Timing numbers for a 383 super commando?

woodwiz

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The motor starts good other than the usual throat clearing. Went looking for my timing light and wanted to see where it was at. The shop put in a electronic setup in the distributor and a better coil.
I checked it with the light all warmed up and idling(forgot to pull the vacuum hose and plug),but noticed the timing mark on the balancer was way off the btdc like +25-30. That did’nt seem right so we pulled and plugged the distributor vacuum line and it recovered quite a bit to the timing plate. This where I’m kinda confused…should I just leave it alone or would setting it at the factory 2*+/-2.5*
Degrees,basically 5*deg. be attempted?
I here some other forums talking about a starting point if 12-15 degrees. Does that sound like a place I should start at?
That distributor setup is a Pertronix unit.
 

woodwiz

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I’ll have to move it to the upper and then check it. Is there more or less vacuum based on those 2 positions?
The car runs well,just thinking with some timing tweaking it could be better.
I was just surprised to see the timing mark as far away from the timing plate.
I can also just leave it where it is and drive it…no pinging!!!
 

woodwiz

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Well the carb is not stock and the internals of the distributor are technically not stock. When I through the light on it of course without plug on the vacuum line the timing mark was way on the plus side of the timing plate btdc. But when I plugged the vacuum line it came back closer. Someone said that the timing plate is marked off in 5degree increments,so from zero to the edge of the plate going BTDC would be 20 degrees. So if I’m already not close to that and it runs good should I leave it alone? Or like you say..these big blocks like 15-20 degrees btdc and see how she runs? Thanks!
 

woodwiz

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Got back from phx.this morning and just put the timing light on the warm engine w/plugged vacuum line and the crude drawing says it all. Did not check the upper vacuum port on the carb. I heard it doesn’t kick in till you go off idle. The bottom is where this carbs vacuum line runs to the distributor and it is constant vacuum. Lossened the distributor hold down clamp and with the vacuum line plugged and moving the distributor so the timing mark would come to say 10-12degrees on the plate the idle dropped a bit…I take it that is normal?

8E171166-F490-4063-8496-1E3FD9C026F9.jpeg
 

woodwiz

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Maybe another dumb question…Each mark on the timing plate represents how many degrees whether BTDC or ATDC ?
 

droptop

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Put the timing light away and set the timing to where is runs best without pinging, and starts easy when the engine is warm. Have not used a timing light in decades.
 

woodwiz

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I did not delete your suggestions and I do have a service manual.Just thought some of you know it alls on here would have ideas to try. So that I shall do…Thank you all…Good bye!!
 

woodwiz

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Sorry for the confusion,I tried your suggestion’s and with those and everyone else’s this bird will survive me fiddling with it to get optimum performance…Bye for now!
 

69hemibeep

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Got back from phx.this morning and just put the timing light on the warm engine w/plugged vacuum line and the crude drawing says it all. Did not check the upper vacuum port on the carb. I heard it doesn’t kick in till you go off idle. The bottom is where this carbs vacuum line runs to the distributor and it is constant vacuum. Lossened the distributor hold down clamp and with the vacuum line plugged and moving the distributor so the timing mark would come to say 10-12degrees on the plate the idle dropped a bit…I take it that is normal?

View attachment 35828
You disregarded using the upper port like the manual says because someone gave you false info. There saved you the reading.
 

woodwiz

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Thanxs Bob! Yeah looking back on the previous owner that had it in high elevation Colorado 6k. Taking that into consideration also. It’s all good runs like a bird should,a coyote will never catch me
 

woodwiz

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Hey Bob/Old angry white guy! You'll be thrilled to know that i took your expert advice and switched the vacumn line to the upper carb fitting and took it for a hard spin and No pinging from either location and starts hot. The manual that i have makes no mention of the upper fitting for the vacumn line...gotta get the better manual! The degrees at idle 10-15* I'll run with that till it does'nt run. Cheer up boss!
We have the same color birds if it matters!

Used-1970-Plymouth-Roadrunner-Road-Runner (1).jpg
 

MoparDan

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Hey Bob/Old angry white guy! You'll be thrilled to know that i took your expert advice and switched the vacumn line to the upper carb fitting and took it for a hard spin and No pinging from either location and starts hot. The manual that i have makes no mention of the upper fitting for the vacumn line...gotta get the better manual! The degrees at idle 10-15* I'll run with that till it does'nt run. Cheer up boss!
We have the same color birds if it matters!

View attachment 35830
Hey Woodwiz, would you mind taking some pictures of the trunk lid hinge torsion bars? My car came with them laying in the trunk and I'm having trouble figuring out how to reinstall them.
Dan
 
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