Post by: beemsquar on November 13, 2015, 08:37:45 PM
I need some help with the stamp markings on my con rods.
I am about to reassemble the crank and add the new bearings etc, but I am unsure which way round the con rods should face.
I didn't take them off to see how they go back as the engineer who measured the runout for me removed them.
They are stamped with a different number of dots on each one from 1-4, which I guess is number 1 being the left hand side of the engine and number 4 being the right hand side if you were sat on the bike?
But should the stamped marks be facing forward or rearward again with the engine the right way up and as if you were sat on the bike?
Any help would be much appreciated!
Post by: Bryanj on November 13, 2015, 09:00:04 PM
Post by: beemsquar on November 13, 2015, 09:37:06 PM
You can see this one has 4 dots stamped into it the others have 3 , 2 and 1 on each one.
[attachimg=1]
[attachimg=2]
Post by: Woodside on November 13, 2015, 10:10:16 PM
Post by: Chris-freckle on November 13, 2015, 10:11:54 PM
Post by: beemsquar on November 13, 2015, 11:25:34 PM
They are a professional engineering company and have all the equipment to do that kind of work, I paid them to check the crank was Ok and to work out which bearings I needed.
I have all the bearings now based on their measurements, but need to work out how it goes back together.
Am I right in saying piston one would be on the left? Is this how you would normally refer to it?
I can't see the number 2 in that picture, let alone the other con rods, that's why I sent it to be measured.
Post by: NigelWilmshurst on November 14, 2015, 05:38:22 AM
Follow the manual word for word and you will have no problems.
Post by: Bryanj on November 14, 2015, 09:04:11 AM
Post by: beemsquar on November 14, 2015, 10:02:52 AM
I will contact the engineer this morning to see if he can shed some light on it.
It was nearly 3 months ago now though, as that's how long it's taken to get all the shells together, seemed to be a European shortage or something!
I have got a small parts washer, I washed most of the parts last night, dried them off with an airline and bagged them all up to keep them clean.
A newbie question for sure, but can anyone shed any light on which bore is number 1? Is it the same on any vehicle? It's a steep learning curve but I'm getting there.
I would love to know if anyone has any recommendations for engineering books etc that give the basic terminology and procedures to follow when building an engine.
Post by: hairygit on November 14, 2015, 10:29:52 AM
Post by: Trigger on November 14, 2015, 11:59:08 AM
Post by: NigelWilmshurst on November 14, 2015, 06:38:48 PM
I checked another cb750 engine I have stripped and is the same as above, hopefully you can get on with the build now, good luck mate and ask away anything else that is not clear.
Nigel
Post by: NigelWilmshurst on November 14, 2015, 06:50:19 PM
Post by: beemsquar on November 15, 2015, 11:00:36 AM
One of the reasons I sent it to a specialist was because I couldn't 100% Read the letters and numbers, I couldn't decide if it was a 1 or a 2.
Glad to have someone with your experience on here brian to confirm everything! I will rake some more photos soon and post.
After the engineer measured the crank runout etc he plastigauged the cases and worked out all the bearings for me, costly but he came out with different shell colours to me, so glad I got a professional to check!
I ended up with all green main bearings and 3 green and 1 yellow for the big ends.
Took ages to arrive and in dribs and drabs.
I called the engineer who stamped the con rods yesterday and he confirmed that if assembling upside down the dots should be facing the back of the engine with the con rods hanging down. Torqued everything up and RE assembled the top crankcase, should bolt it all together today!
Post by: Dave_Canada on November 22, 2015, 03:18:42 AM
[attachimg=1]
Post by: AshimotoK0 on November 22, 2015, 07:32:02 AM
I tried it in Microsoft Picture Manager (comes with MS Office) but this was the best I could get.
Looking at it after a night on the beer is a bit like doing the 'Ink Blot Test' http://theinkblot.com/
[attachimg=1]
Post by: beemsquar on November 27, 2015, 09:22:31 AM