Topic: 1982 CB650SC, Project: "Black and Blue"

[tourmax]

piston pics!



Top to bottom- CB750 DOHC, CB900 DOHC, CB1100 DOHC

750 is 62 mm, 900 is 64.5 mm and the 1100 is 70 mm.

DOHC 750 and 900 pistons aligned at the pin:



The 900 piston has slightly longer skirts, but only the skirt itself by a few MM. The piston crown is obvious.

The 1100 pistons are 70mm, but not usable in the CB650 SOHC block as liners big enough to swallow them woudl be bigger than the "meat" available in the CB650 block. Or at least they would break through in several spots, which is a compromise I'm not willing to deal with. The block will take the DOHC/SOHC 750 liners, but the DOHC 900 liners are just too big. I'm pretty sure the SOHC/DOHC 750 liners MIGHT take the 70mm slugs, but the wall thickness woudl end up too thin to be stable.   

The 1100 pistons also have the larger 17mm pin as opposed to the 15mm pin on the SOHC and smaller DOHC bikes.

Once I get the slugs out of the 627 (IE: oem size) I'll do some comparison pics with them as well.

[tourmax]

got a line on cbx1000 64.5mm pistons. lets hope no one else bids on them so I can see if it's an option for the CB650 overbore with 750liners in a 650 block.....

[tourmax]

well, a set of 64.5mm cbx1000 pistons are on their way and a set of 2004 GSXR1000 rods as well.

The 2004 rods are actually 16mm pins, but they have a removable bushing so they can be re-bushed to 15mm for the Honda piston pins.

I just wish they weren't all TTY rod bolts, but that's the way things go these days. OEM's just loooove TTY bolts.....helps them to ensure that the bolts won't loosen during the warranty period and trash an engine, but completely non-reusable once they've been loosened off. I'll use the orginal rod bolts for setup purposes and drop in some new ones once everything is "hunky dorey"....

Pistons:



rods:





Should be fun. Hopefully, it'll be one heck of an engine once done. Reworked intake ports for downdraft carbs, reworked combustion chambers, 64.5mm pistons (729 CC), GSXR1000 rods, programable digital ignition, Coil On Plugs (sequential firing), and on and on. It remains to be seen if I can pull it all together though...lol!

[tourmax]

Well, just threw in a super low bid on a set of gsxr600 srad pistons. They're 65.5 mm and a 15mm wrist pin. 65.5mm i sthe limit of the CB750 liners (used for hte 850cc kit on the 750) and woudl kick the 650 out to a total 752cc's.

I'm skeptical that they will work in the 650 engine, but nothing ventured nothing gained. If they do work, I could be looking at low friction pistons and very light pieces compared to the Honda piston options.

meh, probably won't accept the bid anyways....I wouldn't.\

[tourmax]

Well, got the liners out of the spare 650 block and the scrap 750 block:



The 650 sleeves pretty much just dropped out at 250f. They needed a little tap with a brass drift to get them all the way out, but just a tap.

The 750 sleeves were a different story. Several heating attempts barely moved them. Tried soaking them in penetrating oil and all kinds of other tricks. I ended up having to turn the oven up to 375 (stay away from 400+ or you might end up annealing the block) and leaving it in there for 30 mins. Then, it still required the brass drift and a hammer. But, they eventually dropped out of the block.

The rust you see on them is just a light surface coat and mostly wipes off with a wet finger. Boring them out to 64.5 mm will clean all that right up, as well as the need to shorten them to 650 length will clean up the nastiness on the bottom taper.

Next up is to repair a couple fins, give it all a good degreasing, blow the paint off it and drop it off at the local shop I use to bore out the block and drop the sleeves in.

Then its a matter of sorting out which piston set will work and have the sleeves finish bored to the pistons. That will be oodles of fun. I’ll probably be making liberal use of the ultrasonic thickness meter to figure out where I can (and can’t) machine the pistons.

[tourmax]

well, gsxr pistons didn't wok out. Seller was just ignoring the offer so i decided to cancel it rather than just let it time out.

then, turned around and made an offer on a 600RR exhaust. It's cheap and will provide me lots of straights, bends and joiners to make a custom exhaust. I believe that year is stainless, but we'll see when/if it gets here. Probably end up being a prototype for a better one down the road somewhere. It's way cheaper to buy the take off exhaust than it is to buy stainless straights and bends, which is mainly why I'm trying to grab a cheap CBR set.

Edit: cbr600rr exhaust is on the way. 26 bucks:







Great starting point for a custom header build. Its stainless, but likely 409 stainless, which can be a pain to weld and retain it’s strength and rust resistance. 409 will rust as it is, welding it only makes that worse if you get carbon (ie: soot, co2, iron, wire brushing, steel wool, etc) in the weld area. Gonna be hard with it being a used (ie: sooty) exhaust, but I’ll manage…

[RAFster122s]

Need to develop a flexible hose with sand blaster spraying in a conical pattern... Then just fire it up and feed it down the inside of the header tubes. Starting with a fine grit until you get it stripping the spot and any rust inside the header...
Then do your welding and cleaning before doing Eastwood's internal header exhaust paint coating to extend the life of the tubes as insurance...

