The road rocket racing sidecar project

[JulianM]

Looking good mate!

We are all waiting to see it running again.

julian

[Rocket Racer]

Had an ah ha moment mid week, split the crank cases and my much abused (white metal) plain bush was starting to break up. Will look to do both my A10 motors with a bearing conversion. Should be back together for the Barry Sheene meeting over Labour Weekend.
http://www.barrysheenetranstasman.co.nz/

Ah the joy of racing (or running) old bikes 

[Rocket Racer]

Thought a picture of the short rod motor with pistons fitted was in order. No wonder they need to be fly cut!
sadly my late crank refused to fit at short notice, the flywheels being 4 mm bigger than the transitional crank hung up on the scavenge oil pipe and my 358 cam would have required the cam followers modifying to pick up full lift as the base circle was smaller the followers couldnt drop sufficiently and I don't have time to modify.

Motor appears to have gone back together well, still need to time mag, set tappets and fit oil pump and new fittings. Might even be able to run up this weekend weather and time permitting...

[muskrat]

G'day RR.
What length are the T140 rods, and how do the big & little ends measure up?
I just fired up mine after the conversion. Beautiful, 60Lb oil pressure. I hope the noise I can hear is just backlash in the timing gears  .
Cheers

[Rocket Racer]

The rods are 1/2" shorter than std A10, these had been resized for an A65 race bike, then the owner decided to go carillo steel. Apparently T140 rods do need to be narrowed, but these were ready to fit as sourced. Gudgeons are as per A10.
The story goes that the T140 used the 750 BSA twin rods so they should feel at home on the short A10.
They are steel caps on alloy, so should keep pressure better.
The motor does get a hard work out so nothings certain. Hoping to give it some quieter running for its first day on the track, build it up and see how we go. The short rod motors are supposed to pull 8k and it will be ibteresting to see how it compares with the previous motor contents which could spin out to 7500 through the middle gears.
Got the wasted bolt and spacers sorted this afternoon but still not quite ready to start and weather here this weekend atrocious
looking forward to seeing this puppy run!

[muskrat]

So why not use A65 rods? They're 6" like A7 but biger big end same as the LJ A10.
In my A7SS racer I used A10 SJ rods shortened by about 2.5mm and A75/T160 pistons. Saw 8K often.
The noise I heard was timing (advanced). Sorted that and balanced the carbs. Beautiful, 30Lb oil at idle hot, 60Lb at 2K hot.
Cheers

[Rocket Racer]

So why not use A65 rods? They're 6" like A7 but biger big end same as the LJ A10.
In my A7SS racer I used A10 SJ rods shortened by about 2.5mm and A75/T160 pistons. Saw 8K often.
The noise I heard was timing (advanced). Sorted that and balanced the carbs. Beautiful, 30Lb oil at idle hot, 60Lb at 2K hot.
Cheers

I would have gone A65 rods, but these came up and no harm in having steel end caps, got it together late Sunday, but weather was rubbish and ideally need a pusher to get the chair rolling fast enough for a bump start on a gravel drive. so hope to fuel it up this coming weekend. Being methanol, the fuel goes in last minute then needs draining after use. But looks promising.

[Rocket Racer]

http://clmintiepix.photoshelter.com/gallery/Barry-Sheene-Oceania-Challenge-2013/G0000LMs3TEbS9po/6/1

if you scroll down you'll find a couple of shots of Bender (306) in action over last weekend 25/26/27 Oct

and a shout out to Tom from the forum who came and introduced himself at the meeting.

[Topdad]

Looks great RR , LOOKS VERY PROFESSIONAL ,  your hardwork as paid off best of luck for your future outings, regards BobH

[Rocket Racer]

Bike went very well for the Barry Sheene, but did lose a number of bolts and broke one of the head steady straps and worse had some damage to the crank cases, so will need further repairs.
My joe hunt mag packed up in the last race, last lap, last corner (but miles from the pits at the bottom of a hill) but all in all had a ball

[muskrat]

The joys of racing, even the lows. I miss it.
Can you hide Pazon inside a JH ?
Cheers

[Rocket Racer]

I'll persevere with the joe hunt a bit longer, not sure why... mainly bloody mindedness.

I must admit the highlight was a race when it showered heavily on one corner and made that sweeper extremely slippery (solo's leaking oil  )
On that corner we were overhauling a couple of 750 triumphs each lap after hanging onto them through the dry circuit, only to be blown back off on the straight. But it was very satisfying sailing past them sideways and carrying more speed. only downside was the joe hunt cancelling the party last lap

[Rocket Racer]

Had one of those "bugger" moments in the weekend: having decided on running a late crank for the motor I had the crank balanced (including some removeable plugs so I can increase the balance factor track side if necessary) I started reassembly only to find that while the flycuts for the pistons were spot on for the heavy crank, they are insufficient to clear the flywheel on the lighter later crank at bdc.  So now need to flycut more metal off the pistons which will adjust the balance.
bugger bugger.
The balancer estimated the motor as previously run was well balanced for a stationary motor  due to the increased rotational weight of the steel capped rods. Just wasnt suitable for a motorcycle.

[muskrat]

Don't you just love modifying one part then discovering you need to modify other bits to make it fit.
Just be careful the pistons don't get too short. I remember a Trihard owner shortened his pistons that much they tried to do a backflip at 8grand.
What factor are you looking at? How do you get to the plugs trackside without taking the barrels off?
Cheers

[Rocket Racer]

without the plugs we're starting at 65%, the plugs will increase the balance factor up to around 70% and should (will believe it when it works) be accessible if we remove the sump plate.
As the bike has a rigid frame and short rods and is pulling 3 wheels and two people, it had my balancer who is very experienced with british iron really pondering (owns an A65).
He did mention that modern roads (higher speeds) have altered the optimum balance from back in the day when they were first sold, which made sense.

Have also realised that my magneto is still away for repair, having broken the points spring in October, so have been trying to chase that down, won't be doing a lot of racing without a mag 

Have swapped my carb floats for some remote ones, so also need to make up some mounts and figure out where to fit them. just as well I've got a couple of weeks until racing. Does look a little concerning having a bare rolling chassis to look at right now.