marting Posted February 2, 2021 Report Share Posted February 2, 2021 Hi all, I have been working with Tim to resolve the issues with his countershaft. After replacing numerous bent and incorrect parts we got the cam to make friends and meet up with the actuating bolt. However, we then experienced issues with the linkage rods not aligning with the lever arms. Manifolds checked and set horizontal and the rear rod was still 10mm out. After some head scratching and further investigations and it looks as if we may have found the issue. The Mk1 PI saloons had countershafts that are almost identical to the TR CP countershafts. See attached extract from the parts manual. The front two linkage rods are the same as TR5 items. The only difference is the rear linkage rod which has a clevis pin arrangement to help with bulkhead clearance. The hole in the countershaft lever for this rod is smaller that the TR one, and I was discussing the reason for this with the Technical Secretary from the 2.5PI register last night. Neither of us really knew why that was. Today I did a mock up. The rear lever arm on the 2.5PI countershaft is 10mm closer in than the CP one. This would be hard to see even with two countershafts side by side. As such I would think that like the reason for the smaller hole may have been to prevent them being mixed up. However, this does not prevent the hole being enlarged and then being fitted to a TR which could be what the issue is here. If your old swivel posts are worn, you may get away with it. However if they are new it would make them bind and would probably stop the butterflies from fully closing. The reason for this update is I have a customer in Lancashire that is experiencing issues with high tick over where this could be the issue, and I have just received a photograph from a TR6 owner in California which seems to be another Saloon one (albeit a modified Mk2 one?). If you want to check yours the arms on a CP countershaft should be equally spaced and the gaps should be 168mm. Kind regards Martin (Fred Millturn Parts) Quote Link to post Share on other sites
Tim T Posted March 21, 2021 Author Report Share Posted March 21, 2021 I thought that I would post a final update on this saga! I now have the correct shaft, brackets, linkages, cams etc. Just about everything that I been supplied previously was wrong and in fact from a Triumph 2.5PI. All looked very similar but wrong. Martin at Fred Millturn Parts was able to supply me with all the correct parts having tested them on his test engine. The vertical linkages in particular which are manufactured to the original design were really easy to fit and adjust. I would like to thank Martin for being so helpful in sorting everything and being so patient. Happy to recommend his parts and service support! Now onto the next problem....... Cheers Tim Quote Link to post Share on other sites
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