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Author Topic: Salt Flash. A Bonneville Beezer.  (Read 41029 times)
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Briz
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« on: November 03, 2013, 12:25:16 PM »

Been meaning to start this build thread off for some time, but hey-ho, other things get in the way.
After our last Speed-week trip in '12 with my somewhat hubristically named 'worlds fastest Weslake' debacle,( rolleyes) I had to decide what to bring to run next time.
Clearly there wasn't any question of there not being a next time.  grin
The Weslake wasn't going to fly again; It was never going to get near a record and besides, I had grown to dislike it a bit.
So I sold the engine on and pondered. A XB9 Buell engine was originally mooted, our friend PJ had one and we did a deal. But I really couldn't get into the idea, and there was little progress.
At the end of March this year, it was the 40th anniversary of me getting my first proper bike; a BSA A10. Suddenly it all fell into place. The Buell plan was ditched.
It was always going to be special-construction, but this time we could run in Vintage. Blown. Methanol.
So we set about sourcing some BSA stuff. After a false lead or two, we (thats me & David who crewed for me last time and will co-ride this time) hit the Newark swap-meet and got some basics:


We also met an old boy who used to run sidecar grasstrack. Paul Grayson in west London. He used to cast his own parts and had a couple of blank alloy cylinder castings. We bought one:


Not the tidiest casting in the world, he never intended to win shows, just races! But the alloy is good and properly heat-treated. Theres also a lot of it! no question of these breaking.
That gets us out of trying to find a good thick-flange original pair of barrels, but leaves us with a ton of machining.

In mid April I topped & tailled and rough-bored the cylinder casting in a spare afternoon. Cored cylinder holes were way off - too close together and one was a bit skewed. Didn't clean up until I got to 72mm. Good job we didn't want the stock 650 70mm bore!


The guys on the A10 forum have been super helpful. http://www.a7a10.net/forum/index.php
One guy-Julian-who restores Lagondas for a living is building a street scrambler A10 has made his own billet crank & barrels. He's offered to help us with cylinder drawings.
Another bloke, Muskrat, had a twin-carb ally head. Wanted to swap for a 4-spring clutch. Only problem, he's in OZ! But then Julian stepped in again and offered to send a spare clutch of his to Muskrat who could then send us the head. How generous was that? He wont even let me pay shipping.

When the ally twin-carb head arrived from OZ, we found Muskrat put a customs value of 300 Australian dollars on it. Had to pay 80 odd duties & vat. rolleyes Still, a good deal.
Dinky turbo is off a punto/Corsa 1.2L diesel. Only 30!


We decided to use a Norton crank, and another good ol' boy, Baz, came up with a 750 commando one. Why? they're 89mm stroke as opposed to 84mm. With a 73mm bore, it gets us 744cc.
Plus, big-journal A10 cranks are rare and fetch big bucks these days.


Early May,  got some work done on the crankcases. Main-bearing upgrades; a notorious Achilles-heel on BSAs. The stock timing side one is just a bush (left in pic) A poor setup which fails regularly and bleeds off oil pressure that could be going to the big-ends.
There isn't enough room to bore out for a decent size ball or roller bearing; the solution is a special INA combination ball-roller bearing:


First, you have to set the crankcases up true & level in the mill. So I took a light cut off the timing face:


These cases are 55-odd years old. Nothing is properly true on them! I knew they'd be out of line; I set them up & centred on the drive-side bearing bore, then removed the LH case & tried to centre up on the opposite bearing bore. Turned out to misaligned by about .006" (timing side hole was out-of-round too!)
Decided to take up the difference on the drive-side one to avoid gear-mesh problems on the timing side. Bored the case to take the new bearing:


Then bolted the other half back on and took a cut out of the oil-seal bore:


Which gave me something to centre up on when doing the drive side; using a Norton superblend bearing, which is 10mm bigger than the stock A10 one:


Finished bore:


Next, oil system mods. I'll continue this later.
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octane
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« Reply #1 on: November 03, 2013, 02:01:16 PM »

...

When the ally twin-carb head arrived from OZ, we found Muskrat put a customs value of 300 Australian dollars on it. Had to pay 80 odd duties & vat.

