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I have a question that seems new to the forum, so I decided to give it a shot.
Calling all experts. My father and I restored a 63 to original specs with numbers matching. It has been 15 years and I took delivery of it from him and doing some tune-ups to it (plugs, wires, etc). Before redoing anything, I had to remove the shielding for the radio which was a pain in ***. I then traced all the wires to the distributor for labeling (I am a big proponent of labeling) and found that all the wires are in their correct positions in firing order, but have all been moved one plug counterclockwise. The car runs, but it could run better.
My question to the forum is 3 fold:
1. If the geared shaft was put in incorrectly would you be able to compensate by moving the position of the plugs?
2. Does this have any material effect on the timing etc?
3. Is it a bad idea, or what would happen, if I move the plug wires on the distributor clockwise one position so that they are in the "correct" spot?
I have a question that seems new to the forum, so I decided to give it a shot.
Calling all experts. My father and I restored a 63 to original specs with numbers matching. It has been 15 years and I took delivery of it from him and doing some tune-ups to it (plugs, wires, etc). Before redoing anything, I had to remove the shielding for the radio which was a pain in ***. I then traced all the wires to the distributor for labeling (I am a big proponent of labeling) and found that all the wires are in their correct positions in firing order, but have all been moved one plug counterclockwise. The car runs, but it could run better.
My question to the forum is 3 fold:
1. If the geared shaft was put in incorrectly would you be able to compensate by moving the position of the plugs?
2. Does this have any material effect on the timing etc?
3. Is it a bad idea, or what would happen, if I move the plug wires on the distributor clockwise one position so that they are in the "correct" spot?
Thanks!
Answer to questions,
1. Yes
2. Yes
3. Bad idea, engine will spit and act like a bad child.
Start over with the distributor installation, remove the wires from the cap after labeling them and turn the crankshaft to where the timing marks on the damper and timing cover are at TDC AND #1 piston is on it's firing stroke. You can do this by removing the #1 spark plug and place your finger over the hole and you will feel compression as the timing marks come together on the damper/timing cover while turning the crankshaft in it's normal rotation.
Install the distributor so after it seats in the engine the rotor is pointing to the #1 on the cap with the vacuum advance control approx in the center of it's space between the coil bracket and intake manifold.
Replace the wires in the correct cap tower and all should be fine. Don't put your face over the carburetor just in case you make a mistake. Search for posts on how to get the distributor to seat in the oil pump drive if that gives you a problem. Don't be afraid to make it right, it's a piece of cake.
You need to remove the dist. and check the position of the gear. With a properly manufactured camshaft the dimple should be pointing the same direction as the rotor tip.
1. Start by setting #1 at 10 deg. BTC, NOT TDC!!! You are on #1 compression stroke if the rotor is pointing about 20 deg. to the right of engine centerline.
2. Remove the dist. check the gear and if it's 180 deg. out tap out the roll pin enough to allow it to rotate, reindex as described, if necessary and reindex the plug wires the IAW the 1963 shop manual if they are not in the correct position. #1 should be in the tower nearest the pass. side of the window, then in the firing order on the inlet manifold.
3. To reinstall the engine, hold the dist. above the hole with the rotor pointing straight ahead. Drop it down and as you do so the rotor will move about 20 deg. CW as the gears mesh. If it won't fully seat you will have to tweak the oil pump shaft slot. A paint mixing stick is a good tool for this.
4. Once seated rotate dist. until the points just open, and the VAC should be about halfway between the manifold and coil bracket interference points This is called static timing the engine and should be close enough to allow the engine to start easily.
5. Once started set timing with a timing light. This must be done at less than 700 RPM because this is where the centrifugal advance starts, but it's very difficult to do on 340/360 HP engines because they will usually not idle stably at that low speed long enough to allow the timing to be set before the engine stalls.
You should tell us what the OE engine configuration is an whether it's been modified.
It is more than a good idea to install the distributor in the design location on a Corvette so there is no problem setting initial timing and to avoid having the distributor oriented to cause the tach cable to be in a bind.
You need to remove the dist. and check the position of the gear. With a properly manufactured camshaft the dimple should be pointing the same direction as the rotor tip.
1. Start by setting #1 at 10 deg. BTC, NOT TDC!!! You are on #1 compression stroke if the rotor is pointing about 20 deg. to the right of engine centerline.
