Topic: Turbo Charged CB550 Landspeed Attempt

[BomberMann650]

Tires OK.............they 'look' fat from the side

Mid-forearm OK...elbows visible.

Yes to smaller diameter springs, front & rear.

Merry Christmas

Meery Christmas

Guess i'll have to fenagale a way to show a little side elbow and keep the bodywork smooth.

Rear shock can stay.  Its a fully featured tool that would cost "whole new engine money" to swap.

[BomberMann650]

A long time friend wanted in on the action.  Though he's good with a mig welder, the tig torch is not his daily driver.
So when the time came to make a bunch of little welds to build up a tail piece.  Figured  he could get some time in with the gtaw machine.

The paper pattern skin sure is a flattering look.  Added bonus, the cavity inside the wire frame offers a lot of space for more electronicals.

[BomberMann650]

Ignition system arrived

What plugs, wires, and caps are good with these?

[BomberMann650]

Much progress that I haven't been sharing here.

But the custom racing sprocket arrived.  It couldn't be any smaller.  Expect this bike might need a little flintstone action to move off the starting grid!
Might toy around in gearing commander some more.  Figure out if 18/38 gearing will be as favorably fast as 19/32.

Other newsz - welding is completed, things are painted.  Tank, seat, sidecovers, tailpiece all put together and wrapped in a wild vinyl coating.  Crank and rod bearings acquired, handlebar set up coming together.  Have oil lines to plump into the turbo
Need to take the rotating assembly to a balancing shop.  Currently reassembling chassis from back to front.
Also gotta order air shocks for the leading link.  Along with tubing for the turbos pressure sensor stuff.

[BomberMann650]

It looks like a complete machine now.

There's still more to do.

[johno]

great photo of the bike 
You have come a long way Bomber, I guess that means your committed now 💰🏍 🏁
best of luck and enjoy
cheers johno

[Shtonecb500]

that bike looks wild as #$%*.

[Old Scrambler]

YES............looking REAL good

Think about a handlebar perch, lever & cable for the rear brake.............I use it a LOT for loading and unloading

[BomberMann650]

YES............looking REAL good

Think about a handlebar perch, lever & cable for the rear brake.............I use it a LOT for loading and unloading

Thanks brother

Did consider a front brake lever a few times.  Getting comfy in the saddle and the fingers reach for a lever that isn't there 😆

For events like El Mirage or Spaceport would need a whole front brake.

[Don R]

 I think there is a lot to be said for standard control locations. We've been riding long enough that the hands know where to reach without the brain telling them.
 I've been scrolling through fairings and for my use it's going to be hard to beat Airtech.  My project is a little more Honda Dragbike style and the only class I care about is having the fastest MPH SOHC4 on the day if I'm ever able to show up.
  I'm closest to Arkansas since the Illinois half mile drag at Rantoul hasn't happened for a year or two. The PO offered to wheel it if I don't want to buy the leathers.

[BomberMann650]

Well, been months since I updated this thread.
After the 1 show, the build took a pause.  Built a bunch of other bikes which helped to hoarde more parts and tools.

Over the holiday - got back into the engine.  Used a proper indexable hone and dial bore gauge to get the cylinders back into fighting shape.
Sorted out some rockers to dunk in the chemical cleaner.  Managed a set of 8 with intact chrome coating.
Then went about reassembling the head.

Thats the good news.  Now the bad news.

That numbskull move i made at the start - Hogging out the intake seats - came back to bite me.
After installing and honing the guides, grinding and lapping the valve seats.  Not one of the intakes can pass the flashlight test.

D.i.Why am I like this?

I've tried twice now to cut the damn things in.  May have simply bored the seat farther than the oem valve likes.
I don't know if I should attempt to fit a +1 valve, or sucker a machine shop into replacing the seats.

The hand cutting and grinding method worked fine for the exhaust side.

[BomberMann650]

It seems this bovine has an uncanny knack for the unlikely.

While we know the 650 camshaft is a direct swap into 550 heads.
Apparently not all 550 rocker arms are created equal.

The particular cam I got off ebay specs to .300" intake lift and around .285" on the exhaust.
(+/- .002")
Just enough lobe that a high spot of casting flash on the rocker arm can contact the cam.  Binding before the chrome paddle can do its job.  Spent a little time fettling those down with the dremel and things are rotating freely.

If this happens with a .300" cam - how are the megacycle cam guys building theirs?

[MRieck]

It seems this bovine has an uncanny knack for the unlikely.

While we know the 650 camshaft is a direct swap into 550 heads.
Apparently not all 550 rocker arms are created equal.

The particular cam I got off ebay specs to .300" intake lift and around .285" on the exhaust.
(+/- .002")
Just enough lobe that a high spot of casting flash on the rocker arm can contact the cam.  Binding before the chrome paddle can do its job.  Spent a little time fettling those down with the dremel and things are rotating freely.

