Fine Tuning Question

[Shane]

Alright I got her running good....

What I am looking for here is suggestions, and ideas/processes on tweaking the timing and fuel mixture to insure I have it running as strong as she can....

I had meant to set it to 10 btdc, but I checked it tonight and its running at about 14 btdc.

The car does not bog or sputter and at higher rpms it doesnt ping...

Should i simply just set it ahead a bit and try it, and then turn it back a bit and try it , and keep going like that until it feels like it is pulling the strongest?

I have the idle adjustment screw on the carb set to two and half turns, is that good enough to run with while I play with the timing?

Thanks,

Shane

 

[Snake]

I think your on the right track.give it as much timing as it will take befor it pings or is hard to start.Timing tape is a great tool are you out for all out power ,or just good cruising.also read you plugs for jetting.

 

[Shane]

I do want to be able to drive the car daily, so I am thinking Good cruising will be smart...I just want to make sure when I mash the peddle down it goes as good as it can...

I will play with it this weekend....I will advance it as much as I can until it pings, and go from there...

 

[moper]

There are articles about how to tune... A few highlights:
Always have timing tape, or a light that has the advance function. Always set timing first*. Because timing will effect carb, carb does not affect timing. You never, ever, tune by advancing until it pings/pulls the highest vacuum at 3000rpm/rpms stop rising. You set by engine design. This will mean total timing could be anywhere from 28-38° total timing not including the vacuum advance. For a typical open chamber iron head engine with a small to med sized cam the total of 38° should be close. The advance curve should be fairly quick, with it all in by 2500 rpm. Then, you set the carb to run the best way with that curve.

*- electronic distributors. Points, you will want to set dwell first, then timing, then carb. Dwell effects timing, timing does not effect dwell.

 

[koryliss]

Shane,

No disagreement to anything in this thread - but an additional thought.

I thing there are two different issues that are being discussed: initial timing (your thought of hard starting) and best total mechanical timing (performance).

A dyno would probably be the best way to fine the best total timing, but I like your approach... and it is a lot more fun that a dyno.

But..., after finding the best timing for performance, should you find that the car is hard starting I suggest not backing off the total but rather (if your distributor permits it) add more timing in the distributor.

Lets assume that your distributor has 16 degrees of timing in it and for example, you find the best performance is at 36 degrees..... but the car is hard starting. 36 minus the 16 in the distributor = 20 at start.. probably a bit much. Put 22 in the distributor (instead of 16) and it would drop the initial start to a more livable number 14.

I admit it depends what distributor you are running and if it is adjustable... but you can have your cake and eat it too!

Kory