Author Topic: Salt Flash. A Bonneville Beezer.  (Read 77816 times)

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Offline Nortonist 592

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Re: Salt Flash. A Bonneville Beezer.
« Reply #30 on: January 18, 2014, 09:15:11 PM »
Lucky you!!!!   But if you want to absolutely forget about the box and clutch run tall primary gears.  And use the final drive for altering the gearing.  Years ago I read where Maico used a tall primary gear which reduced the torque on the clutch.  I'm using 26t on the engine and 42t on the clutch (standard Norton).   The clutch is a composite of old bits I have had for a million years and a couple of new plates.  Five ears flogging it an no problems.  And not expecting any.  The less you have to worry about the more fun Bonneville is.
Get off the stove Grandad.  You're too old to be riding the range.

Offline Briz

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Re: Salt Flash. A Bonneville Beezer.
« Reply #31 on: January 19, 2014, 09:22:30 AM »
Yeah, thats my thinking too; run the clutch fast and reduce the torque it has to handle. Running (belt) 48T on the engine and 72 on the clutch.

Offline Briz

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Re: Salt Flash. A Bonneville Beezer.
« Reply #32 on: January 22, 2014, 06:12:12 PM »
Right!
Its an age thing I guess. Bound to happen. Strength cant be relied upon anymore, not in hard-work conditions.
Only answer is ..... a girdle! :shock:
Nearly 60 years old; what you gonna do?  :cry: 



The Engine! the crankcases!...what did you think I meant??? :lol:  :lol:  :lol:  :lol:
The cases are the weak spot in this engine. Not unknown for old brit cases to break just below the barrel flange.
So some extra support needed to hold things together. One or two substantial studs each side coming up from the crankcase; the primary plate on the LH side and the yet-to-be-done billet inner timing cover on the RH.
Thought awhile about this, its easy on a Triumph with its separate rocker boxes; having 2 separate pieces would tend to bend the head-studs, and a bridge that goes over the top of the rocker-box would be complicated & in the way.
The answer was to mill away the fins in the middle of the head to make room for a bridge piece.



Dug out a billet triple-clamp offcut which was perfect for the job:



A card pattern & a bit of bandsawing had a blank piece.



Loads of milling & fettling; doing the plug-holes here:



And its done! Only took 10 bleedin' hours! :roll:
Outer stud holes yet to be done. I'll do the bottom ends first.




Offline Koncretekid

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Re: Salt Flash. A Bonneville Beezer.
« Reply #33 on: January 22, 2014, 07:12:24 PM »
Good thinking!  Also to prevent this.................
We get too soon oldt, and too late schmart!
Life's uncertain - eat dessert first!

Offline wobblywalrus

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Re: Salt Flash. A Bonneville Beezer.
« Reply #34 on: January 22, 2014, 10:29:30 PM »
Briz, a current subject on my build diary is how to set the ignition timing to minimize cylinder pressure.  We figured this out to deal with the issues you are talking about.

Offline Briz

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Re: Salt Flash. A Bonneville Beezer.
« Reply #35 on: February 01, 2014, 02:59:08 PM »
Yeah; interesting stuff WW.

We had a good example of the law of unintended consequences......
Having made the head brace, it soon became clear that spark-plug access was now impossible! I really didn't want to be taking the tank off to get at the plugs, so drastic action was called for:


Getting the holes in the right place was  ummm.. interesting!


Been making a lot of small uninteresting stuff this week, all the head studs & nuts for example:


Got fed up going thru the ARP catalog trying to find something suitable. Wish they'd list their studs in order of sizes as well as 'kits for xxxx vehicle' I know they have a form you can email with what you need, but they aren't very forthcoming with answers.
So; I made the studs from grade 12.9 allen bolts. Cut the heads off & screwcut 10x1mm threads. I wanted to use fine threads to keep the root size as big as possible, what with cut threads being less good than the rolled (10x1.5) threads, so that the ones I cut were stronger than the factory rolled threads.

I made a few more than needed (bound to lose some nuts  :roll: ) So I did a bit of testing. drilled & tapped a 10mm thread thru a bit of 1" ally plate, screwed a stud in and with a spacer to replicate the head thickness, I set to with the torque wrench & micrometer.
Interesting; at 20 ft-lbs, the stud stretched .003". At 40 it stretched .005", 48 = .006". And so on every 5 ft-lbs or so stretched it another thou.
Each time, I slackened it off before the next 'pull'. At 60 ft-lbs the stud had permanently stretched half a thou, the point at which ARP fasteners reckon a fastener should be scrapped.
Kept on at it, to try & make it fail. 80 ft lbs pulled the stud .011" but it never made it to 90.


