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27-1239 Engine Shaft Rivet

Having acquired a new drive shaft for my crank with worn splines including a new set seven of rivets I thought it was time to change it.
Center dotting the rivet I then ran a 4mm drill though the middle of them just a few mm deep. This I used as a guide for punching the rivet out. Finally pressing the shaft out with only a few tonnes of pressure. All going well so far.
Pressing in the new thoroughly lubricated shaft was fun keeping the holes aligned was fun.
Said Rivets being new old stock! looked like something nasty from a Myford lathe.
Two attempts trying to close them was not nice or inspiring confidence. After a few simple tests I determined they were not fit for riveting, probably made from silver steel.

Fortunately, we stock rivets for the BSA unit single clutch hubs. A little long and with the wrong head shape. That's easily fixed.

Has anyone else had a similar experience?

Mark

email (option): pes.sales@btconnect.com

Re: 27-1239 Engine Shaft Rivet

Successfully riveting the mainshaft flange to the flywheel I found quite difficult...The rivet material is quite hard which makes hand riveting awkward. I'm guessing that in the factory at least, they were machine riveted...Years ago I made a jig to hold the flywheel/ mainshaft to make the rivetting process easier...However, the original rivets I acquired from Russell Motors varied in both the shank length and the head thickness...
The former is obviously important to achieve a properly formed rivet..The latter problem I overcame by fitting a bolt with a hardened roller pressed into the end for each rivet so that they could be individually tightened against the back of the rivet head ....

That said, the rivet material made a hard, sure blow with a fairly lumpy hammer and suitable punch a definite requirement...

Frankly, it was never a job I relished and generally avoided if possible....Some competition machines had the rivets replaced with high tensile screws/bolts after tapping as required and I'm told it was a common modification in Gold Star circles back in the day...
I've never tried it myself and thus haven't investigated the method at all but it seems at first sight to be a good idea...The fit of the shaft to the flywheel is doing the bulk of the work, the rivets serving to ensure the shaft stays in place after fitment...Regarding alignment of the holes I used lengths of silver steel inserted into the rivet holes to keep things in line during initial fitment.....

These days only my M20 retains an original crank...The other three all have pressed up ' modern' cranks, though the original cranks generally don't give any trouble in standard engines....Ian

email (option): ian@wright52.plus.com

Re: 27-1239 Engine Shaft Rivet

Thanks Ian, you convinced me that the so-called original rivets were not the way to go.
I tried to close a couple up and it was not a nice experience.
With a lot less effort than I expected I reprofiled the heads of some rivets we keep in stock.
The only real pain was that they were about an 1/8" too long.

Below the pictures of the shaft and rivets in place.
I used a course polishing mop to debur the heads.
Followed by an ultra-sonic bath.

Mark



email (option): pes.sales@btconnect.com

Re: 27-1239 Engine Shaft Rivet

That looks great work mark - painful but great

Have you ever swapped out the flywheel thrust washers fitted - they are secured with rivets too ?
Br
Jo’b

email (option): jonnyob1@googlemail.com

Re: 27-1239 Engine Shaft Rivet

Thanks John,
I haven't, but I can't see an issue with it. Yes, they are riveted too.

Mark

email (option): pes.sales@btconnect.com

Re: 27-1239 Engine Shaft Rivet

This should be a golden opportunity for any rivet counter...How many rivets are there on an M20?..(it's a lot more than you would think)..Ian:relaxed:

email (option): ian@wright52.plus.com

Re: 27-1239 Engine Shaft Rivet

Just in case anyone has the same problem with the shafts in their M20 cranks I'm happy to offer a repair service.

Shafts and rivets in stock

Mark

https://pesltd.uk/?product=66-0644
https://pesltd.uk/?product=66-0640

email (option): pes.sales@btconnect.com

Re: 27-1239 Engine Shaft Rivet

Dear Mark and dear Ian, I hope it is ok when i rumble in here with my first post.
I'm about to equip my shaft with a new stub. I've already riveted on a test workpiece
with the same metal thickness - everything worked wonderfully.
But I'm still wondering one more detail: Did you drive in your rivets cold or hot?
I have read that rivets with a diameter of 10 mm or more should be
hot-riveted - especially steel rivets. Ok, the rivets on the shaft are smaller in
diameter, but I can still imagine that it can make sense to rivet hot.
Hot riveting would apparently have the big advantage that it would pull the two
connections together even further when they cooled down, making them more stable.

What is your experience if I may ask? Thank you so much for any help you can give!

email (option): beachbraker@gmx.de

Re: 27-1239 Engine Shaft Rivet

Here are some pictures where you can follow the process.

Pressing in the new stump and
Riveting tests on the test workpiece (hot riveting).
The right rivet in the picture was a small miss-hit ...

I would still like to test cold riveting.









email (option): beachbraker@gmx.de

Re: 27-1239 Engine Shaft Rivet

I think you'll be better off closing the rivet cold.
Heating the end of the rivet in situ is asking for trouble.
Remember the mainshaft is heat treated, and the tempering temperature is not that high.
Also the localized heat could bend the shaft, some people use that method to straighten them.

