Problems with pre-engaged starter on Hewland Mk8

[Tony Harman]

Has anyone come across this before.
My new FF1600 engine is fitted with ring gear for pre-engaged starter, now the one to use is Cortina automatic - because it has the solenoid on top instead of underneath- managed to get one of those easily enough(surprise surprise) but I have had to do a fair amount of fettling of the inside of the Hewland adaptor plate, both where the starter motor "nose cover" is and also on the inside of the stud bosses to get it to clear the slightly larger ring gear.
Even though it all cleared when I offered the adaptor plate to the block when we finally had the whole thing bolted together with the GBox the engine won't turn over.
Unfortunately we ran out of time and this has cost me a race start a Combe on Saturday. Still hopefully we will fix it in time for Cadwell in a couple of weeks.
Meantime if anybody has any ideas let me know.