Ever install a distributor backwards?

[Budbeater]

Yeah, I know ancient tech, but its good tech when it works. Now I am not even going to go as far as points etc I just need to know about the good ole HEI (thats High Energy Ignition for all you youngones).

Anyway, has anyone ever installed a distributor 180 degrees off? There are only 2 ways that these things will go in and from what I have heard the engine will even run if it is the wrong way. What are the sounds and symptoms?

The distributor in this 82 Big Block Crew Cab was frozen. The advance mechanism was gummed and rusted and was off by about 50 degrees. When we got the newly rebuilt distributor back into the engine we realized we were going to have to take a wild guess as to which way was the right way since the rotor was now about halfway between the marks we had made to help in the reinstallation. It was hard to start but ran like a champ once going. When we dropped it in my brother set up the timing by using the #4 plug wire. For some reason we can't seem to even see the timing marks when we try to time the engine using the #1 wire (like is customary). Can you time the engine using the #4 wire? Why would we not be able to see the timing marks using #1 that just doesn't seem right. The only things I can think of are that the balancer has shifted or the distributor is in wrong.

Oh, by the way
New:
fuel pump
fuel filters
spark plugs
Plug wires
rebuilt distributor
rebuilt carb (some of the settings are not quite back to where they were when we started)

 

[Greg]

I've had a few dizzys backwards on Chevy V8's and none of them came close to firing, no matter how far advanced or retarded they were. They'd just fire when the valves were opened, resulting in a flame out the carb or pop out the exhaust.

I'd be willing to bet that you're off a tooth one way or the other. Pull the dist, turn the rotor one way and drop it back in. Make sure you're not in the same spot and try firing the motor. If it doesnt run right then, then go back 2 teeth on the rotor.

It should be pretty simple to figure out. Just take your time, think about what the motor is doing & keep an eye out for the obvious. f you pull the valve cover on the drivers side, you should be able to watch the valves move & see when the #1 intake valve closes. You would be close to TDC at that point.

 

[mbryson]

what Greg said. I bet you're off a tooth. You'll need to back the oil pump drive back a hair and move the dizzy back a tooth (maybe forward?).

 

[Budbeater]

Thats what I am afraid of... I personally hate pulling distibutors. It should be such a simple job yet it always takes forever.

I am going to pull the valve cover and bring it to top dead center to check it before I pull the distributor. I will at least know if it is where it is supposed to be.

Thanks guys!

 

[krawlereng]

check your firing order it can be off but still run chevy v8 is 18436572 another possibilty is a bad module or a bad cap that one is pretty common with gm hei. another common problem is the timing tab dosen't match the dampener so you just can't see the mark on it when you try to time it.

 

[78mitsu]

In a chevy BB/SB/4.3/etc., the oil pump is driven off the distributor gear, but without the distributor, it turns freely. So you can put it in any direction you want.

The best way to time a chevy without taking the timing chain cover off is to take off the drivers side valve cover and watch the valves. Rotate the engine by hand slowly the #1 intake will open then close (it's the one higher on the head on a bbc) at that point the piston should just start on the compression stroke. take out the #1 plug and insert a wooden dowel (don't use a screwdriver they're aluminum pistons) when the piston hits the dowel and moves it you're where you want to be just before top dead center on the compression stroke. Generally the +1 piston is labeled on the cap, set the rotor just behind where it would be and as you slide it in, it should line up. (You may want to line up the oil pump as best you can). If you can't get the distributor to drop into the oil pump, rotate the engine a little until it does, then return it to TDC and verify its right. Wire it 184326572 clockwise.

As far as having them run 180* out, I’ve had them run, poorly, but they'll start and run. When you revv them as the timing advances they'll backfire through the carb. It’ll destroy power valves and bend metering rods, it’s not pretty.

Also, chevies are notorious for chewing the #2 exh and #7 int on the Cam. Flat lobes on a cam can make for an interesting running motor. Easiest way to check is to put a dial indicator on the tappet side of the rocker arm and see if the travel is uniform among all the intake and exhaust valves respectively.