Auto fahren.“

    Ferdinand Porsche

    Edited 2 times, last by Schulisco (January 23, 2024 at 12:27 AM).

  • How did you do it with the stud bolts? 76mm crankshaft from the 964? Heads?

    Are there any pictures?

    The effort for KW and 100mm cylinder is definitely high ✌️

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  • Schulisco
    As I wrote above, a K-Jet per se is not the problem, it's specifically with the one designed for the 911 3.0 that the diameter of the throttle body (and gap in the airflow meter) ends up being too small to fully utilize the potential of the 3.6L.

    This post has been automatically translated.

    Alles über den 3.0 US SC Motor 930.16 und viel mehr unter:

    https://nineelevenheaven.wordpress.com/


    - 911 SC 3.0, USA Bj 82, unischwarz, SSIs, eigens entwickelte digitale Lambdaregelung sowie elektronische Kennfeld-gesteuerte Zündung
    - VW Oval-Käfer Export, Bj 1955, 30PS, Stratosilber
    - VW Brezel-Käfer, Bj 1950, 24,5 PS, Grau, orig. Philips Elomar Radio

  • Hi there,

    Thanks for your opinions and thoughts!

    I would basically trust the K-Jet to handle the set-up, but the adjustment will probably be fiddly.

    I had the engine upgraded from 3.0l to 3.2l years ago, with 964 cams and higher compression. This also took a lot of adjustment, time and nerves until the K-Jet ran cleanly and reliably in all areas.

    The engine has machined heads: larger intake ports and larger intake valves.

    Pistons and crankshaft from the 993, of course, otherwise it wouldn't work...

    For the ignition I thought about taking the 964 dual distributor, removing the Hall sensor and installing a Pertronix sensor in its place. The installation space is sufficient for this.

    Then operate it with 2x HKZ 3-pole. HKZ = ClassicRetrofit replica with freely programmable ignition curve.

    fokke

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    911 SC, MJ 78, USA, 930/04
    944 S2, MJ 91
    Honda Zoomer Tokio Style

    ---------------------------------------

  • remove the Hall sensor and install a Pertronix sensor in its place.

    The Pertronix has also tripled in size in recent years. The HEI module also works with the Hall sensor. Costs €8.50. Is installed in 150 million cars worldwide. Supplies up to 5.5A with automatic current limitation and closing angle and also works with extremely short charging and discharging times up to 8,000U and 12-cylinder engines. Simply connect a 0.4Ohm ignition coil directly to it without a series resistor. More ignition power is hardly possible. 123 dual ignition is good at 2.5T€, but also expensive. MSD is cheaper and is installed in every US tuning. They are also used for dual ignition.

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    Gruß

    Rainer

    3.2 Carrera Cabrio, Bj. 11/83, Sportauspuff und KAT-100Zeller von DANSK, späte DME, ca. 230PS, 7"+8" Maxilite.

  • ...let's move on. I got myself an old 964 distributor, overhauled it and set it up with Pertronix.

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    911 SC, MJ 78, USA, 930/04
    944 S2, MJ 91
    Honda Zoomer Tokio Style

    ---------------------------------------

  • You have not answered one question here regarding cylinders:

    964 and 993 have a completely different hole pattern (bolt circle/pitch) for the stud bolts (Dilas).

    Further outwards.

    In addition, the block must be spindled in order to make 100mm cylinders "pluggable" at all.****

    Even if you then set the studs further outwards, you will have the problem that the heads will no longer fit because they will still have the old bolt circle.

    You would then also need 964 heads.

    Channels/valves SC/964:

    38.5/40.5mm. Valves inlet are Ø 49mm -- outlet is bigger -- 41,5 vs 42,5mm

    Exhaust ports I don't know now.

    Cylinder air baffles -- no longer fit -- on the 964/993 there is an Mg component as a replacement which takes over -- is attached to the block with 3x M6 stud bolts -- there is nothing on the SC.

    993KW:

    Well then, buy one! I've been looking for one for a while.....

    And if you actually have 993KW with connecting rod set -- the connecting rods also fit 964 pistons -- vice versa only with rework.

    Head sealing surface SC vs 964/993 is also completely different.


    I think there are a few other issues to address here before you worry about the distributor......

    ****:

    And whether the sealing surface on the 964 is even at the same height as before -- nobody knows that either.

    It could be that the length of the cylinder from the head sealing surface to the base sealing surface is slightly different -- and then all the dimensions are out of kilter.


    I already had all these considerations -- but immediately discarded them due to the lack of compatibility.

    Nfu, Lars

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    Nur wenn du schwarze Striche vom Kurvenausgang bis zum nächsten Bremspunkt ziehen kannst, hast du wirklich genug Leistung(Mark Donohue).

    Im Alter wird man immer knackiger -- da knackt es und da knackt es...

    Sechs 964er bisher mit abgerissenen Dilas --- 14(!!!) Ventilfederbrüche bei den letzten 5 Motoren! 4:3:3:1:3

    Porsche 911 -- der Volkssportwagen...

    "Hoffnung -- ist immer ein Mangel an Information!"

    Wer restauriert -- verliert...