Setting dwell on 318

[markbob]

Hey all

am replacing my points on my 69 318

how do u set dwell angle on the points?

I know a 15 thousanths gap equals a 30 dwell

any tips?

Thx

Mark

 

[dryheat]

Dwell is a function of the point gap. In order to adjust your dwell you just adjust the point gap.

 

[WileE]

Here's the "old school" way we used to do it a long, long time ago: when setting the gap, place a matchbook cover between the points. Start it up & check your dwell meter. Adjust accordingly by feel. The initial gap will vary based on the brand of matchbook, or how worn out it is when pulled from your pocket.

 

[markbob]

Yes but how do u make the gap larger or smaller
my recollection is the screw that mounts the points to the
distributor goes through a hole that is elongated and
this allows u to increase ir decrease the gap

 

[dryheat]

Yes but how do u make the gap larger or smaller
my recollection is the screw that mounts the points to the
distributor goes through a hole that is elongated and
this allows u to increase ir decrease the gap

That is correct.

This is not any easy adjustment to explain in writing (I will try anyway) ... so you might want to search for a video to help guide you.

Underneath your rotor you will see what looks like an 8 sided "nut". Your points have a "tab" that rides along this "nut" and as the distributor shaft rotates it will open and close your points.

With the ignition switch OFF ... rotate the engine by hand so that the points "tab" is resting on the center of a high spot of the "nut" ... this will open your points as wide as possible.

Loosen the screw(s) holding down the points ... but leave them tight enough so that as you adjust your points gap they will stay in place and not slam shut.

On your points assembly you should see a small slot or notch on the edge. Using a flat blade screw driver you can "pivot" the points to open or close the gap as necessary.

Use a feeler gauge (or matchbook) and measure the gap. There is a reason why they call it a feeler gauge ... You should "feel" a slight resistance as you slide the feeler gauge into the points opening ... only with experience will you be able to tell when it feels correct.

When you feel the gap is correct ... tighten the screws (which will probably cause the gap to close slightly so check it with the gauge again) ... install rotor & cap. Start it up and measure the dwell ... it will probably take several attempts to get them set right.

Good Luck ...

 

[vanrj1]

I set mine with 4 $100 bills. It's called a MSD ready run! Sorry, couldn't help myself.

 

[lewtot184]

the only proper way is a distributor machine. everything else is trail and error.

 

[Cranky]

I liked to set my points a bit wide and my spark plug gap a bit tight to account for wear over time then the vehicle will 'drive' into a better tune before it starts to get worse. Keep in mind that as your point gap gets closer, your timing will advance. Nature of the beast. Use good tune ups parts and you should be able to drive it for a good year before having to do it again but that will also depend on miles driven. Point systems are easy and are very dependable but do require more maintenance and once you learn how to tune a point system, there's no trial and error. And a distributor machine is great if you have access to one and you can set your advance curve for best performance and mileage.

 

[markbob]

Well I messed up my original points, so I replaced them....

the car started up fine and ran ok.....I made sure when I installed them that they were opened up all the way...

I disconnected the vacuum line to set the timing, and the engine really smoothed out....I tweaked the distributor to smooth it out even more, but when I replace the vacuum line, the engine starts to die, catches and starts to die again....

I thought I should start over, so I measured the dwell angle, and I cannot get it to read more than 17 on the meter, and my gap is only around .010....
since I already messed up one set of points, I am reluctant to try to bend anything....is this even necessary?

thanks,

Mark

 

[eric383]

Is the vacuum canister on the dist. good. In the past few years I have had 2 cars with bad vacuum canisters. Just put a good piece of vacuum line on the canister and suck on it. If it won't hold vacuum it is no good.

 

[markbob]

Distributor is new and was working fine prior to points getting messed up

 

[67 B-body]

Where did you plug the other end of the vac hose in to? You shouldn't notice much of any difference when plugging it in at idle if hooked up like the factory did. I'm thinking you plugged it into manifold vacuum instead of ported vacuum.

 

[dryheat]

Where did you plug the other end of the vac hose in to? You shouldn't notice much of any difference when plugging it in at idle if hooked up like the factory did. I'm thinking you plugged it into manifold vacuum instead of ported vacuum.

X2 on manifold vacuum ... should connect to small port on the side of the carb.

Also ... there is no need to "bend" anything on your points ... did you try the adjustment instructions above?

 

[markbob]

Thx for replies

The hose is plugged into side of carb and I tried to get gap on points to around .15 or so
my electronic dwell meter reads 17
i will try manipulating it more and recheck

 

[markbob]

Hey all,

got the dwell set to 32....car runs great now, but dies when first started unless allowed to warm up a bit....I think I need to set fast idle, and adjust the choke mechanism....

any tips?

my manual says to bend the choke link to close butterfly valve using second to highest setting on the fast idle cam....

thanks,

Mark