My deck is a measured .006. I installed my distributor and there is about 1/4" between the base and the manifold. The distributor appears to be firmly seated. The rotor is "captured" and turns with the motor (by hand). I've installed alot of distributors but I can't get this one to seat fully. Are shims required for a zero deck? I have pics but my host is not working right now.

 

I remember being told that if I milled my heads I would have to shim my dist. http://store.summitracing.com/partde...5&autoview=sku

 

if it's a small block, then the distributor should drop all the way down. If you have a 1/4 inch then I would think your oil pump drive is not lined up with the distributor. With the dizzy lined up on #1 tdc, pull it out and look on the end to try and figure out approximately which way the piece in the end of the dizzy is pointing and then shine a flash lite down the hole and see if the oil pump drive is about the same direction - dont forget you have to have it a little off in the counterclockwise direction to allow for the cam gear to turn the dizzy gear as they mesh.

I hope this helps.

 

I've done exactly that. The gears have meshed because the rotor turns when the motor is turned. I can feel it drop down, it just isn't dropping all the way. JEGS has an adjustable collar that you can use to adjust installed height. I wonder if that would work?

 

I was looking at that in the JEGS catalog. It looks like something I may have to try. I have "out the box" AFR heads so that shouldn't be an issue.

 

There is no way that I can think of that you would have a 1/4 inch there. Take a look again as I also feel that the distributor is not going into the oil pump shaft. It can turn against the cam but may not be seated to the oil pump shaft.

You can think of it this way. Did they Deck the block 1/4 inch? That is a bunch.
Also if they did deck your block that much then you would also have to have the manifold milled as well so that it would correctly seat against the heads and runners. Been there done that and have the T shirt lol.

 

the gears will mesh all the way around in any position - but until the spade stuck inside the end of the distributor lines up with the oil pump shaft it wont drop all the way down, and like SHAKERATTLEANDROLL said, unless you either had your block decked 1/4 of an inch (and the last block I had decked only needed 16 thousanths of an inch) or your heads machined 1/4 of an inch (which is about 225 thou more than needed), then it is an alignment problem.

if you are sure you have the distributor stabbed correctly in the hole, then (very important this - with the power disconnected from the dizzy), apply a gentle but firm downward pressure to the dizzy and have someone bump the engine over - it will eventually line up and drop down for you.

 

The times I"v done it, alone, I didn't even push the dizzy, it just flopped immediately....

 

I will add that since you can look through the intake and be able to see the Oil Pump drive. It is easy to just use a long regular screwdriver and turn the oil pump drive where you need it to be and stab the distributor. It may take a couple of times as I know with the vacume advance it has to be just right.

 

I got caught on a 283 recently where the distributor would not go home any way I tried it. I then took the sump off, removed the oil pump and drive, discovered the previous owner had fitted a big block oil pump drive (which is about 1/4" longer???).
Replaced that with a SBC one and it went home first try.

 

Isn't the rotor turned by the camshaft gear, not the oil pump. Rotor should turn, but that doesn't mean oil pump in engaged.

Ralph.

 

When you mill the block, the heads come closer together raising the intake manifold, same thing if you mill the heads. You have to mill the intake or the intake side of the heads to get the intake back in alignment. Look at the oil pump drive shaft to see where the slot is, put your distributor back in, turn the engine til the rotor moves about 1/4 turn, pull the distributor out & see if the oil pump shaft rotated also.

 

Just a few things that you might check:

1. Is it a tall deck distributor? There are a few of 'em floating around.
2. Big block oil pump shaft in a small block. It'll fit in the block and do the exact thing you're describing. Been there, done that, just like thmprr.
3. As others have suggested, is it possible that you're engaging the cam gears but not the oil pump shaft? Use a long screwdriver with a mark on it so you can determine the orientation of the slot in the top of the oil pump shaft. You'll have to turn it a few degrees to be in the right spot after the distributor shaft turns when it engages the cam gear.
Good luck, I hate it when things like this slow me down and I'm sure you do, too.

 

I think you would have to mill it 6 feet to raise it 1/4"

 

Ralph you are right the cam gear does turn the dizzy, but the shaft from the oil pump goes up inside the dizzy shaft, so the cam turns the dizzy which intern turns the oil pump. One catch - the oil pump shaft has to be aligned with the inside of the dizzy shaft in order for the dizzy to drop ALL the way down.

 

The same thing happened to me when i installed my Accel,
rotor turned,but dist was not fully seated.
I just re-alligned the oil pump drive,and the dist end to roughly the same direction(or as close as i could get it) and lowered it in slowly so as not to disturb the gear and it fully seated.Steve

 

You're not engaged correctly with the oil pump driveshaft. Here is the distributor installation technique to fix this problem as taken from my "How to Install your Chevy Distributor" paper. For the complete paper with photos, drop me an e-mail request to:
V8FastCars@msn.com
Lars

Instructions:

Hold the distributor body in the orientation show in figure 1 relative to the engine/block and drop the distributor straight down into the block. Pay no attention to rotor orientation at this time. If the rotor is aligned with the oil pump driveshaft, the distributor will drop all the way down and seat. If the rotor does NOT line up, the distributor will not drop all the way down.

If the distributor does NOT drop all the way down (chances are best that it won’t), pull the distributor up out of the block just enough to disengage the rotor from the camshaft gear, and turn the rotor a little bit. Drop it down again. Repeat this until the distributor drops all the way down and the rotor engages with the oil pump.

The distributor will now be all the way into the block, but the rotor will not be properly aligned. You can now pull the distributor up until the cam gear disengages, turn the rotor JUST A HAIR (half a cam tooth), and drop it straight back down again. The rotor will now move one tooth over, and the chamfer on the oil pump shaft will allow the oil pump to line back up. The distributor will drop all the way back in again, with the rotor moved over one tooth. (If it doesn’t work, try rotating the rotor the opposite direction.) Repeat this operation (I call it “walking the distributor”) by lifting the distributor up, slightly moving the rotor, and dropping it back in until you’ve “walked” the rotor around to its correct position as shown in the figure below. Once you get the technique down, you can do this very quickly – much quicker than trying to align the oil pump driveshaft with a screwdriver while looking down the hole. The screwdriver technique also requires that you pull the distributor ALL THE WAY OUT to fiddle around with the screwdriver several times until you get it right. So try my “walking” technique: it’s quick and accurate.

 

Well guys, I got it in. It took more finesse than usual but it's in. I didn't use any hammers or pry bars. I stuck a big screwdriver in the slot on the oil pump shaft and put a piece of tape where it met the manifold flange. I then put the screwdriver in the oil pump shaft of the 383 I just took out and it was the same. That told me there was nothing causing the 1/4" gap. I just needed to take my time and do it right. Thanks for the help.

 

Thats what I did. I slowly rotated the motor while pushing down on the distributor. (I have long arms!) The gears fully meshed and it went right on down.

 

I've had that happen many times. I think thats what I was expecting.