Topic: My 1975 CB550K build...550/650 Hybrid motor project

[SOHC4 Cafe Racer Fan]

Love the wheels and that you went with 17". I'm thinking of either 17" or 18" on my next 750 depending on how well they work with the suspension set up.

[chris mcshifty]

Awesome should be one wild ride on that baby when its done

[purf_man]

I figured I would give them a chance.

Tires and fuel pump were ordered last night and should be here this week.

I still need to find some longer bolts for the rotor.

[purf_man]

[purf_man]

Well def will need a smaller plate to mount the pump with.  This GSXR pump is bigger than I thought it would be.  The pump itself is your typical in-tank Walbro style pump.  Good part being I can prob get a smaller rating pump and swap it if I need to.  I have the parts to keep the quick connect fitting but prob will cut off the tube and replace it with a -4 fitting.

With the sump portion I can fit it in the tank.  I will prob have to slide the sump between the throttles and the head but I think there will be room there.

My tires come in monday so on my day off weds I will get them mounted up.  I was trolling some pics online and I am thinking of the chain guard/mud fender off a CBR250.  Gonna grab my swingarm when I head to the dealer to get the tires mounted and take some measurements off one of their floor models....the plastic guard is only $25 new so it might work out (pending chain offset and length)

[purf_man]

I feel like this has totally stalled.

I took my frame into a shop to get the rear section redone to better fit the seat and some other mods.  The shop is ran by two guys.....a mechanic and a fabricator.  The fabricator has a day job and has been working lots of OT and doubles so my stuff has just been sitting....

They do have it jigged up and braced to cut.

They did get my LS truck coils mounted under the tank in the stockish location.

I have also been having troubles finding a shop to make my tapered adapter  for the VFR800 flywheel and coils....I am trying a new guy (he works at the plant and is in town so at least I can check up more often and kick the can some)  Tomorrow my 550 cases and crank go to him to start on the external oilfeed for it and the VFR stuff.  I am going to set up the 740 and the 550 motors both with the VFR type stuff so I can swap them around easier (still doing the carbed 550 leftovers motor for a mock-up motor to test out the suspension and all before it comes all back apart for paint)

My biggest issue right now is finding bearings for the motors and cam chain tensioners.  I think I might have to find someone to do my engine assembly for me also (I hate having to deal with leaks that pop up and ALWAYS seem to get them)

[purf_man]

[purf_man]

so this has been on the back burner for a bit.  I had a couple shops that took on work....then never worked.

So in the mean time I built a EFI 355 for my S10 to get it back on the road.  it is mostly together and in the process I think I found a new machinist so my 550 cases and 650 crank  are off with him for the VFR flywheel upgrade and external oil feeds.

hoping I can get this project moving some more this summer.

I did manage to pick up my frame from the shop that gave up on it.  has no shock mounts but at least the new tail is on.

I picked up some braze on banjo ends to make my external feeds from.

Tires are mounted up now too.

I am really crossing my fingers on the new machinist to get things moving (that has been the biggest hold-up)  if things get moving my front end is going in for the mods for the second caliper to be added so I can get this thing closer to mocking up.

[Tews19]

I had a friend help me take apart the cases. It was actually really easy. Everything is in good order so I dropped my cases off last wk to an engine shop to have the cases cleaned. I prepped the cases myself and even painted. How come you don't put it together yourself?  I think these engines are better off with those who will ride rather then those who are looking to make money and most likely have the same amount of experience as you do on them.

That being said this is coming from a guy who was afraid to take the tank off my first 550 a few Years ago.

[purf_man]

I am putting it together myself.

I am working out of state and pretty much in an apartment right now.  I have a small one car with my mig in it and a grinder and a set of wrenches.

the plasma and compressor and TIG are back at my shop in TN.

I was hoping to make some progress on this build as it would be easier to move around than my 1962 Fairlane on a rotisserie.

I had a shop do the frame work (was kinda over my level as it was)

and Had a guy do the sleeve/bore for the 750 bits....he didn't want to do anything else he later told me (rally only does bore jobs and sleeves)

Shop that did the frame said they had access to a mill/lathe and could do the minor work for the second caliper/rotor mods....they never came through with it though.

So if I had the tools here to do it I would (half the problem is that I am 50 miles from any sizable town)

I can put the motor together but I need the external feeds machined for (blew through a oil passage in the top case on the relief for the 750 sleeve)  once I get the feeds and flywheel mods finished and mill down the oil filter boss for the DOHC sandwich plate I think I will be good to put the lower half back together.  I still want to send the head out for porting but that has been on hold to get the oil feeds finished.

