Crankcase repair (53 Vincent restoration)

Bought my 1953 Black Shadow back in 2003 in fully assembled state. It hadn't been used for some years. Acquired a new BTH electronic magneto and mounted it. The bike started at first try! Attended the Scandinavian Vincent Club rally in Sweden 2004 and used it the whole season. Second gear was a problem and the old carbs were quite worn. Decided to fix these problems for 2005 but more problems were of course discovered. E.g. the primary drive chain rollers of the middle row had been destroyed by the dynamo sprocket. Also the oil filter chamber and the "bolt ears" at the lower front of the crankcase drive side had been smashed at some point. The man who sold me the bike said he was told that the first owner crashed back in the mid 50's.
Was asking around in 2005/2006 trying to find someone in Stockholm area that would do the weld job fixing the crankcase but without much success. We bought a house in 2007 that needed quite some restoration and we got a third child so not much Vincent time for a few years. About two years ago I decided to finally fix the engine. Now working for a new company I got a tip from one of the colleagues who knew who could do the welding job. Took him about 6 months to get it done but I believe the result is quite OK. I'm not an weld expert though. Attached you find some pictures.
The oil filter chamber thread was very bad so I asked the man to weld up material so I could make a new thread. A Scandinavian Vincent Club member recommended me to buy a Whitworth 2 1/8" and 20 tpi tap from Tracy Tools in UK which I did. They were good to deal with and quick to deliver this one-off tap.
Today I finally found a company that is willing to do the machining. Hopefully in a few weeks time I can start the assembly work!

/ Patrik

Crankcase repair

Got the crank case back from the machine shop. The new thread for the oil filter cap was looking fine. However now after machining it is clear that the welder did not recreate the mounting ear on the drive side in the exact position (where the bolt goes through the motor at position "C" according to MO41). Not enough material on the lower side. It had to go back to the welder to add some more material. Now finally I have the crank case welded up and machined. Some sanding and polishing still to be done before painting.
/ Patrik

Re: Crankcase repair

A little rough-looking, I hope the faces are true to give you a good seal.

Re: Crankcase repair

Looks like your welder did a great job on the repair the second time. Substantial material built up now. Good luck. Keep us posted.

Re: Crankcase repair

That is an excellent case detail diagram, by the way.

Re: Crankcase repair

The crankcase actually went back once agion to the welder. Now the timning side. I had forgotten that the chain had chewed some material and there was a small crack as well. Now some more material. Will order new bearings and now time to prepare and finish up the crank case. Is wet blasting a good process to remove the old black surface treatment and prepare for the new black paint? And what kind of paint process is best for the new black?





/ Patrik

Re: Crankcase repair

Old and new crankcase side by side. The new will be machined to fit the 92mm cylinders. But first I will assemble the Black Shadow engine. The target is to ride the bike to the Scandinavian Rally June 17th. It will be tough but I will give it a try!

/ Patrik

Re: Crankcase repair

That's doable Patrik, it gives you a little over 13 months.

I presume you mean June 2017...?!

Re: Crankcase repair

No. Unfortunatelly I'm talking about June 17th 2016!!!

Re: Crankcase repair

Buellingvincent said:

No. Unfortunatelly I'm talking about June 17th 2016!!!

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Well I wouldn't make any firm commitments if I were you Patrik. Is only 8/9 weeks away. Probably take that long to get the cases back from the painter!

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Well I know it's a bit cracy to believe I can have the engine assembled and up and running in June but I will try at least.
If that won't work I will make sure I ride it this summer.
/ Patrik

Re: Crankcase repair

You've been quiet Patrik, presumably because you are working flat out on the Vin!

6 weeks to go... Are you gonna make it...?

Re: Crankcase repair

Thanks for asking Eddie.
Yes time flies :?

Well I'm been busy investigating what parts I need order and also what remaining work has to be done on the crankcase.

I examined the original Vincent flywheel/crank assembly more in detail a few weeks ago and it was clear that it was not in the condition I assumed (of course). The inner bearings ET92 are not a tight enough fit to the main shafts anymore and these bearings have worn on the side of the flywheels. So I would need to replace the main shafts and fix the flywheels so that means much more work of course that I cannot fix myself (I have no machinery). And having it made for me would take too long time as I really want to ride the bike the upcoming Swedish summer. Preferably to the Rally June 17th !

So I contacted Terry Prince and luckily he had all the parts available to assemble a new 90mm stroke crank.


