Showing posts with label fatigue fracture. Show all posts
Showing posts with label fatigue fracture. Show all posts

Monday, 14 January 2013

There is life in the old blog!

Well, what is new since the weekend? Well...
  • it's snowing
  • the Bantam has been out around the garden
  • Limoncello makes great Martinis
On the bike front, we are still cleaning & inspecting the engine. I've attacked a 14 mm hex socket (not a bi-hex) with a file and have made it fit the connecting rod nuts. The rods are now off and undergoing cleaning. Number 2 is nicely polished.


There are various nicks. This one is typical, but it is minor compared to the abrasion the Ariel fitters cause when they removed the flash around the forging dies:

Hopefully I will show you factory abrasion in another entry - I had cleaned it off Rod No. 2 before I thought to photograph it.

There is a nice little scratch in the cap:

The big end shells are all shot; the journals are a little undersize but are perfectly serviceabe.

All the dings polish out OK. At some point we will do a dye penetrant inspection on these just to be sure there are no cracks.

I have new AOMCC rods in the budget - I am just not yet sure whether I really need to spend the money. The state of the big ends and the mains, which despite white metal flaking were still in tolerance, suggest to me that this engine has had an easy life, though I realise this conflicts with the fact that the bores are 0.020" overbored.

Of course no amount of inspection can tell me what state the material is in - only it's service life could tell me if these rods have been fatigued enough such that they will fail in the next few years. It's a 35 bhp engine - judging by the way I ride the Bantam about Norfolk am I really likely to stress this engine? If I fit the Morgo pump will it see any shortage of lubrication? Shortage of lubrication will trash any big end, old or new - so we are down to loading & rpm...

The crankshafts have now all been cleaned out. Number 3 sludge trap was full past the big end oilway, though there is no damage to the journal or the big end so I think the engine has been lucky.

I've loosely reassembled it all in preparation for taking the bottom end for line boring. Here are the crankshafts back in place:


Here are the cases cleaned up and back together. I am debating what to do with the polishing of these.

And as an aside from the engine, I have been:
  • sketching up a wiring diagram with Microsoft Powerpoint. Currently it has six fuses, no earths (because I haven't put them in yet) and no indicators.
  • I have ordered the engine bearings from Drags
  • I have ordered a replica Lucas 529 rear lamp
  • I've ordered the engine/gearbox mounting set, the coupling gear cover studs and the primary drive screw set from Acme
But now it's back to work. I'm hoping to have a trip to London in a couple of weeks to take the engine down to Ashpoles; that depends on the bearing arriving from Drags.


Monday, 14 May 2012

Back to the weld shop...

With the rear mudguard mounted and the forks in place, it's time to look at the front.

You haven't seen the mudguard I bought from eBay, but it is an original Ariel guard from I think 1953. Luckily it came with the correct aluminium number plate but, like the rear guard it is full of holes.

Here are some 'before' pictures:

There is a nice brass dealer plate. This bike was originally supplied  to Marcel Hallet, of Canterbury.
As usual, we have a fatigue fracture around the mounting thoughtfully chalked in by the eBay seller.
Then a series of pictures showing how the folded seam has rusted out from the inside
This is the worst of it. About 8" of the seam on the nearside has parted company. We will either weld this up & fill with weld or patch from the inside. The side panels are quite sound and will form a strong base to weld to.
And, matching fatigue fracture on the other side.

Time to break out the MIG set again!