Timing guesses

[BadJoey]

I have a 440 out of a 67 GTX . Small cam and intake , 4 speed trans , 780 holley street advenger . 30 over , electronic ignition .  My old Chiltons manuel under challenger says 440 4 barrel should be TDC , 440 6 pack should be 5% BTDC  Not sure where I fit in . Any guesses and thanks

[1 Wild R/T]

You want easy? O best option?

Easy, find the TDC line cut into the damper, make a new line 2.25 inches to the right as viewed from in front & above the the engine..... The new mark is 34 degrees which is typically what a BBM likes as total mechanical timing... Now disconnect the vacuum to the distributor, hook up your timing light, start the engine, Rev engine to 2500-3000 rpms, set the timing so the new line lines up with zero on the timing tab...

Best After doing the above idle the engine & see where the timing is.. Chances are it'll be around 0-10 degrees... Ideally you'd like it to be around 15-20 degrees... So depending on what distributor you have the mechanical advance needs to be altered to limit the timing curve...

Tell us what distributor & we can help more..  Gotta go...

[crackedback]

If you want the engine to run well, throw the book numbers in the garbage.  The book number take things like emissions into account which you likely don't need to worry about.

1wild has some good info.  Most mopars with a larger than stock cam like at least 16-18 initial timing.  Total you'll need to figure out, do some math and get the mechanical advance limited to hit your total number.

It takes work to get it right, BUT, the car will run much better and have a cleaner idle than using the book numbers. 

[BadJoey]

You want easy? O best option?

Easy, find the TDC line cut into the damper, make a new line 2.25 inches to the right as viewed from in front & above the the engine..... The new mark is 34 degrees which is typically what a BBM likes as total mechanical timing... Now disconnect the vacuum to the distributor, hook up your timing light, start the engine, Rev engine to 2500-3000 rpms, set the timing so the new line lines up with zero on the timing tab...

Best After doing the above idle the engine & see where the timing is.. Chances are it'll be around 0-10 degrees... Ideally you'd like it to be around 15-20 degrees... So depending on what distributor you have the mechanical advance needs to be altered to limit the timing curve...

Tell us what distributor & we can help more..  Gotta go...



My distributor is a stock replacement mopar one . Nothing special . My car starts and runs good just a little hesitation when getting into it . I do not see myself changing the weights . I'm going to play with things today . Its been a while but I think it is at around 2.5 to 5 degrees . I'll let yous know . Thanks guys I was going to try TDC per the book but now I,ll try 15 degrees BTDC first .

[DocMel]

The book is ok to get the motor in the ballpark.   For timing, I use the book to get it in the ballpark, then I do it by "Feel and hearing". 

First, we are assuming your carbs are in proper tune, good plugs, gaps, distro components, , battery and alternator is putting out, etc......

Set timing, idle at carb to begin with IAW the book, then

Now attach vacum hose:

1. Set the idle at the carb to factory spec if not done already  (unless Im running a hot cam).  Let car get to operating temp.
    Now while at idle, I adjust the distro until I get just shy of the highest idle by turning the distributor.

2. I then shut down the car, and restart it.   If the car seems to "drag" (which more than likely it will do at this point) while trying the start, Ill fiddle with the distro just a tad until it will start at the point without allot of drag. (In other words, how you were used to it turning over to start)   

3. Start the car, let it idle. Then adjust the idle one more time at the carb IAW factory RPM (Unless you have a hot cam). 

4. Now drive it.  While out on the road, adjust the timing SLIGHTLY if you have flat spots or pinging.  It will NOT take much (If you even have to do it in the first place.  ENsure you dont get o the pint where starting the car "drags" again.  Its a sort of trade off between running good out on the road and no drag while starting.   
   
Once you get here, you are about as close to optimal timing across the board, for your engine and how its set up

Once you get to this point, you could then spend the 50-70 bucks or so at your local dyno shop.  Let them fine tune it and your car will really run.  IT really worth it not just for the t\fine timing, but also if your carbs need fine tuning

[1 Wild R/T]

"My distributor is a stock replacement mopar one . Nothing special . My car starts and runs good just a little hesitation when getting into it . I do not see myself changing the weights . I'm going to play with things today . Its been a while but I think it is at around 2.5 to 5 degrees . I'll let yous know . Thanks guys I was going to try TDC per the book but now I,ll try 15 degrees BTDC first ."

Don't try 15 without being ready to alter the weights.... If you put in 15 base & have 14-16 mechanical (you double the 14-16 because thats camshaft degrees no crankshaft) you wind up with 43-45 total crankshaft degrees, you can do serious damage to the motor with that much timing....

As I posted earlier 2.25" = 34 degrees... set it at 3000 rpms .....

[js29no]

  problem solved! timing WAS 3 degrees, it sounded best @ 18.  checked full advance it was 35, went to the carburetor and the bolts were to long. changed them out rechecked everything and told goe to take it out for a test drive. after doing a burn out leaving the front of my garage and down the road hecame back with a smile.

[BadJoey]

Thanks to everyone , car is now running the way I wanted .Thanks Mark .

[crackedback]

I hope you checked the advance running up RPM until it stopped advancing and not picking a number to stop.  I've had mopar distributors still advancing at 4400 rpm with a garage door spring on the advance weight.

Cool you got it running better.  18 sounds like a good place for initial timing.   

[BadJoey]

Am I safe to assume as long as it is running like a bear everything is good ? If some was off I could tell right ? I could tell before this .   Thanks.

[crackedback]

It's nice that it's running good.

Drive it hard, let it cool off, pull a plug and look for speckling on the white porcelain.  If it's got specks on it, it's detonating and has a bit too much timing, likely your total number.    Search for plugs/detonation for an example on the web.

 

[js29no]

It peaked at 35 degrees, goe ran it up the road and back. when he pulled back into my driveway and shut it off i had him restart the engine, and it fired right back up. no problem at all. i am a bodyman by triad but you guys gave us a good starting point to get the job done. thanks         BTW I had the same thought on checking to see how the plugs are burning. as always thanks for the advise.