Aaaaargh Briz. You should have started this thread way earlier.
I have such a twin-carb head here and you could have had it for free ...AND duties/VAT free.
Anyways: IF you need it for some reason,  feel free to contact me.

Can't wait to see what you're up to here, being a BSA fan and all.

When you have everything ready it should look somewhat like this:
that's my (still to be finished second rebuild ) BeeZZ'er:



, Baz, came up with a 750 commando one. Why? they're 89mm stroke as opposed to 84mm. With a 73mm bore, it gets us 744cc.


...so all you have to do now is pust some kind'a fairing on it and you'll be in 750 ASP-VBF -class
running against my Nimbus : http://www.landracing.com/forum/index.php/topic,13079.0.html

... yeaaah ! ....and beat me....won't be too hard to.

.-)





Good luck !
« Last Edit: November 03, 2013, 02:08:48 PM by octane » Logged

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« Reply #2 on: November 03, 2013, 02:08:55 PM »

I didn't realise you were a BSA man Lars! Cool. Thanks for the offer.
We wont be getting in your way in that class mate; we're running without a fairing.
BTW: that Nimbus looks like an amazing project!

Got the oilway mods on another spare afternoon. The BSA has the oil to the big-ends fed thru the timing side main journal and round a groove in the journal to the pressure release valve.
We're converting to end-feed into the crank, so a way has to be made for the oil to get there.
There is a dowel that locates the inner timing cover which will be put to use here. First up, drill a hole across to the oilpump outlet hole:


A bit heart-in-mouth hoping it doesn't break thru the casting anywhere! It didn't.
Then tap the end for a 1/8bsp pipe plug:


Then bolt the case down timing face up to drill the dowel hole thru:


Lastly, set up the other way up & cut a groove in the bearing hole to re-connect the pressure release valve:



Time to machine the crank; needed turning to accept BSA timing gear & oilpump drive. Also, an extension piece had to be pressed on to get the full width for the main bearing. Oilpump drive is LH thread, so had to screwcut the thread upside-down.


And in the cases (in dummy bearings); endfloat was spot-on at .010":


In June, we drove over to see the event at Pendine Sands.  But Saturday morning, we drove up to Aberystwyth to see the guys at SRM. http://www.srmclassicbikes.com
A very impressive setup they have there; they can do every aspect of bike resto except for plating. They gave us the grand tour.
I handed over a list of stuff we needed and they went off to find it. I had already brought up the subject of sponsorship; I left it up to them how much they wanted to help - anything from a bit of discount to...well whatever.....
The box of parts appeared, and Gary & Geoff there went off to confer.
They came back and said 'right, we'll do 10%'
I wasn't going to show any disappointment and said 'OK'
They then chuckled 'Nooooo, not really! you can have it for nothing'!
At which point we were all overcome with gratitude.
Heres what we got, about 500 worth.


In other news, we got wheels. Thanks to Mook for donating the front one. They're off BMWs and have a unique spoke arrangement that allows tubeless tires.


And back from chrome powder coating:


On July 1st, a package arrived from the states - big thanks to Drift for helping to get this to us.....
Wiseco pistons:

These are much shorter than the stock ones, only 25mm compression height. So although we're running a 5mm stroker crank, the rods will still need to be 0.265" longer than stock.

Cam:

I had Megacycle in California grind this; its based on one of their catalog grinds but has a bit more lift - 10mm! almost 2mm more than the stock 356 cam.
But less duration! Only want minimal overlap with a turbo.
Compare the new one (left) with a stocker:


Lastly, beehive valve springs.  Actually intended for a Ford 4.6L SOHC V8. Just got to find some colletts which will work!








« Last Edit: November 03, 2013, 02:15:43 PM by Briz » Logged

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« Reply #3 on: November 03, 2013, 02:19:27 PM »

Briz, you are as much of a hot rodder as anyone in the Colonies.

FREUD
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« Reply #4 on: November 03, 2013, 03:04:30 PM »

Go the Beeza  cheers

Pete
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« Reply #5 on: November 03, 2013, 03:12:40 PM »

Very cool Briz. Im not much of a m/c guy but this is pretty fascinating to read. Look foward to more updates.
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« Reply #6 on: November 03, 2013, 03:35:38 PM »

I didn't realise you were a BSA man Lars! Cool. Thanks for the offer.


