I have been working with this issue for a couple of weekends and can't figure this one out. I recently changed put a new holley 650 carburetor on my 455 bbo. After the initial start up it ran and sounded fine. After I shut it off And restarted it after 30 minutes it didnt start right up i pumped the gas and a few turns later it fired up and ran. This even happen with the old carburetor which is why I changed it out.

So I decided to redo the timing on the car, bad idea!!! The first attempt at setting the initial timing was horrible. I set it 180 degrees out and it would do nothing but back fire when tring to start. So I removed the valve cover and watched the intake valve to ensure I was setting it on the correct stroke. I set the car to 13 degrees btdc and it started but there was a pinging and popping coming from the engine. So I set it again to 0 degrees (tdc) and had the same result. This time I noticed that the ping and pops were coming from the exhaust manifold were the gasket is missing on the cylinder head. I replaced the gasket and had the same results now I am out of ideas and need some help. I checked all spark plugs, changed distributor, changed vacuum hoses, and exhaust manifold gasket. What Are some suggestion I should try now? Also when I was setting initial timing I put a small screwdriver in spark plug hole and when the pist reached tdc the timing notch on the balancer was not on the timing ridges on the engine block yet. I turn it a little more to line the notch with the ridges but the piston was still at the top of the cylinder, is this normal?

 

Double check your spark plug wires to make sure your firing order is correct and they are all pushed on tight. Also check your dwell to insure your right at 30. If you have to reset it then reset your timing. Are you running manifold or ported vacuum to your vacuum advance? Did you set your timing with it disconnected? Set your Holley A/F mixture screws with a vacuum gauge or a tach for the highest readings.

 

If you were 180 degrees off, then you removed the distributor and instaled it 180 out.

When you reinstalled the distirbutor, are you sure you you are not a tooth off?

I would make sure the #1 piston is at the top of the compression stroke and verify that the timing mark on the balancer lines up with the correct mark on the engine. At this point, the #2 plug terminal on the distributor should be pointed toward the front of the engine. Seee the picture in the Service manual under Emmission Control and Tune-up. If it is significantly off, then something isn't installed correctly. If the mark on the balancer is off, then I would check to see if the balancer is bad and the mark is walking as the engine runs. This will make it impossible to time and it will eventually come apart.

 

think you may be on the exhaust stroke and not compression TDC

 

Brown7373: There is no such thing as being 1 tooth off with regards to setting timing. The engine does not care where #1 is wired. All it effect is where the vacuum advance canister is positioned. I agree that there may be a slim chance his harmonic balancer slipped, slim chance.

Rjohnson: What are you trying to say, cause that makes no sense at all.

 

I am running an hei distributor on this engine. I know that the engine is on the compression stroke because I removed the valve cover and watched the exhaust/intake valves open and close. Were should the inital timing be set I have mine set at 14 degrees BTC. And what should the advance be set too? I am out of ideas so the next thing I going to do is replace the distributor.

 

If you know for sure your 180 off then just take the rotor off and turn it around (notch the other side so it sets down flat).
unhook the vacuum and plug the source, set intial timing to the top of the timing tab. Now plug the vaccum back up to full time manifold vaccum and set the idle and it should really start to run better.
But you really need a " dial back timing light" to get it exact.
The full time vacuum is the key to a smooth running engine.

 

Make sure you have 12v to the HEI and your not using the resistor wire. Did you verify you firing order?

 

"If you know for sure your 180 off then just take the rotor off and turn it around (notch the other side so it sets down flat)."

Why do this when doing it correctly would be the best way? Just pull it out and turn it 180* and start off the right way. The round and square pegs are there for a reason. Do it right.

 

Sure you can install the distributor one tooth off. That doesn't mean you can't time the engine correctly though, provided the vacuum canister doesn't hit a bracket or the block and limit the movement. Ask me how I know.

As far as the balancer separating, I had a similar problem with timing a 69 Corvette. It was running crappy. I set the timing and drive it and it was not right. When I rechecked the timing, it wasn't where I had just set it, or was it.

When I kept the timing light on the mark, I watched it slowly move, without the timing actually changing. The rubber broke loose and the outside ring was slipping, so it was impossible to verify the correct timing...at least by using the balancer mark. Rare, maybe but on a 40+ year old car, not so much. The balancer on my 72 failed a few years ago and I replaced it.

 

He said it was running, therefore it's not 180 out.

 

Are you saying there is not TDC on exhaust stroke then? I was just saying Confirm #1 is on compression not the exhaust stroke