340 timing
10-09-2012, 04:13 PM
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340 timing
ok i,m confused i got my 340 10 degrees before top dead center when i drop the distributor in does it matter which cap hole i make number 1 on the cap i thought that the rotor has to point towards the number 1 cyl on eng. Am i wrong. i was gonna put the rotor just past one of the distr cap holes and drop it in and call that number one but if i do that that rotor could point anywhere.thanks for any info
10-09-2012, 05:22 PM
#2
Mopar Fanatic
Well never tried that just always put the number one wire where it belongs ! If the tip of the distributor doesn't line up use a long screw driver and put it in the slot and turn it back wile lifting on the gear it should back right up and get it to where you need it to point to # 1 . This is what I needed to do to install the gm stile hei distributor as it did not match the oem location of the tip ! Good luck !
10-09-2012, 06:06 PM
#3
The no1 cylinder must be on the compression stroke, and the no1 wire must go to wherever the rotor points. If the rotor is NOT pointing to the "by the book" no 1 cap tower, it will run fine, but if you want to do it correctly it simply is not that difficult and takes VERY little time
To time a SB Mopar:
1--- Determine that no1 is on the firing stroke and there are two ways to do that. If either valve cover is still off, look at either the no1 or no6 valves, with the timing marks on TDC. IF both no1 valves are closed, no1 is ready to fire (compression) and if no6 valves are both closed, then no6 is ready to fire. BE CAREFUL because the opposite two will be nearly equally open (used to be called "split overlap) and it can fool you
The alternate way to determine compression, is to remove no1 plug, stick you finger in the hole, and either bump it on the starter, or wrench it around until you BEGIN to feel compression. You may need to go around once to be sure. When you start to feel compression, pay attention to the timing mark, and slowly bring the engine up NOT to TDC but to where you want the timing, IE 10-12 with a bone stock cam, or 15-20 with a hot cam
2---If there is any reason to suspect the distributor gear is in wrong, or this is a new build, bring the marks to TDC, and check the position of the slot in the gear. IT should point to the far left (drivers side) front intake manifold bolt, which is a close as you'll get to "straight ahead." If it does NOT, as the poster above suggested, just take a big screwdriver and "walk" the gear up out of the helix, and correct it
3---(If you performed step 2, back the engine up with a wrench about 1/8 turn, and bring the marks back NOT to TDC, but where you want the timing.)
Next, with the rotor pointing towards the area of the "by the book" no1 hole, and the vacuum can "in the clear away from the firewall, drop the distributor in. By rotating the distributor body, you should reach a point where the vacuum can is clear of the coil and the firewall, and the rotor is pointing to the no1 cap tower
4---Now, if you have points ignition, use a test lamp or ohmeter, rotate the dist. RETARD (cw) and move it slowly ADVANCE (ccw) until the points just open
If you have breakerless set the dist. so that the reluctor tip is centered in the pickup coil.
5---Start the engine!!!! Notice that I did not say, "prepare for fire out of the carburetor," nor did I say "screw endlessly with the distributor for hours on end."
If you followed this correctly the engine should start!!! and run!!!!
6---Now take your timing light and adjust the timing as necessary.
Some aside:
I ALWAYS, on an unknown engine, CHECK actual TDC accuracy. To do this, get, buy, or make a piston stop.
Like this:
Remove the no1 plug, make sure the piston is down, and remove the battery ground. Install the device, and wrench the engine gently over until the piston stops against the device. Make an accurate, temporary mark directly under 0 (TDC) on you timing tab, onto the balancer.
Now do the exact same rotating the engine CCW
Now you'll have TWO temporary marks, and true TDC will be 1/2 way between. If your old mark is accurate, that is where it will be.
You should also either get the proper size timing tape, or mark your balancer so you can see what your timing curve is doing. Measure all the way around the balancer, accurately, with a small flexible tape. Calculate how many inches per degrees it takes to work out 40*, carefully measure that off with the tape, and mark the wheel. Use a small square and a scribe, and carefully deepen the mark with a small file. I used to do this lying on my back looking up at the wheel, easier than bending over on my head.
Now you can take dividers and divide the 40 in half for 20, half again for 10. Then use your ten setting to mark 50, 60* which will be needed for checking vacuum advance. You can get as fussy as you want, but 5* marks are really all you need. You can get an idea of your accuracy, by rotating any two marks under the timing tab, and checking if they line up at 10ATC, 10BTC, etc.