It seems like this has been shelved for a long time but it has only really been 8 months (between the holidays and the two month long refueling outage with 80 hours a week it doesn't seem that long ago)

My new machinist is only 35 minutes away and said to call in two weeks (from last Monday) if I don't hear from him first.  Crossing my fingers on this guy but have a couple known good machinists lined up that will produce but they are just not local at all (out of state back home that I only visit a couple times a year)

Right now I have the goal of getting the frame back as a roller by new years and to get the big bore motor together and maybe also the leftover motor (650 cases with 550 topend) that I might toss in just to make it a rider.

I am in the position right now of having a very good cash flow but no time/shop to use.  I have alot of irons in the fire back home also so was hoping I could finish or at least make good headway on one project while I was out here for the next year.  A bonus would be making this almost a rider so I can sell off my VTX and not have to move it back to TN (I already have to move a car and two trucks)

[Tews19]

Damn lots on your plate. Even with the build taking longer then expected I am sure you will enjoy the finish product. You stated rotor work.... Member Godffrey does excellent work. Check his work out..

[calj737]

You should check out Mike Rieck for head work. He's a member here and does excellent work.

[purf_man]

Well I got out some of my parts I picked up two weeks ago.

looks like the shop lost some small parts (front wheel spacer and dust caps for the swingarm)  luckily they are still available and reasonably priced.

now that I have my frame in my hands for the first time in a year I popped out the old bearing races and popped in the new tapered bearing races.  Then I spent some time with a dremel sanding powder coat off my stem.  I think I have it almost ready to press the lower bearing on but still have some PC in the top nut threads I need to clean up (need to pick up some paint stripper for it)

so I am close to getting the front end together.  I mocked it up last night and I am going to see if I can get a good measurement to have the one lower leg milled to for the caliper mount here at work.  If I can get that knocked out then I should be done with the front end for now (will be ready for polishing, refurb calipers, and assemble forks)

So I was looking at the stock speedo drive.  the drive plate with the two ears is too big to fit inside my rotors (was thinking of having the pockets machined like some have done)  now I am looking at mounting the chrome dust cover to the outside of the rotor and using a cut down drive plate (cut and weld my stock one to make it almost flat)  I need to mock it up a little tonight to see if it will even remotely work.

Is there a way to re-calibrate the speedo?  I am running a 17" front wheel now so I know it will be reading even higher now.  if the gears can't be swapped would something like a smaller CB twin speedo drive be something to look at?  maybe a drive off a "newer" 80's model sport bike?

[calj737]

Not possible to modify the mechanical speedos for calibration. Another type might work, but you'll have to find one that fits the axle diameter. Many people switch to electronic or GPS speedos with these type of front end swaps for this very reason.

Of course, if you do this, then you need another custom made axle spacer to replace the speedo width. Welcome to custom building 

[purf_man]

I was thinking of going with a GPS unit but figured I would give a try at the stock speedo if I could get it halfway close with minimal effort.

I guess I am having a spacer made up (I will just leave the drive in place for now I think)

[SOHC4 Cafe Racer Fan]

I was thinking of going with a GPS unit but figured I would give a try at the stock speedo if I could get it halfway close with minimal effort.

I guess I am having a spacer made up (I will just leave the drive in place for now I think)

I've heard of people using 400f speedo drives if they run an 18" front wheel, but there are no turn-key speedo drives for a 17" wheel.  You will need to run a magnet sensor speedo (adjusting for tire size) or gps.

[purf_man]

Tacked on the shock mounts the shop gave me.....then it started to rain so I brought everything inside and mocked it up.  Just have the old 650 cases with 550 topend on it.  Trying to get the rolling chassis further along for mock up while I wait on the machine work for the stroker motor.

[purf_man]

So I pretty much have my Toyota where I need it for this winter and with the time change I am back on my CB Build!!!

Dug it out of the spare room tonight and finally checked out my fork lower I had the weld shop sand down for me....still needs more taken off...maybe .060"  I might just go lazy and use the dremel to dial it in now.

Ordered up some silicon connectors for the EFI throttles.

I feel really stalled on the motor not having a good machinist that can do the flywheel sleeve and my external oil mods (anyone in Topeka or Kansas City?)

trying to get back on the rolling frame and getting some of it laid out (oil cooler mount and lines, mounting pump in the tank, front brakes)

maybe by the end of this winter I can at least have a solid roller frame and have located a good machinist.

