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Hi All, pulled the distributor out of my 1963 327 to replace the distributor shaft (Tach gear shot) and I have been having trouble getting the timing correct after.
(pops through the carb after distributor was reinstalled.) I found some threads about the timing needing to be set to 10 BTDC instead of at 0 for checking for #1 position?
my guess is I'm a tooth out, read some threads that the distributor can only be in a certain way, makes sense for the tach cable etc.
I`ve checked the firing order and made sure the wires are in the correct spot etc,distibutor has electronic ignition but still has a coil not HEI. I know this has probably had many threads on it, would anyone have some tips etc for me to check.
it ran fine before the distributor came out and I made sure the dimple on the gear was the same position as the rotor.Engine was rebuilt but with a stock cam.
thanks for any help to steer me in the right direction!
I just put a new distributor in and it was popping before I figured out I didn't have the distributor hold down bolt and bracket in correctly and it was still loose.
Hi Dan, runs somewhat normal and idles fine until I give it some gas then it pops through the carb. The timing was set to 6 degrees BTDC and it seems like I'm close but maybe out one position. I`m busy today but will take a pic of the distributor position. I read from a long ago post the vac advance nipple should point towards the r/r valve cover bolt when timed correctly and mine points more towards the centre of the engine. The replacement shaft is aftermarket but I looked at it closely and it was exactly as the one I pulled out. When I took off the dist gear I made sure to install the dimple on the gear facing the same way as the rotor tip.
I just put a new distributor in and it was popping before I figured out I didn't have the distributor hold down bolt and bracket in correctly and it was still loose.
hello, yes I checked to make sure the distributor hadn't moved and was tight, it seems more that I am out one position when I reinstalled it
If your distributor is installed, as pictured below, then it's installed correctly...assuming #1 piston was at TDC on the compression stroke and the rotor was pointing to the #1 plug wire position on the distributor cap.
Hi Dan, runs somewhat normal and idles fine until I give it some gas then it pops through the carb. The timing was set to 6 degrees BTDC and it seems like I'm close but maybe out one position. I`m busy today but will take a pic of the distributor position. I read from a long ago post the vac advance nipple should point towards the r/r valve cover bolt when timed correctly and mine points more towards the centre of the engine. The replacement shaft is aftermarket but I looked at it closely and it was exactly as the one I pulled out. When I took off the dist gear I made sure to install the dimple on the gear facing the same way as the rotor tip.
Did you notice the dimple orientation on the old shaft? From what I've read here, some engines run better 180° out.
Was your vac can position before more toward the valve cover? If so, I'd guess you're a tooth off.
I think it best to start over with finding firing point TDC for #1, and dropping it back in so that the rotor aligns to your #1 wire terminal. If you still get vapors pushed out the carb, I'd try switching the dimple on the shaft.
Something’s seems off here. Even if you are a tooth out or the gear needs to be reversed 180 degrees - if you installed the distributor with the engine at (near) TDC on #1 and with the balancer timing marks showing 6 deg BTDC, and with the rotor tip pointing directly at the no.1 wire terminal on the cap - it should all be close enough to run OK, although it may need the distributor housing rotated just slightly CCW to get the timing closer to around 10 deg BTDC with a timing light.
That makes me wonder about the shaft and if the orientation of the points plate is properly indexed to the cap terminal placement. Also possible, have you checked the point dwell? The points need to be right on the money or they will throw the timing off. A dwell meter check is best but if you don’t have one at least check with a feeler gauge to be sure they are right.
As long as you can time the distributor without the vacuum advance being blocked by the intake, try advancing the timing to 10 deg BTDC with the timing light and timing marks and see how it does. If it’s OK then you can always pull the distributor and rotate it a tooth CW and reset it and see if it looks oriented as lief.anderson93’s photo shows.
If it’s still popping and running rough, I can’t say the shaft is bad but I would be looking closely at it. You may need to cut a window in the side of an old cap under the #1 tower and with the engine at exactly #1 TDC the points should be closed but on the cusp of starting to open.
Also possible, have you checked the point dwell? The points need to be right on the money or they will throw the timing off. A dwell meter check is best but if you don’t have one at least check with a feeler gauge to be sure they are right.
I've always seen dwell stated as "28-32"; I set it at 30... What figure is right on the money?
I've always seen dwell stated as "28-32"; I set it at 30... What figure is right on the money?
Setting dwell at 32* will yield more coil saturation, which can be beneficial. But it sets the point gap smaller than with the dwell set at 30*, or 28*, and as such the point gap will drift out of spec sooner as the rubbing block on the points wears down and as material migrates across the contacts over time due to the arcing that always occurs. I set point dwell at 28* if the car tolerates it well and runs without any misfiring. This allows more miles between servicing the points.
But, the OP noted that his distributor has been converted to breakerless, so none of this is germane to his question.
Did you notice the dimple orientation on the old shaft? From what I've read here, some engines run better 180° out.
Was your vac can position before more toward the valve cover? If so, I'd guess you're a tooth off.
I think it best to start over with finding firing point TDC for #1, and dropping it back in so that the rotor aligns to your #1 wire terminal. If you still get vapors pushed out the carb, I'd try switching the dimple on the shaft.
ok thanks for the great info!, yes I installed the new shaft the same, with the dimple facing the same as the rotor tip. Engine has been rebuilt but stock cam and before I changed the shaft it ran fine. And yes before the swap the vac can was pointed more toward the v/c
Something’s seems off here. Even if you are a tooth out or the gear needs to be reversed 180 degrees - if you installed the distributor with the engine at (near) TDC on #1 and with the balancer timing marks showing 6 deg BTDC, and with the rotor tip pointing directly at the no.1 wire terminal on the cap - it should all be close enough to run OK, although it may need the distributor housing rotated just slightly CCW to get the timing closer to around 10 deg BTDC with a timing light.
That makes me wonder about the shaft and if the orientation of the points plate is properly indexed to the cap terminal placement. Also possible, have you checked the point dwell? The points need to be right on the money or they will throw the timing off. A dwell meter check is best but if you don’t have one at least check with a feeler gauge to be sure they are right.
As long as you can time the distributor without the vacuum advance being blocked by the intake, try advancing the timing to 10 deg BTDC with the timing light and timing marks and see how it does. If it’s OK then you can always pull the distributor and rotate it a tooth CW and reset it and see if it looks oriented as lief.anderson93’s photo shows.
If it’s still popping and running rough, I can’t say the shaft is bad but I would be looking closely at it. You may need to cut a window in the side of an old cap under the #1 tower and with the engine at exactly #1 TDC the points should be closed but on the cusp of starting to open.
Thanks I will try that and recheck.My distributor isn't in the same position as in the picture from Lief.andersons93. that is a big help and yes I'm not sure maybe I have a defective new shaft I only changed it because the tach drive gear was toast. The points have been removed and it has a small electronic pick up so hopefully that takes the dwell out of the picture.
I've always seen dwell stated as "28-32"; I set it at 30... What figure is right on the money?
Right on the money may have been a poor choice of words. There’s a range where dwell doesn’t have a significant affect on engine performance but it always has an affect on the timing and also spark energy. At some point when the points close up (dwell high) from wear the coil performance is going to deteriorate with weak spark to where the engine cant even run or the points burn. Too wide (dwell low) and coil performance deteriorates and timing is retarded. Thirty (30) degrees seems to about the mark on the GM and Mopar cars I’ve had. Dual points are staggered for some overlap to increase total dwell and coil saturation without as much risk of burning points.
Doesn’t seem to be an issue for Jtrav but now an electronic thing-a-ma-jig has been thrown into the mix.
Actually the distributor window can be oriented in any direction - 360 degrees as long as the rotor tip is pointing to #1 spark plug wire on the compression stoke. Here is the instructions from the Chevrolet Chassis Service Manual, Section 6Y. The General wrote the book and is much smarter than I am:
ENGINE-ELECTRICAL 6Y-26 INSTALLATION-ENGINE NOT DISTURBED (ALL MODELS) 1. Turn the rotor about 1/8 turn in a clockwise direction past the mark previously placed on the distributor housing to locate rotor. 2. Push the distributor down into position in the block with the housing in a normal "installed" position (fig. 15i). NOTE: It may be necessary to move rotor slightly to start gear into mesh with camshaft gear, but rotor should line up with the mark when distributor is down in place. 3. Tighten the distributor clamp bolt snugly and connect vacuum line. Connect primary wire to coil terminal and install cap. Also install spark plug and high tension wires if removed. NOTE: It is important that the spark plug wires be installed in their proper location in the supports. 4. Time ignition as previously described under Tune[1]Up in Section 6.
INSTALLATION-ENGINE DISTURBED (ALL MODELS) 1. Locate No. 1 piston in firing position by either of two methods described below, a. Remove No. 1 spark plug and, with finger on plug hole, crank engine until compression is felt in the No. 1 cylinder. Continue cranking until timing mark on crankshaft pulley lines up with timing tab attached to engine front cover. b. Remove rocker cover (left bank on V-8 engines) and crank engine until No. 1 intake valve closes and continue to crank slowly about 1/3 turn until CENTRIFUGAL jS ADVANCE ROTATING POLE PIECE STATIONARY POLE PIECE MAGNETIC PICKUP ASSEMBLY VACUUM ADVANCE DISTRIBUTOR HOUSING Fig. 151—Six Cylinder Engine Distributor Fig. 16i—Magnetic Pulse Distributor Components CHEVROLET CHASSIS SERVICE MANUAL ENGINE-ELECTRICAL 6Y-27 timing mark on pulley lines up with timing tab. 2. Position distributor to opening in block in normal installed attitude (fig. 15i), noting position of vacuum control unit. 3. Position rotor to point toward front of engine (with distributor housing held in installed attitude), then turn rotor counter-clockwise approximately 1/8 turn more toward left cylinder bank and push distributor down to engine camshaft. It may be necessary to rotate rotor slightly until camshaft engagement is felt. 4. While pressing firmly down on distributor housing, kick starter over a few times to make sure oil pump shaft is engaged. Install hold-down clamp and bolt and snug up bolt. 5. Turn distributor body slightly until points just open and tighten distributor clamp bolt. 6. Place distributor cap in position and check to see that rotor lines up with terminal for No. 1 spark plug. 7. Install cap, check all high tension wire connections and connect spark plug wires if they have been re[1]moved. It is important that the wires be installed in their location in the supports. NOTE: The brackets are numbered to show the correct installation. Wires must be installed as indicated to prevent cross firing. 8. Connect vacuum line to distributor and distributor primary wire to coil terminal. 9. Start engine and set timing as described under Tune-up in Section 6.
Can you convert back to point to see if it makes a difference ?
No unfortunately module was already installed when I received the car and I don't have the points. Car ran fine with no popping through the carb before distributor was removed
Actually the distributor window can be oriented in any direction - 360 degrees as long as the rotor tip is pointing to #1 spark plug wire on the compression stoke. Here is the instructions from the Chevrolet Chassis Service Manual, Section 6Y. The General wrote the book and is much smarter than I am:
ENGINE-ELECTRICAL 6Y-26 INSTALLATION-ENGINE NOT DISTURBED (ALL MODELS) 1. Turn the rotor about 1/8 turn in a clockwise direction past the mark previously placed on the distributor housing to locate rotor. 2. Push the distributor down into position in the block with the housing in a normal "installed" position (fig. 15i). NOTE: It may be necessary to move rotor slightly to start gear into mesh with camshaft gear, but rotor should line up with the mark when distributor is down in place. 3. Tighten the distributor clamp bolt snugly and connect vacuum line. Connect primary wire to coil terminal and install cap. Also install spark plug and high tension wires if removed. NOTE: It is important that the spark plug wires be installed in their proper location in the supports. 4. Time ignition as previously described under Tune[1]Up in Section 6.
INSTALLATION-ENGINE DISTURBED (ALL MODELS) 1. Locate No. 1 piston in firing position by either of two methods described below, a. Remove No. 1 spark plug and, with finger on plug hole, crank engine until compression is felt in the No. 1 cylinder. Continue cranking until timing mark on crankshaft pulley lines up with timing tab attached to engine front cover. b. Remove rocker cover (left bank on V-8 engines) and crank engine until No. 1 intake valve closes and continue to crank slowly about 1/3 turn until CENTRIFUGAL jS ADVANCE ROTATING POLE PIECE STATIONARY POLE PIECE MAGNETIC PICKUP ASSEMBLY VACUUM ADVANCE DISTRIBUTOR HOUSING Fig. 151—Six Cylinder Engine Distributor Fig. 16i—Magnetic Pulse Distributor Components CHEVROLET CHASSIS SERVICE MANUAL ENGINE-ELECTRICAL 6Y-27 timing mark on pulley lines up with timing tab. 2. Position distributor to opening in block in normal installed attitude (fig. 15i), noting position of vacuum control unit. 3. Position rotor to point toward front of engine (with distributor housing held in installed attitude), then turn rotor counter-clockwise approximately 1/8 turn more toward left cylinder bank and push distributor down to engine camshaft. It may be necessary to rotate rotor slightly until camshaft engagement is felt. 4. While pressing firmly down on distributor housing, kick starter over a few times to make sure oil pump shaft is engaged. Install hold-down clamp and bolt and snug up bolt. 5. Turn distributor body slightly until points just open and tighten distributor clamp bolt. 6. Place distributor cap in position and check to see that rotor lines up with terminal for No. 1 spark plug. 7. Install cap, check all high tension wire connections and connect spark plug wires if they have been re[1]moved. It is important that the wires be installed in their location in the supports. NOTE: The brackets are numbered to show the correct installation. Wires must be installed as indicated to prevent cross firing. 8. Connect vacuum line to distributor and distributor primary wire to coil terminal. 9. Start engine and set timing as described under Tune-up in Section 6.
