Somebody check my timing sequence...

[jdubois]

I had the distributor out of the TR3 engine and apart, so I've got to start from scratch again with the timing. I just wanted to double check that I got it correct:

1) I found TDC(ish) on the #1 cylinder by rotating the engine until the #1 inlet valve was open, then continued to rotate until both valves were closed and the pulley mark was at the pointer.

2) Installed the distributor so that the rotor was pointing at the #1 inlet valve pushrod (Is this right? WSM just says "#1 pushrod". Hmm, I'm thinking now that might be the exhaust valve pushrod)

3) Set the points at .015"

4) Set the timing adjuster knurl so that I was on the third mark away from the vacuum unit on the shaft.

5) Rotated the distributor until the points were just beginning to open, then tightened down the distributor clamp.

6) Turned the adjuster knurl so that I was on the second mark from the vacuum unit.

I'm now at (or at least close to!) 4 degrees BTDC, right?

 

[Andrew Mace]

All sounds good to me. If it worked before, and you didn't disturb the distributor drive gear, you should be good to go!

 

[jdubois]

Thanks Andy. I just now want to make sure I have the rotor shaft in the right orientation. I found another diagram in the WSM that shows the slot in the top of the tachometer gear at a 53 degree angle to the stud holes in the housing when in the correct position. So I can use that to double check.

 

[jdubois]

and you didn't disturb the distributor drive gear

There was the rub! I guess I did disturb the gear (I took it out but didn't think I'd done anything to upset it. Obviously I did), and the drive gear now wouldn't fit in at the correct 53 degree angle. I think my timing would have actually been ok in spite of this, but it put the distributor at a weird angle and I'm not sure the vacuum advance line would have fit on.

It took me a few minutes of head scratching and looking at the parts diagram to figure out the problem was that the oil pump drive shaft can only fit into the pump in two positions (correct, or 180 degrees out) because of the slotted drive, and neither of those two positions was the "correct" position for the distributor drive gear. A couple more minutes of head scratching and, ah-ha! I turned the crank pulley until the slot in the drive gear was at the correct 53 degrees, then removed the drive gear assembly and turned the crank back to TDC. This changed the relation between the oil pump drive slot and the drive gear, and now I could put the drive gear assembly back on, and it slipped right in at the correct angle.

 

[Andrew Mace]

and you didn't disturb the distributor drive gear

There was the rub! I guess I did disturb the gear (I took it out but didn't think I'd done anything to upset it. Obviously I did)...

Hey, I've done that myself...more than once. One tends not to think about its orientation as one removes said gear, and then one has completely forgotten that orientation as one tries to get it back in place.

[One = me]

 

[doughairfield]

I wish I'd read this yesterday, i'm having the exact same problem. Struggling with getting the driving gear in at the correct angle. How did you know when it was at the 53 degree angle?

 

[hondo402000]

bring no 1 cylinder to the top, get the damper mark on 0, make sure both rocker arm are loose on No 1 that would mean its on the firing stroke, drop the drive gear in usually one tooth off since its a spiral gear it should rotate in to proper place, where No 1 post on the cap is, you have a little wiggle room.


try that
Hondo

 

[doughairfield]

Sorry, what do you mean by damper mark?

 

[jdubois]

I wish I'd read this yesterday, i'm having the exact same problem. Struggling with getting the driving gear in at the correct angle. How did you know when it was at the 53 degree angle?

Doesn't have to be exactly 53 degrees, just pretty close. Should look like this:

If you can't get the drive gear to seat at that angle, do what I did above.

Sorry, what do you mean by damper mark?

I believe he means the hole in the fan belt pulley should be in line with the marker above the pulley.

 

[doughairfield]

Ok, i've really fiddled with the drive gear. At TDC, I can get the slot to be pointing right at the #1 spark plug, or just to the left edge of the pushrod shaft, but not right in the center of the pushrod shaft. Does it have to be pointing right at the middle of the pushrod shaft to be right? Also, and dumb ? but the little hole in the pulley lines up with the sharp pointy thing on the timing cover to be TDC right?

