SS50 engine troubles

Found the problem for the slipping clutch, it was weak springs, luckaly the local Honda shop sells extra strength clutch springs for a C50 clutch that will also fit the C110 unit. You only need to buy 2 sets as a C50 has only 4 springs.
When compressed to 12mm these gave 9kg's of pressure, compared to the 5kg's I had from the stoch C110 springs.
Also something was found for the gearbox problem, it turns out the old C65 casings have a higher hump inside from the footrest mounting holes. This caused my shifting arm to hit against it and not being able to give the full movement to the shiftdrum.
The piece marked in black marker was cut away and now it shifts like a dream.

RSC front fender, part 2

I've made a die to press the ends of the front fender stays.
It is milled from a piece of solid steel and made specifically for 8mm (alloy) tube to be pressed flat like Honda used to do, with a rounded edge and pressed to one side.
The first test:

You can see some irregularities and a nick from the end of the die, so I made some changes by hand, I was happy by the third test:

And the stays as they should be put together:

I want to put it all together in the weekend as I want to take my time for this. I don't want to rush it in the hour after work that I spend in the workshop.

RSC front fender

As the ss50 engine was built up again, I spent some time on my RSC project.
An aluminium front fender has been lieing on my front tyre for some while now, waiting for brackets to be made.
So I started the process. Found a piece of strong 2mm aluminium and cut out the right shape for a fender stay. It has been modelled after a C110 front fender stay although that has a thinner pressed plate example.

I chose 2mm plate for its strength, because I want it to also function as a fork stabiliser.
Something I experienced with my SS50 on the road with plastic or steel fenders, is that I do want a strong connection between the legs.
I will eventually round the edges of the stay to immitate a thinwall pressed plate stay.
The stays will be riveted to the fender and the 8mm tube will be welded to the stay after it is clamped in place by folding the tabs on the stay around the tube. Just like original fenders.
And to give you an idea of what it will look like:

I will also add a plate underneath the fender that will be riveted together with the stays, to add strength to the fender where it functions as a fork stabiliser. Something also seen in original (steel) fenders, mostly causing them to rot out from underneath.

the oldschool engine runs

And it accelerates a bit quicker then with an original clutch.
I rode it home from the workshop today, hoping I could take it for a ride tomorrow, what is probably the last dry day of this year.
But....shifting is still not the way it should be, so I will have to open it up again and sadly the C110 clutch is also slipping like crazy. Tomorrow morning I will check if I did something wrong with the adjusters, but I am afraid that it is the plates or the springs.

valve spring retainers

The old-school SS50 engine is back together again, and it has run, but I need to make a real testride to feel if everything is allright.
But when checking the head, I found something that didn't work.
I had made triangular valve spring retainers by grinding off parts of the originals, but this resulted in one point of the retainer getting cought on the end of the valve spring, stopping it from rotating over each other.
The solution: making a 6-pointed retainer.

from left to right:
original, old adapted retainer, new adapted retainer


Method: bolt the retainer to a piece of perforated sheet metal with round holes, then spraypaint, this will mark what you need to cut away.
My scales aren't exact enough, but you take off about 2-3 grams, this matters at 12.000RPM.

My new tank

My new tank came in a few days ago, thanks very much to Matt Hummel
Trying it on my bike, to see if it clears the master cilinder, as the toaster tank I am currently using didn't and had to be slightly altered on the bottom to fit.
But this tank clears everything perfectly, probably made for the dual disc setup.
Insides are perfect, outside does have some rust as a previous owner started blasting it, but never finished.
I will have it painted black with white pinstripes, luckaly there is enough of the original stripes left to have them copied.

progress on the Oudshoorn

there is some more progress on the Oudshoorn BMW.
My dad is busy fitting the cilinders, heads and pistons so it will al work together, not to easy considdering everything comes from different models.
- 700LS heads and pistons (car)
- /5 cilinders adapted to fit an R50 case that has been modified for long studs that run all the way up to the rockers.
- R60/2 cranck
- .......


old school altered front brake plate, only it should be in the original leading link front end, there will be an original front brake plate to go in these van Bockel (ceriani) forks.

more new parts on the oldschool engine

New crankcase for the "old school engine"
well, not exactly new, it comes from a used C65 motor. I wanted these because of the mounts underneath the cilinder for a guard plate. At some point an oilcooler will be mounted on here.
After glassbead blasting:


Nice that there is no engine number, the old engine must have had the cases swapped at some point.
BUT.....these are 1960's cases, this means problems like I've encountered with the S90 motor, but didn't expect on this.
different locations for the guide pins, should both be be on the top tappets in this picture, but they are not, so I can use only one that corresponds with my cilinder.

A hole, my piston for the camchaintensioner will not block this and won't be able to build up pressure, will have to find/make a longer piston.

The piston I had in the other cases, with the long spring. And the short spring that was with the C65 cases, this tells me I need a longer piston.

new clutch for the ss50 engine

I have been collecting parts for my "old school tuning" ss50 engine, to replace the original clutch with one from a C110.
The C110 has an aluminium center that weighs a lot less then the original ss50 clutch. Although my engine had a 2plate clutch from a chinese copy. even more weight then the original 1plate, but it was the only complete clutch I had laying around at the time.
C110 clutch:

Only it doesn't fit onto an SS50 crankshaft without modification, so I had my dad grind the inner diameter to fit the SS50 crank, then the splines fit.

On all sides it needed some work, the primairy sprocket needed some work to fit onto the gearbox main shaft. Some spacers needed to fit the whole clutch onto the crank, and a bearing holder had to be fabricated to let oil thru, as the c110 doesn't have that.


To give an idea about the weight loss
2 plate:



C110 clutch:


Now to finish the engine so I can hear the difference in revving, I'm looking forward to starting this up and hearing the difference.


A nice bonus is the difference in primairy reduction.
SS50 originally has 16:69.
my 2plate system had a 17:67 reduction.
And the C110 has 15:70. this means the gearbox will make less revs, letting it shift easier.

90 valves

The valves for the 90 have been done.
Thinned down the shaft for the length it sticks into the port with full lift on the cam.
This means more space for fuel to get thru and a reduction in weight, this will help in the higher revs.
Also they have been ground into the seats to see where the contact is, and the edges sticking out have been removed and rounded to let fuel pass by the valve easier.




Also removed weight from the side of the valve that is in the combustion chamber, the loss in compression is minnimal, but you will notice the reduction in weight.

Sharp edges removed from the combution chamber.
Now only to wait for my titanium valve spring retainers to come in and then the engine can be completed.