There’s been some discussion on an American Mini forum about flywheel and dizzy installation with a comment that I’d like some feedback on by those who have experienced it. This comment refers to the way the distributor driveshaft is installed in the block and how timing is affected. It states:
If you follow the book and line the timing dots up, then fit the dizzy drive shaft as shown in the pic, it will be 180deg out. It’s a fault in ALL the manuals. What you need to do is rotate the engine 1 full turn BEFORE fitting the dizzy drive shaft.
True/false/maybe?
Jack
Jack, what I would do to confirm, is set the engine at No1 Cylinder TDC and insert the shaft as per the manual illustration and once done insert the Distributor and ensure the Rotor Arm is pointing at the 1 O’clock position, that will confirm if you are timed correctly on the distributor drive shaft.
KernowCooper
That’s the way I’ve done it on every car I’ve time over that last 40 years. That’s why I found this advise so strange. Thanks for your response.
Jack
The advice is not strange. The discrepancy is the manual implies that when the cam and crank pulleys are sitting dot-to-dot you are at #1 TDC on its firing stroke. In fact, while the pulleys are sitting dot-to-dot, #4 is also at TDC and IT is the cylinder that is on its firing stroke.
If you leave the pulleys dot-to-dot (don’t turn the engine after fitting the timing components), and then fit the dizzy drive gear as shown in the manuals, then the rotor will be 180 degrees out when you fit the distributor.
Again, the discrepancy is the implication in the manuals that while the pulleys are aligned dot-to-dot you are at #1 TDC on it’s firing stroke when it is really #4 on its firing stroke.
Ah, I see. So it’s a matter of following the manual description rather than actual practice - i.e. putting piston #1 at TDC before inserting the timing shaft in the block. Which is what I’ve always done. Thanks for clearing that up.
Jack
Yes indeed.
Don’t go directly from fitting the timing chain to installing the dizzy drive gear. Make sure #1 is at TDC _ on its firing stroke _ before installing the distributor drive gear.
#1 at TDC with both valves shut, right?
Jack
Yes. Both valves shut. Which means you can grab the rocker arms above #1 and “wiggle” both of them a little bit.
