Ignition timing

[Swedefish]

I`ve been trying to set the ignition timing this week.
In the manual it says that the timing should be set at TDC with the vaccum hose unconnected and 650 rpm.
So I did, then cheked the timing at 2500 rpm and it showed 25*. For what I understand the advance can be adjusted in the dist. but I have a feeling of that 11* is a bit much to adjust, or?
This pussles me a bit since I read that the timing should be arond 36* at 2500 -3000 rpm
The respons on the throotle is very good and I can`t here any pinging.

The dist. is a used one I bought some years ago and I dont no what kind of engine it has belonged to. I converted it from a singel point to a ignitor system because I dont want the ECU on the firewall.

The engine is a 383 built to stock specs and is planted in my -67 Cuda Fastback.
Should I ignore the timing at idle and set it on 36* at 2500 rpm or am I missing something here?
Any help would be appreciated.
 

[Mopar73340]

Does it advance any farther at say 3000-3500? If not I would set it at around 35* total advance which going by your #s would be about 10* at idle. It is possible that it is not fully advanced depending upon the springs that are in the dist. It most likely will run even better with more advance.I have my small block set at around 10-12* at idle and 35* total. I'm sure Chryco may have some more input.

[Swedefish]

Thanks Mopar73340
No, that`s one thing that`s strange to me, it reaches 25* before 2500 rpm and don`t advance anyfurther

[ShelbyDogg]

Are you sure that it doesn't advance any further at high Revs?  The factory stock distro. used 2 springs on the weights. One that was engaged all of the time, the second one after the weights went halfway out and spun a little faster. You could check under the advance plate if you aren't afraid of pulling the distributor out and apart to look. If you are sure that you don't get anymore advance, a prior owner could have pulled out the second spring like I usually did.  If it doesn't ping, you might just leave it alone.
Rob 

[Mopar73340]

Thanks Mopar73340
No, that`s one thing that`s strange to me, it reaches 25* before 2500 rpm and don`t advance anyfurther

It is possible as sated above that only 1 spring is in there or that there are 2 springs like the MP ones that lets all the advance in by 2500, thats why I asked if I advanced any farther by 3000-3500. So since it dosen't I would try init timing at idle at 10* and see how it runs. Also unless you're racing it I would have the vac advance hooked up. It will run better at low rpm with it working.

[Swedefish]

I`ll pull the dist later next week and have a look if there`s 1 or 2 springs.
Is it possible that it could be something in the dist that block the advance plate to reach full advance?
Oh, and it`s only for street, no racing, at least not for this summer 
Thanks guys

[Mopar73340]

I`ll pull the dist later next week and have a look if there`s 1 or 2 springs.
Is it possible that it could be something in the dist that block the advance plate to reach full advance?
Oh, and it`s only for street, no racing, at least not for this summer 
Thanks guys

It's possible but I doubt it. The factory usually used a weak spring and a stronger second spring. The first part of the advance(weak spring) would come in fast and the second would take higher rpm. Whatever the case, I'm sure it will run better with the extra 10* at idle.

[keithcuda]

Sounds like Swede is 0 (zero) at idle. Increase this to 10degrees before TDC, i bet you end up with 35 total at 2500/3000 RPM.

[71383bee]

Sounds like Swede is 0 (zero) at idle. Increase this to 10degrees before TDC, i bet you end up with 35 total at 2500/3000 RPM.

 

It sounds like it's retarded a bit.  You didn't say what initial was at idle.  I would bump it up to 35 and idle it down and check where initial is.  If it is really high in compression it might ping though so be carefull.  The springs only control the rate of advance.  The total amount of mechanical advance is controlled by the length of the slots. 

[Swedefish]

Thanks for the replies, guys.
Did some moore testing today. Set the initial timing to 10* and when I rev it up to 2500 rpm the timinglight fluctuate between 20*~30*, that is, when I hold it at 2500 rpm.
Thinking of , if it could be dist that is bad.
I know that a friend of mine here in Sweden had a problem with the ignitor system and the dist he had at the time,he had trouble with setting the timing also.
 

[71383bee]

You need to expound on your term of fluctuation.  Do you mean that the timing mark moves +/- 5 degrees? 

With the cap and rotor off grab the shaft and see if you can wiggle it side to side.  if so you could have either a bad shaft bushing or a bad distributor or both.  There should be no side to side play.  Also check your reluctor /pickup gap with a NON-METALIC feeler gauge.  It should be around .008" IIRC...Correct me Chryco if I am wrong on that. 

[Chryco Psycho]

.008 is correct

[Swedefish]

You need to expound on your term of fluctuation.  Do you mean that the timing mark moves +/- 5 degrees?  

Yes 71383bee,thats correct.
Just checked if I have any wiggle in the shaft and estimate it to 2mm from side to side (hope this makes any sence ) wich is, if I calculated this correct, 0.07".

[71383bee]

Just checked if I have any wiggle in the shaft and estimate it to 2mm from side to side

Bad sign...

Either the intermediate shaft bushing is toast or the distributor itself is toast.  Was the motor recently rebuilt?  If so the intermediate shaft bushing should have been replaced.  The distributor should have no side to side play.  This will cause erratic timing that will increase with rpm's.

[Swedefish]

Bad sign...

Either the intermediate shaft bushing is toast or the distributor itself is toast.  Was the motor recently rebuilt?  If so the intermediate shaft bushing should have been replaced. 

Yes -71, it was recently rebuilt and I take for granted that they had the bushing replaced, however I`ll give them a call to have it confirmed.
Maybe I should consider an electronic ignition after all