Timing. a year of posts and I just got a little closer to understanding....

[wally426ci]

 

After alot of reading, I am seeing the definition of different timing refferances. Initial: being set at idle speed with plugged vacuum, Total: being set at 2500+ rpm's, and cintrifugal being the difference between the 2.

BUT, my question is, how can i be sure i am getting the most out of my Vacuum advance? when can i measure that and what am i looking for.

And, what does anyone think of the argument of using Ported vacuum as opposed to Manifold vacuum.......

Thanks!

Im also seeing that you could change initial while keeping relatively the same Total....... 

[422STROKER]

I think to check total advance with vac you need a vacuum guage in the car while cruising/driving under a load.  I haven't finalized my timing yet.  I have it set basic so to not worry about detonation and stuff until I got some more miles on it.  I think I could get some more pwr when I advance it a bit more.  I'm running about 14 at idle and 34 @ 3000  I may swap springs etc to change the rate of advance as well.  But for now it's all the power I can handle with these 255's for tires.LOL

Ported vacuum is used for mine, I believe that is the proper way.

Tom

[wally426ci]

Gitty Up Tom, thats what im seeing in other posts as far as ported..... 

[wally426ci]

Car wouldnt even run when i had vacuum disconnected and tried to take the timing down. with the advance hooked up at idle, i have a reading of 20 degrees. when i unhooked it it was reading a wopping 34 degrees, and thats what im @ above 2500 rpms!

 

[422STROKER]

I just fixed a buddies car the other day.  I had to adjust the curb idle speed screw up on his edelbrock carb, the screw was way out to get it to idle at the increased timing. 

Tom

[nivvy]

what ignition/distributor r u running........ I got my 499 idling at 750 rpm in park....... 

[wally426ci]

Stock ECU, mopar performance distributor.... I did try iling it up a good nit but it just sat there and stumbled 

[422STROKER]

Can you get it to idle long enough to change the timing?  Try about 12-14 degrees to start.  I get this idleling at 900rpm in park, it drops to 750 in drive.

Tom

[nivvy]

Stock ECU, mopar performance distributor.... I did try iling it up a good nit but it just sat there and stumbled 

pull the #1 plug... its probably black.... stumbling can be a sign of a too rich condition ... when you idle it up I bet your turned the carb idle speed screw up didnt you.....  what carb are you running again..... 

I am 18* initial and 36* total ........

[wally426ci]

Thats what i did stroker. I did just jet it up a good bit in the primary and secondary. But i also get the slightest stumble accelerating. so i dont think its too rich..... 750 eddie 

[422STROKER]

Did you adjust the pump shot, ie the holes on the front?  IIRC the top hole gives the biggest shot, stock is in the middle.

Tom

[nivvy]

what does your plug look like??? what rpm are you stubmling at???

[nivvy]

Thats what i did stroker. I did just jet it up a good bit in the primary and secondary. But i also get the slightest stumble accelerating. so i dont think its too rich..... 750 eddie 

stubmling or spittering/cracking up.......

[wally426ci]

Havent looked at the plug

I moved it to the lowest hole, i think they said that gives the most fuel. I still think i can get more out of it. Im gonna get a vacuum gauge. Id say its more a little sputtery, not realling cracking up or anything....

[nivvy]

check the plug.........