Your're welcome. YeP: I like Beezers; my first bike that I bought some 36 years ago was a BSA
...er...sort of: really it was a TriBsa .. that is a BSA A10 frame with a Triumph Speed Twin engine.
The one I have now is a ungodly mix of all good BSA-things.
I've had it for some 13 years.

This talk made me curious as I haven't checked the cylinder-head for years.
Came in a box of parts with the bike.
I was quite pleased with the current one-carb set up. Mikuni flat-slide btw.
Works really well.

Anyway , had to dig it out, so here it is:





There's a few repair-welds but it seams to be in excellent order.
Actually is appears to be rebuild with new guides and seat work.

The offer still stands .... and it goes without saying: even if you choose to run with a fairing

.-)


Ohh: and here's the bike:



...as you can see: a mix of BSA parts ( and a bit of Triumph for good measure )


.
« Last Edit: November 03, 2013, 03:38:27 PM by octane » Logged

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« Reply #7 on: November 03, 2013, 04:25:38 PM »

Briz,
Great to see another Beezer coming to Bonneville!  I hope you get to stay for the BUB Speed Trials as well as Speed Week.  I'm in awe of your engine work.  I had heard about guys using Norton cranks in BSA sidecar rigs, but didn't know how it was done.
Tom
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« Reply #8 on: November 03, 2013, 05:42:18 PM »

Briz, in the old dayz we would heat up the crank cases and pull out the dowel pins that locate the right half on the left half.  Then we took out the crank bearing and bushing and we put in new cam bushings.  Next, we bolted the two crank case halves together over a mandrel in place of the crank.  The outside diameter of one end of the mandrel was a tight clearance fit in the bushing hole.  The other end of the mandrel was a tight clearance fit on the bearing hole.  We looked at how the cylinder decks matched.  I remember a unit construction A-65 where they were offset the thickness of a dime.  We milled the decks flat and parallel to the crank center line.  We also line bored the cam bushings.

The dowel pins were never used again to locate the halves together.  Instead, flat areas were filed on the outside of the case joint on both ends of the motor.  Then, we scribed lines across the flats.  Proper reassembly was lining up the flats and scribe marks before tightening the bolts down that held the cases together.

"We"was me watching, paying, and the machinist doing all of the work.  This was not optional on the engines I built.  It was a mandatory thing.  This blueprinting, and a dynamic crank balance job, sure gave these bikes a lot of smoothness and more power.  It also cured the problem with low oil pressure on the timing side bushing. 

This is great that you are building a BSA.  It brings back old memories for a lot of us.

 
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Briz
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« Reply #9 on: November 03, 2013, 06:08:30 PM »

Wow! thanks guys!
Lars; that BSA of yours looks nice enough to eat! That looks a lot like an A10 rather than an A7 head there. You do know those are worth good money, dont you?
You might be interested in the story of my little bobber I built a few years ago: http://www.customcycledevelopments.com/BSA_bobber.html
I used parts from as many different bikes as I could there!

On with the story...
It was at this point that some money became available grin. I had been building a '79 Trans-Am with a 540 inch BBC for some time. It was progressing slowly what with all this LSR stuff. So when I got a reasonable offer for the uncompleted car, I reluctantly went for it (I've never had a really massive big-block before - dont suppose I will now)
So with this windfall, I asked Dave Branch if he'd do me a billet crank, and he agreed to take it on. In doing this, I was able to specify a few things that the Norton crank didn't have.

Anyway, with some customer work out of the way I was able to get stuck into it again.
I needed to assemble a mockup engine assy, so I resumed work on the barrel casting. Sadly, our Julian never came up with the drawings for David to CNC them, so I did it the old fashioned way.
Took the top-end off the Bobber and plotted the top & bottom bolt patterns. The stock barrel was all over the place! fortunately, when BSA designed the A10 they mostly used rational measurement units - sixteenths of an inch here! So figuring out what the dimensions should be was easy.

Top bolt pattern - tapped the holes 10mm rather than 3/8 BSF:


Bottom holes:


And doing the spigots on the ol' rotary:

The rearmost bottom holes ended up too far back and so I'll need to build it up with weld.
The last bit is the hardest; doing the cam-follower bores and the pushrod tunnel.