To time a SB Mopar:
1--- Determine that no1 is on the firing stroke and there are two ways to do that. If either valve cover is still off, look at either the no1 or no6 valves, with the timing marks on TDC. IF both no1 valves are closed, no1 is ready to fire (compression) and if no6 valves are both closed, then no6 is ready to fire. BE CAREFUL because the opposite two will be nearly equally open (used to be called "split overlap) and it can fool you
The alternate way to determine compression, is to remove no1 plug, stick you finger in the hole, and either bump it on the starter, or wrench it around until you BEGIN to feel compression. You may need to go around once to be sure. When you start to feel compression, pay attention to the timing mark, and slowly bring the engine up NOT to TDC but to where you want the timing, IE 10-12 with a bone stock cam, or 15-20 with a hot cam
2---If there is any reason to suspect the distributor gear is in wrong, or this is a new build, bring the marks to TDC, and check the position of the slot in the gear. IT should point to the far left (drivers side) front intake manifold bolt, which is a close as you'll get to "straight ahead." If it does NOT, as the poster above suggested, just take a big screwdriver and "walk" the gear up out of the helix, and correct it
3---(If you performed step 2, back the engine up with a wrench about 1/8 turn, and bring the marks back NOT to TDC, but where you want the timing.)
Next, with the rotor pointing towards the area of the "by the book" no1 hole, and the vacuum can "in the clear away from the firewall, drop the distributor in. By rotating the distributor body, you should reach a point where the vacuum can is clear of the coil and the firewall, and the rotor is pointing to the no1 cap tower
4---Now, if you have points ignition, use a test lamp or ohmeter, rotate the dist. RETARD (cw) and move it slowly ADVANCE (ccw) until the points just open
If you have breakerless set the dist. so that the reluctor tip is centered in the pickup coil.
5---Start the engine!!!! Notice that I did not say, "prepare for fire out of the carburetor," nor did I say "screw endlessly with the distributor for hours on end."
If you followed this correctly the engine should start!!! and run!!!!
6---Now take your timing light and adjust the timing as necessary.
Some aside:
I ALWAYS, on an unknown engine, CHECK actual TDC accuracy. To do this, get, buy, or make a piston stop.
Like this:
Remove the no1 plug, make sure the piston is down, and remove the battery ground. Install the device, and wrench the engine gently over until the piston stops against the device. Make an accurate, temporary mark directly under 0 (TDC) on you timing tab, onto the balancer.
Now do the exact same rotating the engine CCW
Now you'll have TWO temporary marks, and true TDC will be 1/2 way between. If your old mark is accurate, that is where it will be.
You should also either get the proper size timing tape, or mark your balancer so you can see what your timing curve is doing. Measure all the way around the balancer, accurately, with a small flexible tape. Calculate how many inches per degrees it takes to work out 40*, carefully measure that off with the tape, and mark the wheel. Use a small square and a scribe, and carefully deepen the mark with a small file. I used to do this lying on my back looking up at the wheel, easier than bending over on my head.
Now you can take dividers and divide the 40 in half for 20, half again for 10. Then use your ten setting to mark 50, 60* which will be needed for checking vacuum advance. You can get as fussy as you want, but 5* marks are really all you need. You can get an idea of your accuracy, by rotating any two marks under the timing tab, and checking if they line up at 10ATC, 10BTC, etc.
