BSA C15 Timing Side Bush

[bsacad]

Even though I don't have a trials specific C15 I thought I would try posting my question here as there seems to be loads of experience of people working on C15 engines. Hope that is ok?

I have a collection of BSA C15 parts that I have been trying to build into vintage flat track style bike having been inspired by the picture attached.

I have a complete engine and also another bottom end and head that I was thinking of trying to get a bit more HP out of with a few easy modifications. When I finally started looking at these parts last week I discovered I had been very lucky. The head is SS80 that has also been ported and a huge inlet valve fitted. The bottom end was safety wired everywhere, with the kickstart and alternator removed pointing to some kind of race history (grasstrack or road race maybe?). I went in deeper and found the cam was also the SS80 type and the distributor was already removed and the shaft from the oil pump grub screwed in place to stop it working free.

From the things I have read the weak point on these engines is the timing side bush and with the other mods making it a bit more lively I was wondering if the needle bearing conversion had been done. I don't have the tools to remove the crank at the moment (never worked on a Brit bike engine before) and I was wondering if I made the effort to take off the pinion and distributor worm gears if I could see if the bearing conversion had been made from outside the crankcase?

Sorry for the long winded question.

[robido]

Yes you should be able to tell. There will be a close fitting washer on the crank which if you remove it you will see the rollers cage behind it. The washer is a precision fit inside the bearing outer as it keeps the oil in. Hope this helps

[jon v8]

I'd want to start off with a roller bearing big end to build a C15 engine with more output than standard. As B40 RT says the Rupert Ratio book is a bit of a must for any unit single owner. The author,(Dave Smith) is a top bloke and has loads of spares. You can contact him through his website;

http://www.bsawdb40.com/Ratio-Rebuilds

[bsacad]

With all the mods I’ve found on this engine already it may have a roller bearing big end (fingers crossed). I think I’m just going to have to open the cases and get the crank out somehow and have a proper look.