Fire Core Distributor Springs

Anyone running a Fire core Distributor? Would like to know which advance springs to use. It came with two blue springs installed. Wanted to know when full timing comes in using these springs.

16 to 18 degree's from the factory. Most customers have left it alone, unless racing. Which distributor? Thanks for your business. If you need directions, please let me know. Sometimes they were not put into the boxes.

Sorry 16 to 18 would be the amount of mechanical advance, I wanted to know at what rpm with the blue springs will it all be in by. Also I did not get any instructions.

This is what I would do. Install the distributor, get your timing tight and tach. Run the car and watch the timing for advancement. At first sign of advance record that rpm down. Then raise your rpm's up until there is no more advance then record that rpm number. Then you will know the rate of advance for those springs. At that time you can decide if you want stiffer springs or loose springs. Or if you want timing coming in earlier or later. I have done this process I bet a hundred times, it can't go wrong. And another thing. You are going to need a dial back timing light or have a balancer with marks up to 50 degrees or more or,, timing tape on your balancer for this to really work. Or not!

I left the original springs in mine and it's all in by 1800 RPM.Its perfect for a street strip car like mine, it gives you plenty of lead time to get the car moving so you don't get any low end detonation.
Gus

I left my blue springs in and love the way it runs. No instructions with mine either, very frustrating but figured it out.

Thanks Guys!

Superbeedave, sounds good I will give it a try. Currently I am running a MP distributor with the springs that came in the distributor and it is running all in by 2700 rpm. Timing is set to 17 base and 33 total. Running a 500 cube 11:1 all street motor.

At what rpm should the mechanical advance start and be all in at what rpm?

What do you guys recommend?

Rick thanks for the instructions.

We need to know a little more about your entire combo, engine, gear, converter etc...
It all needs to work together.
Gus

Okay here I go:

Carter AVS 800

Edelbrock DP4B ported dual plane intake

Ported Stealth heads with Harland Roller 1.5

Solid street roller cam @.50= 236 intake and 243 exhaust, .552 gross valve lift. Lash at .014th intake .016th exhaust

Valves 2.14" intake 1.81" exhaust

Flow rates
intake
.500 - 285
.550 - 289

exhaust
.500 - 217
.550 - 223

400 block with stroker kit to 499 cubes, compression 11:1

3.91 rear gear with 4 speed

Msd box

3900 lbs weight

mechanical edelbrock fuel pump

stock manifolds with 2 1/2 x pipe exhaust

manifold vacuum at idle 14 inches

I hope I did not miss anything. It runs and idles like a clock.

At 1000 rpm timing is 17 degrees at 1500 rpm timing is 25 degrees, never checked when it starts to advance somewhere between 1000-1500 rpm.

So your saying that your base is set at 17 and idles at 1000? This is too tough for me to figure out! If it idles at 1000 I would say start to bring in the mech. adv. at around 1300 or so and all in be 2000-2200 maybe? Is this really an 11.1 compression engine? With 17 degrees adv. and 18-20 mech. I would set full advancement at 35-37 all in by 2000-2200? Guy's, someone chime in and help, This is a little out of my territory!

Idles at 800 rpm and base timing is the same at 1000 rpm.

17 base with 16 mechanical, total is 33 degrees @ 2700 rpm

Motor made the most power at 34 degrees total on the engine dyno and wheel dyno.

Just got my Firecore plug-and-play distributer last week for my 383... no instructions in mine either, and out of the box has 20* mechanical advance.

Quote:

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Would like to know which advance springs to use.

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I'd suggest (1) setting the initial with the "vacuum gauge method" then (2) with that figure in hand shorten the slots to get 36 total then (3) plug in vac adv & pick a spring combo that keeps you just under the pinging point at WOT up thru the gears on your hottest/driest day then (4) adj vac adv (2 adjustments). Seperate issue- you want the spring/slot adv to start several hundred RPM above the in gear idle speed (or neutral if stick). Keep vac adv capped off for (1) unless going with manifold vacuum & capped off for (2) whether ported or manifold vacuum. A short stroke 383/400 MAY work well with significantly more than 36 total. You can always change your settings. #1 if you can afford it dont scrimp on the octane.