Timing 426 Max Wedge

[64lonske]

I have recently purchased a 64 Polara with a 426 Max Wedge. I am assuming it is stock from all indicators. My issue is that at hard throttle there is a small pinging/knocking. I'm running 105 octane and have my timing at around 10 advanced at idle and 30-31 total advance. I've tried advancing, I've tried retarding, nothing seems to solve it. Any advice would be appreciated. Thanks.

 

[AR67GTX]

No answer but with no more timing than that and 105 fuel I’m surprised it’s pinging. I wonder if it’s one of the 13.5/1 versions with original pistons. Might snake an inspection camera into a couple cylinders to see what the domes look like and how much carbon is in there.

 

[Canadian1968]

Those timing settings should not cause any pinging on their own , especially if your running 105 octane.
Does it have a vacuum advance on the distributor??? If so try plugging that.

You can also start with the basics. Get a vacuum gauge and hook it to the manifold. Set timing at what rpm you want , I would try at least 12 to start. Then adjust your carb and aim for the highest possible vacuum at idle.

 

[33 IMP]

Where are you getting 105 fuel? It's not some "octane booster" added to 91 or 93 is it?
I would try some real 110 in it and see what happens.
As mentioned above, if it's a 12 1/2 or 13 1/2 motor, you might have to go into it internally to lower the ratio, or simply give it a diet of 110.
If it were mine, I'd give it a diet of 100LL mixed with pump gas. (or straight 100LL)

 

[AR67GTX]

Might also try a different timing light to verify the timing. I’ve been reading lately how some of them can look good but read off several degrees. And just to be sure the 31 degrees does include the base timing of 10 deg?

 

[ruffcut]

Try 110 octane or if it is 13 to 1 comp I'd go 112 octane

 

[Jerry Hall]

My 12.5 to 1 motor requires 110 or better. I would run a compression test to see where you are at. Then work from there.

 

[Dan64]

If the car is new to you I would check it with a piston stop to verify TDC and go from there.

 

[64lonske]

Thanks for all the help. I’m using a Sunoco blend. My car storage facility is next to a local airport that has 100LL. I’ll start with a different fuel mix and see. It does not have vacuum advance.

 

[Dave6T4]

Thanks for all the help. I’m using a Sunoco blend. My car storage facility is next to a local airport that has 100LL. I’ll start with a different fuel mix and see. It does not have vacuum advance.

Max Wedge motors never had vacuum advance. Vacuum advance helps with high vacuum cruise conditions. Max Wedge was never designed for this scenario.