[sinister902]

I feel your pain. I actually live only about a half hour from Fast by Gast where paulages sent his transmission, but I almost want to do the work myself. The only thing that doesn't have exact process outlines is how much to machine out of the 836cc kit pistons. I think I'm going to bite the bullet and buy a hobby-size milling machine with boring setup and digital readout and just do it myself. I also just recently scored a zx6r ninja tank with the pump and fuel cap still in it so I can chop the pump mount out and transfer into my honda tank much like it seems your planning.

I'll be watching closely here!

[purf_man]

Couplers before any trimming.  Have my fuel pump mount at work to trim down.  Gonna get everything mocked up in the frame this weekend and see if I can fit it all as planned.

[gdubya]

Just came across this. Anxious to see how the EFI comes together. I will be following this one closely. Considering something similar on my cb650 project.

[purf_man]

So I got a little distracted......Ran into issues finding a "local" machinist, built a 4wd Toyota truck, parted it out, Started building a 1978 Trans Am (like 90% done), restored my 1978 RD400 (95% done), moved to different states twice, got married, passed my PE exam, and had a kid.....oh and built a shop.

in an effort to clean out the shop I dug out my CB project to see if I can push to finish line (or maybe at least get it way closer to reduce the piles of boxes/parts)  Over the last few years I have built my skillset and toolset.

I think I have a new machinist lined out (meeting this weekend to discuss)  So hopefully I can get the sleeve machined for the crank to fit the VFR flywheel.  looking at it I might need to have a small amount taken off the end of the crank (~2mm or so) if I want to slide the flywheel as far inboard as I can.

I polished up my brake calipers and forks.  modded the damping rods for some "gold valves (the knock off Mike's XS valves I already bought years ago)  Rebuilt the calipers with new SS pistons and some EBC pads.  I think just getting the valves fitted to the damping rods and ordering up some springs and I will have the front end mostly ready to go then.

since I am kicking this out to a 750cc motor I think building a new header will be in order.  While the 550 header will fit the 650 motor I think some larger primaries will help and I would like to use the 650 oilpan (deeper)  Since I have a shorter Wheel/Tire combo I am looking to do a flat collector/merge pipe.

For the EFI throttles I am looking at ditching the taped boots and maybe just doing a welded flange on the head to take the GSXR intakes.  this are an oval port so with some porting I think I can deal with the port alignment easier and tuck everything up a little tighter.

I stripped the head down and will need to talk to some folks about finding a proper spring setup and larger valves to drop in.  I had planned on the biggest cam off the shelf but I think more and more I will need a custom grind for kicking up the displacement so much.

I had the boss on the oil filter pad of the lower case half milled down to take a 650SC oil cooler plate.  This coupled with the deeper pan and a large filter housing should get me a fair amount of oil capacity and cooling.  the 550 pickup will need an extension added for the deeper pan.  my 650 head has been drilled and spotfaced for banjo bolts on each end and I just need to pick a spot off the lower end to feed them (I might TIG a bit onto the main oil galley and feed from it)

I am really kicking myself for going to a 65mm bore.....had I done 64mm I could have bought my gaskets off the shelf from Dynoman/cometic.....oh well.

I also need to figure out a new image hosting site since photobucket is super lame now.

[RAFster122s]

You have been busy...
Thanks for the update. You can always upload photos directly to the forum thread.

[purf_man]

Thought I would toss on some current pics.

Great light in the new shop BTW (around 85,000 lumens in 660 sf.....about double what the highest call out is in design guides for a laboratory)

so since I have started this project my resources and budget have changed.

Current throttle body mounting plan (very roughly mocked up) is to have a spacer/flange machined that slips over the stock 650 spigots.  it will be bored/tapered to match up to the GSXR manifolds (being oval in shape I can account for port spacing mismatch pretty easy then)  Mock up is a hunk of 1by that I bored some holes partially through with a fortsner bit and tapped over the spigots....them just wood screwed manifolds to it.  I will model it up this week and hopefully email to my brother to 3D print a prototype to try out at thanksgiving.  if it fits ok he has a HAAS mini machining center (only a 12"x12" work area...but great for SUPER small stuff)  sadly the whole thing in one piece will end up being around 14" long.  If we split it then we can machine it in two pieces and since they will bottom on the OE spigot machined edge and being rubber boots I think it will be ok.  This will tighten up the package a fair amount over my planned silicone tapered hose coupler.

