47-55.1 Eliminate draft tube options

[TX3100Guy]

One step forward, two steps back.......

Engine runs on the new distributor, but I very quickly noticed no oil pressure. Checked all wiring to oil pressure sensor and gauge. Since all was well with wiring, I had a very bad feeling......

After considerable measurements and testing. The new distributor does not engage with the oil pump drive. It seems that while the measurement from the tip of the distributor shaft to the cam gear is correct and since the shaft has no collar on it preventing the shaft from dropping in, the shape of the shaft directly above the gear prevents the cam gear from fully seating, thus the oil pump drive never even touches. The old magneto shaft has a spacer above the cam gear that is smaller in circumference allowing the cam gear to fully seat and then permitting the oil shaft drive to be engaged.

I can use an old distributor shaft in my power drill and get both oil pressure and weeping along the length of the valve train, but with the distributor - nothing.

OLD SHAFT AND SPACING ABOVE CAM GEAR


NEW SHAFT AND LACK OF SPACING ABOVE CAM GEAR

[TX3100Guy]

I tapped out the pin holding the cam gear and with the cam gear removed, the shaft fits all the way down to the oil pump drive, but the top of the shaft tapers out and the hold down clamp isn't wide enough to accommodate the width of the shaft.

I'm a bit confused how without the cam gear the shaft is long enough, although unable to be held by the hold down clamp. Could it be the incorrect cam gear refusing to mesh with the oil pump gear?

[leegreen]

The slot in pump has to be lined up just right, the cam gear turns the shaft a bit as you insert it, is it possible that it is the end of the shaft hitting the top of the oil pump that is stopping it going further and not the spacer above the gear? The way I remember doing this....note relation between rotor and flat end of shaft, insert into block, note the angle of rotor with a felt pen on block, pull distributor out and use screwdriver to turn pump to match, put distributor back in and hopefully it drops into place.

The tang may not fully bottom into the oil pump, does lifting back up the thickness of the clamp leave enough overlap of pump and shaft?

the measurement to check is the distance from oil pump slot to cam gear on both engine and distributor.

[TX3100Guy]

Originally Posted by leegreen

The slot in pump has to be lined up just right, the cam gear turns the shaft a bit as you insert it, is it possible that it is the end of the shaft hitting the top of the oil pump that is stopping it going further and not the spacer above the gear? The way I remember doing this....note relation between rotor and flat end of shaft, insert into block, note the angle of rotor with a felt pen on block, pull distributor out and use screwdriver to turn pump to match, put distributor back in and hopefully it drops into place.

The tang may not fully bottom into the oil pump, does lifting back up the thickness of the clamp leave enough overlap of pump and shaft?

the measurement to check is the distance from oil pump slot to cam gear on both engine and distributor.

Thanks for all this, but I've put a number of distributors in a few engines and never had this issue. If I purposely misalign the oil pump tang on the distributor from the slot on the oil pump itself, the distributor will set in at exactly the same point as if I align them perfectly (I used a Sharpie to mark the depth of the shaft in the block)

Incidentally, witness marks on the cam gear seem to indicate that it is only seating about 1/8 of an inch of its 5/8 inch width.

If I align the oil pump drive shaft on the distributor with the oil pump slot, it will not seat any further. When I removed the cam gear from the shaft, the shaft went a full 1/2 inch deeper in the block and was clearly engaged with the oil pump. Using the

[TX3100Guy]

Here is a picture of the distributor shaft with Sharpie markings at the depth it drops in with the cam gear installed and a second line at the depth it will drop with the cam gear removed from the shaft. Also notice the slight witness marks on the cam gear at its bottom 1/8 of an inch.

[leegreen]

the marks you point out on the gear and looking at the two earlier pictures; maybe the teeth on new gear are not cut as deep as on the old gear?

[1project2many]

I believe I would check the OD of the lower portion of the distributor gear and try to locate specs or a known good part to confirm it is correct.