Dwell angle

Does anybody know the dwell on a acc30 PS forklift?

Done with ignition rebuild, but missing dwell

This is for a 4 cylinder engine? 90 degree crank throws?
If so, 45-47 degrees ought to work. Some sources 55-60 deg. I sure you would prefer an exact spec., though.




Edited by Ferdinand - 18 Dec 2017 at 4:59pm

Thanx, guys. Yes, it is a 4-cylinder engine. It is CNG, though. Now, I am getting 31 deg dwell. Fires right up. I had a bit of rouble with idling, but solved after 1/4-turn on the throttle min bolt at the intake. New set of points gapped at 0.20, right in the middle of the 0.18-0.22 gap range I found somewhere online. No misfiring, no smoke (incomplete combustion). Am I missing something? BTW, how do you measure TDC in this thing? The engine pulley is under the weight. Can get to it and do the strobe TDC. Any tricks on how to strobe this baby?

Hey Ferdinand. Raleigh. Forklift is at my warehouse in Durham.

1978, that's when they still made real tools.

Not sure what you are asking though. The only practical way I know to measure TDC is by removing the no.1 spark plug and physically determining when the piston is up full travel.

Once that is determined, you can put your own timing marks, verify the existing timing marks, or use a degree tape around the harmonic balancer, if it has one. I really don't know much at all about AC equipment. One of the reasons I joined this forum.

by the way, I'm about 20 miles south of you.

Can you  see the back of the engine - i.e. front of the bell housing?

Then might there be a port there (maybe with a cover) that gets you a look at a marker on the flywheel for timing?

Like the timing port on an old Toyota 2F petrol Landcruiser

Ian Beale wrote: Can you  see the back of the engine - i.e. front of the bell housing? Then might there be a port there (maybe with a cover) that gets you a look at a marker on the flywheel for timing? Like the timing port on an old Toyota 2F petrol Landcruiser

Good idea. Old Farmall tractors had a small cover on the bellhousing. You flipped the cover open and the timing marks were on the flywheel.

Adjusting distributor timing will not change Dwell.  Changing dwell (point gap) will affect timing.


Edited by Ferdinand - 19 Dec 2017 at 11:08am

Well, what da dwell?!?! As it turns out... didn’t have my reading glasses on when I took the initial dwell reading, 31. That is the readig for a 6-cyl engine. Laughing at my old self...

The correct reading for my 4-cyl was on the scale below, and it was 60 deg.

Well, the reading is still way off compared to what other posters so kindly suggested, 45-55?

So I increased the gap at the points from 0.20 to 0.22. Well, the dwell went to 65 degrees! Up instead of down?!.

I re-gapped the points again to 0.18, the bottom of the range given. Dwell went back down to 61. I re-gapped once again to 0.20. Dwell went to 63.

I think something might be wrong with my dwell angle reading tool? Isn’t it supposed to be that reduction in the gap = increase dwell, and viceversa?

Regardless, the engine idles at 620 rpm, no misfiring, no smoke. So, I am leaving it alone at 0.20 gap, which is right in the middle of the 0.18-to-0.22 range I found.

yep, look at it this way, if the point gap was "zero" , you would have 360 degrees dwell.

I agree with dave, on this. Pull the distributor. Sounds like to much shaft play.

Is the engine unique to AC?


You might have to machine your own parts. I know of a machine shop near Durham, they do small, one-off jobs, reasonable cost.

You are going to have to get the side play out of that shaft, bushing the housing or having a shaft made.
Should be a data plate somewhere on the engine, many were down by the starter. If not then comparison shopping is in order as many companies used Continental crate engines some used there own. A photo would do wonders on here, lots of minds.

Oh, there is no side play on the shaft. It is rotational play; I can advance the cam to almost fully open the points with its tip with the ignition. Then, I advance the shaft by hand a tad (rotation-wise), and the tip of the shaft's cam gets right under where it is supposed to go to give me maximum points' gap.

When you rotate the shaft does it try to return to initial position? That would be the mechanical advance mechanism, start low advance to gain advance as engine speeds up. If that is flopping the weights are no longer attached to the rotor stub sitting on the distributor shaft(two separate components). Should remove the rotor and take a photo of the internals of the distributor. Your dwell may just be the rotor head flopping loosely rotationally.