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Initial timing

2K views 25 replies 12 participants last post by  Autoengineer_ 
#1 ·
Anyone running a combo of say 36* at idle with 8* to 10* at idle via the can?
 
#2 ·
I run a little more starter friendly 24* initial + 12*. 9* via the can.
 
#4 ·
Explain? Is there something I dont know here from a previous conversation?
 
#8 ·
Sorry. I just dont see why trying to nice has anything to do with anything. I should of asked why would he be mean in a reply?

What I asked is not a choice.

I havent seen much on take and was wondering if someone might chime in.
 
#9 ·
At the risk of starting a fecal storm, I would highly suggest you take the time to read Dave's older posts and there are others who are well versed in distributors and timing settings. Don't be offended, you have to be able to separate the wheat from the chaff.
 
#11 ·
Sorry, I just wanted to give you something to compare to. I didn’t want to write an encyclopedia. Not sure what was going on here. Do a search on IGN 101. Some good information in there and others.
 
#17 ·
Top fuel curve? LOL What does that mean.

That idle timing you have is similar to what my Dad runs.

He runs 18* at idle with 12* can for 30*
 
#19 · (Edited)
I have mine set at 15 initial, 36 total all in by 3000. I tried lighter springs yielding all in by 2400 and the car did not like it. It caused the car to buck.

Ported vacuum advance....Zero vacuum advance at idle. Tried manifold. I prefer my consistent idle speed over any tiny improvement in fuel economy while idling.
 
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#20 ·
Thanks for chiming in.

It looks by you signature that your 385 is very very mild. I bet it is really torquey and pulls great up to around 5500 to 5700. Probably has a very very smooth idle with just 15* of timing at idle.

What do you mean by buck? Can you explain that some more?

On my Dads 383 we have it all in by 2100 and I dont see any difference in either setting. Our combo is slightly larger with bigger heads and cam.

I run the can on manifold vacuum because my Dads cam needs more that 18*. With just 18* it seems dead and the throttle response off idle is dead. The car could use a full point of compression as the cam is on a 112 lsa and somewhat mild.

The compression is at 10 to 1 and idle timing is at 30*. The idle is much cleaner and has better response. Engine just seems to sound much better too.

The cam is 226/234 @ .050 for .536/.536 lift.

How much does your can add?
 
#21 ·
My wagon’s 454 wiht a cheapo HEI is 14* at idle plus 10* vac adv...dist has 22* for 36* all in. One light and one med spring.

My 6.0 has 24* at idle...plus another 10* vac advance for 34* at idle. Full advance is 28* plus 10* at cruise. Computer controlled timing is pretty nice to work with.
 
#22 ·
1978 454 truck motor, low compression, th-400, 2.87, stock 20,000 miles, 160 degree thermostat, 87 octane fuel.

HEI, Initial 20, mechanical 16 all in by 2600 rpm, no vacuum advance. I have no starting or pinging issues.. Got to love that low compression..

When I try the vacuum advance, it has a weird skip sound at idle and runs like I am holding it in the next lower gear while making this weird skipping sound. I loose a lot of torque.

When I put it where the factory suggests, it doesn't have as much bottom and mid range power, once again I loose a lot of torque and it generally doesn't run nearly as good as it does with the custom setting without the vacuum advance connected.
I did try changing the settings of the vacuum advance by soldering the track then filing it.. No good..

Without the vacuum advance my idle and down shifting always have the same feel, we do a lot of downshifting living on these hills here..

What a lot of people on these internet boards do NOT take into account is the difference in terrain everybody faces.. Its all different and needs different ratios and settings.. I would think in the flat lands a vacuum advance would be mandatory..
 
#23 ·
22 at idle on my 388, 14 mechanical for 36 degrees in at 2500. Vacuum advance is hooked to ported vacuum, I have about 42 at cruise rpm. My cam only makes about 10" of vacuum at idle. I played around with vacuum advance on manifold vacuum, but it just seems to run best with ported vacuum.
 
#25 ·
26 at idle with vac advance
18 initial without
36 total
46 total with vac advance
21 total with boost

It works pretty good. Stays cool and get 18mpg so far
 
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