Topic: Salt Racer CB 750 OZ style

[kmb69]

Not sure how much the jeweler's rig had to do with those strange looks, Bro. 

[Jerry Rxman Griffin aka MuthaF'er]

LMMFAO Bro 

[MRieck]

Not sure how much the jeweler's rig had to do with those strange looks, Bro. 

Cheeky texas monkey.

[johno]

Havent done much over the last month, just waiting for the rest of the parts to arrive, am trying the MLS gasket, oil pump kit from our forum buddy Elan,  last night jigged up the swing arm parts for welding this week and I machined up these two piston holders, the wooden square holder is to hold the piston in the vice on the mill to flycut the extra 1mm diam on the inlet valve cutaway and the round teflon piston holder is so I can hold the piston secure while I machine a 3mm squish band around the piston tomorrow night.
starting to get cold here , Jack frost around so cranked up the heater tonight.
ciao johno

[bear]

To flash for me mate.
We use a battery drill and grey duct tape out here in the sticks.

Cheers,
Brian

[Old Scrambler]

Way beyond any of my personal experience.........and well after passing 'motor-building 101'..........but I continue to learn and enjoy new things.

When we measured for clearance, the sides of the valve-pockets needed more relief than the outer edge....................so be sure your centering mark is according to the valve stem JUST past TDC on the overlap stroke.  Will you need to make plug-relief dimples?

If you need to 'shape' the head-gasket to match the head............we are advised to use copper.......NOT MLS. The standard-bore gaskets are advertised to 'fit' the 62mm bore. We tried one standard unit and then measured a copper unit............both were a few thou small of the bore. If the MLS gasket is less than a full 62mm it cannot be 'dressed' to fit. This is especially true if you need to 'shape' the gasket to match the egg-shaped dimension of the head. The standard gasket will tend to shave the flow or 'shroud' the outer edges of the valves.

I am guessing that your squish-band relief is to avoid detonation?

We are getting close to 'cruntch-time'...............you have the winter months to look forward to relaxed shop-time.  I keep thinking that each of us is on a parallel but separate path to new discoveries about these old motors that we love so much.     

[johno]

Yeh  Bear , this is what too much time on a freezin rainy day does to you,   I actually taped up the pistons in duct tape, looked at them and then realised I am now suffering piston breakage phobia after the last blow up.      and off to work on the lathe, enjoyed deciding on the mix of old technology ( wood) and the new technology ( plastic )

Thanks for the warning Den,  I had a spare copper gasket and went to use it but when I looked at it it was for a 500 honda so in the conversation with Dynoman to change it over he tipped me over the edge to try a MLS.   I will check the bore but am expecting it may not be suitable especially as I have allready scalloped the top of the bore this time for valve flow. If so it will be a good  spare for a stocky project.   Your right Dennis, having 6 months to go gives me a nice relaxed approach   unlike yourself. Enjoy the thrash around.
cheers johno

[johno]

Was reading your thread Den,  here is a pic of mine.   I had to make some changes to the piston tops to get enough clearance with my early K head,    a 2mm squish type band around the pistole, then between that and the spark plug area had to take off a couple of mm.

next job,  slight relief of spark plug then valve pockets.

[johno]

spark plug relief, just ground the back rake on the drill to match the 1.5mm depth hole I wanted.

[bwaller]

Good thinking on the piston fixtures.

[Old Scrambler]

J..............we considered trimming the pistons...............but the F2 head has an irregular egg-shaped chamber circumference.  It does not have to be enlarged around the entire perimeter...........only at a few places to assure proper clearance. The difficult accomplishment will be centering each chamber before the Mill gets to do its work.   

[cbornotcb]

Keep up the good work Johno, this should be the start of the warmer weather that tends to draw us into the shed.

In another month, egt's and plug readings will return my way, holidays have been secured for the 2015 event, and I've enlisted the services of a light bullet shaped son to raise the bar, should I finally make it thru the timers 
Tiny

[scottly]

spark plug relief, just ground the back rake on the drill to match the 1.5mm depth hole I wanted.