10-10-2012, 09:07 AM
#4
The no1 cylinder must be on the compression stroke, and the no1 wire must go to wherever the rotor points. If the rotor is NOT pointing to the "by the book" no 1 cap tower, it will run fine, but if you want to do it correctly it simply is not that difficult and takes VERY little time
To time a SB Mopar:
1--- Determine that no1 is on the firing stroke and there are two ways to do that. If either valve cover is still off, look at either the no1 or no6 valves, with the timing marks on TDC. IF both no1 valves are closed, no1 is ready to fire (compression) and if no6 valves are both closed, then no6 is ready to fire. BE CAREFUL because the opposite two will be nearly equally open (used to be called "split overlap) and it can fool you
The alternate way to determine compression, is to remove no1 plug, stick you finger in the hole, and either bump it on the starter, or wrench it around until you BEGIN to feel compression. You may need to go around once to be sure. When you start to feel compression, pay attention to the timing mark, and slowly bring the engine up NOT to TDC but to where you want the timing, IE 10-12 with a bone stock cam, or 15-20 with a hot cam
2---If there is any reason to suspect the distributor gear is in wrong, or this is a new build, bring the marks to TDC, and check the position of the slot in the gear. IT should point to the far left (drivers side) front intake manifold bolt, which is a close as you'll get to "straight ahead." If it does NOT, as the poster above suggested, just take a big screwdriver and "walk" the gear up out of the helix, and correct it
3---(If you performed step 2, back the engine up with a wrench about 1/8 turn, and bring the marks back NOT to TDC, but where you want the timing.)
Next, with the rotor pointing towards the area of the "by the book" no1 hole, and the vacuum can "in the clear away from the firewall, drop the distributor in. By rotating the distributor body, you should reach a point where the vacuum can is clear of the coil and the firewall, and the rotor is pointing to the no1 cap tower
4---Now, if you have points ignition, use a test lamp or ohmeter, rotate the dist. RETARD (cw) and move it slowly ADVANCE (ccw) until the points just open
If you have breakerless set the dist. so that the reluctor tip is centered in the pickup coil.
5---Start the engine!!!! Notice that I did not say, "prepare for fire out of the carburetor," nor did I say "screw endlessly with the distributor for hours on end."
If you followed this correctly the engine should start!!! and run!!!!
6---Now take your timing light and adjust the timing as necessary.
Some aside:
I ALWAYS, on an unknown engine, CHECK actual TDC accuracy. To do this, get, buy, or make a piston stop.
Like this:
Remove the no1 plug, make sure the piston is down, and remove the battery ground. Install the device, and wrench the engine gently over until the piston stops against the device. Make an accurate, temporary mark directly under 0 (TDC) on you timing tab, onto the balancer.
Now do the exact same rotating the engine CCW
Now you'll have TWO temporary marks, and true TDC will be 1/2 way between. If your old mark is accurate, that is where it will be.
You should also either get the proper size timing tape, or mark your balancer so you can see what your timing curve is doing. Measure all the way around the balancer, accurately, with a small flexible tape. Calculate how many inches per degrees it takes to work out 40*, carefully measure that off with the tape, and mark the wheel. Use a small square and a scribe, and carefully deepen the mark with a small file. I used to do this lying on my back looking up at the wheel, easier than bending over on my head.
Now you can take dividers and divide the 40 in half for 20, half again for 10. Then use your ten setting to mark 50, 60* which will be needed for checking vacuum advance. You can get as fussy as you want, but 5* marks are really all you need. You can get an idea of your accuracy, by rotating any two marks under the timing tab, and checking if they line up at 10ATC, 10BTC, etc.
To time a SB Mopar:
1--- Determine that no1 is on the firing stroke and there are two ways to do that. If either valve cover is still off, look at either the no1 or no6 valves, with the timing marks on TDC. IF both no1 valves are closed, no1 is ready to fire (compression) and if no6 valves are both closed, then no6 is ready to fire. BE CAREFUL because the opposite two will be nearly equally open (used to be called "split overlap) and it can fool you
The alternate way to determine compression, is to remove no1 plug, stick you finger in the hole, and either bump it on the starter, or wrench it around until you BEGIN to feel compression. You may need to go around once to be sure. When you start to feel compression, pay attention to the timing mark, and slowly bring the engine up NOT to TDC but to where you want the timing, IE 10-12 with a bone stock cam, or 15-20 with a hot cam
2---If there is any reason to suspect the distributor gear is in wrong, or this is a new build, bring the marks to TDC, and check the position of the slot in the gear. IT should point to the far left (drivers side) front intake manifold bolt, which is a close as you'll get to "straight ahead." If it does NOT, as the poster above suggested, just take a big screwdriver and "walk" the gear up out of the helix, and correct it
3---(If you performed step 2, back the engine up with a wrench about 1/8 turn, and bring the marks back NOT to TDC, but where you want the timing.)
