Building our AC Cobra 289 LeMan

Once we had done the final fit of the throttle linkage, we looked at it once again and thought to ourselves that there might be a problem with the lower bracket once the engine was running . As its only fixed to the inlet manifold at one end, we thought this may allow it to flex (a bit like a diving board) and over time may cause it to snap. So Mark set about once again to make a few improvements. His solution was simply to make a new piece of bracket that could be wielded onto the existing bracket, allowing the other end to be bolted to the the back of the engine head, making the whole unit even more solid.

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We both arrange to get another day together to get on with the build. The last weekend we both had free was end of February where we had respraying the footwells. We were keen to get cracking again. The first job of the day was to refit all the bits we striped off in order to do the painting. This included putting back the peddle box, battery shelf and brake reservoir bracket and reconnect the throttle linkage.

Mark had spent a few more hours over previous weeks polishing up the rods and blades getting them extra shiny in preparation for the final fit. We decided as a little extra that we would make some extra plastic washers for the rose joints to try to prevent any potential rattles between the joint and the bracket.




Once altogether and everything fully tightened up, we then spent over an hour tinkering to getting the leverage of the peddle between idle and full throttle absolutely perfect. I’m glad to say we finally got there. Considering Mark designed our mechanism (based on photos of Andy Gordan’s Car) we are really happy and think it look great.

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We decided at this point to get the throttle linkage mechanism finished and fully fitted. We did the first fit back on 28th January, but now we have all the necessary bits to finish off.

This involved connecting the springs to the throttle lever on the carb and Mark’s newly made bracket as well as make all the connections tight and fully lined up. We carefully worked out the leverage of the throttle going from idle to full to make sure there was always some tension in the springs at all times. We then marked up the position for the spring holes before drilling and connecting them up.

Next we added smaller springs either side of the connections on the transverse rod. This is to keep everything inline as well as to allow some movement when the engine is running. We secured these all in place with collars either side.

When we originally fitted the throttle linkage on the 28th Jan we made a temporary bracket to secure the transverse rod connection to the inlet manifold. The intension was to design and make a better solution and since then that is what we have done. We marked up 2 pieces of the stainless steel for the new bracket and asked our uncle Dave if he could wield it together for us along with a threaded boss on the top that the rose joint screws directly into.

To finish the 2 brackets off we rounded off the corners then shortened where necessary before polishing them both up.

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Once the throttle peddle and pivot where fitted, we moved onto fitting the throttle linkage to the carburettor. This is something we have been thinking about for a few weeks. We had the option to get the bits from Gerry but Mark wanted to design and make our own system. We had pictures of Andy Gordon’s Cobra at Silverstone, once again we used his car as the inspiration as we thought the solution he found was quite a neat one.

Mark spoke to his engineering department at work, asking them if they could manufacture the blades for the rod linkage and also some stainless steel strips, cut to size, that we plan to make a bracket from and mount to the inlet manifold. We have made a temporary bracket for now, that we will replace with a better one later. We have marked up for the new bracket that we hope to get our uncle Dave to wield for us.

We fitted the rose joint on the top of the footwell first. we then slid the 10mm rod into it. We then put another rose joint on the other end which we lined up and marked the hole to be drilled on our temporary bracket fitted to the manifold. Then drilled the hole and fitted the rose joint onto the bracket. We then fitted a blades to each end of the transverse rod.

We linked the blade to the carb using 2 female rose joints and 8mm rod. we had to tap a thread to both ends. We connected the other end to the peddle in exactly the same way using a shorter 8mm rod.
It took a little time adjusting the lengths of the rods to get the travel of the pedal correct but it works really well. We have just got the final bracket to make and fit now to finish this off.

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