installing distributor and oil pump

[Caldwelljj0]

I am installing a military oil pump and distributor. How can I be sure it is lined up for proper firing order?

[Lifer]

The distributor will only go in one way if you still have the military oil pump/distributor because the drive tang on the distributor is offset to one side. This eliminates half the problems you may encounter.

When installed, the rotor should point to the #1 plug wire (7:00 position when at TDC with #1 cylinder at the top of the compression stroke). The adjustment hold-down bolt should be in the middle of its curved slot at this point. If the rotor does NOT point to the 7:00 position, you need to pull the oil pump, turn it counter-clockwise 1 tooth and reinsert it. You may have to do this a couple of times or so until it lines up right.

Once you have the rotor pointing in the general vicinity of the #1 plug wire, it's a simple matter of turning the distributor back and forth as usual to set the timing.

Enjoy getting your hands dirty! That's half the fun, isn't it?

[MSeriesRebuild]

We see the military oil pump still in use with a civ distributor or vise versa fairly frequently. The offset design if installed by a sensible installer will guard against a 180 out situation, however, it can be forced into engagement with effort. So if you think it is impossible to install incorrectly, wrong. It's a common sense thing with one knowing force should not need to be applied; not if you can shove it in, it should be ok. I had one a couple of weeks back that used a civ oil pump and a mil distributor, someone had worked on the oil pump shaft slot with a dremel tool it appeared to widen the slot so it fit effortlessly. We replaced the pump with a new mil spec pump to get things back in line.

[M37UK]

What would be the symptoms of installing the distributor 180 degrees out ?

Just wondering.....

[Lifer]

What would be the symptoms of installing the distributor 180 degrees out ?

Just wondering.....

Most likely, you would get backfiring through the carb if a cylinder fired with the intake valve open. That's a true backfire. It could also "backfire" through the exhaust if the cylinder fired with the exhaust valve open. Either way, the engine would not "light up" and run, and the backfire would scare the bejeezus out of you and anyone else in the neighborhood (simply because true backfires are so rarely heard these days).

[MSeriesRebuild]

What would be the symptoms of installing the distributor 180 degrees out ?

Just wondering.....

The engine will not start, however you will get an occasional backfire is pretty much the typical. It won't be hard to figure out the problem. Now if you change the plugs wires around and put #1 wire where #6 would normally go and vise versa, plus continue to relocate the other wires in accordance with the 1-5-3-6-2-4 firing order; all will be right on time.

[M37UK]

Ok, thats interesting.

I still have the occasional problem of a slight backfire through the carb upon quick acceleration and I am struggling to get to the bottom of it.

[MSeriesRebuild]

Ok, thats interesting.

I still have the occasional problem of a slight backfire through the carb upon quick acceleration and I am struggling to get to the bottom of it.

This would be a totally different issue.

[LmJohnson 13th]

Thanks for the information
Will give it a try.