Honda-SOHC

SOHC.co.uk Forums => CB500/550 => Topic started by: Jimbo550 on October 17, 2012, 05:25:02 PM

Title: Crankshaft shells?
Post by: Jimbo550 on October 17, 2012, 05:25:02 PM: Hi. After stripping the engine down to thousands of parts im now inspecting everything and making a list of new parts to order. Looking at the crankshaft shells they look a little scored and worn so thought i'd replace them while the motor is in bits. I've measures the crankshaft and the journals seem good but not to sure on how to select the correct shells. I don't have an internal micrometer so measuring the case bolted together isn't really an option I have ordered some plastigauge but this will be the first time using it so looking for some advice and helpfull tips.
Title: Re: Crankshaft shells?
Post by: Bitsa (Ralph Wright - RIP) on October 17, 2012, 05:51:56 PM: Hi
Somewhere on the crank journals you will have to use a magnifying glass etched on the fly wheels you will see 5 letters and you match these with the letters on the rear crankcases to Honda's list.I talked to a old racing Honda mechanic about this and he said not alot of difference between all of them fit the biggest and run in carefully.The etching wears with time and you might not see them.So far I have seen them after shit loads of swearing and going blind finally found them.
Hope this helps
Bitsa
Title: Re: Crankshaft shells?
Post by: Jimbo550 on October 17, 2012, 08:39:34 PM: Mmm ok thanks. I'll have a good look for the codes tomorrow and see what I can find. I noticed that David silver spares only stock one size which is the green colour code.
Title: Re: Crankshaft shells?
Post by: Bryanj on October 18, 2012, 07:34:13 AM: Doesn't matter if you had an internal micrometer and how good you are with a micrometer you wouldn't be accurate enough to use the sizes in the manual! Honda used air gauges in production which are accurate to 0.001 mm. I always fitted black shells and ren them in for a couple of thousand miles, never had a problem
Title: Re: Crankshaft shells?
Post by: Jimbo550 on October 18, 2012, 08:08:27 AM: Thanks for the advice. I'll have a good clean of the crank and cases today in order to find these letters and numbers. It would appear that David silver only stock green shells. Anybody know a source for other sizes/colours?
Title: Re: Crankshaft shells?
Post by: Jimbo550 on October 18, 2012, 10:54:24 PM: Well I've searched all over the crankcase and the crank and can't seem to find any letters or numbers anywhere. I've ordered a pair of green shells and I'll try one pair with some plastigauge and see what I get. Thanks for the kind advice.
Title: Re: Crankshaft shells?
Post by: Jimbo550 on October 19, 2012, 02:30:06 PM: I don't have the genuine cb500 manual only a haynes manual. Don't suppose you would have a picture or photo copy of page 49 by any chance!!
Title: Re: Crankshaft shells?
Post by: tom400f on October 19, 2012, 03:43:18 PM: http://www.dotheton.com/downloads/CB500-550_Manual.pdf

Sure enough, on page 49....
Title: Re: Crankshaft shells?
Post by: Jimbo550 on October 28, 2012, 01:43:33 PM: Finally found the stamped letters on the crankcase and the numbers on the crank. It would appear they are all marked as A1 which i think relates to shell D YELLOW. Does this sound correct? On the plus side it seems to be the cheaper shell but on the down side its not in stock with cmsnl.
Title: Re: Crankshaft shells?
Post by: Jimbo550 on October 28, 2012, 07:38:49 PM: I've had a quick look online today and couldn't find any but I'll have a more indepth search one evening this week. Havn't had much time this last week so only just got round to using plastigauge on journals today. Had about .06 clearence and max is .08 so it's getting close.