cylinder head stud threads
Posted: Thu Feb 11, 2021 4:50 pm
Me again - Sorry.
Despite having 3 part engines to amass 2 working engines from i have only 2 head stud bolts. These are 230mm in length and so different to the bigger engines and are only 8mm diameter vs 10mm i believe. Having unscrewed them from the cases, i am on the hunt for replacements but am being stumped by the threads. Using metric thread pitch gauges i cannot get a match and whilst illogical am now assuming they are imperial but dont have any imperial thread pitch gauges. I know that the footrest bolts from memory have an imperial pitch.
The crankcase end is a finer pitch than the head end. i can buy high tensile metric studding, so worst case could tap out holes and helicoil to M10 and use high tensile M10 studding but seems a shame.
Any wise words out there?
Despite having 3 part engines to amass 2 working engines from i have only 2 head stud bolts. These are 230mm in length and so different to the bigger engines and are only 8mm diameter vs 10mm i believe. Having unscrewed them from the cases, i am on the hunt for replacements but am being stumped by the threads. Using metric thread pitch gauges i cannot get a match and whilst illogical am now assuming they are imperial but dont have any imperial thread pitch gauges. I know that the footrest bolts from memory have an imperial pitch.
The crankcase end is a finer pitch than the head end. i can buy high tensile metric studding, so worst case could tap out holes and helicoil to M10 and use high tensile M10 studding but seems a shame.
Any wise words out there?