Thursday, May 22, 2014

CRTT at Summit Point

My 1966 CRTT 250cc Sprint hadn't run since the big end failed at NHMP in May of 2012.  It had been pushed aside as I pursued other project in my frenetic life.  But, with my 350 ERTT off to Australia and with me vowing to get it rebuilt when it came back and with my Dondolino needing attention, the CRTT rose to the top of the to do list.  I had the crank rebuilt by Falicon with a new rod, rod bearing and crankpin.  JE made a couple of new pistons.  I got a new L-1 replica camshaft from Megacycles.  And, Chuck Wagon Racing did a valve job.

When I was putting it together and setting the cam timing, I discovered that there wasn't enough piston to intake valve clearance.
This was hard to understand as the new piston was pretty much a copy of the old piston and that had enough clearance.  As time was running out to get the bike ready for Summit Point on 10 May, I had the intake valve pocket cut deeper.  Then, I discovered that the intake valve was bent and that's why there wasn't enough clearance.  Between having the valve job done and checking the cam timing, somehow the intake valve got bent.  I had
another intake valve, so I installed that with the unnecessarily cut piston.  When I got to the circuit Fri. afternoon, I tried starting the bike by pushing and it didn't fire,  but my ankle is so bad now that I figured I just didn't push it fast enough.
Sat. morning, I put it on some starting rollers and didn't get a pop.  I pulled the spark plug and it was sparking like crazy.  After my experience at Roebling Road, I had made sure that I had the stator leads on the correct spades of the coil.  But, it sure seemed like the timing was 180 degrees out again.  Sure enough, I pulled the rotor and turned it 180 degrees and the motor started right up.  This could only mean that I timed the ignition at TDC overlap, not TDC compression.  I've got to fire my mechanic: Me.
I took it pretty easy in the first practice, breaking in the new motor, but it seemed to go alright.  In the second practice, the motor hesitated a couple of times and there was a lot of backfiring on the overrun, so I came in after 3 laps.  Turns out, my mechanic (me) had failed to safety wire the exhaust header bolts and one was missing the the other was about to fall out, allowing the exhaust pipe to hang about an inch below the exhaust port.  I kept checking the sparkplug and it looked well safe.
By the time the racing started, it was raining.  While watching the V-5, V-3 race, I saw Rich Oldakowski pass Rich Midgely and then drop it in the 'carousel'.  When he tried to pick his bike up, he slipped and fell on his ass, so I knew it was slippery.
My first race was V-2, 500gp, 250gp, with three of the 11 starters in 250gp.  I got the jump on the other 250s, but Craig Hirko on his 175 (200?)Bridgestone out dragged me to turn one, then steadily pulled away.  I watched someone go down in turn one, so I was definitely taking it easy and didn't do any sliding.  I ended up 2nd in class, almost 39 seconds behind Craig, and 4th overall, Craig being 2nd O.A.  I was reasonably please with how the bike was running and it seemed quite oil tight.
So, I lined up for my second race, Formula 500, V-1, and 350gp, with a bit more confidence.  Of the ten starters, six of us were in the 350gp class.  I got a good start and this time Hirko never came by.  Midgely led on his CB350 V-1 bike with Steve d'Angelo 2nd on his 350 Ducati. I worked my way into  3rd O.A., 2nd in class.  On the 5th lap, my motor lost power and, I'm told, emitted a big cloud of smoke and I pulled off.  The motor didn't have any compression and, when I got home and pulled the head, I found that the piston had collapsed in the intake valve pocket, where it had be unnecessarily cut.  Clearly, cut too much.  I got to fire my mechanic.
I failed to take a single photo at the track, but here's one I took touring around on the beautiful next day.

And, here's the piston that failed.

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