2. Remove the dist. check the gear and if it's 180 deg. out tap out the roll pin enough to allow it to rotate, reindex as described, if necessary and reindex the plug wires the IAW the 1963 shop manual if they are not in the correct position. #1 should be in the tower nearest the pass. side of the window, then in the firing order on the inlet manifold.
3. To reinstall the engine, hold the dist. above the hole with the rotor pointing straight ahead. Drop it down and as you do so the rotor will move about 20 deg. CW as the gears mesh. If it won't fully seat you will have to tweak the oil pump shaft slot. A paint mixing stick is a good tool for this.
4. Once seated rotate dist. until the points just open, and the VAC should be about halfway between the manifold and coil bracket interference points This is called static timing the engine and should be close enough to allow the engine to start easily.
5. Once started set timing with a timing light. This must be done at less than 700 RPM because this is where the centrifugal advance starts, but it's very difficult to do on 340/360 HP engines because they will usually not idle stably at that low speed long enough to allow the timing to be set before the engine stalls.
You should tell us what the OE engine configuration is an whether it's been modified.
Duke
Duke and TBarb,
Thanks for the quick messages. The engine is 100% original with matching numbers (dist, carb, intake...even overflow). It has the original Carter carb rebuilt and it is the 340 Horse motor with solid lifters etc. I can dial the idle to 700rpm no problem. I REALLY don't want to have to take anything apart past the distributor unless it is absolutely necessary, like looking for top dead center etc.
Looking at your picture my guess is the gear on the distributor is installed 180* off and the wires were moved to allow the engine to run with the vacuum can in the middle of travel.
I would start over by removing the distributor, checking the lower gear and follow the procedure above. The lower gear has a dimple which will align with the rotor tip when installed correctly. If the camshaft has been changed and the new cam is not a GM cam sometimes the lower gear needs to be turned 180* to allow the vacuum advance to center in it's travel after setting initial timing.
Looking at your picture my guess is the gear on the distributor is installed 180* off and the wires were moved to allow the engine to run with the vacuum can in the middle of travel.
I would start over by removing the distributor, checking the lower gear and follow the procedure above. The lower gear has a dimple which will align with the rotor tip when installed correctly. If the camshaft has been changed and the new cam is not a GM cam sometimes the lower gear needs to be turned 180* to allow the vacuum advance to center in it's travel after setting initial timing.
After many beers I have deduced that you are correct. 180 I am not sure, but we had the engine sent out and likely when it came back "someone" put the cam in and couldn't get it to work (I heard something like that) and they put the cam in 180 off....so likely it was the wrong 180. I have 3 cams because of this. I may try it, but likely am going to take it to someone because I am a wuss. I need the right valve covers put on because 1. They leak and 2. The old guys keep called me out for the wrong ones. Thank you all for confirming what took me like 7 days to figure out (no joke).
Anyone in Austin want to do it for me? I have a lift and unlimited drinks.
One problem I see immediately... assuming your wire numbering is correct #8 is where #1 should be. Do you have a '63 Corvette Shop manual? (If not you better buy one ASAP.) There is a very clear photo in Section 6 of how it should be.
On C2 Corvettes there is ONLY ONE WAY that the distributor can be installed and get the timing dialed in without hitting the interference points - proper wire indexing and the dimple in the dist. gear pointing the same direction as the rotor tip assuming a properly manufactured cam.
BTW if you can get that engine to idle stably at 700 I doubt it has an OE type Duntov cam or any other OE small block mechanical lifter cam.
Bubba has been working on your car. You either need to get smart about it yourself or find someone competent.
One problem I see immediately... assuming your wire numbering is correct #8 is where #1 should be. Do you have a '63 Corvette Shop manual? (If not you better buy one ASAP.) There is a very clear photo in Section 6 of how it should be.
On C2 Corvettes there is ONLY ONE WAY that the distributor can be installed and get the timing dialed in without hitting the interference points - proper wire indexing and the dimple in the dist. gear pointing the same direction as the rotor tip assuming a properly manufactured cam.
BTW if you can get that engine to idle stably at 700 I doubt it has an OE type Duntov cam or any other OE small block mechanical lifter cam.
Bubba has been working on your car. You either need to get smart about it yourself or find someone competent.