Next, with the rotor pointing towards the area of the "by the book" no1 hole, and the vacuum can "in the clear away from the firewall, drop the distributor in. By rotating the distributor body, you should reach a point where the vacuum can is clear of the coil and the firewall, and the rotor is pointing to the no1 cap tower
4---Now, if you have points ignition, use a test lamp or ohmeter, rotate the dist. RETARD (cw) and move it slowly ADVANCE (ccw) until the points just open
If you have breakerless set the dist. so that the reluctor tip is centered in the pickup coil.
5---Start the engine!!!! Notice that I did not say, "prepare for fire out of the carburetor," nor did I say "screw endlessly with the distributor for hours on end."
If you followed this correctly the engine should start!!! and run!!!!
6---Now take your timing light and adjust the timing as necessary.
Some aside:
I ALWAYS, on an unknown engine, CHECK actual TDC accuracy. To do this, get, buy, or make a piston stop.
Like this:
Remove the no1 plug, make sure the piston is down, and remove the battery ground. Install the device, and wrench the engine gently over until the piston stops against the device. Make an accurate, temporary mark directly under 0 (TDC) on you timing tab, onto the balancer.
Now do the exact same rotating the engine CCW
Now you'll have TWO temporary marks, and true TDC will be 1/2 way between. If your old mark is accurate, that is where it will be.
You should also either get the proper size timing tape, or mark your balancer so you can see what your timing curve is doing. Measure all the way around the balancer, accurately, with a small flexible tape. Calculate how many inches per degrees it takes to work out 40*, carefully measure that off with the tape, and mark the wheel. Use a small square and a scribe, and carefully deepen the mark with a small file. I used to do this lying on my back looking up at the wheel, easier than bending over on my head.
Now you can take dividers and divide the 40 in half for 20, half again for 10. Then use your ten setting to mark 50, 60* which will be needed for checking vacuum advance. You can get as fussy as you want, but 5* marks are really all you need. You can get an idea of your accuracy, by rotating any two marks under the timing tab, and checking if they line up at 10ATC, 10BTC, etc.
You got the right man on the job now willysman69.......I bet he has forgot more than most guys know...LOL
10-10-2012, 10:38 AM
#5
10-10-2012, 01:51 PM
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03-13-2013, 07:24 PM
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ok i,m confused i got my 340 10 degrees before top dead center when i drop the distributor in does it matter which cap hole i make number 1 on the cap i thought that the rotor has to point towards the number 1 cyl on eng. Am i wrong. i was gonna put the rotor just past one of the distr cap holes and drop it in and call that number one but if i do that that rotor could point anywhere.thanks for any info
not sure how to use this site yet,i just bought a 86 ramchr w 318 timming mark is on the pass side the tabs on the left the cap is correct 1 tdc
03-13-2013, 07:28 PM
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86,318 timming mark
i just replaced plugs,wires,cap rtr,the engine was popping threw the carb i found tdc,put the t lite on #1 and no mark the moter is running great except when i sut it off it tries to stay running kinda,i looked on the pass side and there is my mark?
03-13-2013, 07:30 PM
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what is causing the t mark to be on the wrong side
03-21-2014, 10:49 PM
#13
The no1 cylinder must be on the compression stroke, and the no1 wire must go to wherever the rotor points. If the rotor is NOT pointing to the "by the book" no 1 cap tower, it will run fine, but if you want to do it correctly it simply is not that difficult and takes VERY little time
To time a SB Mopar:
1--- Determine that no1 is on the firing stroke and there are two ways to do that. If either valve cover is still off, look at either the no1 or no6 valves, with the timing marks on TDC. IF both no1 valves are closed, no1 is ready to fire (compression) and if no6 valves are both closed, then no6 is ready to fire. BE CAREFUL because the opposite two will be nearly equally open (used to be called "split overlap) and it can fool you
The alternate way to determine compression, is to remove no1 plug, stick you finger in the hole, and either bump it on the starter, or wrench it around until you BEGIN to feel compression. You may need to go around once to be sure. When you start to feel compression, pay attention to the timing mark, and slowly bring the engine up NOT to TDC but to where you want the timing, IE 10-12 with a bone stock cam, or 15-20 with a hot cam
2---If there is any reason to suspect the distributor gear is in wrong, or this is a new build, bring the marks to TDC, and check the position of the slot in the gear. IT should point to the far left (drivers side) front intake manifold bolt, which is a close as you'll get to "straight ahead." If it does NOT, as the poster above suggested, just take a big screwdriver and "walk" the gear up out of the helix, and correct it
3---(If you performed step 2, back the engine up with a wrench about 1/8 turn, and bring the marks back NOT to TDC, but where you want the timing.)
