Timing and dwell setting with vacumn advance distributors

[GRUMP62]

Replaced the points on my 292, 62 f-100; set the piont gap to .017 and the timing was good at 8 deg BTDC but the dwell was low at 24. When the engine is rpm increases the dwell drops as the distributor advances. All this is done while the vacumn advance is connected. Should the timing and dwell be done with this disconnected and what RPM should it be done at.

[286merc]

Start off with no vacuum and you should have 2 deg at 800 rpm and 12 deg at 2000. Dwell should fall in the 26-31 range.

With vacuum connected (helps to T off a gauge to check) the additional advance will just start at 7 lbs ft and a max of 12 deg at 20 lbs ft.

[pcmenten]

Carl, you never cease to amaze me.

The timing can be set statically, too. This can be helpful if you've got a slack timing chain.

Turn the engine over by hand in the direction of its normal operation, clockwise if I recall correctly. Carefully turn it until the timing mark lines up with the proper setting. If you go too far, back it up until you go too far the other way and then try again to get it lined up while rotating it clockwise. You're trying to get the timing marks lined up while the chain is tight in the direction of engine operation.

When you've done that you need to get a test lamp, a 12 volt bulb with one wire to go to battery power, and another wire to go to the hot side of the points. Turn the distributor until the lamp just goes out. Go back and forth, on and off to make sure you've got it right. Tighten it down and you're done.

Static timing is a way to avoid the problems of vacuum leaks, slack timing chains, and other tuning problems that would effect engine operation while trying to use a timing light.

I've found vacuum leaks in unexpected places. These can throw everything off. Twice, I've found leaking brake boosters. Make sure there are no vacuum leaks. Adjust the carb idle mixture for highest idle. Turn the idle back to the proper speed and adjust again.

[BB]

It's normal on Ford dizzys for the dwell to drop as the vacuum advance advances .

Barry

[GRUMP62]

THANKS FOR THE HELPFUL RESPONSES!

I STILL NEED TO DO SOME FINE TUNINING VIA SOME ROAD TESTS
BUT EVERYTHING SEEMS GREAT. TRIED TO ADJUST TIMIMG &
COULDN'T GET THE DISTRIBUTOR TO TURN IS THIS A TRICK
OR MAYBE MORE HAN ONE BOLT?

THANKS AGAIN ANDY

[286merc]

Any progress is good news!

Y Block dizzies are known for getting frozen in the block. Lots of procedures around to loosen them, from mild to a Sawzall Ive had good luck with PB Blaster and a fully warmed up engine.

Check the archives.

Also Advanced Auto has a replacement using the 289 style O ring which will eliminate the problem. $51 includes points and condensor. This is the 1965 Ford replacement version. NAPA carries the same at around $90.