Best Answer postve , 12 August 2021 - 10:15 PM
The TDC of the crank (flywheel, pistons, crank pulley) happens twice per cam (and hence dizzy) revolution.
Google the 4 stroke cycle for some graphics that will show this and how it corresponds to the valve actions.
So - if you turn the crank one full revolution you will find that the rotor arm only moves 1/2 a revolution and then the rotor arm will point as you expect. When it does, check that the valves on cylinder 1 are closed. If they are - you're good.
Crazy About Mini's
Posted 12 August 2021 - 12:08 PM
Is the head still on?
Before you flip the dizzy (actually you'd have to rotate the dizzy drive which is unlikely to be wrong if you haven't toughed it), make sure you are checking the dizzy orientation at TDC on the compression stroke of cylinder 1.
From memory, when you set the cam timing cyl one is at TDC on exhaust/inlet stroke - ie valves open as you're timing the cam to the crank, not the ignition to the cam.
Super Mini Mad
Posted 12 August 2021 - 12:49 PM
Is the head still on?
Before you flip the dizzy (actually you'd have to rotate the dizzy drive which is unlikely to be wrong if you haven't toughed it), make sure you are checking the dizzy orientation at TDC on the compression stroke of cylinder 1.
From memory, when you set the cam timing cyl one is at TDC on exhaust/inlet stroke - ie valves open as you're timing the cam to the crank, not the ignition to the cam.
Yes the head is still on and thx Graeme as heading back out shortly as been struggling with this one. I agree as newbie error I did not set TDC before removing timing chain but I figure if I set piston 1/4 at TDC plus check flywheel through hole for the TDC I marked when I put in flywheel I should be good. The position of the dizzy, to your point I guess, was as per when I removed the timing chain.
So at TDC for cylinder head #1, dizzy rotor points 180 opposite from piston number 1 and again I never touched it. I have lined up the CAM shaft key ever so slightly to get that straight line, so that is working out. Also, dizzy rotor obviously does not move as chain is not on so I tend to agree should be fine even though it shows 180 degrees out?
Edited by postve, 12 August 2021 - 12:59 PM.
Crazy About Mini's
Posted 12 August 2021 - 01:42 PM
The TDC of the crank (flywheel, pistons, crank pulley) happens twice per cam (and hence dizzy) revolution.
Google the 4 stroke cycle for some graphics that will show this and how it corresponds to the valve actions.
So - if you turn the crank one full revolution you will find that the rotor arm only moves 1/2 a revolution and then the rotor arm will point as you expect. When it does, check that the valves on cylinder 1 are closed. If they are - you're good.
Super Mini Mad
Posted 12 August 2021 - 02:00 PM
The TDC of the crank (flywheel, pistons, crank pulley) happens twice per cam (and hence dizzy) revolution.
Google the 4 stroke cycle for some graphics that will show this and how it corresponds to the valve actions.
So - if you turn the crank one full revolution you will find that the rotor arm only moves 1/2 a revolution and then the rotor arm will point as you expect. When it does, check that the valves on cylinder 1 are closed. If they are - you're good.
Yes I see that but let me explain better Graeme as issue with my thoughts on this one. What I was saying is that I am lining up CAM/Crank sprocket with the timing chain, and in this state the dizzy does not move as I can rotate with my hand the CAM sprocket slightly to line up - which is is done. Also, when I rotate crank sprocket to be - 12 - again by hand as no timing chain, the dizzy does rotor does not move. Right now I can take a ruler and as per instructions I can visualize a straight line connecting - crank case notch, CAM sprocket dot, and likewise CAM key - so that seems good. Again, dizzy has not budged... All this is with piston 1/4 TDC and Flywheel at TDC.
My point is that the dizzy is pointing at 180 out and was in this position when i originally removed timing chain - again I errored my not setting TDC before removing chain.
What I am thinking is since I manipulated by hand both crank (12) and slightly moved CAM to line up, also confirmed TDC for piston 1/4 without touching the dizzy, should I simply pull out and put back in correctly (point to cylinder #1) as it was not synced ??
Really hope this makes sense Graeme and appreciate your patience along with everyone else/
Up Into Fourth
Posted 12 August 2021 - 03:23 PM
Super Mini Mad
Posted 12 August 2021 - 03:38 PM
Moved Into The Garage
Posted 12 August 2021 - 08:31 PM
When the Dots are lined up, No. 4 is firing. What you are seeing sounds correct.
Crazy About Mini's
Posted 12 August 2021 - 08:39 PM
If you haven’t moved the dizzy drive from when the engine was running, why do you think you need to move it now?
OK, let’s look at this a different way. With your sprocket timing marks aligned, what are the valve/rockers on No.1 cylinder (nearest radiator) doing?
Super Mini Mad
Posted 12 August 2021 - 10:15 PM Best Answer
The TDC of the crank (flywheel, pistons, crank pulley) happens twice per cam (and hence dizzy) revolution.
Google the 4 stroke cycle for some graphics that will show this and how it corresponds to the valve actions.
So - if you turn the crank one full revolution you will find that the rotor arm only moves 1/2 a revolution and then the rotor arm will point as you expect. When it does, check that the valves on cylinder 1 are closed. If they are - you're good.
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