A little off topic, but some of my family were riveters at a ship yard in Barrow-in-Furness.
A child heated the rivets on the dockside.
I don't know if it was him or someone else threw the white hot rivets up to the ship that were caught in tongs.
The rivet was closed with someone each side of the panel timing the hammer hit exactly.
They were paid by the rivet, so the whole family took part.
If one rivet failed inspection a whole days pay was lost per rivet.
I don't expect anyone alive today could do it.

Mark

email (option): pes.sales@btconnect.com

Re: 27-1239 Engine Shaft Rivet

Neat job on the mainshaft rivets Mark...I have a friend who has that (riveter) as part of his trade discription in Plymouth Naval Dockyard....Power tools and ear defenders come into play these days though...and no children or family members:laughing: ....Ian

email (option): ian@wright52.plus.com

Re: 27-1239 Engine Shaft Rivet

The thing with hot riveting is to only heat the rivets, never the part where they will be applied to! so heat the rivet cherry red, then insert them, and rivet. (so do not only heat the end of the rivet.)

My 2p. have done a lot of them, whole chassis of big vehicles, and small parts too.

Cheers,

Lex

email (option): welbike@welbi**.net

Re: 27-1239 Engine Shaft Rivet

Thank you all for those great thoughts - they are very helpful.

We thought about that too - that would be the ideal solution for us.
The only problem is: The heated rivet would have to be inserted into the crankshaft
incredibly quickly and knocked into place, until then the material outside (i.e. the surrounding crankshaft)
would absorb the heat to such an extent that the rivet would be too cold.
This is where the idea came from to bring the entire shaft slightly up to
temperature (perhaps 100 - 150 degreeswchich is not al lot but maybe better than nothing) to counteract this effect.

But whether that will do much... and as Mark already writes, I have concerns about bringing about a material change here.

email (option): beachbraker@gmx.de

Re: 27-1239 Engine Shaft Rivet

So I want to share the progress with all of you.

I did the riveting before christmas but I had unfortunately no time to share with you till now.
In the end I did the cold riveting - it really worked out best like most of you suggested. All of them are a tight fit.
Thank you so much again for that tip and all your help.

Here you can see both sides of the riveting job:






One more thing: I wonder what this little grub screw is exactly for? Is it for fixation?
How do I handle it? Thank you all again!

email (option): beachbraker@gmx.de

Re: 27-1239 Engine Shaft Rivet

Very nice job. Could you share your riveting process.

Is the grub screw not just a blanking plug after the oil way is drilled through?

Regards Ron

email (option): ronpier@talk21.com

Re: 27-1239 Engine Shaft Rivet

Well done, the riveting looks very good.
As Ron mentions the plug is just to close the drilling.
With many of the Big End Pins I make, I use a brass plug to make it easy to drill out if you want to clean or inspect the inside of the pin.

Mark

email (option): pes.sales@btconnect.com

Re: 27-1239 Engine Shaft Rivet

Thank you guys for the quick reply and the praise about the work. :blush:

About the process:
I found it not that difficult - as long as you have the right setup on tools.
First we fixed the stump firmly in the shaft with screws all around - except of course for the place we wanted to rivet.
The riveting itself we did with a set of two hammers - one placed on the rivet we wanted to work on, the second was the hammering one with which we hit the first hammer placed on the overlapping rivetstump. This simply ruled out any slippage or miss on impact.

The most important part in this whole process was the counterpart - which I specially made from solid metal so that it can have a strengthening effect against the blows, keeps the rivet heads in place and also protects the stump and the shaft support from deformation. It is a bit longer than the stump itself (you can see it in the pictures - this metal cylinder).
I didn't believe it - but I also had to place a large anvil underneath so that every blow had its full effect.
As in many other such cases, the riveting was carried out crosswise, not in sequence, in order to distribute the tightening forces evenly.

That's all it was. If I had to do it again, I would only harden the counterpart - unfortunately it suffered from the blows and was deformed on the contact surfaces of the rivet heads. So it is no longer flat and can no longer be used.
I also noticed that the rivets all varied a little in length - even though they were NOS parts from the original packaging from back then. I selected then the longest ones from the set.

Now it's time to assemble. I will keep reporting! :v:

















email (option): beachbraker@gmx.de

Re: 27-1239 Engine Shaft Rivet

Brilliant job. Thanks for sharing. It's always interesting to see different ways of achieving something. Ron

email (option): ronpier@talk21.com

Re: 27-1239 Engine Shaft Rivet

It may be an old wife's tale, but I was told as a child not to hit two hammers together as one might explode.
I'm not sure how it happened, a friend of mine had to have a piece of hammer head removed from his arm when he was an apprentice.

Thank you for the explanation.

Mark

email (option): pes.sales@btconnect.com

Re: 27-1239 Engine Shaft Rivet

Ian showed me a hammer that he'd paid a lot of money for. I think it's called a dead blow hammer. Maybe that could be the type to use?....Ian?


Ron

email (option): ronpier@talk21.com

Re: 27-1239 Engine Shaft Rivet

You are surely right about the exploding hammer. I heared about that too and i guess we should keep this definitely in mind.

We used some tools from the aircraft-company my colleague works in so those tools and the hammer were designed to use it in this manner.

email (option): beachbraker@gmx.de

Re: 27-1239 Engine Shaft Rivet

I don't think you'd be able to close a rivet with a dead blow hammer Ron, as they are normally plastic.
Though I think you can also buy hard faced ones.

Mark

email (option): pes.sales@btconnect.com

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