My new distributor setup's vacuum advance module is buried against the manifold so I cant get the advance I need...If I pull the distributor and set it back in one tooth clockwise (to achieve more turning space), do I
(1) keep the rotor in the same position as it was before pulled and
(2) do I pull the plug wires and set them one terminal back counterclockwise?
Little confused here hopefully someone can chime in...Thanks in advance.


Also hoping someone could suggest the best place to set the timing at for a 305 carb'd daily with a couple bolt ons (carb, intake, hei dist. and a high flow muffler) how much advance should I be running

 

For ease of explanation, let's say your motor is TDC on #1. At this position you want the rotor to be dead center (for 0 degrees timing as an example; which is not suggested) of the #1 wire terminal on the cap.
If you were to turn the base, the rotor technically will not move but you would be rotating the #1 terminal to rotor position or "changing your timing".

Bring your motor to the TDC postion on #1, I'd even go ahead and label where each wire goes on the cap to make it easier on yourself. Now pull your distributor, spin it however you'd like and reseat it. As long as your rotor is center of that #1 terminal you are okay.

Technically your rotor doesn't have to point at the #1 cylinder when at TDC. It is just a suggestion to any future work easier for yourself. As long as #1 wire is on the terminal below the rotor at TDC of cylinder #1, it would work.

 

You can keep the same firing order and move it around counter or clockwise, moving the rotor to match the #1 spark terminal with the #1 piston at TDC. An easy method to get the oil pump key to line up is using the appropriate sized 1/4" socket (match it to the gear on the dist.) and a long extension to move the oil pump drive to accomadate the new dist position; this will stop the frustration with not getting the dist to seat all the way each time you move it.

 

So I could scribe a mark on my dist where my rotor is, move the unit one tooth clockwise, making sure the rotor is in the same marked position when reinstalled? Could I get a confirmation?

Also I just checked my timing with a light, it appears Im at 0 TDC and it seems to run real good...(Think I have a kickdown cable issue...4bbl opens at about 70 in 2nd gear..so im playing with that at the moment as well) A lot of people are saying around 6 BTDC (which is the purpose of moving my dist) I cant get a clear opinion on this...I have a stock 305 with a carb and intake, daily driver

 

If anyone could chime in that would be killer! I have noone else to ask on the matter, and running out of daylight to play with this beast

 

Here's how I would do the distributor relocation: Move the #1 Cyl to TDC (easy to tell with the plug removed, either attach a compression gauge and turn the crank until you start showing a reading, then continue turning until the timing mark is at 0*, or put your finger over the spark plug hole and turn the crank until you feel air escaping then move to timing mark). Pull the distributor and reinstall it where you want it, maring the terminal on the outside of the cap that the rotor now points to. Marking the housing where the rotor points to with a sharpie is a good way as well, then you don't play the guessing game with the cap on and off. Install the cap, and start at your mark with the number one plug wire moving clock-wise around in the firing order (1, 8, 4, 3, 6, 5, 7, 2). You may want to completely remove all plug wires as the length required in your new routing will be different than it previously was. Fire the engine up, if it sounds strange or backfires, you are off on your timing or firing order. Time it to 6 to 8* BTDC and start from there, 0* is quite a bit retarded and may cause hesitation under WOT.

 

Yes.

You are going to need probably 10-18 degrees initial timing, for a total of about 35 ish total at approx 3k rpm, depending on what the motor likes. Then add vac adv after that.

 

ok sweet. 10-18 referring to btdc on the timing tab?? Seems like a lot, it runs good at zero right now but not as good as it should
or is that figure my ~6* btdc + vaccum advance? Or by 10-18 do you mean on the balancer..guess Im a little confused. Just want to be clear on this. My tach isn't hooked up yet because I dont know which wire it was on the factory coil

 

Yep - btdc as indicated by the timing marks. Rough guide for 'what it wants' - plug vac advance, and set timing for best WOT uphill acceleration without pinging, letting the initial be what it may. If the idle's then too crappy or hard to start, might have to fine tune a little further. Then add the vac adv back in.

 

TreeFiddy- (or anyone who wants to chime in) as mentioned before, It was on zero when I dropped the new dist. in. I pulled it back out and moved it over a tooth, now I have all kinds of room to play with.