It broke where you'd expect, at the end of the coarse thread. My cut threads came thru OK. At all times, there was only 1xD of thread engagement in the nut.
So; conclusions: the studs are good enough for the job, and to get the optimum stud-stretch, which is 6 thou, a torque of 40-45 ft-lbs is needed. The thermal expansion of the ally head means we should stay on the cautious side.

The head hold-down is now almost finished. RH side yet to complete. Heres the LH:



Got started on the inner timing cover today. A bit time consuming doing all the holes. Here I am doing the hole for the intermediate pinion bush:

« Last Edit: February 01, 2014, 03:03:24 PM by Briz »

Offline Nortonist 592

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Re: Salt Flash. A Bonneville Beezer.
« Reply #36 on: February 02, 2014, 12:50:15 AM »
Nice chunks of alloy you have there Briz!   Even nicer what you have done with them!!  Looking forward to seeing it and you on the salt.  This time will be a winner.
Get off the stove Grandad.  You're too old to be riding the range.

Offline tauruck

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Re: Salt Flash. A Bonneville Beezer.
« Reply #37 on: February 02, 2014, 08:03:47 AM »
Briz, that's the spirit.

Making all your own stuff is cool.

I love the plug access hole, first one I've seen. That's innovation.

Excellent engineering. :cheers: :cheers:

Offline Briz

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Re: Salt Flash. A Bonneville Beezer.
« Reply #38 on: February 12, 2014, 03:13:49 PM »
Thanks guys!

More progress...
Had word back from Matt Schuss. He says the basic fixed-advance ignition system I had in mind; using a HD pickup plate with a crank-trigger and a simple bosch ignition amplifier will be fine by him. Which saves a sack of dough over having to sort out a magneto or similar. (I already have all the bits)

Been doing the billet inner timing cover and the turbo oilpump. Turned out to be a bit of a long job what with the (RH) head hold-downs too.
I added a few more holding-down fastener locations to cope with the pull of the head studs, including a 3/8 bolt where the old breather hole was.
Note the stock rotary breather is deleted and replaced by a reed-valve (off a Piaggio scooter!). This means it'll exit positive crankcase pressure whenever its there rather than when a valve opens. Exit is at the top.



The turbo oil pump is a cut-down sportster one. I shortened it and just left the old return stage. Blanked off the original outlet and turned off the drive gear & welded on a belt pulley.
The job was complicated by the need for a pressure relief valve which I had to make.
First I worked out that 40psi acting on a 12mm piston made for a pressure of about 7.5 lbs. Found a likely looking spring and set a 7.5-ish lb lump of steel on it which compressed it 10mm. So I machined everything so that with 10mm piston movement, the excess pressure bleeds off back into the pump inlet side.:



Assembled:



And with the drive in place:


Offline tauruck

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Re: Salt Flash. A Bonneville Beezer.
« Reply #39 on: February 12, 2014, 04:17:21 PM »
Beatiful work man.

Great pics.

I thought you guys were all under water by now. :-D

Offline Briz

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Re: Salt Flash. A Bonneville Beezer.
« Reply #40 on: February 12, 2014, 05:50:24 PM »
Not here, thankfully. West Norfolk is the dryest part of the UK. The wind has taken out a few fencing panels though.

Offline tauruck

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Re: Salt Flash. A Bonneville Beezer.
« Reply #41 on: February 12, 2014, 11:39:10 PM »
The Norfolk Broads?. Dry?.

I tested a F3 car at Snetterton once. Are you near the track?.

Good to hear you're not inundated. :cheers:

Offline Briz

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Re: Salt Flash. A Bonneville Beezer.
« Reply #42 on: February 13, 2014, 06:33:53 AM »
'Bout 25 miles from Snetterton. And 60-odd miles from the Broads.
By 'dry' I meant lowest rainfall, which is just as well as this is very low-lying terrain here.

Offline tauruck

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Re: Salt Flash. A Bonneville Beezer.
« Reply #43 on: February 13, 2014, 08:51:21 AM »
Good to hear.

I can't comment on the rain in the UK. The two weeks I was there in 81 I never saw a drop or even a cloud.
 :lol:

Is the day job building custom bikes?.

Regards, Mike.

Offline lsrjunkie

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Re: Salt Flash. A Bonneville Beezer.
« Reply #44 on: February 13, 2014, 09:32:58 AM »
Cool stuff Briz! I'm no bike guy, but I know good fab skills when I see them. The oil pump setup is trick. Looking forward to see this thing run, and keep up the good work!  :cheers:
Maybe there is no Heaven. Or maybe this is all pure gibberish. The product of a demented hill billy who has found a way to live out where the winds blow. To sleep late, have fun, drink whiskey, and drive fast on empty streets with nothing in mind except falling in love or getting arrested.    H.S. Thompson