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Chrysler 440 timing advance curve

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captain_ed

Regular Contributor
I know that we could not find a factory official timing curve for the 440. This should get the job done.

I purchased a new distributor for my standard rotation 440 and am rebuilding my distributor for my counter-rotation 440. I called tech-support to get the timing curve from the new distributor so that both will match.

Mallory YLM578AV marine distributor for Chrysler 440.

Thanks for the inquiry. The advance is as follows .5-2.5 degrees @ 1300 rpm, 7-9.5 degrees @2300 rpm, 11-12 degrees @ 3300 rpm, which gives you a total of 24 degrees at 3300 rpm. Let us know if you have any further questions.

Thank you,
Stan
Technical Service
Prestolite Performance
10601 Memphis Ave. Bldg. 12
Cleveland, OH 44144
 
captain_ed said:
I know that we could not find a factory official timing curve for the 440. This should get the job done.

I purchased a new distributor for my standard rotation 440 and am rebuilding my distributor for my counter-rotation 440. I called tech-support to get the timing curve from the new distributor so that both will match.

Mallory YLM578AV marine distributor for Chrysler 440.

Thanks for the inquiry. The advance is as follows .5-2.5 degrees @ 1300 rpm, 7-9.5 degrees @2300 rpm, 11-12 degrees @ 3300 rpm, which gives you a total of 24 degrees at 3300 rpm. Let us know if you have any further questions.

Thank you,
Stan
Technical Service
Prestolite Performance
10601 Memphis Ave. Bldg. 12
Cleveland, OH 44144
Click to expand...



Its a Wonder Stan didn't clarify that with a dist or crank timing in degrees...
Logical thing is to Get OEM old Distributor in a Dist tester (I guess not many are in USA shops these days - or anyone correctly trained to use them ) & Calibrate the New ? Rebuild to Old specs IF the Mech advance is still free to travel & either Duplicate that OEM curve on the Mallory - (its a one size fits all on the conservative 'White gas' end of the curve)

I'd take a graph of the 2nd to-be-rebuilt oem ? Dist & lay that into the Mallory - not other way around ... but then again I'm looking from a Pro's view.
BTW you'll find an "Official" 440 Curve in a Late '60's Hotrod Mag.
I think it was On Edelbrocks Dyno & Ed Isky was involved

(& I think this is going to be close to my limits of stating info for lurking freeloaders )
Cheers
 
Oh no...... not this again! :D


Its a Wonder Stan didn't clarify that with a dist or crank timing in degrees...
Click to expand...
We should always be talking in terms of crankshaft degrees, unless otherwise spelled out.
Camshaft indexing, LPCP, Spark Advance, etc, are typically spec'd out in crankshaft degrees.

.5-2.5 degrees @ 1300 rpm, 7-9.5 degrees @2300 rpm, 11-12 degrees @ 3300 rpm, which gives you a total of 24 degrees at 3300 rpm.
Click to expand...
At idle RPM, we should see ZERO progressive advance. This is likely why they begin showing the numbers at 1,300 RPM.
I'll take a guess here that these are likely distributor advance degrees only, meaning that BASE advance must be added or factored in when looking at the numbers dynamically.
Not an issue if BASE is known and is accurate.


Logical thing is to Get OEM old Distributor in a Dist tester (I guess not many are in USA shops these days - or anyone correctly trained to use them ) & Calibrate the New ? Rebuild to Old specs IF the Mech advance is still free to travel & either Duplicate that OEM curve on the Mallory
Click to expand...
Taking an old OEM distributor, and running it out on a machine as to lay a curve onto another system, makes a huge assumption that OEM is still correct!


............ but then again I'm looking from a Pro's view.
BTW you'll find an "Official" 440 Curve in a Late '60's Hotrod Mag.
Click to expand...
Do this, and you'll end up with a curve that is suited for Automotive, but not nessarily for Marine loads.
Apples/Oranges.
No offense, but quite honestly, a Pro should know the difference between Automotive and Marine loads.



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