Next, with the rotor pointing towards the area of the "by the book" no1 hole, and the vacuum can "in the clear away from the firewall, drop the distributor in. By rotating the distributor body, you should reach a point where the vacuum can is clear of the coil and the firewall, and the rotor is pointing to the no1 cap tower
4---Now, if you have points ignition, use a test lamp or ohmeter, rotate the dist. RETARD (cw) and move it slowly ADVANCE (ccw) until the points just open
If you have breakerless set the dist. so that the reluctor tip is centered in the pickup coil.
5---Start the engine!!!! Notice that I did not say, "prepare for fire out of the carburetor," nor did I say "screw endlessly with the distributor for hours on end."
If you followed this correctly the engine should start!!! and run!!!!
6---Now take your timing light and adjust the timing as necessary.
Some aside:
I ALWAYS, on an unknown engine, CHECK actual TDC accuracy. To do this, get, buy, or make a piston stop.
Like this:
Remove the no1 plug, make sure the piston is down, and remove the battery ground. Install the device, and wrench the engine gently over until the piston stops against the device. Make an accurate, temporary mark directly under 0 (TDC) on you timing tab, onto the balancer.
Now do the exact same rotating the engine CCW
Now you'll have TWO temporary marks, and true TDC will be 1/2 way between. If your old mark is accurate, that is where it will be.
You should also either get the proper size timing tape, or mark your balancer so you can see what your timing curve is doing. Measure all the way around the balancer, accurately, with a small flexible tape. Calculate how many inches per degrees it takes to work out 40*, carefully measure that off with the tape, and mark the wheel. Use a small square and a scribe, and carefully deepen the mark with a small file. I used to do this lying on my back looking up at the wheel, easier than bending over on my head.
Now you can take dividers and divide the 40 in half for 20, half again for 10. Then use your ten setting to mark 50, 60* which will be needed for checking vacuum advance. You can get as fussy as you want, but 5* marks are really all you need. You can get an idea of your accuracy, by rotating any two marks under the timing tab, and checking if they line up at 10ATC, 10BTC, etc.
To time a SB Mopar:
1--- Determine that no1 is on the firing stroke and there are two ways to do that. If either valve cover is still off, look at either the no1 or no6 valves, with the timing marks on TDC. IF both no1 valves are closed, no1 is ready to fire (compression) and if no6 valves are both closed, then no6 is ready to fire. BE CAREFUL because the opposite two will be nearly equally open (used to be called "split overlap) and it can fool you
The alternate way to determine compression, is to remove no1 plug, stick you finger in the hole, and either bump it on the starter, or wrench it around until you BEGIN to feel compression. You may need to go around once to be sure. When you start to feel compression, pay attention to the timing mark, and slowly bring the engine up NOT to TDC but to where you want the timing, IE 10-12 with a bone stock cam, or 15-20 with a hot cam
2---If there is any reason to suspect the distributor gear is in wrong, or this is a new build, bring the marks to TDC, and check the position of the slot in the gear. IT should point to the far left (drivers side) front intake manifold bolt, which is a close as you'll get to "straight ahead." If it does NOT, as the poster above suggested, just take a big screwdriver and "walk" the gear up out of the helix, and correct it
3---(If you performed step 2, back the engine up with a wrench about 1/8 turn, and bring the marks back NOT to TDC, but where you want the timing.)
Next, with the rotor pointing towards the area of the "by the book" no1 hole, and the vacuum can "in the clear away from the firewall, drop the distributor in. By rotating the distributor body, you should reach a point where the vacuum can is clear of the coil and the firewall, and the rotor is pointing to the no1 cap tower
4---Now, if you have points ignition, use a test lamp or ohmeter, rotate the dist. RETARD (cw) and move it slowly ADVANCE (ccw) until the points just open
If you have breakerless set the dist. so that the reluctor tip is centered in the pickup coil.
5---Start the engine!!!! Notice that I did not say, "prepare for fire out of the carburetor," nor did I say "screw endlessly with the distributor for hours on end."