If this happens with a .300" cam - how are the megacycle cam guys building theirs?

I use Megacycle hardweld rocker arms. They are the best.....better than Web as the have a thicker hardwood on the pad and there is more attention to detail. That goes for the 750 arms as well.

[BomberMann650]

Just enough lobe that a high spot of casting flash on the rocker arm can contact the cam.  Binding before the chrome paddle can do its job.  Spent a little time fettling those down with the dremel and things are rotating freely.

If this happens with a .300" cam - how are the megacycle cam guys building theirs?

I use Megacycle hardweld rocker arms. They are the best.....better than Web as the have a thicker hardwood on the pad and there is more attention to detail. That goes for the 750 arms as well.

I'll keep that in mind.  But for this engine, only the finest junkyard parts are going in 👌🏼

Can y'all believe i sniped a cam so hardly worn it still had its factory coating?!  Sorted through my spare rockers to get a set of 8 paddles with no worn out spots too.

Though this build process is torturous compared to the american v twin.  Got untold weekend hours of precision nail biting and blood sweating into this honda.  When i could have had a big block twin punched out and lobed up - all before dinner time

[BomberMann650]

Today, the effort was made to degree the cam and clay the valve clearances

Which first required the cleaning of the junkyard head, then the check for cam rotation.
Seem to have gotten more than I bargained for with this "cb650" camshaft. 
As once again, i had to make room for the intake lobe to pass in the trough.  Then i noticed a difference between dynomans bronze valve guides, and the oem guide.  Dynomans are bout a 1/4" shorter than stock (accomodating their hi lift cams no doubt).  Not wanting to go through the fuss of changing guides from one door stop to possibly craft another door stop.  I quickly "milled" down the oem guide.  Don't need no stinkin valve stem seals.

I did some general lift measurements on this ebay cam. 
Dial on the lobe
 intake lift .300"
 exhaust lift.286"

Dial on the rocker arm tappet
Intake lift .322"
Exhaust lift .300"
(somewhere around there - i wrote it down but left those in the shop)

Once i remembered how to install a 550 cam and sprocket.  I started at stock timing and again put the dial on the lobe - the dyna ignition crank sensor is an accurate accessory for seeing tdc and some advance degrees.
The intake lobe was opened .005" around 35° btdc.  I neglected to note what it was at .050" lift.  But thats not the fun part.

Since i have the dynoman cam sprocket.  I budged the cam back to full retard.  Bringing the intake opening somewhere closer to 15° btdc.  Since this is a turbo build and maximum rpms are desired.  Figured i'd at least see if this setting was a usable option.  Kinda closer to megacycles 126-00 timing.  I had put in a couple test valves/springs and silly putty on the piston.  So i turned the crank over.

Spoiler alert.  Never go full retard!

While the intake valve had all the clearance it could dream of.  The exhaust valve vacated all the green putty from its pocket.  It didn't lock the crank, but the valve may have received a little push from the piston on its way past.  I didn't have a headgasket or .040" shim between deck and head.  So i guess that means clearance is .040" right?

At this point, i was thinking about buying an air conditioner for the workshop.  Cause the heatwave we are having makes these sort of chores rather uncomfortable.  And the silly putty was starting to melt.

*****If you're still reading.  Thank you.*******

I could use some assistance in setting this cam for use with a turbo.  Once the shed chills out i'll probably go out there and take another set of measurements.  Try to get the actual opening set at suitable intervals. 
I've read that turbos can be mean to valves that are open at an inopportune time.  So any tips to get this degreed in - would be appreciated.

[BomberMann650]

Electrical is done!

Took me longer to plan it than it did to do it.

Battery pos feeds a golf cart relay thats rigged to the tether and a latching button.
Relay output is split to a fusebox and the starter motor relay.
Both relays switches are on a 5 amp fuse
Fuse box is on a 40 amp main setup.

Dyna2000 box is in the tail.  That feeds the coils and crank sensor.  With the retard activator attached to a cat dozers air pressure switch.  Which will short to ground at 4psi.  (Which i calibrated
I theres an electronic tachometer next to analog boost gauge on the tree.
Changed dynas sensor lead clip for a weatherproof 4pin.

3psi Holley fuel pump is on a rocker switch

Went with a ricks lithium vrreg.  Which got setup with my weatherproof clips as well.  The oem stator/fc got their leads extended and dressed up in nice conduit wrap. With the vrreg having a path to the battery pos and grounding strap.  The fc exciter circuit routes back to the fusebox pos post where it can get the switched power signal.

It took a little nudge but i also added a wideband afr sensor to the outfit.

I'll work on attaching the carburetor and afr gauge to the bike while waiting on battery to arrive.

Will be able to set the timing and test run the engine soon!