Doing the cam follower bores was a bit heart-in-mouth as screwing it up would junk the whole job.
First thing was to bolt the stock barrels onto the cases with a pointer in a lifter bore to check for misalignment:

Not too bad, maybe ten thou out.

Set the mill up using the stock barrels. Drilled the angle plate so I could bolt the stock set on and then the ally casting in the same place:


And there's the followers in place! Got the fit just about right...phew!


Time to do some ally welding. Built up the rear barrel flange and got started on ol' Muskys head.
Added bosses for exhaust studs. Dont think shove-in pipes will work with a turbo! Also welded up one of the exhaust valve-guide holes as it was hugely oversize, and plugged up some damage to the gasket surface.


While it was cooling down, I set up the cases and bored out the cam tunnel. Our superduper cam was too big for it!


Thought I'd let that ally welding age for a few days. Plenty else to be getting on with.
Before I could set up the engine/gearbox I needed to know primary length. Primary drive was something that could be done in a number of ways.
Definitely wanted belt drive; could have spent north of 400 on a Commando kit, but with the billet crank, I have the option to have a splined sprocket shaft (which I certainly will choose! - hate tapers)
Also, the Commando clutch was good in its day, but there is better stuff. Such as the Kawasaki GPZ1100 clutch I've had kicking about for decades!
The good thing about the Kwak clutch is that both the basket and the hub are rivetted to their respective drive parts. So grind off the rivets and you can attach it to anything..well almost.
I bought some blank pulleys and a 2" belt from Bearing Boys along with some bearings & circlips. Here, I'm measuring the installed length between centres:


Sadly, the big pulley wasn't solid, but was webbed with big centre bosses, so I machined the middle out and turned up some steel:


Then welded it all up and machined it:


Completed:


End of August, it was cylinder head time, amongst other things...
Wasn't looking forward to doing this! All the valve guide holes were tapered and well oversize, and the valve seats were for the small A7 valves. Too small for our SRM Rocket Gold Star valves.
I'd already welded up the worst guide hole (over 1/16" oversize!).
I set the head up on the adjustable angle plate...

..And remachined the guide holes and machined out the seats. A horrible job; the stock seats are cast-in and are an irregular shape. They're also pretty hard.
This meant that some of the old seat material was still present in the finished insert bore. The hard seat material cut smaller than the remaining ally. I got it as good as I could by taking many small cuts.
Heres the head ready for the new seats:

before doing this, I did all the port-enlargement that I needed to do in the valve-bowl area. A lot easier without the guides in.

Putting new seats in an ally head is a bit fraught at the best of times. You need 7-8 thou interference fit or they'll come loose. This means getting the casting bloody hot (or chilling the seats in liquid nitrogen - not something I happen to have!) And then pounding them in.
Got 3 of them in, but broke one insert so had to take a ride down to Cambridge Rebores on Friday morning to get another.
This of course meant having to re-heat the head. So in the meantime I got the new guides ready.They had to be custom-sized, so I turned the exhaust ones from a small bar of Colisbro and made the intakes out of some Rowe shovelhead ones. made them with 4 thou interference. Probably a bit too much as they were a bastard to get in there! They're not coming out!
Guides in:

Seats in:

Once cool, I had to ream the guides to size. There was about 10 thou to come out of the exhaust ones and it soon became clear that my little adjustable reamer wasn't going to do the job. This Colisbro stuff doesn't like being cut, and tends to machine undersize & sieze the tool. I actually broke the reamer.
I do have a 5/16 machine reamer but was scared I'd get too much clearance, so I tried it on an offcut and it came out just right. Fortunately, I'd left the mill setup from when I'd machines the seat & guide holes, so it was simple to bolt the head back in and run the reamer thru. Came out spot-on. TFFT!

