HELP! Distributor Install L79
04-08-2008, 03:05 PM
#1
Melting Slicks
Thread Starter
HELP! Distributor Install L79
Set my timing mark at 10 BTDC on compression stroke. Walked distributor around and it dropped right in with rotor pointing at #1 tower on cap. Turned distributor counter clockwise and vacuum advance hits intake runner before points begin to open. Now what? Should I try moving timing mark on damper to TDC and re-install distributor with rotor pointing to #1 on cap and then start and time engine with a light?
04-08-2008, 03:15 PM
#2
Burning Brakes
You might have to rotate the drive gear 180* The gear has an odd # of teeth (13) and this will rotate the distributor by 1/2 tooth and give you room to clear the firewall and intake nicely. 
04-08-2008, 03:35 PM
#3
Melting Slicks
Thread Starter
Thanks for your quick reply John. I just had the distributor restored and I checked the dimple on the drive gear and its inline with the rotor. I'm not quite sure I understand. Do you mean to move rotor 180 degrees and then walk rotor around till it points to #1 again? Thanks,Gary
Last edited by 65 vette dude; 04-08-2008 at 03:59 PM.
04-08-2008, 03:57 PM
#4
Safety Car
Thanks for your quick reply John. I just had the distributor restored and I checked the dimple on the drive gear and its inline with the rotor. I'm not quite sure I understand. Do you mean to take it out and re-install 180 degrees and then install rotor to point to #1? Thanks,Gary
04-08-2008, 04:12 PM
#6
Drifting
You might have to stick a long screwdriver down and turn the oil pump shaft so that the dist gear will sit on the right tooth of the cam..
Seems like murphys law prevents one from simply getting the balancer at 10-12 btdc, and letting the distributor fall correctly.
its a trial and error effort until you get it right.
what I do, is drop the dist in the engine, and turn it until the vac can is 1/2 way between its rotation....
mark on the intake with tape, exactly where the number 1 plug terminal should be....
remove the cap and see how far off it is (assuming you have the rotor sitting the correct way)
if its off , then you likely need to rotate the oil pump shaft until the distributor gear sits on the right cam gear and oil pump shaft.
and yes, the dimple on the dist gear needs to line up with the rotor electrode otherwise you'll never get the orientation correct.
Thanks
Aaron
Seems like murphys law prevents one from simply getting the balancer at 10-12 btdc, and letting the distributor fall correctly.
its a trial and error effort until you get it right.
what I do, is drop the dist in the engine, and turn it until the vac can is 1/2 way between its rotation....
mark on the intake with tape, exactly where the number 1 plug terminal should be....
remove the cap and see how far off it is (assuming you have the rotor sitting the correct way)
if its off , then you likely need to rotate the oil pump shaft until the distributor gear sits on the right cam gear and oil pump shaft.
and yes, the dimple on the dist gear needs to line up with the rotor electrode otherwise you'll never get the orientation correct.
Thanks
Aaron
Last edited by aaronz28; 04-08-2008 at 04:16 PM.
04-08-2008, 04:24 PM
#7
Melting Slicks
Thread Starter
You might have to stick a long screwdriver down and turn the oil pump shaft so that the dist gear will sit on the right tooth of the cam..
Seems like murphys law prevents one from simply getting the balancer at 10-12 btdc, and letting the distributor fall correctly.
its a trial and error effort until you get it right.
what I do, is drop the dist in the engine, and turn it until the vac can is 1/2 way between its rotation....
mark on the intake with tape, exactly where the number 1 plug terminal should be....
remove the cap and see how far off it is (assuming you have the rotor sitting the correct way)
if its off , then you likely need to rotate the oil pump shaft until the distributor gear sits on the right cam gear and oil pump shaft.
and yes, the dimple on the dist gear needs to line up with the rotor electrode otherwise you'll never get the orientation correct.
Thanks
Aaron
Seems like murphys law prevents one from simply getting the balancer at 10-12 btdc, and letting the distributor fall correctly.
its a trial and error effort until you get it right.
what I do, is drop the dist in the engine, and turn it until the vac can is 1/2 way between its rotation....
mark on the intake with tape, exactly where the number 1 plug terminal should be....
remove the cap and see how far off it is (assuming you have the rotor sitting the correct way)
if its off , then you likely need to rotate the oil pump shaft until the distributor gear sits on the right cam gear and oil pump shaft.
and yes, the dimple on the dist gear needs to line up with the rotor electrode otherwise you'll never get the orientation correct.
