Hi everyone,I'm currently in process of building my a10 plunger project,when it comes to the engine I'm after some advice/ideas.Id like to Build it with reliability in mind,but I would also like it to keep up with today's traffic,ie cruise if necessary at 65/70 but still have some in reserve to get me out of trouble or the odd silly moment!,My crankcases are late ones I believe 56 the numbers ba10****,from what I understand I can fit the big journal crank and thick flange barrels,I would consider fitting medium compression pistons,unless people think it's a complete waste of time,anyway what are people's thoughts experience,thanks in advance Von.
Hi Von,
The A10 engines can be very reliable and have quite a good performance for touring. The most important thing is to take care when rebuilding and get everything right. If you are going to do many thousands of miles the most worthwhile modification is to convert the oil system to end feed. This greatly improves the oil supply to the big ends and replaces the plain bush with a needle roller combined with a ball race to take the thrust and eliminate the dependency on shims for controlling crankshaft end float.
The use of the larger journal crank and thick flange barrels is ideal but not essential so long as what you use is in good condition.
Medium compression is probably best to get some performance without over doing it. Increasing the gearing by one tooth on the gearbox can help to make the engine a bit less buzzy at cruising speeds without compromising pulling away and acceleration.
You could go a bit further and fit a 357 cam and the appropriate valves, valve caps and collets but this is not really necessary especially as the plunger frame cannot accommodate the down draught angle of the alloy head. Convert to 12v and use a modern voltage regulator. A good magneto is probably as good as anything but electronic ignition is an option. Fit a new carb and away you go.
My wife's '51 Golden Flash is close to what I have described and it has completed many thousands of miles without major issues.
Dave.
That sounds good advice Dave,when you say oil feed conversion do you mean the roller bearing conversion that's done to the timing side plain metal bearing(think that's what I mean?!)the bike will be used for a bit of touring but mainly days out here and there with the odd journey to work,it will be used though as I fear even more so with an older bike months of no use will do it more harm than good (correct me if I'm wrong)
I also mentioned the use of large journal crank and thick flange barrels as all I have is a set of crankcases!,so as I'll have to find said items I just wondered if it was worthwhile using the "better" parts,just out of interest how does your wife find the performance in today's traffic and cruising,also how's the engine running on our unleaded fuel.
Hi,
Yes. The roller bearing conversion that is done on the timing side. As you do not have a crank and barrels then go for the large journal crank and thick flange barrels. It is best to use these old bikes as in my experience they do not like sitting around for long periods. Magnetos in particular can get damp and suffer accordingly. Also, regular use means regular maintenance and servicing which all they need.
As I have not ridden my wife's bike much I can only go by what she says and what I see on the road. I ride an A65 which is supposedly a bit more sporty than the A10 but she has no problem keeping up. Although an A10 can be ridden at 70 mph + it is far more suited to more minor roads and the speed limit is the only limiting factor. Cruising at 60mph there is still enough power for quite easy overtaking of slower traffic. I know that if we get separated by traffic it is not long before she catches up and she has commented at how well her bike went at speeds of up to 80mph to get past the traffic. Unleaded fuel is not a problem and the E5 fuels are OK. We have used E10 when in Europe and the bikes still go OK. They do like the Super Unleaded occasionally and they do run a bit better with it.
Dave.
Thanks for your reply Dave very useful information,out of interest does taking a pillion on the back of her bike really effect it,I'm considering making mine a solo seat?
Hi,
No idea about a pillion on this particular bike but A10s are capable of carrying and good load and pulling a sidecar + trailer. Obviously the performance is reduced slightly with a pillion but not that much. Usually it is camping gear rather than a pillion.
Dave.
Nice looking bike like the Siamese exhaust,and the front end,is that a TLS front brake did it take much effort to fit,fair play to your wife riding that around !,very cool
Hi,
Yes, it is a later TLS and later fork sliders. The brake is very good.
Dave.