I've split my crankshaft for a 277 rephase. The female splined side (Left) has a notch for the crankshaft sprocket. The sprocket is mounted on the right hand side. Does the sprocket come off the right hand side and rotate 87 degrees, or do I cut a notch into the left hand side 87 degrees around?
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mrriggs
XS650 Junkie
When I did mine I left the sprocket on and cut a new notch. I've heard you can pull the sprocket off but I couldn't figure out a good way to do it since the only thing to grab onto is the sprocket teeth.
If you leave the sprocket on the right side of the crank, and keep the cam sprocket aligned to the left side of the cam then your cam timing will be three degrees advanced.
When I did my cam, I marked the sprocket on the right side before removing it, rephased the cam then put the sprocket back on with the marks lined up. The cam degreed perfect the first time, no need to adjust it.
It's always a good idea to degree the cam, even if you're just assembling a stock motor.
If you leave the sprocket on the right side of the crank, and keep the cam sprocket aligned to the left side of the cam then your cam timing will be three degrees advanced.
When I did my cam, I marked the sprocket on the right side before removing it, rephased the cam then put the sprocket back on with the marks lined up. The cam degreed perfect the first time, no need to adjust it.
It's always a good idea to degree the cam, even if you're just assembling a stock motor.
Punkskalar
Hugh's HandBuilt
I pull them apart completely, otherwise you can't get a good weld on the rod pins with the bearings in the way. After you have removed the pins, rods, etc... and cleaned up everything and checked it all for spec, you can press the pins back into the middle 2 flywheels and weld them up. Then install the shims, bearings, snap ring and finally the cam gear. I have a special tool I built from a dead crank for lining up the cam gear, but here is a simple way to do it as well.
I have a special puller I made to remove the cam gear, get creative if you need to, they are tough and I have never seen one broken or tweaked yet...
I install the gear loosely on the female half of the flywheel, and the line up the splines on the 2 halves just as the were stock. You will have to lightly press or tap the 2 halves together until you feel the splines are engaged. Once you have that, the cam gear is located where it needs to be, so pull the 2 halves apart again and rotate the 3 teeth, lightly tap them together again, mark where the cam gear needs to be, and cut the notch out on the female half of the flywheel. If you cut too wide of a notch, don't fret. Press it all together and then weld the cam gear with a tack-weld in place. You don't want it to be able to move, and trust me, if the notch it too wide, it will move eventually and your cam timing will change.
With the 2 middle flywheels together, all bearings in place, and the cam gear situated properly, weld the splines where they come through on the female side. Since the rod pins are already welded in place, you can install the rods, shims and bearings, and press the outer flywheels in place, true them up, and weld the outside of the rod pins as well.
You will have a super reliable and very strong crank if you do it this way...
Any other questions, email is very fast for me, and i get back to you asap.
Hugh
HughsHandBuilt@gmail.com
PS, do not try to weld the crank at all if you have not completely disassembled it, degreased and checked all the bearings for tolerance. Oils and such will stay in the parts and ruin your welds, they will be porous and crack, even if they look "ok" on the outside... Clean is the only way to go when welding these things...
I have a special puller I made to remove the cam gear, get creative if you need to, they are tough and I have never seen one broken or tweaked yet...
I install the gear loosely on the female half of the flywheel, and the line up the splines on the 2 halves just as the were stock. You will have to lightly press or tap the 2 halves together until you feel the splines are engaged. Once you have that, the cam gear is located where it needs to be, so pull the 2 halves apart again and rotate the 3 teeth, lightly tap them together again, mark where the cam gear needs to be, and cut the notch out on the female half of the flywheel. If you cut too wide of a notch, don't fret. Press it all together and then weld the cam gear with a tack-weld in place. You don't want it to be able to move, and trust me, if the notch it too wide, it will move eventually and your cam timing will change.
With the 2 middle flywheels together, all bearings in place, and the cam gear situated properly, weld the splines where they come through on the female side. Since the rod pins are already welded in place, you can install the rods, shims and bearings, and press the outer flywheels in place, true them up, and weld the outside of the rod pins as well.
You will have a super reliable and very strong crank if you do it this way...
Any other questions, email is very fast for me, and i get back to you asap.
Hugh
HughsHandBuilt@gmail.com
PS, do not try to weld the crank at all if you have not completely disassembled it, degreased and checked all the bearings for tolerance. Oils and such will stay in the parts and ruin your welds, they will be porous and crack, even if they look "ok" on the outside... Clean is the only way to go when welding these things...
mrriggs
XS650 Junkie
If you already have the sprocket off then why do you put it back on in the stock location and grind a new slot? If you put it on the left side then turn the right side three splines and press it all together then the cam will be in perfect time (assuming you keep the cam sprocket lined up with the left half of the cam.
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you just re- notch the thing. rotate the right side 3 splines,take note where the new notch must go,mark it ,cut it, reassemble it,true it and your done.
Punkskalar
Hugh's HandBuilt
Kinda, anything can be taken apart
Results may vary... Once you have a properly built crank, you'll never have a problem with it unless you have a catastrophic failure like a broken rod or something, which would probably take the crank out with it anyhow.
I TRY to kill my engine, and it has been torn down and inspected every season. The first year I didn't weld it, and had problems with the crank seperating and the flywheels walking away from each other. Rebuilt it, welded it as a I went, and it has been good to go ever since... Welding is HIGHLY recommended...
