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Mains Jounal Measured with micrometer what colour code is needed ?
McCabe-Thiele (Ted):
--- Quote from: Deano400 on April 09, 2021, 09:39:05 PM ---I had the same issue with one of my crankshafts, only a couple of markings visible. I took my crankshaft to an engineering company I knew and had the crankshaft measured. As Trigger stated all the measurements were identical.
--- End quote ---
At the risk of annoying everybody I feel as though I'm stuck with what to me seems a bizzare batch numbering system of crank bearings with no cross refferencing.
I have 2,3 & 4 mains shells marked as STD D61-A as a batch number - there is a trace colour marking on just one of these as being Green.
The other two 1 & 5 are marked as STD D6H-A at present unidentified as regards to colour as its long since gone.
Has anyone here come across batch number D6H-A with an identified associated colour ?
Am I right in thinking that the lower crank casing marks CAABA refer to the O/D of the shells when they were originally sized by Honda ?
At present my next move is to try to get the crank mains re-measured with a different micrometer - just maybe I can somehow measure the old bearings for 1 &5 thickness wise at a local engineers when I take the upper crank case for the cam chain adjustment bolt modification.
Except that it does not allow for wear Green might be ok for the centre three main bearings.
Not sure how to use Plastiguage to help with identifying 1 & 5.
I'm completely stuck at the moment but time & help here will I'm sure help me see the wood from the trees eventualy !!!!!
K2-K6:
"Am I right in thinking that the lower crank casing marks CAABA refer to the O/D of the shells when they were originally sized by Honda ?"
It's the measured bore size of the crankcase when inspected after line boring operation.
A being smallest, C the largest (this from a 750 manual) sizing different but protocols the same as far as I know.
Have you got the charts from Honda manual that explains it and gives you the correct colour to use? If so, you can with accurate crankshaft mic measurements derive the colours from those letters and just the accurate dimension.
McCabe-Thiele (Ted):
Screenshot 2021-04-10 132841 by Macabe Thiele, on Flickr
K2-K6:
"Not sure how to use Plastiguage to help with identifying 1 & 5."
Likely that these two are going to be at least Brown to then check with plastigauge.
McCabe-Thiele (Ted):
--- Quote from: K2-K6 on April 10, 2021, 01:49:20 PM ---"Not sure how to use Plastiguage to help with identifying 1 & 5."
Likely that these two are going to be at least Brown to then check with plastigauge.
--- End quote ---
That's an interesting comment as I have completely unscientifically asigned Brown to 1 & 5 on the basis that my cranshaft main jounals are most likely to be in the range 1 of the table so using the crankcase allowance in column C that gives me Brown, as both bearings 1 & 5 are the same batch number STD D6H-A they are both Brown plus the only hint of any colour on the shell edges is rust brown!
Next question to self is what size plastigauge do I need for the clearance range of 20-46.
I am guessing I only really need to use the 8 bolts that secure the mains when checking not put back all the upper & lower crancase bolts.
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