Author Topic: 76 CB550 Cafe build (Read 92338 times)

tshrey · « **Reply #625 on:** June 25, 2022, 08:26:48 PM »

Spent some time on the lathe today. I don't like the weird stock linkage on the rear brake, made my own two piece sleeve to put a heim joint on the actuator. Now just have to modify the rod with the new thread for the heim.

grcamna2 · « **Reply #626 on:** June 25, 2022, 08:41:56 PM »

subscribed

tshrey · « **Reply #627 on:** June 29, 2022, 02:04:50 PM »

Went for a ride, noticed over hard edges the sensation was still there in the steering head. WTF? I finally figured out what it was (the spacer being on top of the race definitely was one component, but apparently not all). The top triple hole for the stem is a tiny bit (.3mm maybe?) bigger than the stem. I usually don't torque the top nut down hard, never could understand what the point of it was. The point is to hold the top triple in place on the stem apparently. Tightened that up with a wrench and now no more sound at all.

Took some oil out, determined to figure out what is going on with the clutch and the stupidly hard pull. Everything inside the cover is set up correctly, but when I look at my clutch pack there are no gaps in it. It is totally full of clutch discs and steel. If I look at this video it is clear that there is a gap underneath the top (wider) clutch disc:

https://www.youtube.com/watch?v=rS97OkyZENU

Maybe I have an extra plate or disc in there and it is preloading the springs? Looking later tonight.

tshrey · « **Reply #628 on:** June 29, 2022, 06:14:09 PM »

So I do have a gap in there, it just wasn't obvious because for some reason my clutch plates want to stick together a lot. I picked up a set of OEM springs, what was in there was definitely stiffer so I swapped them out. Still seems like way too hard of a pull. A spring scale says 17# to pull it. That seems to be a common measurement for people who say this is too hard, with 10# being more normal. But I'm really out of ideas at this point.

tshrey · « **Reply #629 on:** June 29, 2022, 07:18:24 PM »

Looking on another thread someone showed a 74-75 basket and all the fiber disc fingers are the same width. The 78's had a basket where the top (away from the engine) fiber disc had wider fingers on it and the basket had room for that. My basket is definitely the latter. Would that make some kind of a difference? Also, this is the way the mechanism is supposed to look on the cover, correct?

EDIT: little more research, it looks like the 550F baskets were what had the wider top slot for the last fiber disc. So apparently that is what is in my 550k engine.

tshrey · « **Reply #630 on:** June 30, 2022, 02:54:55 PM »

Pulled the alternator rotor off, made a little block off plate for the oil plug and then cleaned everything up to verify the oil is coming out of the crank seal. Sure enough it is.

But while the engine was running I was looking at the spinning crankshaft. Doesn't this seem like way too much vertical motion at the crank?

https://photos.app.goo.gl/LoUYp3yM1kiyhAcU9

Godffery · « **Reply #631 on:** June 30, 2022, 07:16:17 PM »

Quote from: tshrey on June 30, 2022, 02:54:55 PM

Pulled the alternator rotor off, made a little block off plate for the oil plug and then cleaned everything up to verify the oil is coming out of the crank seal. Sure enough it is.

But while the engine was running I was looking at the spinning crankshaft. Doesn't this seem like way too much vertical motion at the crank?

https://photos.app.goo.gl/LoUYp3yM1kiyhAcU9

Yeah, that seems a bit much.?! So that would point to worn main barrings or a bent crank!

tshrey · « **Reply #632 on:** June 30, 2022, 07:28:03 PM »

That would be on par for this build. I checked the bearings when I rebuilt the motor and they plastgauged to spec. But I also checked the runout on the very end of the crank when I did the upgrade to the modern rotor and that was crazy perfect. So either the crank is bent in such a way that the tip is perfect or my bearing measurements sucked.

After throwing wrenches around the garage earlier I just said ok and tore into it. Engine will come out of the frame in the morning...