Thanks
Aaron
04-08-2008, 04:40 PM
#8
Burning Brakes
I re-read your post and you might be okay. Pick the distributor up and move it counter-clockwise by a tooth. It probably won’t go all the way down because it has to fit into the notch at the top of the oil pump. Once you feel comfortable with the distributors position (clamping screws should be approximately parallel to front axle) either try and move the pump shaft with a long screw driver or disconnect the coil and tap the starter ... it will fall into place. Normally the dimple is aligned with the rotor ... the 1/2 tooth trick is used when you can't quite get into the correct location ... so forget that for now sorry!
04-08-2008, 04:41 PM
#9
Instructor
Vette Dude, One more thing. If you have followed the good advise above and dist still hits the intake, rotate the dist drive gear 180* until the dimple and rotor tip are 180* apart. I am seeing some drive gears with the dimple in the wrong spot. Before you do this make sure everything else is correct. Bill
04-08-2008, 06:08 PM
#10
Burning Brakes
Member Since: Jan 2005
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Set my timing mark at 10 BTDC on compression stroke. Walked distributor around and it dropped right in with rotor pointing at #1 tower on cap. Turned distributor counter clockwise and vacuum advance hits intake runner before points begin to open. Now what? Should I try moving timing mark on damper to TDC and re-install distributor with rotor pointing to #1 on cap and then start and time engine with a light?
I had the same issue when I put mine back together. I couldn't time the engine with the narrow range of motion I had with the distributor. The vacuum can hit both the intake runner and the coil/bracket. What I wound up doing was removing the coil and its bracket so that I could turn the distributor across a wide range. (Note I said 'removed' the coil and bracket but not 'disconnect') I left the coil and bracket hanging by the wires, started the car, timed it so that it ran correctly. I shut it off, set the engine back to TDC, looked at the relationship of the rotor and #1 on the cap. I was able to start moving the distributor over tooth by tooth, turning the distributor back until I had the same relationship between the rotor and #1 while the vacuum can was right in between where the coil/bracket and the intake runner. Fired it back up, fine tuned the timing with the light and it works perfect.
Hope this helps.
Gary
04-08-2008, 06:50 PM
#11
Melting Slicks
Thread Starter
Gary,
I had the same issue when I put mine back together. I couldn't time the engine with the narrow range of motion I had with the distributor. The vacuum can hit both the intake runner and the coil/bracket. What I wound up doing was removing the coil and its bracket so that I could turn the distributor across a wide range. (Note I said 'removed' the coil and bracket but not 'disconnect') I left the coil and bracket hanging by the wires, started the car, timed it so that it ran correctly. I shut it off, set the engine back to TDC, looked at the relationship of the rotor and #1 on the cap. I was able to start moving the distributor over tooth by tooth, turning the distributor back until I had the same relationship between the rotor and #1 while the vacuum can was right in between where the coil/bracket and the intake runner. Fired it back up, fine tuned the timing with the light and it works perfect.
Hope this helps.
Gary
I had the same issue when I put mine back together. I couldn't time the engine with the narrow range of motion I had with the distributor. The vacuum can hit both the intake runner and the coil/bracket. What I wound up doing was removing the coil and its bracket so that I could turn the distributor across a wide range. (Note I said 'removed' the coil and bracket but not 'disconnect') I left the coil and bracket hanging by the wires, started the car, timed it so that it ran correctly. I shut it off, set the engine back to TDC, looked at the relationship of the rotor and #1 on the cap. I was able to start moving the distributor over tooth by tooth, turning the distributor back until I had the same relationship between the rotor and #1 while the vacuum can was right in between where the coil/bracket and the intake runner. Fired it back up, fine tuned the timing with the light and it works perfect.
Hope this helps.
Gary
04-08-2008, 07:08 PM
#12
Melting Slicks
Thread Starter
Gary,
I had the same issue when I put mine back together. I couldn't time the engine with the narrow range of motion I had with the distributor. The vacuum can hit both the intake runner and the coil/bracket. What I wound up doing was removing the coil and its bracket so that I could turn the distributor across a wide range. (Note I said 'removed' the coil and bracket but not 'disconnect') I left the coil and bracket hanging by the wires, started the car, timed it so that it ran correctly. I shut it off, set the engine back to TDC, looked at the relationship of the rotor and #1 on the cap. I was able to start moving the distributor over tooth by tooth, turning the distributor back until I had the same relationship between the rotor and #1 while the vacuum can was right in between where the coil/bracket and the intake runner. Fired it back up, fine tuned the timing with the light and it works perfect.
