Author Topic: Crankcase - ancient hieroglphics what are these?  (Read 744 times)

Online McCabe-Thiele (Ted)

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Crankcase - ancient hieroglphics what are these?
« on: March 21, 2021, 01:54:54 PM »
Do this series of letters have any meaning to what's inside the casing?


.casing marks by Macabe Thiele, on Flickr
Honda CB500 K1 (new pit dug out ready)
Honda CB400 four super sport (first money pit)
Link to my full restoration http://www.sohc.co.uk/index.php/topic,23291.0.html

Online K2-K6

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Re: Crankcase - ancient hieroglphics what are these?
« Reply #1 on: March 21, 2021, 02:11:37 PM »
Yes, it's where they sit in tolerance terms when originally measured prior to production assembly.

Should have similar on crank to work out which thicknesses needed for shells to assemble with correct running clearance.

There's a working chart in manual to explain, ordinarily.

Online McCabe-Thiele (Ted)

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Re: Crankcase - ancient hieroglphics what are these?
« Reply #2 on: March 21, 2021, 03:45:47 PM »
The fact there's a C there Ted isn't the best news, the only colours ever fitted to that journal would have been either brown, black or blue. Black and blue are very hard to find.

On the crankshaft are 5 numbers and 4 letters printed onto the edge of the webs, see if you can find them. Also there are numbers and letter on the rods.

The conrods have a large leter C on them, I haven't taken the crank right out yet but have undone No:2 conrod & the big end shell was in good condition.
Honda CB500 K1 (new pit dug out ready)
Honda CB400 four super sport (first money pit)
Link to my full restoration http://www.sohc.co.uk/index.php/topic,23291.0.html

Online McCabe-Thiele (Ted)

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Re: Crankcase - ancient hieroglphics what are these?
« Reply #3 on: March 21, 2021, 08:44:06 PM »
C is the weight code, Honda made sure that all the conrods weighed the same so the crank was better balanced. It also means if you ever need a new conrod you had to order it by weight code. One the other side of the rod will be a number, that's the diameter of the journal the rod goes on.

Only two of my conrods have numbers on the opposite side to the big C  - one marked  2 was in cylinder 4 , one was marked 3 was in cylinder 1. The other two rods had no legible markings aside from the big C.
« Last Edit: March 21, 2021, 10:38:58 PM by Macabethiele (Ted) »
Honda CB500 K1 (new pit dug out ready)
Honda CB400 four super sport (first money pit)
Link to my full restoration http://www.sohc.co.uk/index.php/topic,23291.0.html

Offline Bryanj

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Re: Crankcase - ancient hieroglphics what are these?
« Reply #4 on: March 21, 2021, 09:42:37 PM »
And here was me thinking it was a Millyard special!!

Online McCabe-Thiele (Ted)

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Re: Crankcase - ancient hieroglphics what are these?
« Reply #5 on: March 21, 2021, 10:39:41 PM »
You do realise Ted that the 400 only has 4 cylinders 😯😯

Just a typo but in my defence it does have a 5 bearing crank!
Honda CB500 K1 (new pit dug out ready)
Honda CB400 four super sport (first money pit)
Link to my full restoration http://www.sohc.co.uk/index.php/topic,23291.0.html

Online McCabe-Thiele (Ted)

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Re: Crankcase - ancient hieroglphics what are these?
« Reply #6 on: March 21, 2021, 10:41:43 PM »
And here was me thinking it was a Millyard special!!

In my defence I have had to invert all my markings as the engine is upside down - just a typo 4 is next to 5 on my keyboard - sorry for the drama.
Honda CB500 K1 (new pit dug out ready)
Honda CB400 four super sport (first money pit)
Link to my full restoration http://www.sohc.co.uk/index.php/topic,23291.0.html

 

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