Actually the distributor window can be oriented in any direction - 360 degrees as long as the rotor tip is pointing to #1 spark plug wire on the compression stoke. Here is the instructions from the Chevrolet Chassis Service Manual, Section 6Y. The General wrote the book and is much smarter than I am:
ENGINE-ELECTRICAL 6Y-26 INSTALLATION-ENGINE NOT DISTURBED (ALL MODELS) 1. Turn the rotor about 1/8 turn in a clockwise direction past the mark previously placed on the distributor housing to locate rotor. 2. Push the distributor down into position in the block with the housing in a normal "installed" position (fig. 15i). NOTE: It may be necessary to move rotor slightly to start gear into mesh with camshaft gear, but rotor should line up with the mark when distributor is down in place. 3. Tighten the distributor clamp bolt snugly and connect vacuum line. Connect primary wire to coil terminal and install cap. Also install spark plug and high tension wires if removed. NOTE: It is important that the spark plug wires be installed in their proper location in the supports. 4. Time ignition as previously described under Tune[1]Up in Section 6.
INSTALLATION-ENGINE DISTURBED (ALL MODELS) 1. Locate No. 1 piston in firing position by either of two methods described below, a. Remove No. 1 spark plug and, with finger on plug hole, crank engine until compression is felt in the No. 1 cylinder. Continue cranking until timing mark on crankshaft pulley lines up with timing tab attached to engine front cover. b. Remove rocker cover (left bank on V-8 engines) and crank engine until No. 1 intake valve closes and continue to crank slowly about 1/3 turn until CENTRIFUGAL jS ADVANCE ROTATING POLE PIECE STATIONARY POLE PIECE MAGNETIC PICKUP ASSEMBLY VACUUM ADVANCE DISTRIBUTOR HOUSING Fig. 151—Six Cylinder Engine Distributor Fig. 16i—Magnetic Pulse Distributor Components CHEVROLET CHASSIS SERVICE MANUAL ENGINE-ELECTRICAL 6Y-27 timing mark on pulley lines up with timing tab. 2. Position distributor to opening in block in normal installed attitude (fig. 15i), noting position of vacuum control unit. 3. Position rotor to point toward front of engine (with distributor housing held in installed attitude), then turn rotor counter-clockwise approximately 1/8 turn more toward left cylinder bank and push distributor down to engine camshaft. It may be necessary to rotate rotor slightly until camshaft engagement is felt. 4. While pressing firmly down on distributor housing, kick starter over a few times to make sure oil pump shaft is engaged. Install hold-down clamp and bolt and snug up bolt. 5. Turn distributor body slightly until points just open and tighten distributor clamp bolt. 6. Place distributor cap in position and check to see that rotor lines up with terminal for No. 1 spark plug. 7. Install cap, check all high tension wire connections and connect spark plug wires if they have been re[1]moved. It is important that the wires be installed in their location in the supports. NOTE: The brackets are numbered to show the correct installation. Wires must be installed as indicated to prevent cross firing. 8. Connect vacuum line to distributor and distributor primary wire to coil terminal. 9. Start engine and set timing as described under Tune-up in Section 6.
Ron,
If there were no vacuum cannister involved, your statement would, basically, be true. But, if you were to install the distributor cap, say, 90* clockwise from where it is supposed to be, where does that put the vacuum cannister? There is a very logical reason why the distributor and cap have to be oriented like is shown in my picture.
distributor trouble
