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Firecore distributor users...proceedure for setting up initial and total timing

Started by GrandpaKevin, August 18, 2017, 10:35:07 AM

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GrandpaKevin

I need some advice on setting up a Firecore distributor and adjusting the initial and total timing on a fresh 440 Six Pack engine.

In the past I've always used a standard Mopar electronic distributor and plugged the vacuum advance port and adjusted total timing to where the engine felt good usually 35 to 38 total.
Occasionally I would change the springs inside the distributor to get total timing in quicker.

This particular set up is going to be more for street drivability than total maximum performance.

I've never messed with trying to adjust initial timing or using the vacuum advance on the distributor.

I'm using a brand new unmodified Firecore distributor with vacuum advance.

From doing some research the procedure most suggested is:

Use a vacuum gauge connected to the port in the intake below the carbs?

Disconnect the vacuum advance hose and plug the distributor and the port on the carb.

Get the car running up to operating temperature and get the idle stabilized and then advance or retard the timing watching for maximum vacuum adjusting the idle up or down as needed during this process.

Once I've done this I need to back off the timing a degree or two.

I need to check and see where my initial timing is at, then raise engine RPMs up to about 2800 and see where the total timing is.

If my total timing is too high I need to adjust the advance slots on the Firecore distributor to get total advance timing between 35 and 37. That might be a whole new series of questions.

Reconnect all vacuum lines and take the car for a drive and listen for pinging or bucking during starting and adjust timing if needed?

Am I missing something or doing something wrong?

Is there an initial timing number I should be looking for?

Can I do this initial timing set up with the car idling in park?

Any other suggestions or advice?

Thanks.

Chryco Psycho

This is where a timing light can come in handy by checking the best timing at idle
generally I shoot for 16_20* curve with initial around 16 & total around 36*\7 I do not connect the vacuum advance at all

303 Mopar

CP did my Firecore on the 505 stroker in the Charger and it runs like a banshee!





Topcat

I'm very seriously tempted to buy one.

Let me know how it works out.

GrandpaKevin

I wasn't real confident with my cheap HF timing light so I borrowed a nice digital Snap On one.

I have a feeling my initial is too high but if I lower my initial won't that also lower my total advance?

Is it real difficult to adjust the advance settings on the Firecore distributor?

Thanks.

Chryco Psycho

Yes lowering the initial timing lowers the whole curve & therefore the total timing so you need to lengthen the curve , keep in min dthe engine spends most of its time with total timing or close to it so total is more important than initial is .

GrandpaKevin

I got the Firecore distributor installed, a real nice piece.

I also replaced the questionable MP orange ECU with a new HIREV7500 unit.

I was told by a few Mopar guys the 440 engine is going to like more initial timing which it definitely did.
With the initial timing in the low 20's the idle was real stable and the car didn't want to stall when put in gear like it did with initial at 15-17.
I currently have the initial at 21 but might bump it up to 22-23.
I was also able to turn the idle screw way down and the idle was excellent.

Of course the Firecore mechanical advance is listed at 22-24 so total timing is waaay high at 44 plus so I need to adjust the limit in the distributor.
I'm thinking of setting the intial at 22 and have the mechanical advance set at 15 for a total of 37?
I can them back off to 21/36 or up to 23/38 if needed.

I can see the 2 phillips head screws, what is the proceedure for adjusting this?
Firecore's instructions are pretty vague on doing this but I understand it is the same proceedure as a Mallory distributor?

Is it best to remove the distributor?

Do I need to disassemble the distributor?

Should I loosen both phillips head screws at the same time?

What needs to be turned inside the distributor to adjust the mechanical limit?

Should I change the advance springs?

Thanks for any advice.



Chryco Psycho

I oulkd set it for 22* initial with a 14* curve , not sure about the adjustment without having the instruction to look at though , springs will slow or speed the curve so total advance is reached sooner or higher in RPM but doesn't change the curve , iif it will not detonate bring in the curve sooner is usually better

GrandpaKevin

Quote from: Chryco Psycho on August 23, 2017, 03:11:24 PM
I oulkd set it for 22* initial with a 14* curve , not sure about the adjustment without having the instruction to look at though , springs will slow or speed the curve so total advance is reached sooner or higher in RPM but doesn't change the curve , iif it will not detonate bring in the curve sooner is usually better

That's exactly what I did.

I removed the distributor, pulled the rotor off, loosened the 2 Phillips screws and inserted a 9/64 drill bit into the slot giving the correct gap for 14* advance.
It took me awhile to figure out how to get the drill bit inserted, the plates slid in the right spot and then get the screws tight.
Not a whole lot of room to work with.

I ended up at 22 initial and 36 total which the engine seems real happy at.

I'll recheck the timing after a few miles.

Chryco Psycho