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Distributer Insertion

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BMCMidgetLover

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I have everything lined up, and yet the distributor will not seat so that the clamp is around the distributor, yes the clamp bolt is open and the clamp is free around the distributor, but all screws are completely loose or off the motor. I know the rotor/shaft is at least in the top of the slot because I can rock the shaft back and forth a small amount but not turn it. Yes, the shaft is free when its out of the motor. Is there a secret to this? When I have done this in the past once everything was lined up it just slip in.
 
Two things have to line up the gear that drives the dizzy and the oil pump drive.
 
Could it be that the drive shaft has lifted slightly when the distributor was removed. I am not sure if this is a similar arrangement to what you are describing but you have to be very careful when removing and replacing this drive otherwise your timing will be out.

DSCF0035.jpg
 
I spent a lot of time with two 1275. One in a car another out. In both cases I could only get the distributers (I have 2) in one way, I could not rotate the shaft and then reinsert it, it would not seat. To me this meant that in one case cylinder one was 180 degrees from the second engine both had the pulley marks where they should be, at the timing pointer. To me that makes no sense, something here on my part is not understood.

Please educate wheat have I missed?
 
as the dissy drive has an offset slot the dissy can only go in one way, as far as timing goes you could put the drive in any position and set your plug leads to suit by putting engine on TDC #1 ,look where your roterbutton is pointing then arrange your plug leads in the cap to suit, then do final timing by rotating the dissy,so if your dissy wont go all the way in then you need to remove the drive gear[screw a 1/4unf bolt into in to it to remove, then keep replacing it, turning it, until it drops[you will feel the bolt rotate as it drops] you may have to wiggle it a bit to get it to go into the lower housing
Russ
 
BMCMidgetLover said:
I spent a lot of time with two 1275. One in a car another out. In both cases I could only get the distributers (I have 2) in one way, I could not rotate the shaft and then reinsert it, it would not seat. To me this meant that in one case cylinder one was 180 degrees from the second engine both had the pulley marks where they should be, at the timing pointer. To me that makes no sense, something here on my part is not understood.

Please educate wheat have I missed?
Click to expand...

For info the image I posted was for a 1098cc A Series engine, it is important to set the distributor drive correctly as otherwise the ignition timing will be totally incorrect. It is easy to set the distributor drive in apparently the right position, but exactly 180 degrees out by omitting to select the correct cylinder eg No1 which must not only be at top dead centre but must also be on its firing stroke with both valves closed, (No4 cylinder will have its inlet valve just opening and exhaust just closing).

It sounds to me that your drive may have been put in 180 degrees out, you can't just rotate the distributor 180 degrees and re-insert it because the drive has an offset dog.

Good luck.
 
As above, a Lucas dizzy will only go in one way because the slot in the drive gear is not centered on the gear. It is very common for the drive gear to NOT be installed in the position shown in the service manuals. When that happens, there are two possible corrections.

1) You can pull the drive gear as Meyers said. The drive gear is tapped so all you need is a long bolt to use as a handle. Thread it in, pull the gear out of the block, then re-position the drive gear where you want it. Refer to the service manual. It will show the position of the drive slot. Prior to moving the drive gear, bring cylinder #1 to TDC on its firing stroke (both its valves closed, zero timing mark lined up).

2) The second option is to leave the drive gear where it is and follow Zabond's recommendation. Determine where the rotor is pointing when the engine is sitting with #1 at TDC on its firing stroke. Put the spark plug wire for cylinder #1 on the cap where the rotor is pointing. Install the other plug wires counterclockwise around the cap in the order 1-3-4-2. The plug wires won't be ordered as shown in the manual but they will be correct for how the drive gear is installed.

Regardless of which way you decide to address this, set the static timing for about 8 BTDC to get the engine started. Once the engine has warmed up, set the timing dynamically with a light.
 
dklawson said:
As above, a Lucas dizzy will only go in one way because the slot in the drive gear is not centered on the gear. It is very common for the drive gear to NOT be installed in the position shown in the service manuals. When that happens, there are two possible corrections.

1) You can pull the drive gear as Meyers said. The drive gear is tapped so all you need is a long bolt to use as a handle. Thread it in, pull the gear out of the block, then re-position the drive gear where you want it. Refer to the service manual. It will show the position of the drive slot. Prior to moving the drive gear, bring cylinder #1 to TDC on its firing stroke (both its valves closed, zero timing mark lined up).

