Small Block Timing

[JMB340Challenger]

Just wondering how people have their small block timing set? I run the MSD billet and I'm at 36* all in by 2500 with the lightest springs and BLACK MSD bushing, so my initial is at 18*. It runs good this way, but I'm wondering if anyone has tried the aftermarket bushings, like from FBO that have a lower advance number...like 14*, which would put my initial around 22* and still keep my total at 36*. I'm wondering if that extra initial advance is worth the tinkering?

[brasil]

...I am running my 340 ( built to 1970 Spec. )  also with 16 deg @ idle...with 18 deg advance...so total is about 34-35 deg
@ 2600-2700 rpm...  I have the Accel Distributor ( similar to the Mopar performance Distributor )...  I use the Stock springs that came with the Dizzy ...changed to different springs...but the stock set up worked better...

If you go with lets say with 22 deg @ idle...  your starter might be unhappy....

My car runs good  with 16 +18.... and a little vac. on top... ( 10 deg )


Greetings Juergen   

[73_Cuda_4_Me]

I'm running a 1970 340 with Comp Cam in my 73 Cuda with factory dizzy... I modified the dizzy with self-made stopping plate to limit the total advance. I measured the pins spacing in 5 degree increments, and cut slots from minimum at idle to 36 deg all in (2.060 to outside of pins on my 14 degree advance unit). Because idle and vacuum liked 18 degrees advance the best, I had to limit mechanical to additional 18 degrees total (9 at dizzy). Runs SO much better!

Also, I swapped the elongated spring for a silver spring from a dizzy advance kit... at idle, the dizzy wanted to wander up to 5 degrees bouncing around. With the 2nd spring holding weights better, timing is rock solid at 18 at idle, and starts advancing at 1200, all in at 2800 RPM...

Engine/Cam did not like more than 18 initial.

[cudabob496]

22 initial seems too high, and will stress
your starting system.

[vinb]

I have been running my '73 340 @ 34' all the time, very responsive , easy starting , no ping.. I guess it just my set up..

I am using a 309 comp cam right now.

[cudabob496]

I have been running my '73 340 @ 34' all the time, very responsive , easy starting , no ping.. I guess it just my set up..

I am using a 309 comp cam right now.

wonder if you can have pinging/detonation and not hear it?

seems if at 34 degrees at idle, and you smash the throttle, you should get detonation!

[brasil]

..agree  !  34 deg all the time ??  That will cause a lot of stress on the engine...
Indy cars....  use this set up...  ( because they run FULLTROTTLE all the time... )

Greetings Juergen

[nqkjw]

I tune a lot of small and bigblock mopars for myself ,family and mates.I get my total right,all in by 3000max and then check the initial.I like to see around 16 initial but anywhere from 12 to 18 I'm happy enough with.
I reckon the tune you have is about right.
 

[cudabob496]

think my initial is around 17

[JMB340Challenger]

Good stuff guys. I appreciate the comments. I've just heard of some people liking a bit more initial with a nasty cam, to help with the idle and throttle response. Car runs real good at 18* initial...so I'm in no rush to toy with it. Thanks!

[solarguy]

I use one of the FBO bushings in my MSD dist. Adding an extra few degrees to my initial really smoothed out the idle while keeping the total at  36.  I remember when I was first setting it up, I ended up using the black MSD bushing and one light and one med spring and wishing there was a way to further limit total advance.  A few years later, on FBO's web site, I saw those and ordered.  couldn't be easier to set up the MSD dist's. 

[cudabob496]

Good stuff guys. I appreciate the comments. I've just heard of some people liking a bit more initial with a nasty cam, to help with the idle and throttle response. Car runs real good at 18* initial...so I'm in no rush to toy with it. Thanks!

with my cam, I could not get a decent idle, until I put some small holes
in the throttle plates, to allow more air.