Build Diary
December 2007


8th December
Finally got a few hours with the 'car'.
Fitted the driveshafts (they fit) and all the other bits of rear suspension/brakes.

Propshaft
Fitted the propshaft for the first time.  This was described earlier, and has a slider, but the good news is that it fits (I ordered the right length).  It also clears the clutch slave cylinder (just).  

For the centre-bearing mount I popped in a few bits of wood and got out the spirit level.  According to various people these two part props require a special trick to balance them.
The problems come because the UJ's are not CV joints.  By this I mean that as you rotate one shaft a constant speed the other shaft will speed up and slow down depending on the phase of the UJ.  This effect increases as the angle between the input and output shafts increase (it goes away when they are parallel).  The solution to this problem is to have the CV at one end of the shaft rotated by 90degrees from the one at the other end.  In this way the acceration and decceleration effects described here do not change the speed of the engine to diff, but only affects the speed of the intermediate shaft.  This is a neat trick (probably invented about 200 years ago!).

For this to work perfectly is is important for the plane of the diff to be parallel to the plane of the output shaft.  This is a good start.

With three UJ's (on a two piece shaft) you can't do the phaseing trick.  The "best" solution is to have one UJ straight* (i.e. no angle) and do the phasing trick on the other one.  In an bike-engined install the only joint that can be straight is the rear one, and that is quite easy.  So.  as the diff face is basically vertical, you end up with a basically horizontal propshaft from the diff to the centre bearing.  Then the run from the centre bearing hopefully is phased correctly.

Issues:
1) *the problem with running a zero degree angle is "brinnelling" this is to do with not using a UK properly, so that it doesn't flex, and hence wears badly.  I am told!
2) The front prop in this case also sees quite large angles, and larger UJ angles are undesirable as the shaft will be pulsing (radially) which isn't the best.

My Solution:
Run a small angle lower at diff end, higher at centre-bearing end (maybe 0.5deg).  This should give the UJ a bit of anti-brinel angle.  Also this takes the worst out of the prop angle at the front.

I took a few photos, the prop ends up very close to the drivers side of the tunnel, due to the strange geometry of the striker/phoenix chassis.  These photos seem to agree with those of other BEC'ers (Chris Gamlin being my best reference).  If I get vibration then I will have to move the mount!





Gearlever doesn't fit anymore, no space in the tunnel.  Never mind!

Handbrake
Managed to bodge up some wire and adapter for the handbrake.  This looks to be coming together nicely.  The lengths all work (under the driveshafts on the way back, and then back over the driveshafts and into the top of the inverted sierra rear calipers.  Yup this needs a photo).

I am hoping to get some nylon tube to run the brake cable in.  This will protect the occupants, and allow me to run it back into the tunnel.  Standard Phoenix has a handbrake mounted on the outside of the tunnel, but I don't like this.  There is loads of space on the passenger side of the tunnel.

Pedals and such
Fitted the clutch pedal needed to drill some holes for the new master cylinder (sv650 rear brake), for which I have made a bracket to support it.  This all fits together beautifully (yes photo needed here too),  only problem is the threaded push-rod isn't long enough, probably need a longer clevis or some other way of extending it (it is only M8 rod so there are lots of solutions).  Brake pedal, bias bar and one cylinder went in nicely.  For the other master cylinder the hole didn't line up.  Looks like the person drilling had a slow moment and put it a bit low.  Turns out the push rods on the brake master cylinders are too long! this is easy to fix, but I got tired to came home.  For the record.  Messing around with the pedals is a lovely job when there are no panels in the top or side.  I have heard horror stories on this on, so this is worth remembering.

Fuel pump
Not 100% certain where to mount the fuel pump.  This is a carb car to the pump doesn't do that much.  I fancy lower than the tank so that it doesn't have to work too hard, and also at the back of the car (out of the way).  I am presently thinking about a braket that uses one of the diff mounting bolts (solid enough).  I will make up a braket and see what I think (the good thing is that I can do this from home, as I have the pump here).



Actually on the point of panelling.  It seems that most people like to do this really early.  I don't quite get it.  Surely it is easier to do almost everything (at least trial fitted) before paneling.  I don't see myself putting the floor on until the point when I need it to support the bodywork (June 2011 at present rate of progress).



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