Timing Questions
#1
Timing Questions
I am close to starting up my '79 Mini after 10 months of rebuilding. The car was in storage at my father's home and he drove it monthly while he had it - at least until it lost oil pressure. The engine developed a leak at the drive shaft that was repaired by a local british motor garage. The engine was cleaned, painted, some gaskets replaced, radiator pressure tested, new hoses, and was given a good inspection. It only has 30K miles on it since new.
The engine is back in the car and I was planning to set the static timing with my old distributor and then install a new distributor with electronic ignition in the same orientation prior to firing it up and setting timing for the Stage 1 kit that I installed. My issue is that my setup does not seem to reflect what I have read regarding setting the timing.
Here is where I am and my assumptions:
My engine was supposedly run and checked out with good oil pressure after repair using the old distributor - but I was not there to see this process.
Currently the car is up on jack stands as I have not completed the front suspension so taking it somewhere is not likely until I finish it out.
Any suggestions/help would be much appreciated - something does not look right and I do not which direction to turn.......
Thanks!
The engine is back in the car and I was planning to set the static timing with my old distributor and then install a new distributor with electronic ignition in the same orientation prior to firing it up and setting timing for the Stage 1 kit that I installed. My issue is that my setup does not seem to reflect what I have read regarding setting the timing.
Here is where I am and my assumptions:
- #1 cylinder is the radiator end of the engine
- distributor appears to only install one way due to the tab on the bottom being offset from center when installing into the engine i.e cant' be installed 180 degrees out
- TDC was set using the larger mark on the pulley and the timing marks on the engine block
- piston is visible at the top of the stroke through the #1 spark plug hole
- I have read that the rotor should point to the #1 cyclinder at TDC - mine does not it points to essentially a 9 0'clock position
- I took pictures of the orientation of my distributor and the plug wire locations when I pulled the engine.
- My pictures show the vacuum advance is at a 1 or 2 o'clock position when installed
- My notes show that the #4 cylinder was at the 9 o'clock position on the distributor - therefore #1 was at 3 o'clock position
My engine was supposedly run and checked out with good oil pressure after repair using the old distributor - but I was not there to see this process.
Currently the car is up on jack stands as I have not completed the front suspension so taking it somewhere is not likely until I finish it out.
Any suggestions/help would be much appreciated - something does not look right and I do not which direction to turn.......
Thanks!
#3
Hi..On new builds did you set dizzy drive shaft as pic.............
and now to set timming ......Remove rocker cover and remove plugs pop in 1st gear and pull car forward untill NO:s 1-2 rockers are rocking this is firing stroke....
now remove dizy cap and put a dot of white paint opp rotar arm on block...
now pop dizzy cap back and make sure NO: 1 lead is opp white dot and firing order is 1-3-4-2 in anticlockwisr order........
now replace cover and your ready to prime oil preassure...undo large bango bolt above oil pressure switch and fill with oil replace bolt and turn engine over untill oil pressure reads 50-75 psi then replace plugs and try and start engine..............good luck............Mark
and now to set timming ......Remove rocker cover and remove plugs pop in 1st gear and pull car forward untill NO:s 1-2 rockers are rocking this is firing stroke....
now remove dizy cap and put a dot of white paint opp rotar arm on block...
now pop dizzy cap back and make sure NO: 1 lead is opp white dot and firing order is 1-3-4-2 in anticlockwisr order........
now replace cover and your ready to prime oil preassure...undo large bango bolt above oil pressure switch and fill with oil replace bolt and turn engine over untill oil pressure reads 50-75 psi then replace plugs and try and start engine..............good luck............Mark
#4
What some manuals don't tell you is that later distributers, or distributers made from newer stock to fit older blocks (ie: Pertronix and Aldon) often times have the rotor pointing the opposite way (180 out) as from what they were when the original motors and dizzys were built and assembled at the factory-- (25D vs 45D and 59D bodies)
To check, remove the caps of both dizzys and look which way the rotor is pointing, then look at the way the offset is on the spindle drive end (end that goes in the block). I would almost bet you dollars to donuts that your distributers have the rotors pointing opposite directions when the drive dogs are offset the same way.
No need to panic if this is the case: all you need to do is move wires by swapping 1&4 and then 2&3. Still same firing order, but instead of #1 being at 1, 2, or 3 o'clock position, it's at 7, 8, or 9 o'clock position.
Oh, also just because the timing mark on the pulley lines up with tdc for cylinder #1 it doesn't mean #1 is on the firing (compression) stroke-- it could be on the exhaust stroke. When #1 is on compression stroke #4 is on exhaust stroke, and vice-versa. This also explains why if it doesn't fire with the wires hooked up one way, it's worth simply swapping the wires as I described earlier to see if it fires then. If it really irks you, you can reset the drive spindle later after you know it runs...
--Spank
To check, remove the caps of both dizzys and look which way the rotor is pointing, then look at the way the offset is on the spindle drive end (end that goes in the block). I would almost bet you dollars to donuts that your distributers have the rotors pointing opposite directions when the drive dogs are offset the same way.
No need to panic if this is the case: all you need to do is move wires by swapping 1&4 and then 2&3. Still same firing order, but instead of #1 being at 1, 2, or 3 o'clock position, it's at 7, 8, or 9 o'clock position.
Oh, also just because the timing mark on the pulley lines up with tdc for cylinder #1 it doesn't mean #1 is on the firing (compression) stroke-- it could be on the exhaust stroke. When #1 is on compression stroke #4 is on exhaust stroke, and vice-versa. This also explains why if it doesn't fire with the wires hooked up one way, it's worth simply swapping the wires as I described earlier to see if it fires then. If it really irks you, you can reset the drive spindle later after you know it runs...
--Spank
#6
Well - I have been officially humbled again as a noob on my rebuild project. I compared the two distributors - original vs. my new electronic ignition flamethrower - and they are set up exactly the same. Then, after talking to a friend at work who has rebuilt a couple of older US vehicles, I came to the conclusion how little I really understood about the mechanical operation of the automobile engine. But I will plead the 5th - I'm an electrical engineer not a mechanical one...
Now that I understand more about the mechanical relationahip between the crank and distributor rotor, it took five minutes to turn the crank one revolution to the TDC mark on the pulley and have the rotor pointing in the correct direction and now the plug wires make sense vs. when they were removed. I guess if I had taken more time to read and understand TDC and compression vs exhaust stroke - this would have been easier
Before I fire the engine up, what is the best way to generate some oil pressure? I have read that pulling the plugs & wires, disconnect coil from distributor and turning the starter over a few times will build up oil pressure. I have also heard you can use a drill to run the oil pump?
Thanks for any help........
Now that I understand more about the mechanical relationahip between the crank and distributor rotor, it took five minutes to turn the crank one revolution to the TDC mark on the pulley and have the rotor pointing in the correct direction and now the plug wires make sense vs. when they were removed. I guess if I had taken more time to read and understand TDC and compression vs exhaust stroke - this would have been easier
Before I fire the engine up, what is the best way to generate some oil pressure? I have read that pulling the plugs & wires, disconnect coil from distributor and turning the starter over a few times will build up oil pressure. I have also heard you can use a drill to run the oil pump?
Thanks for any help........
#7
I didn't get pressure on mine until I did what mk1leg suggested in an earlier post- disconnect the large banjo bolt on the oil pressure switch and prime with oil. We had to do that several times, but the pressure came right up after that. Good luck, and by the way, my 1275 was 180 degrees out, too, and I had to remind my mechanic that the timing marks line up on exhaust as well as compression! So even the experienced sometimes go wrong.
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