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MG MGB Technical - Click-adjust

How many clicks on the click-adjust are required for a B (0.15) I use 8 for the TD (0.12), so I'm assuming 10-11 for the B. Thought I'd check the BBS to confirm.
Bob Doc
Robert Dougherty

8 cold, 7 hot I'm told.
Dan Robinson

You should confirm the number of clicks as per the pertronix instructions. For my B it is only 5 clicks to get to .015 cold. I don't know if mine is different, but I have confirmed the gap with a .015 feeler gauge.
Don Scott

Bob - It is easy enough to determine the number of clicks. Just use a 0.025 or 0.030 feeler gauge along with the 0.015 gauge and run the rocker down on the two of them until you get teh heavy click. Remove the 0.015 feeler and count the click to run the rocked down against the larger feeler. That's all there is to it. Cheers - Dave
David DuBois

Check out the data table at

Ron Bland

I used that method and got 8 clicks for .015, which doesn't make sense, since I get 8 clicks on the TD for .012! One of life's mysteries! Gap seems right, so....
Robert Dougherty

Robert - it makes perfect sense because the click adjust turns the adjuster screw to set the gap - if the screw is a different pitch then you get a different number of clicks per thou!

I presume the TD has a finer pitched thread - dunno cos I don't get to work on them too often!
Chris at Octarine Services

Bob & Chris - The adjusting screw in the TD is metric (8X1mm if I'm not mistaken), where as the MGB is 5/16-24. Sorry, the pitch and TPI don't convert easily, but that is why the same number of clicks for differnet clearances as Chris says. Cheers - Dave
David DuBois

1mm pitch is 39.4 thou - 24 tpi pitch is 41.67 thou

8 clicks on the adjuster is 15 thou on 24 tpi but 14 thou on 1mm!

I am suprised that the TD has a metric thread, I would have guessed at British Standard Fine!
Chris at Octarine Services

Chris - The XPAG/XPEG engines used in the T series cars used the Nuffield Mad Metric fasteners. This was an obsolete French Standard Metric (most of the pitches are now refered to fine metric) with BSF sized heads. I won't swear that the valve adjuster screws are a metric thread, they are about the only thread in the engine I haven't actually measured, but since the rest of the threads in the engine are either metric or BSP, I would assume that the valve adjusters are also. If anyone has the head off of a XPAG/XPEG engine, you might check the threads and let us know. Cheers - Dave
David DuBois

This thread was discussed between 06/09/2005 and 10/09/2005

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