I am working on a 1966 Buick 401 in a gran sport and getting information that conflicts with my understanding. I would like to hear your ideas on this.

Engine idles well and drives a light throttle well. Open the throttle at anytime including in park and it bogs and sputters.

Engine rotates clockwise and so does the rotor. Timing tab is located at 11 oclock position. I put a timing light on it and could not see the balancer mark. I found the mark by laying down on the floor, it fires at 7-8 o'clock position.

Is this too far advanced or retarded? Rotor is past #1 terminal when #1 cylinder is at tdc on compression stroke.

What say you?

Been a LONG time since I've seen a nailhead.
Mark is a long way from home if at 7 or 8 o clock.

Does the balancer have and inner and outer ring?
Could've spun outer if so.
Any ndex marks between inner and outer?

Are you sure your on number 1? Sounds far enough off that it shouldn't run.

Balancer mark at 0* puts #1 at tdc this has been verified with a straw in the plug hole. Nailhead #1 is on the pass side. I feel the same way about how does it run at all that far out. 90* on crank is 45* on distributor. So it appears to be 40* advance or more at idle.

I believe it is too far advanced and needs to be retarded. I cannot twist the distributor enough to correct this as the vacuum advance will hit the firewall. I am going to pull the distributor and reset according to the manual which shows the distributor vacuum advance pointing differently.

Sounds like your thinking right

And when you get it figured out, how about some pictures of this Buick?

The balancer outer hub may or may not have shifted. You need to find true top dead center. There are tools online available, but basically it involves inserting a stop into the engine and rotating it back and forth until it hits the stop, and true TDC is in between those marks. Then you can mark the balancer and set your timing from there. To find out if your balancer outer hub has shifted, pull the spark plug on cylinder #2, and turn the engine over until the piston is pretty close to top dead center on compression stroke. Just eyeball it, doesn't have to be perfect. Then look at the timing marks on the balancer and see how close they are to the timing pointer. If it's shifted, you'll want to get a new balancer. But in the meantime, you can get it close by putting a mark on the current balancer at true TDC.

Working on old stuff is fun. Back to the basics, that many have forgotten.

1966 numbers matching complete Buick Gran Sport. Had it about a month now. No rust california car last licensed in 1989 with the black plate.

Could it of jumped time unless someone pulled the distributor and put it back wrong. I would be inclined to check the timing marks on the gears as well. That far advanced starter shouldn't be able to fire it off.

Thats from the days when cars were cars. Nice ride for sure

Making sure your timing light is on the plug wire that goes to the number one cylinder. The distributor may not be in the correct place and they just started the plug wires according to where the rotor was when number one was on the compression stroke instead of pulling the distributor back
Out and turning it correctly.

That is a sweet looking machine!

Danny, I think you hit it right. If I moved all the wires 1 terminal clockwise I should have enough rotation in the adjustment to get it timed right. Probably off 1 tooth.

Thanks for the compliments on the car, hopefully it will get painted back to the original saddlemist color and new interior kit.

Timing is probably not the problem. Spark advance is done with vacuum. What your describing sounds like a vacuum leak. That vacuum line to the distributer is the spark advance. Once you verify the timing start looking for cracked or missing vacuum hoses. look for hose tits with nothing hooked to them. The vacuum line to the transmission modulator valve is only rubber part of the way. Some of it is stainless steel. Check it for rust holes. Check the big line to brake master cylinder.

X2
Once timing is verified, check vacuum advance. Make sure it's hooked up to the proper port on the carb, above the throttle blades. There should only be vacuum with the throttle open, none with the throttle closed. And you should be checking timing with the vacuum advance disconnected. If it's hooked up wrong, it'll retard timing when you open the throttle, the exact opposite of what you want it to do.

I have seen this a couple times before. If I understand your you're saying Danny, At some point in it's past, distributer was removed and reinstalled incorrectly, and plug wires were walked around the cap to make it run. Then timed by "ear"....Get #1 piston at top dead center, pull dist. cap identify # 1 on cap see if rotor is pointing at #1 plug wire on cap. If not Dist will have to re indexed to #1 then plug wires walked back on cap. That should get timing marks very close to pointer. If balancer outer ring slipped and walked that far off, the balancer is toast and probably would have came apart. Only time I have seen a balancer outer ring shift, was on press fit style being hammered on and damaged.

Could that scenario be tested by moving timing light pickup clamp one wire ahead or back on dist cap to see if mark comes back to pointer? Just thinking out loud here....Lol

With the distributer removed, if you remove the #1 plug and stick your thumb over the hole, then turn the motor by hand till you feel compression, ( only every other time the cylinder comes up will it be the compression stroke) then watch with a flash light to get the piston all the the way up, you can put the distributer in any way it will drop in on the oil pump and spline with the cam shaft gear. Install the rotor in the distributer. Wherever the contact is for the distributor cap is where your #1 plug wire goes. Then following the sequence 18436572 install the rest of the plug wires, the engine can be timed using a timing light and the timing marks, by turning the distributer just like normal. Its pretty common rather than putting the distributor in "correctly".