Timing Needle Bearing conversion

[mark]

Greetings All. This is my first post having just joined. Have just started restoration of a 1955 Road Rocket. The engine has a big journal crank and big valve head and thick base cylinder. I found that the cases are not a matched pair as the numbers stamped below the generator are not matched. So I think that the motor is mainly big valve super rocket with the original drive side crankcase. The crank spins freely but the cam is fairly tight to turn. The engine number is correct for 1955 so I want to keep it. Since I am going to have to have the cases checked and probably have the cam bushes and mainbearings reamed true I am considering sending it to SRM in England and get them to do their  Timing bush conversion as well as whatever else is required. It won't be cheap but is it worth it? Any comments regarding this would be most appreciated.

Regards
Mark
Melbourne Australia

[LJ.]

Hello Mark, nice of you to join us.

I think this is really a personal decision depending on how you intend riding your BSA and how deep your pockets are, there is nothing wrong with the standard timing bush if it is fitted correctly and bike is ran sensibly. There are plenty of good running bikes out there to proove this fact, why would one want the conversion? maybe someone who has one can give us his opinion.

[Brian]

Hi Mark, welcome to the forum. I'm not too far from you, over in Mt Gambier in croweater land. As LJ says there is nothing wrong with the original setup, actually the whole motor is a very good design. A stock standard motor put together properly will give many thousands of trouble free miles so dont worry about having to do any modifications unless you want to. All my bikes run on the original timing side crank bush set up etc.  My plunger A10 has done 50,000 miles that I know of and is still running the original std size white metal bush on the timing side.

Brian.

[muskrat]

G'day Mark, I'm not far away either, south coast NSW. I had a "56 A7SS done by a mob called Bulldog over in WA about 15 years ago. It worked really well. I even raced it for about 6 years. The bearing isn't cheap, about $130 and not easy to get. The unmatched cases will have to be Line reamed and top face machined square to crank. It might be cheaper to find a matched set of cases. Check out Beezabill in WA http://www.geocities.com/beezabill/ I just found my old log book. The machinist in WA was Dean Harrison 09 459 8603 $670 back in 1990, don't know if he is still around.
Best of luck

[muskrat]

G'day again Mark, there's a motor on eBay in Melb item # 190325185140 starting at $500 it would cost that much to get a set of cases from UK or US.
Cheers.

[beezalex]

It won't be cheap but is it worth it?

No.

[rocket man]

Hi Ive had the SRM needle roller convertion, its a good modification if you can afford it.
I live in England so i didnt have any problem, they took my whole bike away and
they did a first class job. My crank cases dont have matching numbers either,
the plain bush is alright but like any bush if you dont change the oil regular
it will ware and also when it does ware it starves the crank of oil then it can throw
a conrod through the drive side casing which might have happend to your engine,
here's a few pics of my bike, I took them at srm during the rebuild.