DO THE TON

Blood Sweat Tears and Grease => Projects => Trackers => Topic started by: randy lahey on Jan 20, 2017, 04:03:53

Title: '74 cb360 build
Post by: randy lahey on Jan 20, 2017, 04:03:53
I bought this '74 cb360 in the summer thinking I could at least get it running before winter.  I got one almost complete bike, and a rolling chasis with a rubbermaid bin full of a disassembled engine and other parts.  Not realizing how little free time I have, i'm only now feeling like I'm actually making progress.  Unfortunately I didn't take any "before" pictures, I was too eager to rip into it which also led to me not documenting much of the disassembly which I'm feeling now.

Anyways, here's where I'm at now.  I chopped the rear and welded in the stock hoop, and de-tabbed the frame, made an underseat battery box, and fiberglass seat pan. I bought new parts from 4 into 1, with another pending order for parts I'm surely going to forget, and using bars, levers, and a speedo that I got off ebay for cheap.  Just got stuff back from powder coating and assembled what I could. That's the spare gas tank and front wheel, which I won't be using.  I still have to build the wheels.  I was gonna buy new mikesxs rims and paint the hubs, but decided to powder the stock rims (using 2 1.85 rear rims) and hubs instead.
Title: Re: '74 cb360 build
Post by: irk miller on Jan 20, 2017, 09:17:09
Sweet.  Following along.
Title: Re: '74 cb360 build
Post by: randy lahey on Feb 10, 2017, 17:46:02
Figured I'd write a bit of an update, although I haven't made much progress.......quite the opposite really.  I started painting the engine covers and components.  I sandblasted them and used dupli-colour engine enamel in flat black (or as they call it, "low gloss black").  The instructions called to cure it buy baking at 300 degrees, so I just threw the parts in the oven.  This turned out to be a pretty stupid idea, particularly throwing in the cylinder right side up.  As you can see in the picture below, the heat expanded the aluminum enough that the iron sleeve moved up about an eighth of an inch.  I figure I can just heat it up again and pop it back down....but this has also made me seriously consider boring my extra set of cylinders (which has a gouge in it) and throwing in some gs850 pistons. 

I also found out that when dupli-colour says their paint resists chemicals, they don't mean the grease and wax remover they sell.

The other setback I had was spending a bunch of time sandblasting the stock rims only to find a pinhole in one of them.  I was planning on using 2 back rims, but one was rustier than i thought.  So now i figure I'll just buy some mikesxs rims because they're cheap and I know they work, although I don't really care for the "H" profile they have and I'm too cheap to buy rims from other retailers.  Is there a generic rim size that works with these hubs or any other cheap options?
Title: Re: '74 cb360 build
Post by: irk miller on Feb 10, 2017, 18:28:52
Look on eBay for 36 spoke aluminum rims.  There are plenty on there.  The steel rims are heavy as hell anyway, so maybe it's a blessing in disguise.  I went with two 18" D.I.D. rims I got used for cheap.  I also say do the GS swap or go with the hi comp Wisco pistons that are 1 over.  It's not a huge investment and worth the extra punch. 
Title: Re: '74 cb360 build
Post by: randy lahey on Feb 10, 2017, 18:38:28
Yeah, I'm definitely leaning toward to the 378 conversion using gs850 pistons, according to my calculations, it'll cost me about $400 and my cheapness is the only thing stopping me  ;D.  Is there a specific year of gs850 pistons that work?
Title: Re: '74 cb360 build
Post by: irk miller on Feb 10, 2017, 18:52:11
I send my jugs to Ohio and $70 total will get them bored.  Crazy PJ is the biggest expert on this, but I used pistons from a '79.
Title: Re: '74 cb360 build
Post by: randy lahey on Feb 11, 2017, 10:54:22
I just bought some gs pistons off ebay, so I guess I'm officially going the cb378 route.  I should point out that I'm in Canada and everything is more expensive so mentioning your $70 bore job compared to my quoted $200 makes me a little envious  ;D. 

