questions about procedure for timing

[NickDawson]

Hey folks!

File this under the "novice shade tree mechanic" rather than specifically rover...and in that regard, I'm grateful for all the handholding and patience in this forum!

I've been curious about the procedure for setting timing for a while. While re-reading the WSM for my 2.5L petrol last night, I noticed the following:

http://farm5.static.flickr.com/4138/4951582208_4728c7030d_b.jpg


what is dynamic? Does that simply mean engine running?
2,000 RPM - really? Unless my tach is installed wrong (hey, nothing wrong with a few luxuries) I only hit 2,000 going 65 with the peadel floored. That seems like high revs, no?
vacuum pipe disconnected - which one? The advance on the dizzy or the one to the engine?


From those specs, do I understand that i:
get someone to rev the engine to 2,000 RPM, disconnect the vacuum pipe to the engine and use my timing gun to time it in?

If so, help me understand 16" before top dead center - I get what BTDC is, but how do I measure that with my gun and the notches on the wheel? I guess what I am missing is that my notches aren't marked in any way. Which is 16 BTDC?

Now I've also tried the "ear" method and its close cousin, the beer method. What is prompting this question is how loud my engine seems right now. Based entirely on my own opinion, if feels like its just running too high currently. When I dial the timing back by ear, it sounds better, but begins to backfire at deceleration. It is also dieseling again - but suspect that is unrelated?

Looking forward to the education - thanks all!

-N

[scott]

Just my way of doing things

-d/c vacuum adv and adjust time a an idle 'til ripples in my beer are as small as I can get 'em

-hook vacuum guage to vacuum advance line and adjust mix 'til I get the highest vacuum at idle

-adjust idle to 700 rpm

-repeat process two more times

-reconnect vacuum adv

-drink the beer

[gudjeon]

There are strobes (timing lights) that have a degree scale built into them. You can turn the scale onto 16 deg. and it will strobe on the TDC mark. Static= not running. Dynamic=running. If you have points I always set mine with an ohmmeter so that they just open up on the the desired spec. I went to pertronix so now I have to strobe.:thumb-up:

[NickDawson]

There are strobes (timing lights) that have a degree scale built into them. You can turn the scale onto 16 deg. and it will strobe on the TDC mark. Static= not running. Dynamic=running. If you have points I always set mine with an ohmmeter so that they just open up on the the desired spec. I went to pertronix so now I have to strobe.:thumb-up:

Thanks!
My gun doesn't have a scale, its just a light, button and the wires...

I'm very close (as in shopping right now) for a pertronix, but want to make sure I understand the process with points.

I'll do some reading on using an ohmmeter - sounds like an interesting alternative.
[edited to add:] did some reading - if I understand correctly, you are talking about static timing and using a test light or the volt meter to determine when the points open and close. That never made sense before - it just clicked! I'll give that a try and see how it works.
According to my book that should be TDC - so I check for light/voltage (open points) at TDC - correct?

[gudjeon]

I use the multimeter set on resistance testing (ohms) to find out whether the points are just opening. The actual value does not matter, you are just checking for open or closed circuit made by the points. I set the point gap as normal on the higher value because as the rubbing block wears in, you are still in the ball park. Small dab of grease on the block works wonders.

Disconnect distributor wire and set engine to desired point of #1 btdc where it should be static timed. Nothing running at this point makes it easier to time in than ever. Using ohm meter connected to distributor wire and ground, swivel the distributor just until points lose contact. This loss of connection will be evident by the use of the meter. A test bulb does the same thing, but this is even simpler as you are not dealing with any power in the circuit.

When it just looses contact, you are the correct point of your static timing and can bolt the distributor down. I have verified such settings with a strobe and it is darn close. What people tend to forget is points send a signal to the coil to fire when the points just open or lose contact.:thumb-up:

Good luck. Once you figure this out and carry it out a few times, you are ready for any EM pulse weapon that they can throw at ya'.

[NickDawson]

All in all, pretty easy!
Thanks for the help gudjeon!

I dont think I was far off when I started. Nice to finally know how to do that. When I'd tried before I was turning it and visually watching for the points to open - I suppose that's not too different, just less accurate.

My engine is idling at 700rpm - same as before, and now I've learned (Because its in the WSM, who'd have though? </scarcasim> ) that 700 is spot on.

It is dieseling when I cut it off - that must be something else still.

[jac04]

It is dieseling when I cut it off - that must be something else still.
Not necessarily - could be improper timing causing excessive combustion chamber temperature.

[NickDawson]

Not necessarily - could be improper timing causing excessive combustion chamber temperature.
I could be wrong, but I feel like the timing is dialed in pretty close to accurate at this point...

[Nium]

Failed fuel shut off solenoid. It's not shutting off the fuel, instead of not letting the fuel flow. Perhaps.