Ariel Owners Motorcycle Club

I'm in the process of restoring a 1958 Ariel Square Four that was dissembled in 1978. I'm having a problem with the connecting rod bolts, part number 1096-48 and part number k13848. When I installed new connecting rod Bolt 109648 the rod bolts hit the front of the right hand crankcase. The rods are original, and have been resized.

Has anyone run into this situation before?

The original bolts do run close to the case and the replacements may be a little longer, remove a little metal from the case or the ends of the bolts. I assume this is happening with pistons and cylinder fitted because without the rods will end up in a different position within the case, causing your problem.

People have run into this before? Is there a measurement that is known? It was a tad discouraging assembling the whole bottom end and not have it rotate 360 degrees!

hi i always grind a little bit out of the casing before i start rebuilding it and then i know it will not catch

How much do you grind? On both front cases?

Hi

If the issue didn't exist before changing the bolts then the cause is most likely the bolts or incorrect assembly. The last thing I'd be doing is adjusting the crank cases to fit - adjust the components which are the cause, if the assembly is correct make the bolts identical to those removed.

Regards Mick

hi the last time i done a rebuild i think i took out about 3mm but i think it depends where the bolts come from

The bolts are new old stock with castleated nuts. Unfortunately, I have only found six bolts. They came under part number 1096-48. Nuts were sn3. Is the small steel washer under the nut used on all the square fours?

You are assembling with the head of the bolt in the big end cap and the nut in the con-rod, aren't you?

Yes.