If you followed this correctly the engine should start!!! and run!!!!
6---Now take your timing light and adjust the timing as necessary.
Some aside:
I ALWAYS, on an unknown engine, CHECK actual TDC accuracy. To do this, get, buy, or make a piston stop.
Like this:
Remove the no1 plug, make sure the piston is down, and remove the battery ground. Install the device, and wrench the engine gently over until the piston stops against the device. Make an accurate, temporary mark directly under 0 (TDC) on you timing tab, onto the balancer.
Now do the exact same rotating the engine CCW
Now you'll have TWO temporary marks, and true TDC will be 1/2 way between. If your old mark is accurate, that is where it will be.
You should also either get the proper size timing tape, or mark your balancer so you can see what your timing curve is doing. Measure all the way around the balancer, accurately, with a small flexible tape. Calculate how many inches per degrees it takes to work out 40*, carefully measure that off with the tape, and mark the wheel. Use a small square and a scribe, and carefully deepen the mark with a small file. I used to do this lying on my back looking up at the wheel, easier than bending over on my head.
Now you can take dividers and divide the 40 in half for 20, half again for 10. Then use your ten setting to mark 50, 60* which will be needed for checking vacuum advance. You can get as fussy as you want, but 5* marks are really all you need. You can get an idea of your accuracy, by rotating any two marks under the timing tab, and checking if they line up at 10ATC, 10BTC, etc.
The following users liked this post:
RacerHog (03-22-2014)
03-23-2014, 07:30 PM
#15
The no1 cylinder must be on the compression stroke, and the no1 wire must go to wherever the rotor points. If the rotor is NOT pointing to the "by the book" no 1 cap tower, it will run fine, but if you want to do it correctly it simply is not that difficult and takes VERY little time
To time a SB Mopar:
1--- Determine that no1 is on the firing stroke and there are two ways to do that. If either valve cover is still off, look at either the no1 or no6 valves, with the timing marks on TDC. IF both no1 valves are closed, no1 is ready to fire (compression) and if no6 valves are both closed, then no6 is ready to fire. BE CAREFUL because the opposite two will be nearly equally open (used to be called "split overlap) and it can fool you
The alternate way to determine compression, is to remove no1 plug, stick you finger in the hole, and either bump it on the starter, or wrench it around until you BEGIN to feel compression. You may need to go around once to be sure. When you start to feel compression, pay attention to the timing mark, and slowly bring the engine up NOT to TDC but to where you want the timing, IE 10-12 with a bone stock cam, or 15-20 with a hot cam
2---If there is any reason to suspect the distributor gear is in wrong, or this is a new build, bring the marks to TDC, and check the position of the slot in the gear. IT should point to the far left (drivers side) front intake manifold bolt, which is a close as you'll get to "straight ahead." If it does NOT, as the poster above suggested, just take a big screwdriver and "walk" the gear up out of the helix, and correct it
3---(If you performed step 2, back the engine up with a wrench about 1/8 turn, and bring the marks back NOT to TDC, but where you want the timing.)
Next, with the rotor pointing towards the area of the "by the book" no1 hole, and the vacuum can "in the clear away from the firewall, drop the distributor in. By rotating the distributor body, you should reach a point where the vacuum can is clear of the coil and the firewall, and the rotor is pointing to the no1 cap tower
4---Now, if you have points ignition, use a test lamp or ohmeter, rotate the dist. RETARD (cw) and move it slowly ADVANCE (ccw) until the points just open
If you have breakerless set the dist. so that the reluctor tip is centered in the pickup coil.
5---Start the engine!!!! Notice that I did not say, "prepare for fire out of the carburetor," nor did I say "screw endlessly with the distributor for hours on end."
If you followed this correctly the engine should start!!! and run!!!!
6---Now take your timing light and adjust the timing as necessary.
Some aside:
I ALWAYS, on an unknown engine, CHECK actual TDC accuracy. To do this, get, buy, or make a piston stop.
Like this:
Remove the no1 plug, make sure the piston is down, and remove the battery ground. Install the device, and wrench the engine gently over until the piston stops against the device. Make an accurate, temporary mark directly under 0 (TDC) on you timing tab, onto the balancer.