 

[jdubois]

Does it have to be pointing right at the middle of the pushrod shaft to be right?

No, the position is not overly critical. All you're doing is getting the distributor roughly in the right place. You'll correct for any error in the next step when you turn the distributor body to cause the points to be just beginning to open and then tighten down the clamp.

Also, and dumb ? but the little hole in the pulley lines up with the sharp pointy thing on the timing cover to be TDC right?

Right. As long as both valves on the number one cylinder are fully closed and the hole in the pulley lines up with the "sharp pointy thing", you're at TDC.

 

[TR3driver]

Just to clarify a bit, "top dead center" (TDC) refers to the position of the piston being at the top of the stroke. Since these are 4-stroke motors, the piston is actually at the top twice per complete cycle. So what you are looking for is not only TDC (as shown by the hole matching the pointer), but TDC with #1 firing.

Afterwards, just as Jeremy says, you need to set the static timing. Note that there is a certain amount of backlash in all the components, so when checking timing you should always turn the motor forwards and stop at the point you want. If you try to back up even a little, things will not be aligned as they will be when the engine is running. So, if you go past the point, you have to turn the motor two full turns (and this time stop at the right place!).

Also, if things don't seem to be making sense, note that it is possible for the little hole to not be at TDC. The hole is in the pulley half, which can be bolted to the hub in any of 6 positions. Only one puts the hole at TDC. A quick check is to remove the #1 plug and look down the hole; you should be able to see the piston top without too much trouble. Or poke a pencil or similar into the hole, it should touch the piston within an inch or two.

 

[doughairfield]

Ok, I did verify that the hole in the pulley, when lined up with the mark on the timing cover does correspond to when the #1 piston is at the top of the combustion chamber.

As I turn the crank, the intake valve, second from the front starts to open, which I assume to be TDC.

I made 2 revolutions to be back at TDC and made sure the driving gear lines up roughly with the number 1 push rod shaft.

I fit the distributor on and set it to 2 marks on the vernier scale.

I'm not able to turn it clock wise for the point to begin to open, I have to turn it counter clockwise, which puts the tip of the vacuum advance pointing roughly towards the front of the car.

After putting the distro cover back on and trying to start the engine, I still get a puff of gas vapor out of the carburetors.

Not sure where I'm going wrong here.

 

[Don_R]

If you turn the crank and the intake valve moves you ARE NOT at the correct TDC, you are at the top of the intake stroke.

TDC is the top of the compression stroke. as the piston moves down both valves need to be closed.

the next TDC should be correct.

 

[Roger]

If, when you start to turn the crank, the inlet valve is opening you were at TDC Exhaust, not TDC Firing. In other words, 180 distributor degrees out. You can easily check - try swapping plug leads 1 with 4, 2 with 3.

 

[doughairfield]

Face+Palm. Thanks for clearing that up. I rotated to the correct TDC and the distro rotor is 180 degrees off from where it should be at the correct TDC (when both valves are closed and the piston is on it's way down).

My #1 lead off the distributor isn't long enough to reach to the #4 plug. I'll pull it all back out and try again with it in the correct place.

 

[jdubois]

So, if you go past the point, you have to turn the motor two full turns (and this time stop at the right place!).

Hmm, I was going back a half turn and then forward again. Is that not enough to remove the backlash?

If you turn the crank and the intake valve moves you ARE NOT at the correct TDC, you are at the top of the intake stroke.

I think this is why the WSM says to rotate the crank until you see the intake opening, then continue on to TDC. That way you know you're at the correct one.

 

[TR3driver]

Hmm, I was going back a half turn and then forward again. Is that not enough to remove the backlash?

That would work, too.

 

[jdubois]

Thanks Randall, you scared me for a minute :laugh: