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Discussion Starter #41
Big giant delays due to school and money and illness. Making my way back to it. Engine parts have been vapor blasted and pistons coated, sending cylinders for bore and hone soon, them time to buy and assemble new valvetrain. Hoping to get VB pics up within a week. Sorry :)
 

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Discussion Starter #42 (Edited)
Okay, finally an update, but it'll be short. In the middle of seven weeks of final exams, and recently got over nearly eight weeks of a severe respiratory infection that I seem to have picked up in my travels. But, I DID promise a slow, living-room build, so that's what ya get!

Here are some photos of some of the cleaned, vapor blasted parts. Dmitri did an excellent job, gave me a great price, and I had the parts back within a week. no shipping costs because he's only about an hour away from me. He's also super friendly, and has a truly enormous collection of vintage bikes stashed away. all types, all years, all makes. It was mind boggling.

Just got done de-greasing, blowing out, and re-assembling the carbs. Working on prepping the head for some upgrades, and took measurements to port out the carb isolators for a smoother flow. Hope to have those done by later tonight. The Workspace:
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Reassembled Carbs:
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Close-up of the VB finish. SOOOOOO Nice. I hope the pictures do it justice. It looks like a really well-done silver metal flake paint job.
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Cylinder head top and bottom. It'll be going out to have the valve seats re-faced (or replaced with hardened inserts if necessary) some of the pitting is pretty deep. Also going to do bronze valve guides, before having everything lapped in.
KIMG0821.jpg KIMG0822.jpg

Finally, A close-up of the appearance of the brass on a carb after vapor blasting. I love how great this particular combination of material and finishing looks. Too bad it'll be hidden inside an overflow tube :-( Again, like a really incredible metal-flake with an appearance of more depth than is really there.
KIMG0828.jpg

More to come soon hopefully!
-TomSL
 

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Discussion Starter #43 (Edited)
Well, more progress this evening!

I bought a random pile of used parts from a scrapper on that one auction website a few days ago, and they arrived today. About $20 including shipping. The packing job was not pretty (thrown in an envelope with absolutely no padding) and the parts looked like junk, but I was hopelessly optimistic, and wanted to avoid spending $200 on new valves.

Here's a shot of the work bench - AKA Kitchen Counter - this evening
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The Situation: This is a new (to me) head from captb that went off and got VB'd at Primo Metal Finishing in RI. I took apart my old head, but was unable to remove the intake valves due to general ham-fistedness. Springs and retainers came out and were measured as shown:
Valve Springs.JPG

So, I could probably get away with the springs I had, but replacing them isn't a bad idea either. So I replaced:
Inner spring for R intake with one in the ebay bag that was 39.2mm
Outer spring for L exhaust with one in the ebay bag that was 48.4mm
Outer spring for R exhaust with one in the ebay bag that was 48.5mm
The rest were worse than I already had on hand, so that was the best I could do.

Retainers and keepers (the little half-circle clip thingies) looked good, so no replacement necessary.

The exhaust valves from the old head looked okay, just a bunch of carbon build-up. The intake valves from the ebay bag were supremely rusty. I was a little nervous, but here's what I did. First, the bag came with an exhaust valve that I DEFINITELY would not be using. It was in deplorable shape. So I chucked it up in the ol' drill, and went at it with steel wool after letting it sit in mineral spirits for about 20 minutes. No change. So I went for it; with 400 grit wet-dry soaked in mineral spirits and it worked magically. That passed my test, so next was the rusty intake valves. Soaked in a mineral spirits bath for about a half hour at this point, I chucked up the really really bad one, and just spun it like there was no tomorrow. After some significant heat buildup, and wrapping up my thick rubber gloves in the drill and twisting my wrist, most of the rust was gone. A new piece of 400 grit, then some OOO steel wool, then a paper towel with 5w fork oil on it yielded this result:
KIMG0833.jpg KIMG0834.jpg

So, I did the other intake valve, and then decided to touch up my exhaust valves too, from the old head. At the end of it all, I used the OOO steel wool and some 5w fork oil to lightly polish the valve stems. Don't worry, my digital micrometer (fingers) says the shaft diameter is still well within spec :)
Here's what they all looked like. I also used cutips to clean out and the lubricate the valve guides, since they'd been sitting in a corner for a while after being vapor blasted. Checked everything out, and all the valves now like all the valve guides, so hopefully I can get it all back together soon.
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By the end, the head had a bunch of oily fingerprints on it, so I wiped it up with mineral spirits, and it looked like new.
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When all was said and done, I got the new springs and valves I needed, plus all of the below spare parts for a rainy day. Even included another clutch gear for me!! that alone was worth double the price I paid for the whole lot. All in all, a pretty good night of wrenching. Gotta take what you can get!
KIMG0837.jpg

I was originally planning to send the head off for hundreds in rebuild costs, but I think I'll first go buy a lapping stick and some compound, and see what I can do in the kitchen.

-TomSL

Edit: Forgot to mention I've also done some more grinding with the Dremel. Starting to clear out the passageway for the new KA Slipper to move through. It's a slow process, and not overly pretty, but It'll get the job done I hope, and won't cost me anything. Also took the liberty to remove some gouges in the same area created by the engine running with a very loose timing chain. Looks much better. Pictures when I get it all done.
 

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Discussion Starter #44
More work and more little purchases completed.

Got all the filing done on the cylinders and head for the KA Slipper tensioner. I didn't like the dremel results, so I used a long hand file and a bunch of patience. It moves very freely from back to front and looks relatively clean - for hand work.
KIMG0840.jpg KIMG0843.jpg KIMG0844.jpg

Also decided I want the ability to vacuum-tune the carbs. I filed the surfaces flat on the lower internal sides of the intake ports, center-punched and drilled with a 3mm TiNitride bit. By hand, the holes ended up being within a couple degrees of perpendicular to the surface but not perfect. If necessary, after I drill and tap for 5mmx0.8 I'll use a flat counterbore to sink the fitting and ensure a good seal. Why internal surfaces? Because most of the time I'll be running the cylinders linked together, and I wanted the engine to look as clean as possible. It'll be a little difficult to get in there with tuning hoses once the carbs are on ,but I'll cross that bridge when I get to it.
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Lastly for now, this is the first time in nearly a year that all these parts have fit together with the new tensioner in place. Getting closer!
KIMG0842.jpg
 

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That really great looking motor. Nice job on it. I wish there was a vapor blasting place near me to have some parts done.
 

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Discussion Starter #46
Thanks Curtis. It's been a slow road, but it should turn out alright.

The vapor blasting is really like magic. I highly recommend Dmitri. He's such a nice guy, and loves to talk bikes. If anyone wants his contact info, just PM me, or look him up on Facebook.

If anyone wants to have it done but aren't local, you're welcome to ship parts to me and I can drive them down. I don't know if it would save you any shipping costs (maybe b/c boston is a major hub?) but willing to help out if it does.

As a side note, my Magnesium side cover was VB'd at the same time as everything else and has not yet been painted. No oxidation discoloration at all as of now. Dunno how long that'll last, but looks pretty good right now.
 

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Discussion Starter #47 (Edited)
Welp. Bought some drill bits and taps online. I ended up buying bits and taps on ebay, because Ace and Home Depot didn't have anything available and the employees were HUGELY unhelpful. Drilled the 3 mm hole out to 5 mm. Even though the bits were marked, and I measured them several times with a caliper, the hole ended up being 5.2mm in diameter. CURSES! maybe it wasn't perfectly straight? Tried the 5 mm tap anyways. it grabs slightly, but doesn't cut anything. Tried starting the 6mm tap, and the cutting edges of the tap were stripped off by the aluminum of the head. This was when I turned them by hand, with no handle attached. just finger pressure on the square shank. JUNK!!!

No I go on an adventure to fix this little snafu. I'll also probably have to bump up to 6mm vacuum ports now, which I was hoping to avoid. oh well!! Hopefully updates soon. I also have HondaBond HT and some replacement case dowels on order, so I'm hoping to get the bottom end back together over the next couple weeks. Those should be the last necessary replacement parts.

Question: I have photos of the disassembly process for shift fork orientation, but I didn't mark which shift fork went in which position. Any advice on how to properly get the forks back in? Also, I only encounterd one of the little half-circle bearing retainers from the lower case, but there's two different locations that have grooves. CMSNL only shows one in the diagram. How many should there be, and where is the appropriate location?

Thanks!!
-TomSL

Edit: I lied. CMSNL shows two set rings. Darn. Gotta find a second one.
 

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I just installed my shift forks minutes ago! There are two identical larger forks and one smaller on on a 350. The small one goes in the middle. Orientation of forks, referring to pins, is: pins tot he outside on the large forks, and pin towards the chain on the small fork.
 

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Discussion Starter #49 (Edited)
Thanks!! exactly what I needed.

More big exams coming up. Huge one end of July, so having the engine back together by the end of August and sealed up for temporary storage (until the frame is done) seems like a reasonable goal. Got Hondabond HT and some replacement case dowels in the mail recently, so lower end should be pretty much ready. lots of degreasing and assembly lube in my future!

Edit: Here's all the photos I have related to the shift forks. This is as they were when I took them apart. Believe it to be correct, as transmission seemed to function correctly before tear-down. Just in case people in the future search for CB350 CL350 SL350 shift fork orientation. Sorry for the quality on some of them, but if you look closely, you can see what's going on.

KIMG0509.jpg KIMG0513.jpg KIMG0514.jpg KIMG0515.jpg KIMG0516.jpg KIMG0517.jpg
 

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Discussion Starter #50
Reviving my own old thread! I've been exceptionally busy trying to become a doctor when I grow up. Also managed to have a child, so, you know, there's that.

I went through all my goodies today and got organized, figured out what I had, and what I needed, and also managed to get the transmission and crank pretty much assembled and into the upper case half. Today I ordered:
1) a shift pin to replace the one I seem to have lost that goes in the countershaft, on the kickstart side.
2) a new main bearing locator dowel, which I think may be in the bottom of my vapor-blaster's debris filter.
3) the correct output shaft seal. The one I have must be for a CB, cause it's itty bitty.

Case halves were soaked in heavy duty degreaser for 20-30 minutes multiple times. Disassembled main shaft and counter shaft. Clearances all look good. Put on a bunch of engine assembly lube. Re-assembled the shift drum, shift forks, and keeper clips. I installed a new kickstart gear on the main shaft, as the one I had was missing a tooth, and had some bronze particulate matter on it. A while back, I bought a gear from someone that came with a custom milled bronze washer to do away with the wobble that I guess is inherent in these. Man does it feel nice now. Rock solid, JUST the right amount of slack was taken up with the extra washer.

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I put the little rubber sealing ball in the lower case half and installed some brandy-new case dowels, then set everything together as I finished up for the night. I'll wait to post a picture until I get all the seals in and the case halves properly mated and sealed.

Lastly, I couldn't stand the look of the original hardware. The cases look so purty, and the hardware is old and greasy and dirty and discolored. I tried to clean them up, but I ended up deciding to just order a big kit from AlloyBoltz. They have a really nice looking kit that is all stainless hex-head screws, so I'm pretty excited to get those.

Most importantly, I found someone local who is confident he can give me what I need as far as bore, hone, milling clearance for the slipper tensioner, and doing cylinder head work. All at a very reasonable price.
 

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Discussion Starter #51 (Edited)
Found more goodies!!

Holy Moley!! Today was a good day....

Win #1: Got the transmission lined up now that the second shift pin got here, and the bronze spacer for my kick start gear was a bit too thick. Took off about 0.0035" and it is spot on. Literally couldn't be more perfect. It won't quite free-wheel by itself, but there is zero wobble.

Win #2: Got the cases sealed up with Hondabond tonight. managed to get lucky and use *just* the right amount. The squeeze-out is uniform all the way around, with no missed spots. Hopefully the inside looks as good. Plus, the stainless bolts from AlloyBoltz look awesome on the freshly vapor-blasted cases.

Win #3: I went through with my brother and checked specs on everything as we went along. Everything looked great, except the oil pump. The bore was waaaaay too big. I kept trying to think of what might have caused it, because it didn't look very worn, but it was obviously out of spec. it was about 0.754"......that's pretty close to 19.3mm....... Holy Cow! Do I have a Cappellini high-flow oil pump!?!? Pump bore is 0.7534" and piston is 0.7496" That's approximately as tight as a new oil pump, but bumped up by 3mm :)

Got the cases buttoned up, as well as the right side cover and all associated parts beneath it. Just need to find a correct SL350K2 oil slinger cover. The one I have is for a CB350, so doesn't line up correctly on my Mg side cover. Next time I'll work on the charging side of the engine, get the rest of the covers on, and snap some photos.
 

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Discussion Starter #52 (Edited)
More Pictures!!!

Did some work on smoothing the timing chain galley between the cylinders, as the slipper gets snagged a bit on the casting imperfections inside.
IMG_20180408_195814.jpg
Decent amount of metal had to be removed

Also, found my flat-plate timing chain that I bought about 2 years ago. So I cut off the old timing chain (cases are already sealed) with a dremel.
IMG_20180408_104717.jpg

AAANNNND...then I found out that the new cam chain (labeled on the box as 94 links) actually only has 84 links :-(
Time to hunt for another one.
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Moving up on the engine, I started some work on the head. First, I noticed one exhaust port was cast with a pretty big step right at the exit. Used a dremel with a large round carbide, followed by sanding drums, followed by polishing buffs. Removed some casting imperfections and smoothed things a bit, and then polished just at the exit of both exhaust ports.
IMG_20180408_112418.jpg IMG_20180408_112713.jpg IMG_20180408_121744.jpg

I decided to polish up the combustion chambers. Please note, I have no idea what I'm doing, so this isn't necessarily to improve performance, but I can do it now, so I might as well. I didn't remove any of the deep machining marks in the chambers, because I don't want to have to CC everything and deck the head and such. Just buffed up to 320 grit, and then polished with some mothers. If nothing else, it makes for decent pictures.
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Lastly, I checked all my valves, springs, and retainers. Lapped in the valves.
IMG_20180408_123432.jpg

Cylinders are out for bore and hone. Head is out for machining of timing chain galley, test, inspection, and reassembly.
 

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Discussion Starter #53
CaptB,
I do still have your CB head, with the ports drilled and tapped on the intake side, and I think it's all ready to go. However, I elected to go with my original SL head (both were vapor blasted when I took everything down there) for now just because I now have two full sets of carbs for this bike.

In the future, I think I'll have a head built-up from your CB core using new valve seats, bronze guides, Ti retainers, SS valves, etc. and get some VM30's for it. Unfortunately, I won't have the spare change for that set-up for quite a while.

Next step after the cylinders and head are installed is to send the Cam and lifters up to a place I found who can hard-weld and regrind. They also have the equipment to parkerize the cam. From the reading I've been doing online, it sounds like this is a good idea on flat tappet cams. Any HT members have experience with this coating on their cams?
 
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