The road rocket racing sidecar project

[Rocket Racer]

The bike ran reasonably well at Taupo, the oil pressure copper line failed, so needs a flexible line and a rocker oil feed bolt was lost, so minor issues. Main learning was that refitting an 80lb oil gauge was a mistake with an uncalibrated OPV. excepting idle the gauge read off the dial, really needed a 100lb guage  . now this motor does run a timing side conversion and SRM pump, but seems to be constantly reliant on the OPV, so I need this to be set around the 50lb level.
I have just had a simple test jig made so I can review blow off pressures.

Quite interesting to compare old A10 type which rely on the ball bearing which as soon as lifted fully opens three vent holes, whereas the more modern OPV plunger is more progressive, only opening via two holes and like a throttle slide the holes are progressively opened as the plunger exposes them. Winding out the dome cover lowered the blow off pressure. the Les Williams tri type have quite high full blow off and with oil and a compressor could still stand 90lbs before fully open although start blowing off lower.  In my case not helped by an engine rarely run below 6000.
I need to tinker more but my first thought is that with an oil gauge fitted a std ball bearing OPV is just fine .  Far lower and far more crisp blow off.

[Rocket Racer]

didnt realise I was being recorded! Must have been a mobile phone...
https://www.youtube.com/watch?v=1t9f3mdCGm4

It was too hot to be in race leathers, The final Pukekohe festival, over 400 bikes and entrants including three of the 10 Brittens !
Blew the head gasket so not a success for me. Mind you the Yamaha sidecar pictured next to us had the front wheel collapse! Luckily not hurt. 

[Kickaha]

Mind you the Yamaha sidecar pictured next to us had the front wheel collapse! Luckily not hurt.

Grant and Matt, they travelled up from Rangiora and Invercargill, Matt was my swinger for the first season I did riding the LCR, I raced against Grant and Matt before that when they rode the Windle F1 and I was a passenger on an LCR

[Rocket Racer]

Nice guys, they were very lucky! thought they had a flat tyre and decided to quietly motor back in, until they hit the chicane on the back straight and the steering and the front wheel went in different directions. Luckily on the last race before they headed off, so they had a better weekend than I did. I didnt see the hub, was in the queue for the pit crossing during bike recovery. Great to hear there are four classic big wheelers down south, might need to bring mine down one day.
I have a bit of review to do, Might be bottoming out head bolts on the shortened cylinder? Thats twice the heads blown on that side now. But the BSA national rallies coming up soon and want to get the '54 RR revinned although unlikely in time for the rally, will probably take the ZB33

[Rocket Racer]

pulled the top down and the problem was a little unusual, the head bolts had been rubbing on the top section of the bolt and had lost the tightening into friction as the head was pulled down. So when the engine heated the bolts lost their tension on the head and the head started weeping! So the head holes need more clearance so it tightens down!
After similar problems in October, I threw in some 10.5's in that I had (they were grooved ones from Baxters in the US), however they had offset pins and dont come up fully the deck height.
So I've just invested in some 10.5 hepolites also from the US (should arrive sometime in March), hopefully these will sit flush with the deck height.
Also looking to buy some fresh concentric alcohol 30mm's as my carburation was lay rich with the TT's which also have always suffered with float swill. Will look to jet it up on a dyno before racing again possibly in the spring

I've also bought a '51 ZB34GS to take to the track and circulate at meeting along with the sidecar. Can't help myself... I did sell my vincent, so just BSA's in the shed now.

[Beeza]

Nice to see this one coming along again Tim, we’re going to get the 54 road Rocket back on the salt next month all going well. As for head bolts, I have used 10mm metric fine socket head high tensile bolts, the thread pitch is close and tapping into the barrel is very cautious, also drilling the rare alloy head for clearance is a no going back episode, but it will give deeper thread embedment into the barrel, also APR H/T head washers. I did use those Baxter 10.5s, but ended up designing my own now, about 11 to 1 forged with thin rings.
I’m using with great effect a pair of 32mm Mikunis wit Noton manifolds, however porting is quite adventurous on my bike, you may be able to go back over my past posts to see why.
Cheers mate

[muskrat]

G'day RR.
Hows the solo going.
I think this pic would be you on the chair after a solo race!
Cheers

[Rocket Racer]

Barrels getting a hone, skimming head and barrel, new valves and seats ground, new 10.5's powermax have been flycut for clearance and once top ends on the exhaust will gain the option to fit an air/fuel meter to get the jetting right for methanol. Have fitted a set of concentrics with methanol internals. May be the last build I do with it.
Still planning on having a solo racer to give me another few years trackside with it. Will look to renew efforts with the A7SS projects which had stalled with the rolling chassis largely complete (do need a good solo race seat) 

[RDfella]

to get the jetting right for methanol.

When I ran methanol in the BSA, found it ran just as well with the main jet in my pocket rather than the carb.....
On methanol, as long as it runs rich you're OK (power is not down as it would be on petrol). Run lean and a piston's gone in seconds. Not sure a meter's going to show much on dope.

[muskrat]

to get the jetting right for methanol.

When I ran methanol in the BSA, found it ran just as well with the main jet in my pocket rather than the carb.....
On methanol, as long as it runs rich you're OK (power is not down as it would be on petrol). Run lean and a piston's gone in seconds. Not sure a meter's going to show much on dope.

G'day RR.
You would know all this already.
RD's not far off the mark. With meths it can run 20% rich with no drop in performance. With twin 932's on the A7SS I had 680 main jets.
The only problem I had was at the end of the Creek's straight was the slides were frozen wide open  and had to hit the kill button for a second to get them to drop
Cheers

[Rocket Racer]

Thanks guys, I hear what you're saying. An engineer mate who worked on both tuning a landspeed indian (sidevalve) and on a track vincent so done a lot with methanol tuning pointed out to me that often main jets on methanol are not the limitation, it can be tap or bowl restriction that negates effect of altering the jetting.
On the TT's it was seriously rich last outing, black smoke. wasnt good and too much does result in bore washing. I'm now fitting 30mm concentrics and the advantage of the australian supplied set up for the air/fuel gauge is that it is designed for methanol readings and should give me settings in real time set up on the chair. and at all the openings. Once the engine is back together and I'm back from the IOM the first challenge will be determining cutaway, I think I'm in the ballpark jetwise.
https://raytechautomotive.com/products/lambdaking

[Rocket Racer]

Finally got the barrel and head back, skimmed, seats ground for the new valves and bores honed. So should be able to start top end reassembly this weekend.

I also had a chat to my engineer about my A7ss bottom end which I want to prioritise (with the a65 crank etc) so I can progress its build next. He'll get onto it this weekend as its been sitting around for a while doing nothing . Not getting any younger and when I retire proper wont have any money for that sort of caper.

[Rocket Racer]

Generated some serious power after a days testing at Taupo, sadly didnt get past race 1, the head steady held it together and allowed us to get it shut down before the clonking turn fatal.
Appears damage limited to the resleeved barrel
first pic of engine is as assembled after being pushed back in after a dnf
The poor lone head stud at the front snapped

[muskrat]

Commiserations RR 
Trials and tribulations of racing.
Been there, done that a few times with thin flange A7 barrels (un-sleeved 1mm os) @ 14:1.
Hope your crank and rods are OK.
Cheers

[a10 gf]

  ...& the 'like' refers to the detailed pics, fascinating, not the mishap.
Best wishes.