Anybody know how much advance you're supposed to have during cranking before the engine fires?

Hate to tell you this, but the procedure a billion years ago in HS auto shop was keep rotating the distributor in small increments until the engine runs. It was one of our final exams.

Of course we are talking old school points distributors and no control boxes back then.

I would imagine it would depend on engine specs. I get no kickback at 18 degrees initial, 10.5/1 static compression ratio. When I reinstalled the engine after the rebuild five years ago it started at near zero degrees advance, then promptly overheated until I advanced it to 12. Some of the smog engines had an ATDC rather than a BTDC setting.

There are several factors that dictate how much initial timing you can/should run. It really boils down to how much your motor can stand and the distributor set up you run. Starter kick back is usually do to to much initial advance.

Most iron headed pontiacs like total advance at 36. The amount of mechanical advance will then determine what your initial advance will be to achieve that.

For me I have a converted points distributor (Daves small body HEI) and I modified the oval limiter with a set screw. I also have a RobbMc starter after struggling with hot start problems. I run at 16° advance and 36° total. I run my adjustable vacuum can at 10°

Your best bet is to get a pen and paper, grab a timing light and do some recording. Disconnect you vacuum advance get your idle as low as possible and record your initial timing. Rev the motor to about 4500 and record your total timing. The difference will be your mechanical advance. From there depending on the distributor you run you can plan your next move.

That I can vouch for. My 455 was broken in and tuned on a dyno and it was happiest at 36 total - even with a set of aluminum E-heads.

Aluminium heads seem to be able to run with a bit less total, initial and mechanical, vacuum is not considered when talking about total.
I also tuned mine on a dyno and got best numbers with only 28 total. I welded the distributor plate to stop the mechanical from returning to zero for an initial of 16-18. Then only the top of the advance curve is used for 28-29 at 3200 rpm. Started with 32, adjusted up and down and 28 was the magic number. That set the initial at 9 which caused it to run like crap at idle as well as over heat, thus the plate weld.

I have no operational choke or fast idle on my carb. When I first start it idles at 350-400 rpm, has about 5 inches of vacuum and the air fuel ratio is 16-16.5/1. as it warms up the idle slowly increases as well as the vacuum and the A/F ratio drops. If I had the initial set to 12 I would have to warm it up with my foot on the gas pedal.

Never had kick back with this engine, used to get a lot with my 69 GTO. That car had a slow crank and there just didn't seem to be enough momentum to push the piston up when it fired. Was set at 12 initial. I have a High Torque starter in the Bird there was a stock one in the GTO.

Well initial timing and timing during cranking are two different ball games. You're only cranking at a couple hundred rpms so your not really getting there till the engine actually fires.
Anyways I think I discovered why it was acting up. When I was leaving town last weekend it was cutting out pretty bad and I noticed my throttle position sensor numbers were all bouncing over the place. 0 to 14 to 5 to 3 etc. Went back to Summit...again...and spent $50 on a new one. 5 minute install and it made the trip home(200 miles) without incident. I'm pretty sure that's what was causing the kickback. Must've been dumping weird amounts of fuel just at the wrong time.

BTW. People seem to say you only need 6-10 degrees adv during cranking.

You have an efi setup
TPS sensors usually have a smooth sweep of voltage
05-5 volts Some go 0-12
But if you were to back probe the signal wire and step on the gas it should give you a nice steady sweep of voltage up and down with pedal travel
When it’s jumpy the computer doesn’t know where the throttle plate is
So inturn the control didn’t know how much fuel the car wanted to start or run right
So your discovery is right on and your problem should be corrected
Nice job on repair

Thanks Mickey. I have yet to test my theory. I was so frustrated when I got home that I put her away and haven't touched her since. I probably will get out there and crank her up today to see if she starts smoothly without the kickback issue. I think I got it though.

Hey Bob, glad you had a better drive home than on the way.
Don't really agree with the two different ball games thought. Initial is what you have whether it's turning at 100 rpm or at 7000 rpm, as long as there isn't any mechanical or vacuum advance added. Set the initial to 40 and you will be more likely get a kick back than if it's set to 10. I agree one only need a bit of advance to start but after it fires one wants more at idle. If you wanted 24 at idle and your engine can only take 10 or less when cranking, then you can get the extra advance with the vacuum advance connected to the manifold pressure port.
As you already know, I'm not an expert and this is just my opinion.

In a carburetor setup, that is true, since in most cases your static timing is what you have during cranking as well. Unless you have a vacuum compensated system directly connected to manifold.

In the case of an EFI setup like Bob's, the timing map contains areas that are only active during crank, and others that take over during running. As cranking rpm is really slow, it doesn't require the same amount of initial as when the engine is @ idle anyway. And, the lower you have it, the easier the engine will turn before firing. This is because, as you add timing during crank, the combustion is starting sooner before TDC, which creates work on the piston as it travels upward.

In a modern EFI ignition map, you'd often see single digit values in the areas using during crank. Then once it fires, it goes into a different area of the map adding more timing closer to what we traditionally see in a carburetor setup.

Yup, thats one of the good things about the EFI, you can adjust just about everything everywhere. I asked around and people say 6-8 BTDC is a good place to be during cranking. Anything to make it easier to start is good for me since the starter takes a lot of heat from the headers. Not sure how long the mini will even last.
I went out last night and started the car. No kickback. Looks like the new TPS did the trick.

Since I'm , as one person on this site called me when he read I use a slide rule, Ancient, I don't know what a MAP is. Something to do with absolute pressure?
So when you installed the EFI system you ended up with computer controlled fuel and ignition systems like in a new vehicle? The EFI system changes the timing as the engine needs change?

Someone will be installing variable valve timing next.

The "map" I was referring to in this case, was the ignition advance table. His system is both ignition and fuel are computer controlled, although some are offered as fuel-only (still uses distributor for reference, but no timing control). There can even be multiple timing tables, one as a base table, then others for compensation of things like engine warmup temperature, barometric pressure, limp home, octane, or fuel type adjustment, etc. Professional race-oriented equipment even allow for varying the timing for each individual cylinder to optimize combustion for any variance in heat, air/fuel distribution, knock sensitivity, etc.

There is something called a MAP sensor (manifold absolute used on speed density and mass airflow based systems). But that wasn't how I was using the terminology.

Variable valve timing is really complex to setup on an cam-in-block setup. Although both GM and Chrysler have done that.

Cool. Thanks for the explanation.
I wonder if after I paid for and tuned a QFT 1450 it wouldn't have been cheaper to go the EFI? But then I don't trust computer controlled stuff. Seems nine out of ten snags with a newer car or truck is engine control box related. I'm even thinking of going back to points due to the module in the HEI.
, I always carry a spare one of those just like I used to carry spare points and condenser.

Funny you should say that because when I tell people about all the crap I've had to go through getting all the bugs worked out of this thing I usually say that I figure I could have bought two great carburators for the same money. I'm learning a lot though so I guess I could look at it as paying for my continuing education.

Nothing wrong with paying for education, I went back to college when I was 32, took me ten years to pay off the loans and I lost three years wages. Wish I could have gone to school for two or three more years. So much to learn, so little time.

This is more like paying to teach yourself.
Would be nice if the manufacturers had a tech line with real tech people, someone who actually knows the product and can walk you through the trouble shooting.
Holley/QFT suggested I buy a Holley book and learn how to tune, I suggested he learn how to tune if he's answering the tech line.

Then again solving the problems oneself most likely teaches more than someone telling one to replace part A with part B and no reason as to why.