Julian's Scrambler build "Post 1"

[JulianM]

Next job i'm in the middle of now is converting to a Yamaha FZR Clutch, including Cush Drive
Why an FZR?   Because I happened to just have a dismantled engine in my shed. 
BUT it is a really nice little light clutch and capable of about 130 break +  so will not struggle with my micky mouse figures,

Pics to follow.

J

[JulianM]

Barrels as from 4pm Friday,







Julian

[a10 gf]

Barrels

! Respect & admiration.

[bsa-bill]

Just gets better and better

[JulianM]

Thanks guys,

Hopefully it works too  ;o)

J

[JulianM]

Clutch conversion.

Thinking about the power etc and what to do I had a few concerns. My idea is to get it to 800cc with a CR of 10.5:1 and make a real torque monster. Hopefully achieving 60hp in the process.  So a standard or even uprated A10 clutch will not do!
A Suzuki GS or GT500 is an easy swap but both of these are about 50hp in stock form and I know from past playing that the GT550 clutch is not capable of much more than 60hp and with nowhere near the torque of an 800cc 4 stroke!!  So I cancelled these out.
I considered a Commando conversion but then realized I had a stripped Yamaha FZR750 engine in my stores. And the clutch on this is the same as that on the FZ1000, both of which out power my meager 60hp by about double!  It's also a nice 8 plate job weighing a lot less than my standard A10 clutch unit. Plus it has a cush drive, so the plan was to make it fit!

I am not going through the process here as it is not an easy conversion and not a recommendation unless you really need a super clutch.
Just here to show what I'm doing and why.

The two compared for size


8 nice fat plates!


Clutch basket offered up for fitting


Gear wheel cut for cush drive springs and pegs, and the centre fitted with the bearing carrier.




Assembled and splined drive/carrier shaft almost ready




More to follow.
Julian

[muskrat]

Gee mate looks like one of those "now I'll have to do this to match that" type of builds. Wish I could play with stuff like that.
One of my favorite sayings " lots is good, more is better but TOO much is just enough".
Cheers

[JulianM]

   Yep,   it does seem like chasing the weak link!  but trying to do it before I need to instead of after 

One of my guys just came in with the wheels after painting the hubs and re-spoking so lots for me to do.
Added to the fact that I just went to collect my new crank so it's all coming together!

Julian 

[JulianM]

Little pic of the new crank against the old one.  
88mm Stroke and 3KG Lighter.  65% Balance Factor.
And the crank counter weight mass is in a much smaller diameter so the weight saving will be multiplied grately!



Wheels all built up and hubs now painted in frame colour, Tyres and tubes fitted, So fitted the rear for a try out.








Julian

Block also finished, pics to follow shortly.

[a10 gf]

Again, impressive work! What's the plan with the timing side ?

[Hubie]

Looks like it's going to be awesome!  I wish I had your skill 

[JulianM]

What's the plan with the timing side ?

Hi,
Nothing trick, just a slight mod on the roller conversion. Nothing to speak of other than a little top hat bush.

"Quote"
Hubie,
Looks like it's going to be awesome!  I wish I had your irritating habit to change everything you touch    "Quote"

Fixed it for you 

[The pirate]

Hi, the rebuild is awesome. I have a question? wont there come a time when the power will blow the cases and barrel to bits - as these bikes were never designed for this, as a standard bottom end and barrels prove time and time again.

It is still brilliant engineering whatever your motive.

[JulianM]

Hi there,

Yep, there surely will come a time, but I "think" for now I have covered every post,  New designed Crank and rods, new pistons, new designed stronger barrels, "Wills Ring" head sealing so no gasket problems. Strengthened block and head studs.  I don't think the crank case will suffer too much and due to the heavy duty barrel hopefully this should add strength to the crank cases instead of the other way round.
I am aiming for 60hp which in my thinking is not a great deal, though "we shall see"    Am fairly confident all will stay together. It's not an endurance racer either, so I'm unlikely to hold it at full power for long.
For my day job I do this kind of thing all the time and some engines make a BSA look strong so get used to looking for weak spots. I think it will hold together for anything I will throw at it. 

Regards,
Crossed fingers Julian.

[The pirate]

I remember years ago, throwing on - clipons, very high comp pistons, bigger carby and changed the oil and went road racing, illegal road racing- the barrel parted company from the rest of the engine and a conrod tried to walk along the road - funny if it was not so expensive.