I set it at 6 btdc because a lot of people were saying that is a good one to go with...After moving it a tooth over (clockwise) I couldn't find my mark on the harmonic balancer (upon first start up)...Found it was wayyyy over past the timing tabs...But ran awesome (revving in idle) I adjusted it back to 6 btdc to be safe (thinking this was "optimum")...These adjustments ARE with vaccum advance capped. Drove around for a few and decided to plug vaccum cansiter back in but doesn't seem to make any difference. haven't played with the canister yet.

Can I go further? It had '*****' when it was way past the timing tabs (no idea how much advance it was/how it would do under a load) Looking for opinions on this. Again, Im working with a 'stock' 305, stock cam, weiand intake, brock carb, accel hei dist. Runs good, but I think it ran the same/better when it was all stock and at zero tdc. Input/insight would be appreciated, I have a basic timing light to work with, definitely think it would run better with more advance tho. Help!!

 

Ok anyone who's interested, I just set it to 8 tdc, vaccum advance plugged in and it runs wayy better. Think Ill leave it alone?? Also I need to go ahead and get plugs could someone recommend a plug type and gap for my setup?

 

And it may run way better again if you set it to 12 or 14. Ie, give it the timing it wants, rather than just setting to some number you thought of arbitrarily. You are leaving performance on the table.

That it runs better with the vac advance plugged in shows it wants more timing. Vac adv should essentially have no affect on performance; it's only there to lower emissions and reduce fuel consumption.

 

TreeFiddy - Im gonna turn it up then. It has low miles but seems like it spent its life on 0 for timing. I definitely want more performance (hence looking for tuning info) Just dont wanna do any damage.

So basically I can keep turning up till I hear a ping at WOT and then back off a hair? Is what Ive gathered..Could someone confirm/correct?

And I should add, maybe I didnt type clearly, the vac advance doesn't seem to make a difference (again I haven't tried setting it, I am using it as it was pulled from the box new)

So any insight on these details would be appreciated. I have the weekend off and Im going outside now to change the plugs. So two things here:

1: 12-14 btdc is common? on a setup like mine? (obv. not gonna just crank it up to 14 but can i gradually step it up to that level)
2: Chaning the plugs. what would be a good gap to go with

 

follow up to the plugs: im gonna go ahead and use my r43ts delcos with a .45 gap (seems to be the general consensus) Again all I really have to work with is 'general consensuses' As for the timing I will gradually step it up. Ill try 10 and see how she works. How will I know if its pinging.

 

Does the #1 plug wire go where the rotor pointer is ?

 

How will i know if its pinging. How loud is it. Extremely faint or what? Hard to tell between a ping and an exhaust leak??

I've been all over the board from 0* TDC to 12* BTDC, running 10* BTDC with four turns out on my vaccum canister at the moment. Again this is a 305 Carb HEI, no computer, ~70,000 easy miles.

Neither the base advance nor the vaccum advance makes a huge difference. The "ping" is faint at 8* BTDC with one turn out on the canister, but I swear this is an exhaust leak. Even at 12 it runs real good ("ping" or "leak" maybe slightly more evident). I welded up my exhaust a few weeks back with a cheap 110 mig w.o gas and a 30' exension cord, needless to say wasn't running very hot, bubbly in spots and wouldn't be suprised if there was a leak. I can hear it when the rpm's increase.....Wouldn't a ping have more of a metallic-y sound? Or like a tick? Its really racking my brain. Someone online said a ping would be noticeable even with the radio on. If that's the case this isn't a ping.

If it's pinging, should it also be, bad throttle response, lack of power, anything? It runs pretty good at all the above mentioned settings. Maybe as you advance the timing, low end power is increased but at WOT its basically all the same. I just wanna be in the 'safe zone' and if I ever required more performance I can add some advance.

Ive been reading and reading and reading and reading to the point of frustration. And I realize one person can't just say, oh yeah a ping sounds like This. Or sounds like marbles hitting a tin can (Wtf??) So I need some kind of different approach here. What else can I look for if there's too much advance, or could someone describe a 'ping' sound without using the terms "like" or "as" if that's possible. Thanks in advance to all the people who have taken the time to read this and offered their two cents on my issue.