2) The second option is to leave the drive gear where it is and follow Zabond's recommendation. Determine where the rotor is pointing when the engine is sitting with #1 at TDC on its firing stroke. Put the spark plug wire for cylinder #1 on the cap where the rotor is pointing. Install the other plug wires counterclockwise around the cap in the order 1-3-4-2. The plug wires won't be ordered as shown in the manual but they will be correct for how the drive gear is installed.

Regardless of which way you decide to address this, set the static timing for about 8 BTDC to get the engine started. Once the engine has warmed up, set the timing dynamically with a light.
Click to expand...

If option #2 is selected, would the timing marks now be against #4. I understand why I am in this situation. The motor was rebuilt and the #1 cylinder's valves are now reversed with #4. In other written words, When the timing mark is at the pointers, #4 cylinders are closed and # 1 are rocking. Again wouldn't the timing mark now be against #4?

Thank you
 
Last edited:
The dizzy turns Counterclockwise and #1 is at about 2:00.
 
Remember that #1 & #4 pistons are both at TDC at the same time just ones on comp other on exhaust, if your timing marks are lined up you are at TDC on #1 or #4, if you turn the engine 360* you will still be at TDC on both cyls but one on compression& other exhaust that's why you need to watch your valve rockers to find out which cyl is on compression so if the marks line up and #1 valves rocking turn the engine 360* and #4 will be rocking & #1 on compression,
 
zabond said:
Remember that #1 & #4 pistons are both at TDC at the same time just ones on comp other on exhaust, if your timing marks are lined up you are at TDC on #1 or #4, if you turn the engine 360* you will still be at TDC on both cyls but one on compression& other exhaust that's why you need to watch your valve rockers to find out which cyl is on compression so if the marks line up and #1 valves rocking turn the engine 360* and #4 will be rocking & #1 on compression,
Click to expand...
And then #1 will be firing, and the picture would be correct in Robert Bently.
 
BMCMidgetLover said:
If option #2 is selected, would the timing marks now be against #4. I understand why I am in this situation. The motor was rebuilt and the #1 cylinder's valves are now reversed with #4. In other written words, When the timing mark is at the pointers, #4 cylinders are closed and # 1 are rocking. Again wouldn't the timing mark now be against #4?
Thank you
Click to expand...

Turn the engine through one more complete revolution. The timing marks will line up again. Then you will find the valves for #4 are open and #1 are closed. #1 and #4 reach TDC at the same time. However, when one is at TDC on its firing stroke, the other is on its exhaust stroke... one crank revolution out from each other.

I don't want to duplicate or confuse you about Zabond's and my earlier post.

First, as mentioned earlier you have to be certain that you are working with cylinder #1 (water pump end of block) at TDC on its FIRING stroke. To determine this, remove the valve cover. If the engine has just been rebuilt or worked on, make sure the valves are adjusted properly. With the valves adjusted, turn the engine over by hand in the normal direction of rotation. Stop when the TDC pointer lines up on the pulley. Grab the rocker arms above cylinder #1 and try to wiggle them. If the rocker arms are TIGHT and cannot be moved you are looking at #4 TDC on its firing stroke. Confirm this by grabbing the rocker arms for #4. They should be "loose" so you can wiggle them. To get to #1 TDC, turn the engine through one more complete revolution. Again... make sure the timing pointer lines up and that the rocker arms above #1 can be wiggled.

Now that you have #1 at TDC on its firing stroke, remove the dizzy cap and look at where the rotor is pointing. The spark plug wire for #1 goes at that position on the cap. Fit the other wires counterclockwise around the cap in the order 1-3-4-2. What you are doing is putting the plug wires on the cap in the order which is correct for how the drive gear is in the block. Your timing marks are not "out", you still use the timing marks the way they are supposed to be used. What is "out" is that the plug wire positions on the cap may deviate from the factory positions. Again, the timing marks are still the same, you have just rearranged the plug wires to compensate for the drive gear position.

If you don't like that, your alternative is to start as above by getting #1 to TDC on its firing stroke. Then with the distributor removed you thread a long bolt into the dizzy drive gear and use the long bolt to pull the gear out of the block. Re-orient the gear so that when re-inserted the drive slot in the gear matches the pictures you find in the service manuals. Then re-fit the dizzy and set the static timing.

In my earlier post...
Option 1 was to re-position the dizzy drive gear so the drive slot matches what is shown in the manuals.
Option 2 was to re-position the plug wires around the cap to compensate for the drive gear being in the wrong position.
In both cases, the timing marks are still used as normal.

Sorry... not very concise but I don't know how much depth to go into to explain the process.
 
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