Author Topic: Crank markings  (Read 576 times)

Offline ogri211

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Crank markings
« on: April 19, 2018, 10:44:22 AM »
I've just got home and I am ready to rebuild my engine I was going to put new shells in the mains if I could get them, the trouble is I cant find the markings on the crank does anyone have any hints to try and see them I've tried cleaning them and shining a torch but cant find anything
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Offline Deano400

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Re: Crank markings
« Reply #1 on: April 19, 2018, 10:57:54 AM »
Had the same problem with mine. Tried cleaning with petrol, different lights, magnifying glass, but some were just invisible. In the end I had them measured by a friend of mine at an engineering company. You may end up having to do the same.  :(

Offline MrDavo

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Re: Crank markings
« Reply #2 on: April 19, 2018, 11:28:40 AM »
I found I needed real sunlight (rare in Manchester), then suddenly there they were!

It seems odd that they measure the most tiny tolerances with really accurate gear, then record the results by scratching them on the flywheel with a child like scrawl using an engraver.

I suppose where else would you put them, and how long would it take?
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Offline K2-K6

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Re: Crank markings
« Reply #3 on: April 19, 2018, 01:02:48 PM »
As above,  get it out into proper sunlight to see if you can spot them,  it'll probably be 16 to 32 times brighter than most torches so you've much more chance. Take it away from a bright background as well else your pupils close down in response.

Try polarising sunglasses as well to see if it helps.

Offline Trigger

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Re: Crank markings
« Reply #4 on: April 19, 2018, 02:58:58 PM »
As above,  get it out into proper sunlight to see if you can spot them,  it'll probably be 16 to 32 times brighter than most torches so you've much more chance. Take it away from a bright background as well else your pupils close down in response.

Try polarising sunglasses as well to see if it helps.

You must have some torch if the sun is only 16 to 32 times brighter  ;) ;D ;D ;D

Offline K2-K6

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Re: Crank markings
« Reply #5 on: April 19, 2018, 05:02:08 PM »
It's a fair cop Trigger, I haven't got one of those 100bazillion candlepower torches like what they advertise in the weekend papers  ;D ;D ;D ;D

I was just thinking in camera F stops of how much reflected light from Ogri's torch versus the sun,  about F2.8 to F16 ish.

The Polaroid sunglasses are just to look cool while searching :D

Offline ogri211

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Re: Crank markings
« Reply #6 on: April 19, 2018, 09:04:38 PM »
Ive had a look still nothing did someone say they were done with an engraver I thought they were painted on.
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Offline Nurse Julie

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Re: Crank markings
« Reply #7 on: April 19, 2018, 09:13:49 PM »
Ive had a look still nothing did someone say they were done with an engraver I thought they were painted on.
Definitely engraved, very feint but will be there somewhere.
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Offline Deano400

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Re: Crank markings
« Reply #8 on: April 19, 2018, 09:26:08 PM »
Couple of pics of what mine looks like. Some markings you can see some you can't.

Offline ogri211

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Re: Crank markings
« Reply #9 on: April 20, 2018, 06:53:06 AM »
Thanks for the pictures I will have one last look today I can't see any yellow paint it's looks as if the old shells will be getting refitted they are not too bad I would have liked to put new ones in since I have spent so much on the bike I will check them with plasitigage to be sure.
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Offline MrDavo

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Re: Crank markings
« Reply #10 on: April 20, 2018, 12:04:09 PM »
With my 750 crank, and the replacement one I bought from Ashley, there were letters literally scratched (but very faintly) into the cheeks of the flywheels. Not at all obvious, but once you've seen one catching the light you'll wonder how you so completely missed them before.

I looked on Google for photos, but what you can't easily see you definitely can't easily photograph.

There were also marks on the rods and caps that apparently were Japanese characters, I just made sure I kept them together as pairs and not get them mixed up.
1969 Honda CL450 'Scrambler'
1974 Kawasaki Z1A
2005 Harley XL1200R Sportster
1985 Porsche 911 3.2 Carrera Sport
1978 VW Bay Window camper van

 

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