Godffery · « **Reply #633 on:** July 01, 2022, 05:59:53 AM »

I wonder if the update to the modern rotor threw off the balance? I'm not sure if these cranks were originally balanced with the rotor in place, or separately?

tshrey · « **Reply #634 on:** July 01, 2022, 06:14:47 AM »

The fact that the rotor/crankshaft isn't keyed I think would prevent that from being the case. Unless you need that stupid hunk of metal hanging there as a damper of some sort.

Eh, at this point what the hell do I know?

tshrey · « **Reply #635 on:** July 01, 2022, 08:07:09 AM »

Getting ready to pull motor, figured I would make it as light as possible so I pulled the sleeves off. This seems... terrible.

I will obviously recheck (and it seems like replace) the bearings, but would just bad bearings do that or did my machinist makes the bores too big when I went with the larger pistons? Are those pistons ok to still use?

The sleeves still have the hone in them, even where the pistons were scuffing.

On the upside I'm pretty much positive that was the buzzing I was hearing that I thought originated from the valvetrain. So that mystery is at least solved.

tshrey · « **Reply #636 on:** July 01, 2022, 10:48:56 AM »

Engine is out and I'm disassembling it. First thing I notice is that every bolt holding the cases together, little guys and the big ones around the crank, backed off stupidly easy. Like single digit foot pounds easy. No wonder I had slight weeping between the case halves in some places; one of them was finger tight. I torqued every bolt to spec when I built this, but I'm wondering if using the snazzy stainless bolts screwed me up because you have to use a non-galling compound when you put them into aluminum.

@calj737 when you build motors like this do you raise the torque setting by a percentage to make up for the extra lubrication of the compound?

tshrey · « **Reply #637 on:** July 01, 2022, 03:04:36 PM »

I don't get what that means - torque is torque. If it has a setting for 'galling compound applied' then it is adding some percentage to its setting before it stops at the given torque. I just checked every thread in the case, they are all good. I think I need to add a little extra and then after a heat cycle go back and retorque all of them. Have to look up what that 'extra' is though.

I don't have a tool for measuring the inner bore of the case bearing mounts, so I ordered that. Can't select bearings until I get that measurement. The crankshaft runout is less than .0001 when I put it on v blocks and the surfaces that run in the bearings are smooth and measure to spec so at least my crankshaft is good.

EDIT: I just saw in a youtube video that the letters stamped on the back of the lower case are the bore sizes, so that lets me order the bearings now without having to measure.

grcamna2 · « **Reply #638 on:** July 01, 2022, 03:33:29 PM »

Quote from: tshrey on July 01, 2022, 03:04:36 PM

I don't get what that means - torque is torque. If it has a setting for 'galling compound applied' then it is adding some percentage to its setting before it stops at the given torque. I just checked every thread in the case, they are all good. I think I need to add a little extra and then after a heat cycle go back and retorque all of them. Have to look up what that 'extra' is though.

I don't have a tool for measuring the inner bore of the case bearing mounts, so I ordered that. Can't select bearings until I get that measurement. The crankshaft runout is less than .0001 when I put it on v blocks and the surfaces that run in the bearings are smooth and measure to spec so at least my crankshaft is good.

I personally use anti-seize compound or a 'thread lubricant'? very sparingly,mainly because it's easy to overtorque a fastener with that lubricant on the threads.I Do use some,just enough to get the threads operating smoothly;after I've applied the small amount I'm pleased with to the threads,I thread the matching bolt/nut parts up and down until the coating is on the threads evenly.

tshrey · « **Reply #639 on:** July 01, 2022, 03:51:43 PM »

Agreed, it is used lightly. But this isn't anti-seize, it is anti-galling that you have to use when you put ARP stainless fasteners into aluminum. At this point the threads in the case halves are coated so I'm going to totally clean off all the bolts before I put them back in. I have to find my plastigage and check the bearings that are in there, maybe they are fine and it really was just the case halves not being tight enough.

RAFster122s · « **Reply #640 on:** July 01, 2022, 04:08:32 PM »

Adding "extra" as you put it risks the threads stripping in the cases. Better to have your torque wrench calibration tested than to start second guessing the anti-galling compound. If anything the anti -galling allows the torque to go a tad higher than it would have been with dry bolts.
You are going down a very dangerous path not knowing materials engineering taught in engineering school...you may end up with an expensive mistake.

tshrey · « **Reply #641 on:** July 01, 2022, 04:18:03 PM »

Yeah, sorry, I was saying it backwards. I just want to find a document that recommends a % change when adding a compound like that.