Terry is off soon for an eye operation but the op was delayed a couple of weeks so he managed to assemble the crank for me before going to hospital. It will be air freighted from Australia tomorrow! Together with two special tapered roller bearings I need to fit instead of the standard E91 and ET92 as the primary sprocket has chewed a bit on the case so there is not much material left for the outer circlip to rest on. Terry and I agreed this is a good solution. The 100mm bob weight crank I bought from him for the Holder crankcase is fitted with 30mm main shaft and to eliminate boring the case to fit 72mm bearings he recommended fitting tapered roller bearings. By fitting these only the inner circlip is needed. So I'm doing the same on the Shadow engine instead of trying to fix the case around the outer circlip as this probably would mean a lot more work (and time). A plus is that more space is provided for an oil seal carrier. However I need to have two spacers made to sit between the taper bearings.

Std setup (ET91 in the picture should be E91):


My new setup using ET-15101/15250X from NTN:


One crankcase half and some of the covers are back at the welder to fix small dents, more cosmetic fixes than strength related. Hope to fetch the parts tomorrow.

In parallel I have been trying figure out how to remove the old stove enamel paint. Been checking out different types of blasting processes, chemicals etc. Talked yesterday with a company manufacturing stove enamel and their technical guy strongly recommended not to use strong acids or alkalics. He said probably the paint is still there but the alu is not! He suggested MEK or acetone but also asked the obvious, why do I need to remove all of it.
I visited a sand blasting company but realized this is too tough on the metal so next week I will bring the parts to a company doing ice blasting and soda blasting. Already discussed with the owner and he said they can blast for me within a few days.

Haven't decided yet if I will paint the engine myself or have it powder coated or spray coated by a pro. Still to be investigated the coming days.

Will order the remaining parts this evening from different companies. Hope to have all of the parts within a couple of weeks.

So I am fully occupied and still haven't given up the attempt to ride the bike June 17th. But at least I will ride it this summer.

Cheers / Patrik

Re: Crankcase repair

Forgot to mention that Tracy Tools in the UK is shipping me today a set of thread taps and dies I need to fix the cranckcase and to make some shorter crankcase bolts as I will not use the front prop stand and mag cover.

Re: Crankcase repair

My wallet cried for you when I read "air freighted from Australia..."

Re: Crankcase repair

swooshdave said:

My wallet cried for you when I read "air freighted from Australia..."

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Dave, Patrik is build a Vincent...

Air freight from Australia, or anywhere else in the near solar system, is the least of his financial worries...!

Re: Crankcase repair

Buying a new twin crank/flywheel with rods from Vincent Owners Club's Spares company in UK would cost me 2,836 GBP incl. European VAT. Shipping by truck to Sweden not included.
I paid 2,300 AUD for the Terry Prince crank+rods which is about 1,200 GBP. Air freight is 250 AUD or 127 GBP. I will need to pay import tax and VAT when the parts arrive to Sweden but the total cost will actually be far less then buying in Europe.
/ Patrik

Re: Crankcase repair

Buellingvincent said:

Buying a new twin crank/flywheel with rods from Vincent Owners Club's Spares company in UK would cost me 2,836 GBP incl. European VAT. Shipping by truck to Sweden not included.
I paid 2,300 AUD for the Terry Prince crank+rods which is about 1,200 GBP. Air freight is 250 AUD or 127 GBP. I will need to pay import tax and VAT when the parts arrive to Sweden but the total cost will actually be far less then buying in Europe.
/ Patrik

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No VAT if, repeat, if you live out of Europe :!:
and you wonder why some of us want to leave the E.U. :?:

Re: Crankcase repair

Well you always have to pay VAT wherever you source from. If buying within EU I pay VAT directly to the seller. If buying from outside of EU I do not pay VAT to the seller but I pay the VAT when entering to goods into EU.

Anyhow I have now some result of the paint removal exercise. I bought a gel type of paint removal available here in Scandinavia. Contains 15-30% Dimethyl Sulfoxide and 1% Cocoalkylaminetoxilat. Applied it with a brush on a cover to test. After 24 hrs no visible change. So I thought this was a dead end. But after about three days laying in open air on the floor of the garage the kick start cover looked like below. The paint is like a soft skin that I now can just peel off. I didn't expect it to be that easy. Maybe on the cylinders and heads where the surface is more rough it will be more difficult.
/ Patrik

Re: Crankcase repair

One trick with paint stripper is to cover it with aluminum foil, it helps keep the vapors in. Really speeds up the process.