Is this the V6 manifold vacuum port?

Not being argumentative about this... but ....

1116163 crosses to a Standard VC24A, or an Airtex 4V1005.

Go to the RockAuto catalog and enter the GM PN.

VC680 brings up nothing. If you use the application list for the VC680, it brings up a VC24A.

Possible the total advance is determined by a stop in the distributor, not by the advance canister?

"Perfection is the enemy of the good."

 

James ,
Yes your 1970 vintage was original with a Prestolite distributor.
That definately implies you have an unknown DR.
Still waiting on you to identify your specific DR distributor.
It might make a difference at to what canister is appropriate.

The total allowable vac advance for the 3 distributors that I previously listed is roughly 25*.
Realize that the correct DR distributors are both vacuum advanced and also mechanical advanced.

Yes I made a mistake the 1116163 part number is GM and not DR.
Also the DR packaging is marked D-1328 as jeepcj mentioned.

 

Agree with oldtime. You really need to set your Delco dist to 225V6 specs (if needed). The dist mechanical adv needs to be limited to 13-15* adv. Once this is done then the available vacuum advance can as suggested above (Tim's VC24A) which injects 12* crank will leave you with 32* total advance. FSM sez 28* but The 225V will perform very well up to but not over 32*.
Note: The DR dist has no provision for limiting the amount of advance produced by the vacuum can. Also note the VC24A is non-adjustable.
Do you need to change the mechanical advance built into the dist? Like said, it should be in the range of 13-15* crank.

 

What's more important is what is the built in mechanical advance in the dist you are using. Since your vacuum can is not working at present then start your engine and watch with a timing light to see what advance you have on the crank. You have to run the engine up to at least 2000RPM to get all of the built in advance out of the dist. So if you have an initial 5* at start and end with 20* total at 200RPM then you know the dist is 15* total. That is what you are looking for. I have also replaced the vacuum can with the dist still in place.

 

A V8 distributor won't work in a V6. If that number is stamped into the body, it may have been rebuilt, and a V8 body used to build an odd-fire V6 distributor. Rebuilders do stuff like that. The cam lobe on a V6 has six points, a 350 cam lobe will have 8. The oddfire cam lobe will be ground 45-75-45-75-45-75 IIRC, so that the firing positions match the crank offsets.

 

Tim, and all others. Please don't think I was being argumentative about this, I see it as we were all working together to try and find the best solution for the op,s problem. I am not one that thinks he knows it all or is always right, I welcome others suggestions or corrections and I hope we all feel that way. I see too many times on forums where the members fight back and forth about who,s right and whos wrong, I hope this site never becomes that way and hope know one thinks I am that way.. So no harm intended or taken here.

 

Really the mechanical timing in the dist was the magic missing number here. was hoping you didn't need to pull the dist because many reinstall incorrectly (180* out, or a couple teeth off). So, if you know there is 16* mechanical advance in the dist, you can set your initial anywhere from where it is now up to around 12*, at 12* you would have a total timing (no vac advance) of 29* (initial + mechanical in dist) , while cruising (part throttle) vac advance is operative and with a 16* can, at part throttle cruising you would have a total of 44*. I think it will run well at this setting. You can set you initial lower than 12* if you want, but that will also lower your total timing figures (no vac advance) by the same amount you lower the initial. If you still need to verify the mechanical in the dist, hook up your light, unhook the vac and plug it, have someone rev the motor to 2500-3000 rpms (mechanical timing should be all in at this point), check the timing and subtract your initial. If you don't want to rev it that high, you can take off the springs on the weights, start it, give it a bleep of the gas pedal and look at the timing. taking the springs off will fling the weights out at or close to idle, and give full mechanical advance, then check the timing, put springs back on. Just a side note: Sometimes the starter will kick back a little at start up with the springs off.
SORRY FOR THE DOUBLE POST

 

Really the mechanical timing in the dist was the magic missing number here, as Walt has been mentioning. I was hoping you didn't need to pull the dist because many reinstall incorrectly (180* out, or a couple teeth off). So, if you know there is 16* mechanical advance in the dist, you can set your initial anywhere from where it is now up to around 12*, at 12* you would have a total timing (no vac advance) of 29* (initial + mechanical in dist) , while cruising (part throttle) vac advance is operative and with a 16* can, at part throttle cruising you would have a total of 44*. I think it will run well at this setting. You can set you initial lower than 12* if you want, but that will also lower your total timing figures (no vac advance) by the same amount you lower the initial. If you still need to verify the mechanical in the dist, hook up your light, unhook the vac and plug it, have someone rev the motor to 2500-3000 rpms (mechanical timing should be all in at this point), check the timing and subtract your initial. If you don't want to rev it that high, you can take off the springs on the weights, start it, give it a bleep of the gas pedal and look at the timing. taking the springs off will fling the weights out at or close to idle, and give full mechanical advance, then check the timing, put springs back on. Just a side note: Sometimes the starter will kick back a little at start up with the springs off.

 

If you are a few teeth off, it wont start. if you are 180* off it wont start and will probably backfire through the carb pretty loudly. When you put it back in your rotor should point right where the #1 plug wire go,s on the cap, or just slightly to one side or the other of it depending on how high your initial is. If you are off a tooth or two the rotor will be in between the #1 tower or more to the next tower, lift the dist up (you don't need to take it all the way out, just clear the gear engagment, you will feel it.) turn it slightly accordingly and drop it back in, try to start.

 

Don't be too concerned about alignment yet because it may not have been correct prior to this exercise. Bring the crank to TDC and No1 piston on compression. Check to see if rotor is pointing to No1 tower on cap (if not then rotate dist until it is) and note where the vacuum can is pointing and the window in the cap is located. You need to make sure the vacuum hose will not be hit by the fan and that you will be able to adjust the points with allen tool while the engine is running. If all looks good then you are for fine tuning.

 

Remember that there are only three locations where this distributor is timed correctly, not six like most other six cylinders. You need to be at TDC (not 180 out) and you need to have the odd-fire angle order correct, ie 45-75 from #1 (if that is correct) not 75-45. We discussed this in an earlier thread, and IIRC there is only one location (in terms of rotation) that is both correct and convenient.

 

Remove the cap and grab the rotor and twist it clock wise. If it won't move try counter clock wise. That part is supposed to move a few degrees and spring back. If it dont move then it is rusted and sticking. It may be difficult to get a few drops of oil in there but must keep it off the points. The rotor must move CW a few degrees and snap back via the two springs on the adv weights.

 

Also make sure your springs on the advance weights are not froze up or rusted, same with the weights, then try again.