Searched this forum for over an hour and consulted Bill Silver's engine rebuild manual, but could not find that answer to what seems a simple question. How do you disassemble a CA crankshaft?
CA parts diagram shows exploded view of the pieces. My brother has a 12 ton press and we put the crank in it with a right-size impact socket on the con rod shaft trying to push it out of the starter rotor end. Couldn't get it to budge and stopped because we didn't want to break anything.
Is big brother's press not big enough? Looks like there's lead in the center of the conrod shaft. Does it need to come out first?
I don't see any splines in the exploded view. What is the best way to keep things lined up when puting it back together again?
I am trying to make one good crank out of parts of 2 cranks. Thanks for any help.
Crankshaft disassemblyCan't offer much help here as I've yet to try this operation. I'm interested in how you get on, though!
I dismantled a BSA Bantam crank using my 10 ton press at home and the press was creaking a little when the crankpin finally started to move. I had to build a special jig so that I could hold the crank securely in the press. How are you supporting the crank in the press? It may be that 12 tons is not enough for these cranks or that (perhaps) you are pushing against the wrong surface. For rough alignment, you can scribe a line across the crank webs before dismantling. and then line it up again on re-assembly. For final alignment you will require V-blocks a dial gauge and a big lead hammer. I watched Allen Millyard build one of his 5-cylinder Kawasaki cranks using just a big vise and regular worksop tools so your's is not a trip into the unknown. G
'60 C77 '60 C72 '62 C72 Dream '63 CL72
'61 CB72 '64 CB77 '65 CB160 '66 Matchless 350 '67 CL77 '67 S90 '77 CB400F ThanksThanks for the help, guys.
I am probably more like Graham and inclined to be adventurous. I also don't think it will pay to ship 2 cranks 2 ways and have machine shop work done as well. They are boat anchors as is, so I guess I can't hurt them. I cut 2 10" sections of 3/8" thick angle iron. 5" sides so pretty hurky stuff. We didn't put all 12 tons to work, but the angle iron seemed to handle what we gave it and should work fine. Slid those under the outside counterweight and pushed against the con rod shaft. Requires a spacer under one side of the counterweight. Anybody know about the lead in the center of the con rod shaft? If anyone else has any ideas I would appreciate any further help that can be offered. Sounds like you are doing all the right things, Bill. Maybe you need that extra 28 tons as Steve suggests.
Cannot see that the lead in the pin would have any effect as the pin is parallel. I have a couple of the webs (with pin attached) so I'll take a look at them. It might be possible to rig up a lever and pivot with a 4-1 ratio so that you could amplify what you have at the moment. That would be quite an interesting (and perhaps scary) project. You would need some fairly chunky bar for that one. I'll get around to looking at my cranks some time but it's painting weather and my rainy day project is a poor man's big bore kit using CB750 liners and CB350 pistons. At least you can make two kits with one cast-off CB750 barrel..... Let us know how you get on. G '60 C77 '60 C72 '62 C72 Dream '63 CL72
'61 CB72 '64 CB77 '65 CB160 '66 Matchless 350 '67 CL77 '67 S90 '77 CB400F Bill
The 'lead' you were looking at is, I believe, an aluminum plug which blocks off the oilway drilled through the crank pin. It breaks through into an annular groove in the other side of the web, providing an oilway to the big end. As you can see, the pin is parallel so the 'plug' does not interfere with the dismantling process. Incidentally, you can use those holes to roughly align the crank at reassembly time. G
'60 C77 '60 C72 '62 C72 Dream '63 CL72
'61 CB72 '64 CB77 '65 CB160 '66 Matchless 350 '67 CL77 '67 S90 '77 CB400F
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