[Old Scrambler]

Get 'er done! I don't know much about electrical, but keeping it simple and having a back-up battery seems to work for me. Are you using the battery for starting and ignition power? Several racers use 2 batteries, one for each duty.

[scottly]

Battery pos feeds a golf cart relay thats rigged to the tether and a latching button.

How much current does the golf cart relay draw?

[BomberMann650]

Battery pos feeds a golf cart relay thats rigged to the tether and a latching button.

How much current does the golf cart relay draw?

I hadn't considered if the relay had a parasitic draw.  Ideally... the big output should have o.L when the deadman switch is hit.
But i peeked through the sales brochure - the switching coil inside the relay is a claimed 2 watts.  (Wouldn't be surprised if it was actually 5 watt)
With the way i've wired it.  All current through the relay should be null when the tether gets yanked.

I have noticed before, some switching relay setups can have a parasitic draw.  Installing light bar wiring harnesses.  The power to the lamps is out.  But there's still something on.  Turned out it was the led indicator on the switch drawing current to let the user know it was in the off position 🥴🥴

My machine doesn't have any indicator lamps - figure the display of the afr guage will let me know if i've left it on.

[BomberMann650]

This oughta get people talkin 

Started the engine - and it comes on like someone had kicked a hornets nest.
Obviously had no idea or reference to what kind of jetting this d.i.y. setup would need. 
So i went with a pilot size that woulda worked with the factory airbox.  Genuine Mikuni 42.5 - already ordered 47.5 and 52.5 pilots should should settle this idle.

So i got a runaway engine on my hands now. 
But damn if it doesn't sound neat.

There's a little drip in the fuel system.  My fault for not using thread sealant during assembly. 
Other problem is how easily this holley mighty mite 3psi pump can overwhelm the float needle and just piss fuel onto my work bench.

Another thing to work out is the tachometer - i was cheap and got one of the few mini 13k digital tachs off amazon.  Don't know if its broken or if i wired it wrong.  There's no movement when power is applied (i.e. the startup dance) and i didn't notice it tracking during the limited run time.  So would be open to recommendations on a budget friendly tach with 13k high mark.

[Old Scrambler]

Your pilots are likely WAY too large.........standard Mikuni for my RS34 set is 17.5.........It won't idle and will foul the plugs if below 2300-rpm if the pilots are fat

BTW...... If you have any sort of aggressive cam, don't idle below 1800

[MRieck]

Your pilots are likely WAY too large.........standard Mikuni for my RS34 set is 17.5.........It won't idle and will foul the plugs if below 2300-rpm if the pilots are fat

BTW...... If you have any sort of aggressive cam, don't idle below 1800

Yeah but that is for a rack of 34's....what is he running ...an HSR-42?

[BomberMann650]

While i appreciate the point of reference on the rs34 setup.
The oem 069a carbs with airbox were using size 40 pilots (on a keihin scale)

Due note i have a big 40mm HSR feeding a turbo and plenum of my own construction.
Actually got my hand sucked into it pretty hard.  Boost Gauge is showing a 15 to 20 in-hg vacuum below 1500rpm (guessing by ear cause amazon tach is defunct)
Then it goes out through a set of oversize d.i.y pipes boasting a 29mm i.d.  collecting to 1.5" for the waste gate and turbo inlets.

The cam is supposedly a cb650 - but specs closer to megacycles hot street cam.  Best Dial indicator measured .321/.308 at the tappet. 300/286 on the lobe.  I installed it pretty darn close to the oem mark, maybe 2 degrees behind.  Nothing too radical on the cam timing
Ignition timing is set to a 35degree full advance.  The dyna 2000i box is set to a boost curve with a switch waiting to see pressure.  The curve has a 5degree advance below 1000rpm - so I can't retard static timing much more without sending spark on a chase during startup.

Am putting a good bit of faith into innovates afr wideband sensor.  Assured by ZR zlock racing to be a reliable data point. 
On first startup, the meter was showing 15-17 and it took a lot of blue tape and pokey holes to get idle afr down to 11.5.  yes thats rich - but safer than the alternative.

Forgot i had shut the fuel tap, accidentally - and as it bowl emptied it leaned out to 18.  had to shut it down asap.  The sound of a 550 running lean is hair raising. 
Had it happen with the old 75 when my carb sync hose melted and the cylinder was able to breathe through the brass adapter straw.

By the time i had fuel under some control.  The turbo started puking oil out the exhaust.  Probably because i half assed my drain setup.  Have some 10an hose and fitting ordered to fix that issue.

[BomberMann650]

Your pilots are likely WAY too large........

Yeah but that is for a rack of 34's....what is he running ...an HSR-42?

Sharp eye MRieck - is the HS 40mm but they're hard to tell apart

[scottly]

You don't tune an engine this way.