What goes in this hole then?

[chaterlea25]

Hi Simon,
It can be a tricky job on your own!!!
You can use some parallel pieces of metal to support the pistons as you lower the cylinder
another pair of hands is also advisable if you have not done this before
Lube up the ringclamps well  and tighten until the clamp is just free to turn on the piston
the parallels will keep the pistons upright, place the cylinder over them and gently push the cylinder down squarely!
HTH
John O R

[Richard]

John has pipped me by replying first but I use two strips but plastic bits that were cut from my  facia board when fitting it, across the crancase each side of the rods then bring the pistons down onto them, this keeps the pistons secure and then I positon the ring gaps and oil the piston and rings then place the barrels gently on top and using a plastic stylis from a pda i carefully push the rings in one at a time on each piston while keeping a gentle pressure on the barrals with my other hand it is a bit hairy at first but i have done this for some time now also with my A65 I find it easier than using ring clamps as I just cannot get on with them, but it stops me getting frustrated when the clamp goes down and the ring pops back out
It may well be that if I was shown the technique of using clamps by someone who knew the knack then it may work for me but until then the above method works
Richard
Warning 
there is a greater chance of breaking a ring with my method

[nigeldtr]

Hi Simon,

Not being funny but what sort of ring clamps are you using. I originally had some that we like a long pieces of spring steel coiled up and adjusted with a key. I found these were  either too loose or too tight (un-even pressure not closing clyindrically) and decided to buy ones of a single ring with a screw for tightening. These worked fine, nipped up and then just eased off. My son lowered the barrels while I checked the rod cutouts at the bottom of the barrels to see the rings were going in ok. With two, went togther relatively easy (the nearest thing to giving birth that a man will experience). I used to do this all by hand but after breaking a number of rings, I prefer to use the one piece clamps. If I get time I will add a pictures tomorow.

PS I used a couple of 5 " gauge plastic railway sleepers to support the pistons - I think in the instruction booklet they recomend 2 peices of 3/4" wood and cloth stuffed in around the crankcase opening to stop any bits falling down the hole

Nigel

[trevinoz]

Nigel,
         I have a set of Terrys ring compressors which I bought over 40 years ago. They were available in several sizes and were cheap.
They are just  bands of mild steel with a rolled end which captivates a toggle and screw and the other end is like a hook which accepts a threaded toggle.
Very easy to use. I use a pair of socket extension drives to support the pistons when fitting the barrel.
Trev.

[Mosin]

Well I've now spent a total of five hours trying unsuccessfully to get the bloody barrell down over the pistons, using every single one of the hints and tips suggested here. Finally, I realised the problem....

I had ordered a full set of plus 020 rings from C&D autos. They arrived in two packets both clearly marked plus 020. Just to be on the safe side, I opened the first packet and checked the rings inside the barrells to make sure that the fit was right. It was. Perhaps foolishly, I did not check the second set, assuming that it would be exactly the same as the first. It wasn't. It turns out that C&D sent me one set of plus 20 and one set of plus 60! There was no way on earth that the were ever going to fit into my plus 020 pistons.

As you can imagine I am pretty furious about this and will be on the phone to C&D first thing on Monday morning.

Bah.

[Richard]

Frustrating
Richard

[RichardL]

IMHO, you must check and, if necessary, file-fit ring gap for each ring in its target cylinder, even if they are, indeed, both the correct oversize. I assume the judgement of 0.060"-over is based on more than just the end gap not fitting. But that is not my point. When you are sure you have the correct rings you will still need to check all the gaps.

Richard L.

[orabanda]

I use a similar method to Trev.



These ring clamps came from British Only  (in NZ) and they are low cost but good quality.

A couple of pieces of 1" square soft wood to go under the pistons, and fitting the barrel is a 10 minute job, for one person.

Richard

[RichardL]

Richard,

Though it's an old picture, it's never too late to say, "beautiful work." Of course, you've spoiled us and we naturally expect no less from you. It's also, I think, a rare shot of a breather pipe in place.

I do wonder, why do you run the blocks longitudinally rather than across the case so that both pistons sit on both blocks, as shown in various manuals?

Richard L.

[orabanda]

Richard L,
Thanks for the kind comments!
I have never found a breather pipe on the swing arm engines (only the semi-unit), so I made that one.

Here's a better pic:



I simply find it easier to get the 1" wood out afterwards (don't forget to have the base gasket in place!).
More pics from this rebuild:




Also, here is this bike on the dyno 2 days ago; more about the timing settings, etc in a post to follow:





Regards,
Richard

[chaterlea25]

Hi Richard,
Great photos!
Looking through them one shows the battery tray bracket over the frame cross tube, there seems to be a large gap there like on a RGS frame, I have heard that some early (54/55) frames also have the larger gap,
Just curious????
In the photo of the bike on the dyno, it looks like you have a different clutch from standard????
hard to se as its spinning but it looks alloy???
I also thought about fitting a breather pipe but I didnt want to reduce the size if the breather hole, so I left it alone
Cheers
John

[orabanda]

John,
This is a Suzuki GS550 clutch, which a mate of mine in Perth knocks up.





I have them in all of my swing arm bikes.

The rigid and plunger A10 have the standard 6 spring clutch (with the dome cover). Apart from fitting an alloy pressure plate, and setting them up with a dial indicator, they are standard (and really nice clutches).

Here is the standard clutch on my plunger bike:



Now, I am building a Super Rocket special (BTH maggie, TLS brake, roller bearing timing side bearing, etc...) and have had my mate do a belt drive. I love japanese 2 stroke dirt bikes, and had a spare clutch from a PE400 Suzuki which I am restoring, and this has been converted to belt drive for the Super Rocket.


This is Colin Tie, who prepares the clutches, and one of his many Gokld Stars.

Richard

[chaterlea25]

Hi Richard,
 Thanks for all the info, I thought it was something like that,
Does he attach the Suzuki clutch basket to the BSA chain wheel?
and does he modify the clutch centre to fit the BSA/Triumph centre adaptor?
What kind of centre bearing does he use?
Do you have some photos of one dismantled?
I have bought a couple of GSXR clutches on ebay with a view to doing this mod
These are similar to the GS or GSX except they have sawtooth like splines on the outer of the plates,
A friend of mine has a standard one of these clutches on a big bore GSXR 13**cc using a 750, 6 speed box
and it has not given him any trouble!!!!
so I dont think 20something bhp on your flash will bother it!!
However on my SR with high comp pistons and spitfire cam etc, the 4 spring clutch I have presently slips when the engine comes on the cam around 4000rpm,
Hence the Suzuki  conversion!!!!!
Regards
John O R

[rocket man]

thanks for the pics Richard, you have a very good setup there
and looking at your bikes you do a good job on them lovely



dave

[orabanda]

John,
Here is more detail on Colin's clutches.
His passion is Gold Stars (here are a couple of them; there's more than this!):



He rides his bikes every weekend in club events

He is a skilled machinist, and wanted a better clutch for his own bikes.

He buys industrial chain wheels, and adapts the clutch to them. This one is steel sprocket.

 





This is the clutch on my RGS replica. It has an anodised (hardened) alloy sprocket, and is much liter than thges steel.



I gave him a clutch out of a GN250 Suzuki which he adapted into his 350 Gold Star; he said it was a great clutch!

Regards,

Richard