Started to plastigauge the bearings, but they really look like hell, I'd like to just replace them. Anyone have a source for C & D (green and yellow) main bearing shells?

EDIT: I found the greens at cmsnl. Apparently the yellows are just not available anywhere. Fantastic. I guess I will plastigauge what is there.

Godffery · « **Reply #642 on:** July 01, 2022, 05:20:06 PM »

The Stainless Steel bolts themselves might be a possible cause for loosing torque on those? Perhaps you could consult someone that specializes in metallurgy or at least grades of fasteners?

tshrey · « **Reply #643 on:** July 01, 2022, 05:30:52 PM »

That's why I asked Cal!

I know he has built up engines using ARP 12 points, he is where I got the idea.

Also, the crankshaft seals that were the original reason for falling down this ridiculous rabbit hole were sourced from 4into1. They do not have the lip on them that the OEM seals have, so you actually can remove and reinstall them with the motor assembled. I'm getting OEM style ones that have the lip when I reassemble this.

tshrey · « **Reply #644 on:** July 02, 2022, 08:13:44 AM »

I'll do the marker, that is a good idea. I didn't really think the fasteners were the issue, more that maybe that lube let them back out easier due to vibration. I used a torque wrench from work that gets calibrated every six months, so I have no reason to believe that they weren't torqued correctly when I first built the engine.

If the bearings plastigauge ok I can use them? They don't look great to me (probably because of the bouncing shown in the video) but I also can't find the yellow shells anywhere.

grcamna2 · « **Reply #645 on:** July 02, 2022, 08:26:13 AM »

Quote from: tshrey on July 02, 2022, 08:13:44 AM

I'll do the marker, that is a good idea. I didn't really think the fasteners were the issue, more that maybe that lube let them back out easier due to vibration. I used a torque wrench from work that gets calibrated every six months, so I have no reason to believe that they weren't torqued correctly when I first built the engine.

If the bearings plastigauge ok I can use them? They don't look great to me (probably because of the bouncing shown in the video) but I also can't find the yellow shells anywhere.

Pics of the bearings ?

tshrey · « **Reply #646 on:** July 02, 2022, 08:51:25 AM »

I'm at a cabin with spotty service. Hopefully this link works:

https://photos.app.goo.gl/1eH77eCJiWwwGaQb8

grcamna2 · « **Reply #647 on:** July 02, 2022, 12:34:54 PM »

Quote from: tshrey on July 02, 2022, 08:51:25 AM

I'm at a cabin with spotty service. Hopefully this link works:

https://photos.app.goo.gl/1eH77eCJiWwwGaQb8

The picture is clear;they look ok to me.

tshrey · « **Reply #648 on:** July 02, 2022, 01:02:45 PM »

Ok, that's good. Wasn't sure about the shiny/not shiny on the same bearing surface. Couldn't find my plastigauge, more is coming tomorrow so I'll see how they measure.

tshrey · « **Reply #649 on:** July 04, 2022, 08:00:36 AM »

Thanks for everyone's help so far. Plastigauge checks out, all the bearings are at the first measurement on the paper or a tiny bit less, so~.06mm.

Two things when I did this that I noticed. I borrowed a digital torque wrench from work that still had the calibration seal on it and set the bolts to the low end of the range. Bolts were cleaned and the threads were cleaned out pretty well, so just a small amount of the stainless compound in there. Once I got everything to torque and backed off the bolts I can verify that none of them were anywhere near that torque when I first disassembled the engine. Like half, at most.

Second, I had my manual in front of me to get the tightening order and noticed that the two bolts on the alternator side of the motor are supposed to have a '9' stamped in them and the manual says to make sure those bolts go in those holes. I'm using 10 identical bolts - are those two a little bit longer or something? That is the side that was wobbling in the video (and the seal that was leaking).

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Author Topic: 76 CB550 Cafe build (Read 92338 times)