So.....anybody interested in 2 gs850 pistons? lol
Title: Re: '74 cb360 build
Post by: redwillissuperman on Feb 11, 2017, 12:34:23
I'm glad to see that the steel sleeves come out so easy!  I have some 69.5mm forged Pistons to try that will probably need new sleeves.
Title: Re: '74 cb360 build
Post by: nismoman8899 on Feb 11, 2017, 17:46:12
I might bw interested  in 2. How much
Title: Re: '74 cb360 build
Post by: randy lahey on Feb 11, 2017, 18:34:00
Well that was quick lol.  I haven't received them yet, but I am in Canada so I'm not sure what the shipping would be like.
Title: Re: '74 cb360 build
Post by: nismoman8899 on Feb 11, 2017, 19:02:36
Email set for every hour to check for new mail haha.  I was debating on purchasing the  4 i posted but didnt let others go for it. Let me know if you do decide to sell 2. Im in illinois
Title: Re: '74 cb360 build
Post by: redwillissuperman on Feb 11, 2017, 22:03:48
Email set for every hour to check for new mail haha.  I was debating on purchasing the  4 i posted but didnt let others go for it. Let me know if you do decide to sell 2. Im in illinois

I'm making sleeves for the 69.5mm.  That makes displacement 385cc. I have a backup plan if that's not enough speed-

(https://uploads.tapatalk-cdn.com/20170212/6f4b0ea66550aa12bcad32a9f253e047.jpg)
Title: Re: '74 cb360 build
Post by: nismoman8899 on Feb 11, 2017, 23:44:49
Nice!
Title: Re: '74 cb360 build
Post by: randy lahey on Mar 19, 2017, 11:46:21
It's been a little while since my last post and I'm bored at work so I figured I'd give a little update.  I've pretty much got the wheels built.  I had the hubs powder coated, used new spokes from 4 into 1, and rims from mikesxs.  I've built bmx wheels in the past and didn't find it too challenging, but never motorcycle wheels. This was a little more complicated due to the mikesxs rims being a little rough around the seam, and also my lack of a proper truing stand.  I didn't want to buy a stand figuring I could just make one, but instead I improvised.  I also got a pair of second hand shinko 244 tires that were never used for $30 a piece!

I've also got the bottom end of the engine together.  I sandblasted all the covers and painted them with flat black engine enamel.  I got a set of stainless hex head bolts which is kinda essential considering how fucked up the stock phillips bolts get.  I'm not using the electric start So I removed everything involved with that.  For the starter hole I've heard that a freeze plug works to block that but I haven't got one yet.

I am going the 378cc route and I've got the pistons and cylinders back from the machine shop, got the gs850 rings, and a head gasket ordered from coppergaskets.us.  I did have to order new cam chain tensioners because out of the two engines I have, the slipper on one is broken and the other one is missing.....apparently a common problem with these things.

I have some free time coming up and a lot of the parts and stuff I need, so hopefully next update won't be too far away.  Spring is also fast approaching so i kinda gotta get a move on.  Next update should have wheels mounted, and all or at least part of the top end done.

Title: Re: '74 cb360 build
Post by: HURCO550 on Mar 19, 2017, 23:29:05
Looking great man! I'm a sucker for shouldered aluminium hoops too. Nice work
Title: Re: '74 cb360 build
Post by: randy lahey on Apr 14, 2017, 08:25:13
Well I've gotten quite a bit done since my last post.  I've been meaning to update my progress a little more, but I'd rather be working on my bike than writing about the work I've done on my bike  ;D.  Anyways, I've got the engine finished, and the wheels built and mounted.

So as I mentioned earlier, I had the cylinders bored and fitted with gs850 pistons.  The bottom end internals checked out so I just cleaned and reassembled with new seals and gaskets.  It only had about 11,000 miles (or kilometers?) on it, so it wasn't in too bad of shape.  As for the top end, with the conversion i had get a copper gasket from coppergaskets.us at .4 thickness, which is a little thinner than stock.  I cleaned up the cylinder head (although it did have some damage in one cylinder that apparently I didn't take a picture of, I don't think it will have any effect.), half-ass polished the exhaust ports, and lapped the valves.  Unfortunately once I got the head torqued down, i realized the spark plug threads were pretty chewed up on one cylinder, but I just so happened to have a spark plug thread repair kit to fix that.  I degree'd the cam and it was about 3 degrees advanced, which should give it a little more low end power at the sacrifice of losing some off the top end, but given the high RPM oiling problems of these engines, I figured that's a good thing. 

The wheels are mounted with shinko 244 tires, 3.00x18 on the front and 3.5x18 on the rear.  My choice of these tires was based on getting a used set that had never been used for $30 a piece, but also because that's pretty much the look I'm going for. 

Sorry for the shitty pictures, my "workshop" is in my dank old farmhouse basement and the lighting sucks.