Just replaced my Mallory with a used '57 TBird distributor. Seller said it was just rebuilt, it's straight, no excess play, clean. It reportedly has new condenser, rotor and points, which is all consistent with what I'm seeing. I set the point gap, and the dwell while cranking the engine is at 27. With #1 cylinder at TDC (compression stroke), the rotor is pointing directly at #1 sparkplug on the cap.

The engine backfires violently and won't start.

Car was running before the dizzy changeover. I have checked and rechecked all the plug wires for correct sequence and good connections. Nothing else (coil, carb, etc.) was changed. WTH? What should I check next?

I’ll suggest that you double check that you are indeed on #1 compression stroke and not #1 overlap.  TDC on the damper comes up on both.  Still sounds like you’re 180° off on the distributor.  You might also check that the point gap is in the vicinity of 0.017”-0.019” at high point on the distributor lobe while you’ve got the cap off.

 

I'll add that you can pull the passenger side valve cover off with the damper on TDC and both the #1 valves should have some play in them if you are on #1 compression.  If the valves are both tight, then you're likely on #1 overlap (180° off).

 

I'm assuming you are working on a Thunderbird which shouldn't present an issue as far as a slipped damper as far as timing readings or the TDC mark is concerned.  On the non-Thunderbird dampers, a slipped damper will throw you a curve.

 

Lorena, Texas (South of Waco)

OK, I'm gonna run back down and pull the valve cover and check they're both closed. It's gotta be something stupid like that. Thanks

It was something stupid like that. Fired right up. When am I gonna learn not to be in such a hurry.

Joey

I think Ted is correct. The distributor is installed so it fires with the valves on that cylinder open. You can STATIC TIME an engine. Find the 0 on you timing mark on the dampner with the engine off. Take off the valve cover on the number one cylinder ( or really any cylinder) to confirm the two valves are closed and that piston is at the top of its stroke. Turn on the ignition and rotate the distributor until the points break and you see a spark. The rotor is now pointing at number one cylinder ( or any cylinder you want to fire now). Turn off the ignition, tighten the distributor hold down to just snug. Replace the spark plug leads in the right sequence, Number one spark lead MAY NOW HAVE CHANGED its location on the cap, in direction of rotation. The engine will start and using the new number one spark plug lead location time the engine with your timing light. You did replace that valve cover, right? Pete

Thanks much gents, as always. Now I gotta set initial timing, then check centrifugal, and then vac advance. Got my timing light and analyzer... but it won't happen til later because now it's raining cats and dogs here.

The same problem was on my Y. I just solved the problem by turning the cap 180 degres.

It now appears that I have sprung an oil leak from the bottom of the oil pump, which I took apart to get at the oil pump drive shaft. When I put it back together I noticed the only gasket was a very light O-ring, it looked OK so I re-used it.

The NAPA guy came up empty on his computer with regard to the O-ring, but suggests that he could probably match one up, as their stock O-rings come in many sizes. But it occurs to me, mightn't the correct O-ring be flat sided on one side? Does anyone know?

Also (and maybe more important) was there ever a gasket under the square-ish cover plate that is held on with four small bolts? There isn't one there now...should there be a paper gasket maybe? Seems odd to me to just have metal on metal and expect it to seal. If there is supposed to be a cover plate gasket, couldn't I make one?

Is this the oil pump you have?







The plate at the lower right is sealed to the pump housing with an o ring that has a square profile. You can barely make out the groove in which this o-ring fits in the pump housing. The screw at the upper right is sealed with a gasket which looks to be paper.

A paper gasket seals the pump to the engine block. The oil pickup tube is sealed with a thick round rubber gasket.


Lawrenceville, GA

Charlie, i have noticed  that the o ring has been  normal o ring section in the gasket sets lately and will work. As most folks have the cast pump and dont use the o ring for aluminum pumps, there should be one laying around in a gasket set somewhere?? i have a few.

  AussieBill            YYYY    Forever Y Block     YYYY

 Down Under, Australia