Hope this helps.
Gary
I had the same issue when I put mine back together. I couldn't time the engine with the narrow range of motion I had with the distributor. The vacuum can hit both the intake runner and the coil/bracket. What I wound up doing was removing the coil and its bracket so that I could turn the distributor across a wide range. (Note I said 'removed' the coil and bracket but not 'disconnect') I left the coil and bracket hanging by the wires, started the car, timed it so that it ran correctly. I shut it off, set the engine back to TDC, looked at the relationship of the rotor and #1 on the cap. I was able to start moving the distributor over tooth by tooth, turning the distributor back until I had the same relationship between the rotor and #1 while the vacuum can was right in between where the coil/bracket and the intake runner. Fired it back up, fine tuned the timing with the light and it works perfect.
Hope this helps.
Gary
04-08-2008, 07:39 PM
#13
Race Director
65 vette dude -- In a similar situation I followed Lar's advice to "walk" the distributor in a reverse-rotation sense to get to its correct position. Unfortunately, I can't find my instructions how exactly to accomplish this task. Maybe someone else here will remember the details.
04-08-2008, 08:30 PM
#14
Instructor
Vette Dude,
One other thing you may want to check is your plug wires. Is the #1 plug wire on the correct distributor tower? You may need to rotate all the wires one tower clockwise or counter clockwise.
Good Luck.
Larry
One other thing you may want to check is your plug wires. Is the #1 plug wire on the correct distributor tower? You may need to rotate all the wires one tower clockwise or counter clockwise.
Good Luck.
Larry
04-08-2008, 10:53 PM
#15
Melting Slicks
Thread Starter
Yes,I double checked my clocking using a ohm meter and that is correct. Number one tower is the first one after the widow. The thought has crossed my mind about moving all the wires one tower forward or backward and I might be able to gain the extra distributor movement I need to correctly set my timing. I shouldn't have to do that though. I'm beginning to think that my damper might have slipped. Oh well,tomorrow is another day. Thanks all for the great suggestions.
04-08-2008, 11:07 PM
#17
Melting Slicks
Thread Starter
65 vette dude -- In a similar situation I followed Lar's advice to "walk" the distributor in a reverse-rotation sense to get to its correct position. Unfortunately, I can't find my instructions how exactly to accomplish this task. Maybe someone else here will remember the details.
04-08-2008, 11:11 PM
#18
Melting Slicks
Thread Starter
04-09-2008, 08:41 AM
#19
Le Mans Master
note that in some rare cases, the rotor tip opposite the dimple is nec.
If you are absolutely stuck and it is not working out with the rotor tip in line with the dimple, doesn't hurt to try.
PS - you can also simply re-clock the plug wires on the cap, but purists will now show up in this thread and stone me
(I say, what goes on underneath the big ignition shield piece stays underneath the big ignition shield piece; just like Vegas, no one will know)
If you are absolutely stuck and it is not working out with the rotor tip in line with the dimple, doesn't hurt to try.
PS - you can also simply re-clock the plug wires on the cap, but purists will now show up in this thread and stone me
(I say, what goes on underneath the big ignition shield piece stays underneath the big ignition shield piece; just like Vegas, no one will know)
04-09-2008, 12:29 PM
#20
Melting Slicks
I had to position the dimple 180 out for correct orientation of the vac. adv. can.
note that in some rare cases, the rotor tip opposite the dimple is nec.
If you are absolutely stuck and it is not working out with the rotor tip in line with the dimple, doesn't hurt to try.
PS - you can also simply re-clock the plug wires on the cap, but purists will now show up in this thread and stone me (I say, what goes on underneath the big ignition shield piece stays underneath the big ignition shield piece; just like Vegas, no one will know)
If you are absolutely stuck and it is not working out with the rotor tip in line with the dimple, doesn't hurt to try.
PS - you can also simply re-clock the plug wires on the cap, but purists will now show up in this thread and stone me
(I say, what goes on underneath the big ignition shield piece stays underneath the big ignition shield piece; just like Vegas, no one will know)