I'll get some pics once it is all sorted but here is the 650 DOHC oil cooler adapter.  I had the boss on the 550 block that the oil filter bolt threads into cut down to allow this sandwich plate to sit flush on the block.  I ordered up a TTR400 oil cooler adapter bolt and we will bore/face the sandwich plate to accept this and allow any oil filter housing/bolt combo to be ran (looking to run a large/long filter housing with the sandwich plate to gain a little oil capacity/cooling effect)  I debated a custom bolt but I think this is a better solution.  plus if I round off a bolt I don't have to make a custom one again.  I also broke down the factory lines that came with the cooler.  I have a nice set of tubing benders for instrument tubing and a hydraulic flaring tool now so will be making up new lines after I mount the cooler (there will be a section of flex hose to  keep any stress cracking at bay)  Waiting on my header to get here (a few weeks out) so I can mount the oil cooler and route/fab oil lines.

I think a small tab or maybe a bolt on bracket for the fork damper will be all that is needed.  I might see if I can get the stud/pivot off the damper and swap the threaded end for a tab that I can bolt to the frame easier (or maybe just welded directly)

The 650 oil pump bolts onto the 550 cases but has an additional oil galley to feed the transmission.  since I am running the full 550 transmission I don't need this feature.  it is off the oil light passage (which was made about 1/2" longer)  I simply hacksawed it off and ran a 1/8" NPT tap farther into the port to get the switch back into the stock 550 location without having to get too crazy.  The pump rotor is the same diameter but is 5mm thicker (27mm thick vs 22mm)   BUT the pump ends up being thicker.  If they machinist I have laid out can get in there I am planning to mill the mounting pad for the oil pump down a couple mm and counter sink the pump cover plate to fit it all under the stock 550 side cover.  We will need to also mill off the same amount of the pump shaft support boss on the pump housing.  this should get me more oil flow in the motor and hopefully more stable oil temps/cooling.

You can see I already have had the head spotfaced in the oil galley on both sides to be externally fed.  I tapped the feeds on the bottom of the head and plugged them with a allen setscrew.  I bought a billet main oil galley plug to have drilled/tapped/faced for a banjo bolt and will feed the head from that (maybe a hardline or maybe just some flex lines)

I need to bore out the damping rods in the forks for the Mike's XS "gold valves" I bought years ago.  Once clearanced the forks are ready to assemble with new seals.  since I had wheels laced with 17" hoops I am no longer running a speedo drive.  Both calipers have been rebuilt with SS pistons, new seals, and EBC pads.  they will be fed from the stock block with SS hoses.  I need to figure out a master cylinder to use.  my stock one was pretty crusty and I can't get the circlip out (very rusted in place it seems).  anyone have a bore size recommendation?  BTW the wider front hoop and smaller diameter makes assembly a chore.  the tire BARELY clears the brake pivot bracket.  you have to put the bigger lower bolt in first and get finger tight.  Then you put the two 6mm bolts in the upper bracket and swing into position....and tighten with a open end wrench.  I have a 1/4"-5/16" clearance on either side of the tire/rim to the brake brackets. (BTW I am not running calipers in the rear.....I just got my fork lowers mixed up when doing mock up)

I am not sure I will end up keeping the fiberglass pan.  the shop that had it when doing the frame mods really bashed it up.  I am a tall guy (6'2") but don't need all that length.  I might just section a few inches from the center to shorten it up and maybe fiberglass up a "tunnel" in the middle and a hump at the front.  I plan on all electronics (ECU, power panel, battery, regulator) to be located in the rear cowl.

I have a donor GSXR600 airbox on the way to grab the airhorns from and a couple sensors.  Those will get used in designing a new air filter housing (likely a simple AL pair of plates with some UNI foam on a wire frame.

Anybody know of a smaller front fender I could try out?  I have a shorter tire than stock and it is pretty chunky (110 section width)  Maybe just 3D print a buck and pull a mold to make a composite one?

I am up in the air on a fuel pump.  the GSXR600 pump assembly I think will be too tall to fit in the tank.  I have looked at Harley Sportster pumps which look perfect but they are crazy expensive.....the solution might be more 3D modeling and a alloy sump that bolts to the bottom of the tank with a pump/filter/regulator built into it.  Gotta love being able to design stuff and just 3D print it before committing to having things machined.

[purf_man]

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