Next day I finished blending the new seats to the ports and then got the ol' valve-seat cutting gear out to finish the valve-job. Did a 3-angle job on the intakes (I already did the first angle in the lathe before I fitted the seats). On the exhausts, I had bored them to the max size I could, so no room for a 60-degree cut. A bit of lapping, and its good to go, apart from some port opening-out on the intake side.
Checked valve-stem protrusion expecting to have to cut the seats some more to get them to spec, but found they were all within 5 thou of each other! They're actually about 40 thou less than what I think is stock (1.8") at 1.760" I most definitely wont be sinking the valves deeper to get the 1.8" spec!
There it is done:

Next; setting up the drivetrain...
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« Reply #10 on: November 04, 2013, 01:42:24 AM »

That sure is impressive, Briz.  How are you feeding the oil into the crank with the roller bearing on the timing side end?  The oil cannot be force fed through the bushing and into the crank with that setup.
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« Reply #11 on: November 04, 2013, 02:48:23 AM »

Awesome stuff. Any comment I'd make on tech stuff would just show my ignorance. You rock brother. cheers cheers
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« Reply #12 on: November 04, 2013, 11:02:25 AM »

Briz,
Thanks for sharing your Beezer build here. The past few days I've been doing the same type of work on English Thunder, a Vincent I hope to have ready for SW next year. Keep up the good work and photos.
John
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« Reply #13 on: November 04, 2013, 05:04:44 PM »

A Vincent Eh? Thats major-league stuff compared to this! Hope to see you with it next year.

That sure is impressive, Briz.  How are you feeding the oil into the crank with the roller bearing on the timing side end?  The oil cannot be force fed through the bushing and into the crank with that setup.

I'm going for end-feed WW. There is a number of ways to do it; fairly common mod on A10s. I'm going to make a new inner timing cover out of 1" ally plate as I'm planning for a few other things it will need. I'll be putting a sportster oil pump where the generator was to feed the turbo, and I'm replacing the timed breather with a reed-valve setup.

Next installment:
Linking up the engine & gearbox. I'm using a motorplate behind the primary so there is a support bearing behind the clutch. Eliminates the massive overhang on most old Brits; Must have been loads of flex when power was applied back in the day.
Used 10mm ally plate. I knew the distance between engine & box (see above) So i bolted it to the mill and first bored a hole for the crankcase register and then one for the support bearing.
Then I clamped the gearbox shell over the latter hole and using a turned plate to centralise it, I plotted the mounting holes:


Did the same for the crankcase:


Did the necessary drilling and then using the same X & Y coordinates, I drilled the engine plates:


Heres the assembled cases in the jig. Just plonked in there at the mo' Got to figure out the best position yet.



Before I could set the engine up properly, I had to get the sprocket line established. Which meant getting a sprocket on the rear wheel; which is a BMW front wheel. Not the most straightforward job!...

Interestingly, BMW - 'uber-germans' who probably sneer at our outdated imperial measurements, have made the bolt pattern PCD of their front discs.....8"! cheesy Not 200mm or anything rationally metric (unless 203.2 mm is rational!)

Meanwhile, some shiny bits turned up.
Custom length con-rods with Triumph big-end size & 17mm pin holes from R&R in Illinois.
Big thanks to Drift for handling logistics!


Some progress made on the frame. Halfway thru doing the engine mounts here.


OK, you're thinking 'WTF? has he gone nuts?, a gooseneck??? aint this supposed to be serious? What next? 6-bend pullbacks?' cheesy  cheesy  cheesy
Well, there's method in the madness; The turbo has to go somewhere, and in front of the frame tubes looked better to me than anywhere else. So the gooseneck allows this and keeps it from interfering with the front wheel.
Dont worry; it'll be as tough as the Forth bridge when I'm done!


There you go; looking a bit tougher!


I finally gave up trying to get Avon to sponsor us. Loads of calls & emails but couldn't get a 'yes' or a 'no'. rolleyes
Bought some today. Local car tyre place supplied & fitted for the same price as buying off the internet.
We have a rolling chassis now:



Which brings us up to date as of a month ago. Working to earn right now. Will be back on it in about 3 weeks. Turbo setup next.
Oh, and Dave has started on our billet crank! grin
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« Reply #14 on: November 04, 2013, 11:34:10 PM »

Briz, did you get rid of that goofy taper and woodruff key where the clutch attaches to the main shaft?  That setup could not transmit much power.  If you did, show some details.  We never figured out that one.  Sometimes the two parts were tack welded together and we ground the tack off to take everything apart.         
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