[tourmax]

well, going the "full monty" on the CBR exhaust:



Under seat muffler and mid pipe. It means I'll have to ditch the rd500 tail light and go to a thinner LED solution, but it should look pretty cool when done.

I'd worry about rear brake/running light visibility with a smaller tail light, but the red LED turn signals I have to put on does red for tail lights, bright red for brake lights and flashing/sequential yellow for turn. So basically, the rear running and brake led "strip" will go from the outer end of one turn signal to the other.

[tourmax]

Need to develop a flexible hose with sand blaster spraying in a conical pattern... Then just fire it up and feed it down the inside of the header tubes. Starting with a fine grit until you get it stripping the spot and any rust inside the header...
Then do your welding and cleaning before doing Eastwood's internal header exhaust paint coating to extend the life of the tubes as insurance...

I'm more thinking something like a bottle brush type of deal and varsol.

Scrub, rinse, repeat.

Sandblasting won't work as these pipes have a couple cat converters in them. I'm undecided on keeping them or cutting them out. Personally, I'd like to keep them for the environmental benefits if nothing else.....

[tourmax]

I've been struggling with the choice for gauges. The CB650SC gauges were shot, so I ordered new faces. Now, I'm struggling with the speedo actuation and the tach. I had started converting the cable tach to electronic and I was planning to drive the speedo off the output sprocket.

Then I started thinking a GPS speedo might be a nice solution. But I can't find a matching speedo and tach (appearance wise) and I can't find gps speedo with the same sweep as the SB900 gauge face.

Then, I dug out an older electronic gauge set. Speed sensor is independent of the wheel size (programmable), tach is electronic and as a side bonus it has a fuel gauge, trip, odo, clock, gear indicator and the standard suite of warning lights.

I'd prefer the look of two separate gauges, but this kind of sealed the deal:





300 grams vs 1.469 kg.

Decision made.

 

It's all going behind a small air deflector, so the gauge is mostly going to be hidden anyways.

Here's a stock pic of the gauge lit up:

[tourmax]

So, I'm waffling back and forth again on what to do first.

I'm thinking I might put the frame build on the back burner for the immediate future and concentrate on the engine and supporting systems. I'm planning to use the original frame to pick up the critical dimensions on a frame jig. As long as whatever I build for the Honda OEM flexi-frame is dimensionally true to it, it should simply unbolt from the OEM Honda frame and bolt right in to the new frame.

That will allow me to at least keep the bike as a roller so it's not taking up space the lift for months or years.I've got other projects that I need to get on the lift so having it locked up with this bike isn't really a manageable situation.

The frame build alone can take months to complete and while I technically don't need the lift for that, having the remains of the bike parked on the lift for that long isn't a great option.

[tourmax]

Well, it seems the frame build is back on.

The cbr swingarm is in:





But its so wide, I had to use a portapower to spread the swingarm pivot points out this much:



Thats a good 3 inches extra width.

I had hoped it would go in with just a little tweak, but thats waaaay too much. The swingarm pivots are no longer parallel which just won’t do.

So, it seems the engine has to go on the back burner and the frame is priority again. I think I’ll follow the general concept of the Moto Martin frames…

[tourmax]

well, the last parts of the rd500 is about to be taken off the bike. I picked up a set of wrecked r1 forks:



Yup, pretty messed up! But it was also only 60 bucks. You'd pay more than that for just the triples. As to the messed up legs: one leg looks like it may be salvageable and another 70 bucks got me another pair of legs for the same model:



They are also a little tweaked, but it's very minimal. I should be able to make a good front end out of the parts coming from the two "broken" ones. They all need to be taken apart and gone through anyways, as I always do when repurposing used/damaged parts.

The bent tubes I can straighten at home (v-blocks, runout gauge and hydr press, done many before) as longs as they're just lightly "tweaked" and don't have wrinkles of kinks. The aluminum tubes are a little bit more difficult to straighten, but it can be done. The 2004 r6 wheel has the right bearings and rotors to slot right in.

Same with the triples. If they're "tweaked" a little careful pushing and prodding on the press usually gets them back to true, as long as they're not bent really badly that is.

Brake calipers I've already got covered with a set of Yamaha blue dot monoblocks out on the shelves somewhere. I'd rather have the gold dots from an r1, but that is something that can come later down the road.

So, if it works out right, a little over 250 Cdn gets me an R1 inverted fork setup.

What's nice is that since I need to turn out a new steering head for the frame build, I can simply make it match the dimensions of the R1 steering stem and bearings so the R1 front end will bolt right up like it's made for the bike.

