NEED HELP WITH 57 BUICK CONVERTIBLE IGNITION TIMING

would appreciate help with this timing issue i have with my buick 57 convertible 364ci.. the engine ran nicely & has only done 10,000 miles..but i noticed that both the timing marks would not align & when timing light was used it showed the marks were 1.5" apart. if i moved the dizzy & make the balancer timing mark move toward the fixed timing mark on timing cover the engine would retard..so i decided to remove dizzy & reset the timing.. but at first i made the mistake of setting the dizzy 180 degrees short of TDC & when i started the engine there was a large pop sound up thru the carby which also caused the fuel line to split short of entry to the carby & where the fuel filter joins,, so i replaced the hose & filter & again re-set the distributor with both #1 cylinder valves closed & after 2 revolutions on powerstroke & with rotor pointing at #1 on dizzy cap & with points about to open..i then started the engine & again there was only minor back fire thru carby .. it was then obvious i would need to reset dizzy so the timing mark were 1.5" apart as when engine did run nicely...so i reset the dizzy & the engine ran somewhat smoother & with minor smoke coming out valley cover But the engine also sounded louder & like a tractor engine or old wooden boat or as if there was a hole in valley cover(but there is no hole)...i put the timing gun & it showed same timing as when it did run nicely & prior to removing the dizzy..it ran till it got warm then engine stopped running ..it restarts easy enough just louder with minor rough idling so i decided to try reset the dizzy one tooth over from when it now ran but that was no good ..i decided to reset the dizzy under one tooth from when it just previously ran but that too was a no go...so i reset the dizzy back to where is does run but still sounds like a tractor or sounds as if there is a hole in valley cover ..there is some black residue exhaust that has exited the tailpipes too .. could of the first mistake of re-setting the dizzy 180 short of powerstroke have caused a gasket to damage within carby somewhere or between carby & inlet to sound like a tractor now or do i still have the timing wrong ? anyone know how to solve this problem? thanks john

Check the muffler(s) and resonator(s) for damage.

I've seen backfires split a muffler case open like an over-rip watermelon.

The backfire could have damaged the carburetor inside. I don't know what make or model you have, but some had a diaphragm or other parts that were sensitive to pressure.

Your vibration damper could have shifted. If you examine the front pulley closely, they have a rubber insert between the hub and the rim. This rubber can deteriorate from age, heat, and being soaked with oil and the rim can turn on the hub. This would account for the timing marks being so far out.

In that case you would do well to ignore the timing marks and set the timing using a vacuum gauge, adjust so as to get the most vacuum at idle. Make sure the idle speed is slow enough that the centrifugal advance does not kick in.

The vibration damper can be rebuilt but this is a specialist operation, not something you can do at home. I doubt you want to ship your damper away to the US and wait a few months to get it back.

To find TDC without taking off the head, you need to buy or make a gadget that threads into the #1 spark plug hole and has some kind of pipe or hose on it. Stick a kid's balloon on the end and turn the engine forward slowly by hand. You will see the balloon inflate, when it is at its fullest you are at TDC. I know it sounds silly but this method can get you within a couple of degrees.

Thankyou guys ...its definitely not the mufflers with holes because the noise is around the valley cover inlet carby area ... but the carby still seems to work fine ..its a carter 2 barrel WGD type...& i think Rusty ,your definitely right concerning the damper ..i believe it has slightly moved.

On 1960 Buicks, there is a round steel plug in the bottom, center of the intake manifold that could have blown out in the backfire. You will have to pull the intake to get to it. A standard flat freeze plug can be used as a replacement. 1957 may be the same.

Thanks Dave , on 57 inlet there is no plug underneath ..i got a feeling it could be the carby to inlet paper base gasket ..the carby base gasket has the exhaust channel that runs thru it ..wouldnt take much to burn a piece out of this gasket as shown..

I have removed the inlet manifold & discovered that there was a large plug underneath the inlet ... infact it blew out due to the backfire & was the reason the engine sounds like a tractor ...My hat goes off to Dave (61 polara) you hit the nail on the head my friend ..!! ... i appreciate everyones input ..with great technicians like these guys ... were in good hands ...cheers !!!