Amazing crankshaft repair

[HopperParticipant @hopper]

Those gentlemen on the subcontinent are at it again. This popped up while viewing a posted video in another thread so rather than hijack that thread, I think this effort deserves a thread of its own. Not just for the amazing machining and welding skills under very basic conditions, but for the hair-raising WHS aspect of whirling truck crankshaft and human hands and tools interfacing perfectly. Especially the external lapping of the big end journal — without setting it to rotate concentric first! And all done with a nonchalant durry hanging out the corner of his mouth in the time-honoured manner.

 

And you have to be a pretty good welder to chip the slag off with the end of the next welding rod like that. Wish my "stick" welding was half as good.

 

Edited By Hopper on 19/02/2023 08:50:06

Edited By Hopper on 19/02/2023 08:57:39

[HopperParticipant @hopper]

[Mike PooleParticipant @mikepoole82104]

Amazing how they do so much with so little. I suppose having a team of helpers handy is useful but I think a hoist would be handy when jobs get that heavy.

Mike

[Mike HurleyParticipant @mikehurley60381]

Fascinating and a bit humbling, how these guys do such a job with limited resources, just a boat load of skill and experience.

[CirclipParticipant @circlip]

Wonder what the accuracy of the centre to centre distance of the cylinders on either side of the central journal is? The late Sir John used to do some fantastic weld rebuilds.

Regards Ian.

[Howard LewisParticipant @howardlewis46836]

During WW2 when steel was at a premium, teh Midland Red bus company used to repair broken crankshafts.

the methos was to clamp the twom halves together, and nthen drill and tap so that the bntwo halves could be bolted together.

The engines were low revving and low compression, so the stresses bwere quite low.

Engines nrepaired iun nthis way lasted for ma long btime, past the the end of nthe war!

Wouldn't be keen on that sort oif reoair now, though!

I've heard of engines in ships having their journals reground in situ!

Hope that they cleaned carefully afterwards!

Howard

[Ady1Participant @ady1]

Great to watch

We had plenty of folk who could do pretty much everything like that until the spare parts market turned skilled men into men who fitted pre-made spare parts

At sea they had piles of bar stock and lathes for when they needed stuff because it took too long to get the bits

Aircraft made the availability of instant spare bits much easier and highly skilled men less essential

The guys who still do my head in are the people like James Cook who went around the world with no support at all and no decent maps, just the skills of the people on board- if they didn't die of something horrible, you couldn't even drink without risking yourself

Edited By Ady1 on 19/02/2023 11:06:34

[SakuraParticipant @sakura]

Wrong on so many levels and yet the skill and outcome is undeniable.

[noel shelleyParticipant @noelshelley55608]

The outcome is all that matters ? I was on board a liberty ship, the main engine 3xpansion was fitted with strange pipes that could be moved over the bearings on asking their purpose I was told that if a bearing ran hot this was to feed cold water to cool it – stopping the engine was NOT an option ! U boats and all. Noel.

[Robert Atkinson 2Participant @robertatkinson2]

I was wondering what the bit of wood between the headstock and wall was for.
Stopping the headstock mooving or holding the wall up?

Robert.

Edited By Robert Atkinson 2 on 19/02/2023 12:17:04

[Tony Pratt 1Participant @tonypratt1]

Posted by Sakura on 19/02/2023 11:18:31:

Wrong on so many levels and yet the skill and outcome is undeniable.

He most probable did the self same repair a week ago.

Tony

[Martin Johnson 1Participant @martinjohnson1]

Well I was trained in a leading UK manufacturer of large marine diesels. The scene in which an external lap was put on a crank throw to "tidy it up a bit" was enacted on a daily basis here in the mid seventies.

Martin

[john fletcher 1Participant @johnfletcher1]

I was on SS Sandsend Oct 1956 a liberty ship, Southampton to Port Said, didn't make it as we had series boiler problem, later we were towed to John White by tug for repair. Our Chief told us lots of stories, one was when they went up a river some where in South America and got stuck on a sand bar for a couple of tides, bent the shaft a bit. Colin didn't say how that was fixed. We were in Port Said crossing over to where the pilots lived and the small boat had a strait eight petrol engine, amazingly only four working, the "master" said only four rods/pistons. Its remarkable what the so called third world can do. John

[Mick B1Participant @mickb1]

Posted by Mike Hurley on 19/02/2023 10:21:05:

Fascinating and a bit humbling, how these guys do such a job with limited resources, just a boat load of skill and experience.

The human energy output manipulating heavy workpieces accurately is pretty impressive too.

Edited By Mick B1 on 19/02/2023 15:50:23

[old martParticipant @oldmart]

I wonder if the guarantee was longer than a week?

[GavlarParticipant @gavlar]

One of the many things I find incredible watching some of these videos, is how many machine operators seem to use a pair of ancient calipers and a ruler for 'precision' work, where you or I would use a micrometer or at least a vernier.