Hey Johno, I would use a ball-end end-mill to cut the relief. They leave a nice finish and a nicely rounded contour. Also, if you need 1.5mm depth at the spark plug center line, remember that the ground-strap extends back about 3mm before curving back, so that depth should be for a minimum of a 6mm diameter spot.

[MRieck]

spark plug relief, just ground the back rake on the drill to match the 1.5mm depth hole I wanted.

Hey Johno, I would use a ball-end end-mill to cut the relief. They leave a nice finish and a nicely rounded contour. Also, if you need 1.5mm depth at the spark plug center line, remember that the ground-strap extends back about 3mm before curving back, so that depth should be for a minimum of a 6mm diameter spot.

I cannot argue with that

[johno]

Went around the place seeing how the other half live, checked out a few factories in Europe, Munich BMW, very funky museum

[johno]

Beemers were in to landspeed records way , I measure all their record holders up just in case 

[johno]

well had a good holiday, squared the slate with the ol girl.........Back to the shed

Finished the pistons and all balanced.

[johno]

The clearance for the spark plug is not for electrode clearance but is to give the chance for the flame front to get a good head of speed and front rather than get snuffed by the quench front.....who knows .........giving it a go.

The exhaust is through the piston wall , the inlet is right on the edge man,  It was playing on my mind and especially where the valve plunge cut is really close to the back of the ring land, real close, real close ,  it was stressing me out but rightly or wrongly two people have encouraged me to use them, stayle current world record FIM kawasaki 207mph said  " dont worry I run mine like that all the time " and forum ledge Dennis who runs the same piston and the top landing hasnt collapsed.  So WTF will give it a go. with the cam lift , valve size and small bore things get real tight . 

[johno]

This is the 4th check and measure assembly to make sure it all misses.    could throw the cam in from 10 feet 

[Bill/BentON Racing]

Nice! Saw this pic a lot last few weeks.....recognize that tensioner! Haha. G'luck mate, Bill

[johno]

Just checked  TDC, put on head , set tappet clearance etc rotated 3 turns , pulled head ..........all good

clearances ended up with including head gasket  1.3mm thick ( bout .050 thou)
valve to piston inlet.... 1.8mm ( .072 thou)
                       exhaust..2mm ( .080 thou)

Gap from spark plug tip to piston flat (not drilled relief) 1.7mm ( .068 thou)
piston edge squish band 1.6mm,   next flat stage 1.6mm,

Bottom line it all misses 

[Old Scrambler]

OK..............so your back from traveling and settling things in your life

Good looking clearance numbers..............Nice finish to the sharp edges on the pistons ............and no DROPS

I don't know what your carburetor plan is..........but at your low altitude the choices are numerous. Road test by Christmas?

I see you have been studying my chassis...............Yes, the lower hoop gets by tail lower but crunches my legs to get my big feet on the pegs.  The real benefit was to get it narrower for my knees to tuck.  When I am on the bike, the only part of me that is wider than the crank is the hand-grips. Even though my oil tank is moved inward, my inner thigh gets quite warm..............especially riding bake after a run. I'm planning to install a thin layer of heat-wrap inside of my leathers.

[754]

I have been to that Beemer vier zylinder building (4 cylinder) i think they hang from the top, not supported underneath.  They have a killer theatre up above the Museum.
 Did you get to the Deutsches Museum?

[bear]

Back on track.
Good to see mate.

Cheers,
Brian

[MRieck]

The clearance for the spark plug is not for electrode clearance but is to give the chance for the flame front to get a good head of speed and front rather than get snuffed by the quench front.....who knows .........giving it a go.

The exhaust is through the piston wall , the inlet is right on the edge man,  It was playing on my mind and especially where the valve plunge cut is really close to the back of the ring land, real close, real close ,  it was stressing me out but rightly or wrongly two people have encouraged me to use them, stayle current world record FIM kawasaki 207mph said  " dont worry I run mine like that all the time " and forum ledge Dennis who runs the same piston and the top landing hasnt collapsed.  So WTF will give it a go. with the cam lift , valve size and small bore things get real tight . 

It won't be a problem Johno.