Jeez man, this thing is getting right out of hand! It's going to basically be a modern sports bike except for the SOHC 650 (punched out to 729) lump hanging from it....lol!

[Alan F.]

Yup, sounds like a showbike that just might go (& stop) as well. With the right placement the finished product could be featured across to the other end of the internet and back again. There have been a few members with bikes that got heavy notoriety like that. But I don't think it's ever the goal, just build what makes you happiest and scratches that itch the best.

[tourmax]

Well, spooling up to build the frame. I need to build the jig, but thats the easy part.

I also need a bender, which I currently don’t have. I could go out and buy one, but good luck finding anything under a grand that isn’t a “pipe crumpler”. So I’ll build my own bender. Steel and hydraulic bits I already have on hand.

But I don’t have the right tooling to machine out the dies that I need.

So, time to build a radius turning tool. The beginning:



Shoukd take me the better part of a week to get it built. Then it will be on to building the bending dies and the rest of the bending machine.

Once the R1 triples get here, I’ll start machining the steering head. Plan is to machine the head to the triples, instead of the usual “make the triples fit the head”. Making it this way makes it a snap to source replacement bearings and seals.

[tourmax]

Yup, sounds like a showbike that just might go (& stop) as well. With the right placement the finished product could be featured across to the other end of the internet and back again. There have been a few members with bikes that got heavy notoriety like that. But I don't think it's ever the goal, just build what makes you happiest and scratches that itch the best.

Nah, not my thing. I’m building what I want to build. Truthfully, the pleasure is in the building, not accolades or even the finished project.

I guess its the old “the journey, not the destination” thing…

[Alan F.]

Well then thanks for taking us along, cool stuff.

[tourmax]

Changing up the headlight:



Kinda cool looking. the upper is the HI/Lo beam, the lower is a DRL.

It's not that I don't like the cbx750 headlights, it's more because I'm planning to put the Interceptor back together and I want the dual lights to give it the "endurance racer" look it used to have:



The interceptor was originally taken apart to power an Argo 8x8:



It was fun and scary fast, but I eventually went back to the Kohler magnum, mostly for the fuel mpg. The V45 would suck through a tank pretty fast while the old  Kohler will run a good 8 hrs on a tank. The speed was fun, but not really something you can use a lot in an 8 wheel skid steer (could be downright scary sometimes when you tried to turn too hard). The V45 also was waaaaay over the max input RPM for the skid steer transmission. It took the rpm, but I was always conscious of the fact I had it way outside it's design limits and not to shock load it whenever I was driving.

I think I must have known that I'd eventually put the V45 back together because even nut and bolt I took of fit is in bins out in the storage shed.....

[tourmax]

Well:



Thats what I was greeted with in all 4 exhaust ports. Aluminum corrosion that fills the port floor to roof.

Might be a good thing that I have another head….

[Kelly E]

I've taken apart quite a few bikes in the last few years but I've never seen that before. Even on the bikes that were stored outside.

[fizzlebottom]

wtf how does that even happen??

[tourmax]

wtf how does that even happen??

Left outside for 15 years. Probably mice or something crawled up inside there and nested, which wreaks havoc on anything metal, electrical or mechanical.

I was thinking I might try and fire the engine up to see what it did, but not anymore. This thing is coming apart for sure now....

[fizzlebottom]

Yeah man. Hot tank that thing for about a week. See what comes back out. It might just be held together with insect glue and mud

[tourmax]

Yeah man. Hot tank that thing for about a week. See what comes back out. It might just be held together with insect glue and mud

Prob strip it down and give it a couple goes in the ultrasonic cleaner. Then see what I've got to work with.....

[tourmax]

Postman brought me a few goodies today:





R1 forks. The one with the triple tree is really messed up, the other side fork lower is actually snapped off at the brake bracket. The side you can see has a good sized bend in it. But, I only paid 40 bucks for it and the triples are still straight and good. The separate legs also have a slight bend in the lower tubes, but well within the range to straighten them. Paid 40 bucks for this also.

I also have another set of legs on the way. Advertised as “bent”, but its so slight you couldn’t tell in the pictures so they should be even easier to straighten. Paid 50 bucks for those.

Toss in a set of seals for right around 25 bucks.

So I’m in to an r1 front end for about 155 bucks. Not bad considering a full set that is advertized as “not bent” goes in the $400 and up range, usually closer to 500-600 for a straight but cosmetically distressed set.

As a side note, these are 98-99 forks, about 20mm longer than the 2000+ forks. When offered up to the bike, they are the same length as the rd500 forks on it now. The only “problem” is they don’t stick up above the top triple so I can’t attach clip ons to them. No worries though, i just ordered a set of clip ons with a 1” riser. I had to order new ones anyways (rd clip ons are waaaay to small to fit on the 50mm r1 tubes) and the riser will put them at almost the same height as the rd500 bars.