So 3 out of my 4 camshaft journals are screwed up although one of those three is usable if necessary. I was going to swap in a new head, but the head I got from ebay was such a piece of crap that I decided to try swapping the journals over. I plastigaged my one good original journal and I got .051mm. This is journal B. The next three are results from the swapped journals: A - .076mm C- .038mm D- .051 mm. What I'm wondering is what is the level of tolerance I should be looking for? I know this is not recommended by many, but its my bike and this is what I'd like to try. If anyone knows enough about this to help me out I'd appreciate it.

Do you mean swapping the top caps of the journals? I will check the manuals specs this evening.

I think so? Its the pieces that the valve cover bolts thread into and are milled with the head(thus me checking the clearances when swapping them. Also I tested the other "usuable"(the threads aren't in great shape but I can probably still reach torque specs) original one and I got .051mm as well.

UPDATE: I found this in the haynes manual:



Does this mean that there is too much clearance on journal A? Or that it's within service limit, but not as good as "standard" so its still usable?

The journals and caps are line bored as part of the manufacturing process and are all matched together, that's why you cant buy the caps as individual parts. If you start mixing and matching you really are on your own. Not only is it the issue of clearance its also if the journals are all perfectly in line and if the upper and lower halves are perfectly concentric.

Without some accurate and specialist measuring equipment to check its impossible to say

It might work and prove to be reliable, it might not. Sorry but its the only answer I can give 

Swap the high dimension A with the low dimension C journals and see if you can get all of them near the nominal measurement of .051mm, same as the other 2, if possible.

Torque down the cam bearings checking for a significant increase in torque necessary to turn the camshafts by hand as you tighten the caps. No valve shims or anyother resistance sources.

With a little oil on the bearing surfaces if the resistance does not increase much then you're ok at least to try it, definitely not a  recommended repair operation. If OK then remove the cams and reassemble the rest of the valve components as you would normally.

regards
mech

Quote from: sledge on March 16, 2015, 12:13:32 PM
The journals and caps are line bored as part of the manufacturing process and are all matched together, that's why you cant buy the caps as individual parts. If you start mixing and matching you really are on your own. Not only is it the issue of clearance its also if the journals are all perfectly in line and if the upper and lower halves are perfectly concentric.

Without some accurate and specialist measuring equipment to check its impossible to say

It might work and prove to be reliable, it might not. Sorry but its the only answer I can give 

+1

                                                                                                                                                                                                                                                                                                                                                                                                         

So I went ahead and gave it a go at switching them. Bike wont start, I didn't change anything else other than let the carbs sit for a few weeks and I don't think that wouldve hurt them. Today I decided to recheck valve clearance with the swapped journals and I think I found the problem although I'm not sure if its related to swapping the journals or just how I put it back together or something. Valve clearance is as off as .96mm(with a 2.60x shim in there already). 3 out of the 4 are off now. The other two are .75mm with a 2.60x shim and .4mm with a 2.55x shim. These seem like huge differences, almost too huge to be due to just swapping journals. I could be wrong about that, but is there any other reasons this could happen? All the buckets look normal, spin freely and move up and down a bit when pulling the shim out(so not stuck vertically). I'm pretty sure I'm just going to part this bike out, but I figured I'd give it one last shot and see if maybe this is the last thing I need to fix. Thanks.

A shameless solicitation here..

I have a 2006 head lying around, valves are bent. Other than that, just swap over your parts onto it and you should be good to go.

I actually have a head that is probably all good, but the valves are wacky so if I were to go through the trouble of swapping valves I have the parts. It just seems really difficult to swap valves.