This list is really great... lots of good info, even from the sidelines! I
have been lurking for months and will remain in digest mode due to lack of
time to go through all emails (about a week an a half behind on the
digests!), but I have a query for the collective wisdom of the list.
My 1963 TR-4, misses when idling, not bad, but annoying knowing it can be
better. Looked into situation and found a few things.
1. The timing chain was stretched beyond the 0.40" specified in manual, so I
replaced it, being careful not to disturb position of cam and crankshaft
gears. Checked the Bentley manual and found the clocking marks (scribed line
on each sprocket which line up at TDC) on sprockets to clock camshaft to TDC.
2. With crankshaft at TDC (confirmed with position of valve rockers 7 and 8,
as per Bentley manual) the rotor contact for the distributor is pointed at 4
o'clock (engine block at 12 o'clock) instead of 11 o'clock as specified. I
checked the ignition wires and they are connected to each spark plug in the
correct sequence. I then removed the distributor and the pedestal and
repositioned the distributor shaft where it mates to the camshaft so the
rotor would point in the proper direction at TDC. The engine would not run
at all after I reassembled the distributor so I returned it back to the 4
o'clock positon and it now runs again but still misses occasionally.
I smell the work of a DPO who probably got into a little trouble replacing
the timing chain a few years back and stopped short once the car was running.
I would like to return the engine to its specification, but find the concept
of timing is too much like three dimensional chess for me to handle.
I am thinking of taking off the timing chain with the engine at the present
TDC postion, rotating the crankshaft 360 degrees by pushing the car in gear
and then replacing the timing chain. From the TDC position I have noticed
that the crankshaft turns two revolutions before returning to TDC again
(presuming that the first revolution is the power stroke for cylinder # 1 and
the next the exhaust) so this would allow the rotor to be at the correct
position at TDC and the camshaft would be repositioned to make the valves
operate in the correct sequence to make the engine work, but do I gain
anything else?. I am not sure about the rest of the engine, but this should
work for cylinder #1! I am also thinking that the timing might still be off
a fraction of a gear pitch so even if I reclock the engine to specs, I still
may get the occasional missing problem.
Am I on the right track? Any pitfalls to watch for? Any other indications
to find TDC more accurately?...this way I can just start from scratch and
troubleshoot from there.
I will check the digests and respond to any comments or questions from there,
so my response to any questions might be a little slow but not due to any
lack of interest in an answer. TIA
Jim Gerakaris, San Jose, CA
63 TR-4 CT28595 (trying to get mechanically sound so I can paint!)
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