Jagguy
Freshman Member
Offline
OK, I've been messing around with this issue long enough for me to get completely confused!
I bought a 67 MGB a couple months ago. Pretty nice driver but has a nagging running hot issue.
At first I figured it was a cooling system problem but after replacing the thermostat and having the radiator rodded and the block flushed it still runs hot.
Hot meaning after 30 minutes driving the gauge is about pegged..
Oh, and I do have an IR thermometer and have checked the accuracy of the gauge.
So I check the timing. The marks are at 6 o'clock on the timing cover.
The timing mark on the pulley idling at 750 rpm with the vacuum advance line plugged is at about 4 o'clock using a timing light.
Humm...
I turn the dizzy clockwise to set the timing and it barely runs. Not really driveable.
I check for tdc with the #1 piston at the top of the stroke and the marks on the pulley line up with the marks at 6 o'clock.
I turn the dizzy back to where it was and its running well again but hot.
I'm starting to get confused.
Turning the dizzy clockwise advances the timing right?
With the timing mark at 4 o'clock it's retarded right?
When I turn the dizzy clockwise the rpm goes down! Shouldn't it increase?
One thing, it has a Pertronix unit on it. I'm not a real fan of those. I got a set of points and a condenser to check for any improvement but I also need the low tension lead adapter so I have that coming before I can try it with points.
I need to replace the front seal so I will be able to check for a cam-timing problem. Never know with a 50 year old car...
Does any of this make any sense? I would like to drive this for longer than 30 minutes!
Thanks for your time and your thoughts.
I bought a 67 MGB a couple months ago. Pretty nice driver but has a nagging running hot issue.
At first I figured it was a cooling system problem but after replacing the thermostat and having the radiator rodded and the block flushed it still runs hot.
Hot meaning after 30 minutes driving the gauge is about pegged..
Oh, and I do have an IR thermometer and have checked the accuracy of the gauge.
So I check the timing. The marks are at 6 o'clock on the timing cover.
The timing mark on the pulley idling at 750 rpm with the vacuum advance line plugged is at about 4 o'clock using a timing light.
Humm...
I turn the dizzy clockwise to set the timing and it barely runs. Not really driveable.
I check for tdc with the #1 piston at the top of the stroke and the marks on the pulley line up with the marks at 6 o'clock.
I turn the dizzy back to where it was and its running well again but hot.
I'm starting to get confused.
Turning the dizzy clockwise advances the timing right?
With the timing mark at 4 o'clock it's retarded right?
When I turn the dizzy clockwise the rpm goes down! Shouldn't it increase?
One thing, it has a Pertronix unit on it. I'm not a real fan of those. I got a set of points and a condenser to check for any improvement but I also need the low tension lead adapter so I have that coming before I can try it with points.
I need to replace the front seal so I will be able to check for a cam-timing problem. Never know with a 50 year old car...
Does any of this make any sense? I would like to drive this for longer than 30 minutes!
Thanks for your time and your thoughts.