I was coming back from the Half Fast car club breakfast running about 25-30, beautiful cool sunny morning, all smiles when she bucked, snorted, spit, back fired and died. I coasted onto a side street and tried to start up again but it seemed she was fighting herself, like out of time. I had tools so I pulled the timer cover and found the nut loose on the shaft and the rotor spinning freely. Apparently the nut coming loose caused the pin holding the rotor to shear resulting in totally random firing. I pulled the plug from #1, got her as close to TDC compression as I could, then put every thing in place as best I could. She started but ran very poorly so I drove home ( less than a mile) and made a new pin to hold the rotor in place. She then started and ran normally so I shut her down and went to more pressing matters. Later in the day I noticed water on the floor---the head gasket is leaking by #4 on the valve side. Do you guys think the running out of time blew the gasket?
John,
My guess is that it is unrelated. When it is timed correctly it is firing at the highest pressure point and any incorrectly timed firing would be at a lower pressure.
Just my take on it, either way sounds like if you have a leak the head needs to come off.
Good luck,
Jim
Yes, Jim, that is what I was thinking. I just ordered a new gasket and will change it next weekend. I'm wondering how tight the nut should be on the cam. I pulled until the motor started turning. Should I hold the motor with the starting crank and tighten some more?
I would tend to disagree that the correct timing would be the highest pressure, an advanced spark could cause greater pressure, if the ignition happened well before top dead center, the explosion would happen as the momentum of the car continued to compress the exploding gasses causing enough pressure to blow a head gasket.
Best
Gus
Are you using a locking nut? Vendors sell a nylock nut for the rotor, which is thin like the original.
Jim
No, just a plain nut. Maybe I need to get one of those. I don't want this to happen again.
No, just a plain nut. Maybe I need to get one of those. I don't want this to happen again.
John -- I put a couple of drops of Loctite on them. No problem after that, and you don't need to make a trip to find a special nut.
for future reference, an upholstery or body nail (not the tack) from the welting or under the cushions works well as an emergency pin to hold the timer. They are about half an inch long and may be trimmed a bit with a side cutter if needed. This worked for us and kept us off the trouble trailer as we drove the last 40 miles home. I also didn't have the nut on tight enough.
Thanks all for the input--I'm pulling the head and also locking the nut this weekend.
If the timing was late the engine may have run way hotter than it's used to. If you have an aluminum head, extra heat may have caused warping.. check the head for straightness when it's off (not as urgently needed if you have a std head)