Now do the exact same rotating the engine CCW
Now you'll have TWO temporary marks, and true TDC will be 1/2 way between. If your old mark is accurate, that is where it will be.
You should also either get the proper size timing tape, or mark your balancer so you can see what your timing curve is doing. Measure all the way around the balancer, accurately, with a small flexible tape. Calculate how many inches per degrees it takes to work out 40*, carefully measure that off with the tape, and mark the wheel. Use a small square and a scribe, and carefully deepen the mark with a small file. I used to do this lying on my back looking up at the wheel, easier than bending over on my head.
Now you can take dividers and divide the 40 in half for 20, half again for 10. Then use your ten setting to mark 50, 60* which will be needed for checking vacuum advance. You can get as fussy as you want, but 5* marks are really all you need. You can get an idea of your accuracy, by rotating any two marks under the timing tab, and checking if they line up at 10ATC, 10BTC, etc.
To time a SB Mopar:
1--- Determine that no1 is on the firing stroke and there are two ways to do that. If either valve cover is still off, look at either the no1 or no6 valves, with the timing marks on TDC. IF both no1 valves are closed, no1 is ready to fire (compression) and if no6 valves are both closed, then no6 is ready to fire. BE CAREFUL because the opposite two will be nearly equally open (used to be called "split overlap) and it can fool you
The alternate way to determine compression, is to remove no1 plug, stick you finger in the hole, and either bump it on the starter, or wrench it around until you BEGIN to feel compression. You may need to go around once to be sure. When you start to feel compression, pay attention to the timing mark, and slowly bring the engine up NOT to TDC but to where you want the timing, IE 10-12 with a bone stock cam, or 15-20 with a hot cam
2---If there is any reason to suspect the distributor gear is in wrong, or this is a new build, bring the marks to TDC, and check the position of the slot in the gear. IT should point to the far left (drivers side) front intake manifold bolt, which is a close as you'll get to "straight ahead." If it does NOT, as the poster above suggested, just take a big screwdriver and "walk" the gear up out of the helix, and correct it
3---(If you performed step 2, back the engine up with a wrench about 1/8 turn, and bring the marks back NOT to TDC, but where you want the timing.)
Next, with the rotor pointing towards the area of the "by the book" no1 hole, and the vacuum can "in the clear away from the firewall, drop the distributor in. By rotating the distributor body, you should reach a point where the vacuum can is clear of the coil and the firewall, and the rotor is pointing to the no1 cap tower
4---Now, if you have points ignition, use a test lamp or ohmeter, rotate the dist. RETARD (cw) and move it slowly ADVANCE (ccw) until the points just open
If you have breakerless set the dist. so that the reluctor tip is centered in the pickup coil.
5---Start the engine!!!! Notice that I did not say, "prepare for fire out of the carburetor," nor did I say "screw endlessly with the distributor for hours on end."
If you followed this correctly the engine should start!!! and run!!!!
6---Now take your timing light and adjust the timing as necessary.
Some aside:
I ALWAYS, on an unknown engine, CHECK actual TDC accuracy. To do this, get, buy, or make a piston stop.
Like this:
Remove the no1 plug, make sure the piston is down, and remove the battery ground. Install the device, and wrench the engine gently over until the piston stops against the device. Make an accurate, temporary mark directly under 0 (TDC) on you timing tab, onto the balancer.
Now do the exact same rotating the engine CCW
Now you'll have TWO temporary marks, and true TDC will be 1/2 way between. If your old mark is accurate, that is where it will be.
You should also either get the proper size timing tape, or mark your balancer so you can see what your timing curve is doing. Measure all the way around the balancer, accurately, with a small flexible tape. Calculate how many inches per degrees it takes to work out 40*, carefully measure that off with the tape, and mark the wheel. Use a small square and a scribe, and carefully deepen the mark with a small file. I used to do this lying on my back looking up at the wheel, easier than bending over on my head.
Now you can take dividers and divide the 40 in half for 20, half again for 10. Then use your ten setting to mark 50, 60* which will be needed for checking vacuum advance. You can get as fussy as you want, but 5* marks are really all you need. You can get an idea of your accuracy, by rotating any two marks under the timing tab, and checking if they line up at 10ATC, 10BTC, etc.
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a.johansson84
Interior/Exterior Electrical
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05-27-2012 03:30 AM
