I borrowed a dwell meter from someone at work and I thought there would be instructions with it. I don't want to fry this thing and have to buy it. Any help?

Wow, I have a few dwell meters.. I havent used them in years.... Ill have to get one out and remember how to hook it up...

I dont think you will fry anything though

very simple

big black wire to ground on engine
other wire to hot side of coil
switch to dwell if switch to 4 cylinder
some dwell meters have 3 wire, ground, hot coil, point side ( ground coil ) some have 2 wire ( mine )
some have switch for 4 6 8 cylinders and a rpm / dwell switch

you really cant hurt em, do what looks right

Cool, thanks. I'm hoping to get Pertronix for Christmas but until then, I figure I might as well set the car up properly with the equipment it currently has.

Some don't have a 4cyl scale(got two of them). Double the 8 cyl scale.

Ok. I did it. The needle was registering JUST before the 25 (on the 8 cyl scale). So i figure that's about 49 1/2. Close enough that I don't think I want to even mess with it. I looked at my timing too which appeared to be just a bit retarded. I reset it and the idle smoothed out just a bit and it seems to run ever so slightly better although there is still a slight miss that seems to worsen somewhat at higher RPM. Now that the major issues (it runs, fixed brakes and clutch) with the car are sorted out, I will start concentrating on the little stuff like getting the trunk hinges replaced with the JWest hinges and getting new ignition parts like plug wires and such. The car pulls so well and performs so well overall that I really doubt that I can get it to do much better. I'm so happy with it, I could spit!!!

Excellent job. However, 3 or 4 degress of dwell will make a lot more difference than you might think.

What's a dwell meter?

A meter that measures point gap in degrees of rotation of the distributor rotor. It's a very simple and handy device but generally doesn't work for solid state ignition systems.

Connections are distributor side of the coil and ground.

Damn Carl, it was a comment about the anitquity of points, but thanks for the explaination.

The sad part is that I remember in high school auto shop when a dwell meter was innovation!

Boy, am I glad we don't have to mess with those stinkin' points anymore. I had a '68 Cougar with a 302 that couldn't go 12,000 miles without arcing the points so bad it would barely run.

Ah, the good old days ...

4.5 degrees is out enough to cause trouble over time..... let me think about this... hmm...

In the view of the perfectionist, you are a fool... in the eye of the artist, that'll do. Let's hope every system on your car isn't out of spec by 2-3%.

Hmm... dwell angle increased..oh wait, bad math... you are near 10% out, in phase..

Whatever! It's all just numbers!


M

Oh good, trig. Will you just say something controversial.

Let me translate Miles post. If you set the timing with the dwell off by 4.5 degrees, then the timing will off by 9 degrees. Is that right Miles?

The slight missing is because you are on the high side of the dwell limit. If you back it up a tad it will really run sweet.

So how do you do that? PITA until you get good at it. get the plastic piece of the ponts which rides on the lobes to the highest point in lift. You must be able to recreate this over and over. Now figure out where you last seen your feeler gage and measure what the gap of the points contact is. Now loosen the points hold down screw and close the points gap by a .001 from what you just measured. put it all back together crank it up and measure dwell. should have moved a degree or two.

If you moved it too much well, you shouldn't have listened to me. Just left the damn thing alone and drive it.

I don't know if it's that acute.. () but it would be a concern... timing is a much more subjective thing.

The dwell should be as close to spec as you can get, you can run your timing up +8, without hating your car... not that your car won't hate you.



I still have points, you have near 6 weeks til your Pertronix is a done deal... I would adjust it.. if for nothing more than the experience!

-insert gratuitous cursing in mostly caps-

Damn Joe fast posting typey boy! Yes!

M

Oh, OK, now I'm typey boy?

FUCK it, I'm going to the bar.

Talk to you FUCKERS later. (sorry B.)

No, Joe Ricard is typey boy.

We need a hear no evil smiley for me...



M

Yup guilty of being a typey boy all DAY LONG. I am either making up shit for the design project or typing into the infurnal machine. Or posting stuff here

49 isn't THAT bad is it? I thought spec was 47 +/- 3. Is that right? That would mean that 50 is still "in spec". Or is spec 44 +/- 3?

That's a dog goned good question... 45° here...

I am not sure what happens if it's short, but if it's long, it acts like Joe mentioned, missy.

If I am thinking correctly, long dwell will build up black thingy where combustion used to happen..




M

So how greatly would a short dwell affect power? I understand that longer dwell means longer spark which in theory would mean more complete combustion. If I tune it to 45 will I lose efficiency? Or will any loss be made up in the correction of the misfire? I realize that ideally there should be no misfire But I'm wondering what is the "point of diminishing returns"?

The dwell angle is the charging period for the coil.... 45 degrees times 4 (cyls) open, plus 4 closed equals 360 degrees. Retrograded dwell is as bad as anything you could do with it.. no worse... no better.. just wrong.

It's the real electro-mechanical link between your spark, and your injection..

You need the strongest charge possible per firing for maximum efficiency, and performance.

Fiddle with the timing all you want, until it sounds lopey, or weak... but set your dwell at spec. Timing off-spec does no good on a stock motor with injection, anyhow.

Remember when you read this, I am not my own mechanic, so fly it up another flag pole before planting it on the moon.



M