Duke
Appreciate the reply...but the engine was completely redone by a non "bubba" as you call it. Yes 8 is where 1 is supposed to be, that was the point of this post. The cam and the lifters are legit OE. Nothing on this car isn't OE. I never said it idled stably at 700...I said I could get it to idle no problem at 700. There are only two people who have ever touched the car and it is RIGHT.
After many beers I have deduced that you are correct. 180 I am not sure, but we had the engine sent out and likely when it came back "someone" put the cam in and couldn't get it to work (I heard something like that) and they put the cam in 180 off....so likely it was the wrong 180. I have 3 cams because of this. I may try it, but likely am going to take it to someone because I am a wuss. I need the right valve covers put on because 1. They leak and 2. The old guys keep called me out for the wrong ones. Thank you all for confirming what took me like 7 days to figure out (no joke).
Anyone in Austin want to do it for me? I have a lift and unlimited drinks.
Looks like you have done your homework, don't be afraid to give it a try. bring the damper marks up to the TDC when the rotor is pointing to your #1 on the cap then remove the distributor and see where the dimple is on the lower gear. Not knowing the car history the damper could have slipped giving a incorrect top dead center reading and things adjusted to compensate. Duke may comment on that, I believe that could stir the pot some with this distributor setting.
By the way, nice looking engine compartment. probably the best way to go about it us to verify the damper timing are correct first. The cam can be installed 180* as you mention without any issues(timing chain gear alignment dimple at 12o'clock), the crankshaft does not care.
Looks to me like you can get right with the world if you advance the distributor one tooth clockwise and advance the distributor wires, one hole clockwise to get them in the correct spot.
When you get done and if this is correct, your vacuum advance nipple should be pointing directly at the RR inboard valve cover bolt.
If you're squeamish about pulling the distributor all the way out, try this fix first.
After many beers I have deduced that you are correct. 180 I am not sure, but we had the engine sent out and likely when it came back "someone" put the cam in and couldn't get it to work (I heard something like that) and they put the cam in 180 off....so likely it was the wrong 180. I have 3 cams because of this. I may try it, but likely am going to take it to someone because I am a wuss. I need the right valve covers put on because 1. They leak and 2. The old guys keep called me out for the wrong ones. Thank you all for confirming what took me like 7 days to figure out (no joke).
Anyone in Austin want to do it for me? I have a lift and unlimited drinks.
The only part that is 180 degrees off is the "driven gear" with the "roll pin hole" is the drawing below. This gear has a dimple on it that will line up with the rotor tip with factory GM cams. If you remove the dowel pin and spin the gear 180 degrees and reassemble the dist, the dimple will face away from the rotor tip, and the gear tooth in line with the rotor tip will be 1/2 a tooth off at the driven gear.
This 1/2 tooth change in alignment between the rotor tip and driven gear tooth, top... or valley, by spinning the driven gear 180 degrees, will provide alignment adjustment to allow you to orient the plug wires per the factory configuration, and set the timing without having the vacuum can bind against the manifold or valve cover.
Hopefully this will save you time and money (to enjoy the car and family).
The only part that is 180 degrees off is the "driven gear" with the "roll pin hole" is the drawing below. This gear has a dimple on it that will line up with the rotor tip with factory GM cams. If you remove the dowel pin and spin the gear 180 degrees and reassemble the dist, the dimple will face away from the rotor tip, and the gear tooth in line with the rotor tip will be 1/2 a tooth off at the driven gear.
This 1/2 tooth change in alignment between the rotor tip and driven gear tooth, top... or valley, by spinning the driven gear 180 degrees, will provide alignment adjustment to allow you to orient the plug wires per the factory configuration, and set the timing without having the vacuum can bind against the manifold or valve cover.
Hopefully this will save you time and money (to enjoy the car and family).
Thank you for that suggestion! I am definitely going to give this a shot.
Thank you for that suggestion! I am definitely going to give this a shot.
One more question for you 63 340HP. You have the exact same engine. I am hearing that timing is a challenge with a light due to the idle vs mechanical advance. Any tips or tricks on that one? Thanks again!
Looks to me like you can get right with the world if you advance the distributor one tooth clockwise and advance the distributor wires, one hole clockwise to get them in the correct spot.
