Recent Posts

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A7 & A10 Engine / Re: Home-made tools
« Last post by RichardL on Today at 04:18 »
Two things I wanted to do:
1. Surface grind my Ariel hub sprocket so it would be in balance. It was too thick for about 120 deg of arc. (Operation was successful. Balance now very close.)
2. Cleanup my Ariel hub with a turned finish look. (Photo shows partly done.)

Both of these needed a lathe, which I do not own. Wish I had named my daughter "Necessity" so I could hope for a grandson named "Invention."

Here are video Parts 1&2 for item #1, above.

https://youtu.be/ULWXOq2UegM
https://youtu.be/7v4jJ-DgU-I

Here is the video for item #2, above.

https://youtu.be/O9Ja9jETRuc

Photos show sprocket waiting for paint, the hub on its way to being done, and the hub turning motor.

Hope you find this amusing.

Richard L.
2
Yes the later one is also more useful because it has the combined oil drain plug and oil level plug, so you don't even need to measure the oil going in when you top it up.
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A7 & A10 Engine / Cylinder head damage
« Last post by Minto on Today at 01:09 »
Just realised that some damage to my iron cylinder head is possibly worse than I first thought. The damage seems to be  fairly common as I've seen a few on eBay damaged in the same place, the timing side inlet rocker cover screw thread part has cracked. It's been welded by a previous owner though not very well. My concern is that it may have internal damage extending into the inlet port and thus effecting induction. I poured some brake cleaner into the hole which leaked straight out onto the fins, the corresponding hole on the drive side held the brake cleaner.
I've wedged and modged some chemical metal into the voids in the crack and the weld and it now seems to hold tight, but am I hoping against odds that this is the extent of the damage?
Opinions or advice as always, very much appreciated.
Jase
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Lucas, Electrical, Ignition / Re: aftermarket starters
« Last post by KiwiGF on 12.05. 2021 22:12 »
Just a quick update.
Was looking at the fitting instructions for electric starters on Vincents, and they advised no more than 2* of advance be used for starting. Also, that the auto advance unit be checked to ensure the springs are in good condition, thereby ensuring the unit is fully retarded at rest. It is all about preventing kick-back on the starter, as aftermarket units have no capacity to deal with that (apart from breakages).
Essentially, for those fitting electric starters to really any machine this means setting ignition timing to 2* at full retard, and letting the amount of advance as the revs rise be whatever they are. Should the amount of advance be insufficient, then a delve into the auto advance unit is required in order to widen the advance band. I'm running a distributor, but the innards are practically identical to those in an auto unit. I have already widened the advance band (I'd already guessed around 2* would be required rather than the 8 I'd been using) but have not yet verified figures with a strobe as I've been busy strengthening the starter gearbox mounting and replacing the ratchet with a sprag clutch.
Regarding the latter, have to say I was a bit surprised at the torque / tension going through the starter mechanism. Roughly 250 ft/lbs torque at crankshaft and 2 1/2 tons force trying to pull the starter off its mountings. No wonder the mountings were distorting.

My recently acquired B44 kick backed like a mule once I had re-commissioned it, positively dangerous I thought, they have a reputation for that, plus being hard to start.

I found weak/loose springs on the advance retard unit, so it was pretty much fully advanced at kickstart speed, also the unit was marked 5 degrees (advance), which equated to 10 degrees retard available at the points, them driving at half speed. Lucas made these AR units with various specs.

The timing is set at 28 btdc on the B44 so I took a dremel to the advance retard unit “slots” to increase it’s range to about 12 degrees, so about 4 btdc at full retard. and also bent the spring tabs to increase spring tension (new springs will be ordered once I find a source).

I checked the timing using a strobe, and it still gets full advance at a fast idle so I reckon even stiffer springs would work ok, and reduce it’s tendency to pink at low revs in high gears.

It no longer kick backs when starting. It does “puff” sometimes after it bounces backwards off a compression stroke, but not badly enough to be called a kick back. I’m not sure if that type of “reversing” action would damage an electric start.

All this got me wondering how the boyer and other electronic ignitions affect the starting of bikes like the B44 and whether some of the reputation for being awkward to start is undeserved. Also if pinking could be caused by an electronic ignition having insufficient advance, or it advances at too low an rpm.

One would like to think the various electronic ignition makers “copy” (or improve) on the original design, but who knows!

I have both Boyer and Pazon ignitions to try out at some point, but I will be watching out for kick backs and use a strobe to get an idea of when full advance kicks in.

The boyer unit is well known for damaging norton commando electric starters, allegedly it “defaults” to fully advanced when the battery voltage drops (as it would during starting.....) and some ignition units allegedly need a couple of revs of the engine to “orientate” themselves before they will provide a spark, which of course would prevent a bike starting first kick!
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Lucas, Electrical, Ignition / Re: aftermarket starters
« Last post by RDfella on 12.05. 2021 20:26 »
Just a quick update.
Was looking at the fitting instructions for electric starters on Vincents, and they advised no more than 2* of advance be used for starting. Also, that the auto advance unit be checked to ensure the springs are in good condition, thereby ensuring the unit is fully retarded at rest. It is all about preventing kick-back on the starter, as aftermarket units have no capacity to deal with that (apart from breakages).
Essentially, for those fitting electric starters to really any machine this means setting ignition timing to 2* at full retard, and letting the amount of advance as the revs rise be whatever they are. Should the amount of advance be insufficient, then a delve into the auto advance unit is required in order to widen the advance band. I'm running a distributor, but the innards are practically identical to those in an auto unit. I have already widened the advance band (I'd already guessed around 2* would be required rather than the 8 I'd been using) but have not yet verified figures with a strobe as I've been busy strengthening the starter gearbox mounting and replacing the ratchet with a sprag clutch.
Regarding the latter, have to say I was a bit surprised at the torque / tension going through the starter mechanism. Roughly 250 ft/lbs torque at crankshaft and 2 1/2 tons force trying to pull the starter off its mountings. No wonder the mountings were distorting.
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I think its not a breather its the oil drain bolt that is being referred to
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A7 & A10 Engine / Re: cylinder liner thoughts
« Last post by RDfella on 12.05. 2021 11:54 »
I don't have my 60's piston catalogues in front of me, but the B series had three different lengths of conrod (the ZB had the longest, the CB was shorter and the DB shorter still) so presumably gudgeon pin to crown height changed as well - ie there might be a more suitable version that would do.
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A7 & A10 Engine / Re: cylinder liner thoughts
« Last post by chaterlea25 on 11.05. 2021 23:23 »
Hi All
Yes the B31 piston compression height is too low compared to the A10

John
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Clutch, Primary, Gearbox / Re: Geabox casing mismatch s/a
« Last post by muskrat on 11.05. 2021 21:22 »
G'day Fellas.
I once worked in a factory making elevators. My job on the horizontal borer was machining gearbox's and brake systems from raw castings.
Some castings were anything from 1 to 5 mm higher/wider/longer than the last one. They all got set on the same point so some needed more machining than others. So in the end we'd have this situation being discussed. All the shafts would be in the right relationship to one another and work fine but some of the covers would overhang the case.
Jules, if the shafts fit and turn I wouldn't be too fussed on the miss match of the covers.
Cheers
10
Wanted & For Sale / Re: BSA 7" Hub
« Last post by TT John on 11.05. 2021 13:44 »
Hello Musky

Yes it is mate, and in very nice condition too.

Kind regards John
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