I also find it astounding that they seem to have a complete and functioning set of arms, legs, fingers, toes and eyes given the total disregard for any form of PPE, baggy clothing and flip flops being the norm.

[larry phelan 1Participant @larryphelan1]

Never judge a book by its cover !

Not much sign of a DRO, there !

Needs must !

[Mike HurleyParticipant @mikehurley60381]

Yes, needs must. I'm still in awe of the work by these chaps. However, in reality, I must assume that a 'reconditioned' item like this will have a limited life afterwards. In no way can a guy (no matter how experienced) with some old calipers get the dimensions correct to the nearest thou / micron or whatever the original design space of the affected part was, which will result in an inefficent engine proboably using excess oil and poor MPG. Is a weld ever going to be 100% as strong as original solid material no matter how well done?

MTBF? probably low

Yes, I know the many stories of .the 'old guy' in 'our factory' who could do this, that and the other by eye at 100 paces while standing on one leg etc etc but most are folklore. Experience is very important, and i'm not decrying the 'old guy' in any way as they often have years of sound practical knowledge that is important to be passed on to the younsters.

I still think these crankshaft guys are pretty cool though!

[Ady1Participant @ady1]

Some of these guys don't do anything else, Gearbox rebuilds just for the hell of it, never see their family etc

We had a problem one dark cold sunday evening in January and limped to the garage for a Monday book-in and fix.

He was in, working away and fixed it on the spot!

A lot of them are self made guys who once they are millionaires say:

"I wish I'd spent more time with my family"

[SakuraParticipant @sakura]

Posted by old mart on 19/02/2023 16:28:45:

I wonder if the guarantee was longer than a week?

When I was a foreman mechanic in the 70s, I overheard a customer ask the salesman how long the warranty was on a second hand banger. His reply;

"It's a forecourt warranty"

Customer; "How long is that?"

Salesman; "Until you get off the forecourt!"

[HopperParticipant @hopper]

Depends on the material, the rod and the welder, but the weld can be stronger than the parent material in some cases. And he looked like he knew his welding. To get a weld so well done the slag just drops off like that is not easy.

With the spigoted join it could be spot on alignment. There is one scene there where they are checking the alignment of all the main bearing journals with a dial indicator with long probe. They showed the reading and I think it was within a thou. Then setting the phasing of the bigends with wire pointer in the lathe. So, yeah, I reckon it could be possibly as strong and as accurate as the original Indian made Tata truck crankshaft (which snapped in the first place!).

Or it may not be quite as good as a brand new crank but it must be a lot cheaper. Looked like they had lines of them stacked up there and were doing a good trade.

Right now I am struggling to weld bits of 1" angle iron together to make some motorbike petrol tank brackets without it looking like a seagull flew over and dropped a load on the job!

[SamsarandaParticipant @samsaranda]

In my youth I came across a similarly skilled craftsman in our local town, his workshop was very stark and basic, just like those featured in the videos from the Indian sub continent. All the local garages used to send their rebores for him to do along with crankshaft regrinds and other difficult weld repairs. He operated in an old Mews Stable building that had a cobbled floor from the days when it housed horses. When you went there you would always find a number of reboring machines scattered around and working away on car cylinder blocks. I took him the cylinder block from my old side valve Ford Popular, a 50’s vintage car, it needed a rebore because a ring had broken up and had damaged the cylinder. He rebored all four cylinders, supplied the oversize pistons and remetalled the main and big end bearings, reground the valves and set their clearances and supplied the gaskets necessary to re-assemble the engine, the cost astounded me it was only £22 10 shillings, this was in 1966. The gentleman was a highly skilled old style craftsman, he reminded me of “ Sir John “ and his expertise with weld repairing motor shafts. Dave W

[mgnbukParticipant @mgnbuk]

And he looked like he knew his welding. To get a weld so well done the slag just drops off like that is not easy.

That big oil cooled welder will help – there was a much smaller "Oxford" oil cooled welder where I started my apprenticeship & that even made my welding look good – no comparison with cheapy aircooled buzz boxes. Using Oerlikon electrodes with the Oxford the slag would start to curl up from the starting point before a decent run was completed & just fall off if left to cool.

I can appreciate the workmanship and ability to work with such (by Western standards) basic facilities, but I cringe every time they drop or drag machined parts on a concrete floor – surely a bit of wood doesn't cost the earth in Pakistan ?

Close-ups of the big end journals showed very heavy wear that I doubt would "polish out" with a bit of oiled emery cloth. No doubt 2 doors down from the "crankshaft repair guy" is the "oversize shell bearing guy" who makes up suitable bearings to fit the repaired cranks.

There are numerous videos of all kinds of small manufacturing facilities in that area that I find to be rather compelling in a vaguely horrified kind of way. I would expect that a lot of the people engaged in such activities don't get to an old age for a great many reasons.

The lathes featured seem to be locally manufactured. I had thought they would be Chinese, but a quick Google brought up 3 different makers in the Lahore area. All belt drive headstocks appear to the norm, as do home made brazed carbide tools.

Nigel B.

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