When you get done and if this is correct, your vacuum advance nipple should be pointing directly at the RR inboard valve cover bolt.
If you're squeamish about pulling the distributor all the way out, try this fix first.
Gave this a shot and it is not firing at all. I am not sure if it needs to go two teeth? It isn't bucking or anything...almost like no spark. Any suggestions? I assume this will do the same thing as moving the gear 180 degrees because the implications are the same...moving everything forward.
Gave this a shot and it is not firing at all. I am not sure if it needs to go two teeth? It isn't bucking or anything...almost like no spark. Any suggestions? I assume this will do the same thing as moving the gear 180 degrees because the implications are the same...moving everything forward.
I also pulled the distributor out...it is not 180 degrees out...so I am going to start over and get TDC set so that everything is kosher before I muck with anything.
One more question for you 63 340HP. You have the exact same engine. I am hearing that timing is a challenge with a light due to the idle vs mechanical advance. Any tips or tricks on that one? Thanks again!
Originally Posted by GTOguy
Do what tbarb said in the second post and you will be good to go.
The Post #2 procedure works, and if it does not the driven gear on the distributor should be rotated before following the Post #2 procedure a second time.
The stock centrifugal advance springs under the rotor on a 63' distributor are stiff and should hold the advance back at 700 rpm. The typical reason a distributor fails to hold the advance at low rpm is that it is missing the "stop bushing" located on the advance pin under the rotor football in the diagram. This stop bushing limits the advance pin travel, the mechanical advance measured in degrees. This advance pin and stop bushing also locates the start and stop positions for the mechanical advance. A thicker bushing is used to reduce the advance pin travel to reduce the mechanical advance (a benefit to most high performance engines), and it also starts the advance pin in a location with a little more tension on the advance springs and more tension on the advance springs at an idle helps to keep the idle timing stable.
If you want to get into modifications to optimize the GM distributor mechanical advance assembly, the slot where the advance pin travels can be shortened to assure you limit the advance to the desired number of degrees. You accomplish this by brazing metal into the ends of the slot, to shorten the slot travel range (with the distributor disassembled). If you add metal to close the slot at the end of the travel range where the advance pin rests at idle, the resulting slot start point positions the advance pin where the advance springs are under a greater tension at idle (compared to a stock or worn distributor). This detailed modification helps to hold the mechanical advance steady at low rpm, even with low tension advance springs and a radical lumpy idle cam.
Most engines can get by with a distributor setup using a fat stop bushing to limit the advance and position the start and end point tension on the advance springs, but if you absolutely have to have the strongest advance spring tension to achieve a stable timing position at idle, modifying the slot as detailed above is the solution.
These little things that racers learned to do fifty years ago, to improve upon GM's systems, can make this car hobby frustrating, or fun, depending on your point of view.
Got it. Well, I got everything apart and will be TDCing the car later tonight. I went from not wanting to mess with the distributor to completely taking all the electrical apart, which is fine because once it fires I am going to do it all over again as I ordered tune-up parts for replacing things, as the restoration on this engine is approaching 18 years of age. Its all the fun little things now like ride height, wipers, glove boxes, and the convertible top (which I hear is a project all by itself). Probably need a carburetor rebuild shortly too because things are starting to stick and I don't think the second set of barrels is opening. Good times!
Boom! Ok, I have to thank many many people for this one. I pulled the whole damn thing out...all the plugs...put it in TDC -10 degrees, put in new plugs (others were 20 years old), then hooked it all back up. Minor issue with missing a tooth...moved it forward AND....fired right up!
Some learnings from the. It wasn't that scary, although I did start to wonder how much a flatbed was gonna cost in case of a non-start. I also learned that the forum was right about the idle. The tach seems to be off about 500rpm (gauges need to be rebuilt). When I used the tach/dwell the tach was at about 1000. Anything under 1K and man it didn't like it. So the people that pointed out that the Duntov cam doesn't like to idel at 700 rpm....they be correct. At 800 is starts to sputter like mad. So timing, well, I took it at 1K and put it at +8 or so. It seems to like it. I adjusted the carbs and Dwell, and off and running.
Next is to replace the cap as it is old...and then on to the convertible top...that is another topic.
06-07-2018, 09:22 AM
1963 C2 Distributor Setting
