Higher All In Timing

[Markie]

What are your thoughts on higher all in timing? My 440 in my 69 charger is 40 degrees all in at 2300 rpm with no pings and the engine starts up in a split second with electric fuel pump and mini starter.

 

[Kern Dog]

40 degrees is a LOT.
Most of the time, we read from guys with detonation issues. With them, they need less timing and later timing.
It seems to me that you sure wouldn't want or need the timing to be maxxed out below the stall speed of the converter or at the point where you might release the clutch when racing.
Here is my own curve with a Mopar Performance electronic distributor. Note how slow the curve starts. From idle to 1750, it advances 1 degree.

The curve below is with a new reproduction distributor from Rick Ehrenberg. The curve starts right off idle.

I limited the total advance with this:

\

FBO ignition sells them. I have mine in the "14" slots but I got 15 degrees of advance. That is close enough for me,
Regarding your advance....40 degrees may be past the point where it makes the most power. The multitude of dyno tests across a wide variety of Big Block Mopar builds shows that the sweet spot is usually 34-36 degrees.

 

[Budnicks]

You didn't say if it or was stock or modified, rebuilt engine etc.

what fuel do you run ? 87, 89, 91 even 93 oct, if they have that in Hawaii ?

the Octane rating can make a difference too
Or if it's a high level of Ethanol % (Corn based or Methanol Alcohol)
it will resist pinging, & you can run more timing then too, & it will like it too

Not sure the gas mixture you guys have there in Hawaii now...

(*** edited, added) Or whether you have a 4 speed & low gears
or a high geared set up that, puts a load on it early
or a stock Torque converter & 3.23:1 or 3.55:1, less tolerant to advanced timing
verses like a 2800-3200 stall with 3.91:1+ to like a 4.10:1 or steeper gears
where the load is applied in high gear can make or break it, under load
steep/er gears you can get away with more timing under a load***
***loosen the distributor, so it can be moved, but not loose
set the idle up to like 2000+ rpm
***disconnect the vacuum advance, plug it
then turn/advance the distributer, to it's highest RPM afterwards,
shown on a tach, not touching the throttle
back it off maybe 1* & then go road test it, under a load in high gear
like up a slight grade
if it pings under a load, then back it off, a 1*- 2*'s at a time
until it won't ping under a hard load
& that's about the place your engine wants the timing to be...


40*s isn't that uncommon
but with todays crap swill fuels/crappy gas, it's not the norm
head designs on a stock 440
are like the heads on a SBC on a big block
(I know sacrilegious) they are a pinch point, not the best design for a 400+ cid engine
& the engine can't get the needed flow it wants
hence the added/needed timing, to band-aid/make up for it short comings
in a too small design for that many cubes (even on a 383/400 etc.)
a factory 375hp hyd. FT cam is like advertised 268*/284* (ish)
228*-241*@ 0.050" lift & 0.450" in./0.458"ex. (ish) gross valve lift, with stock rockers
the moderate 10-12* ATDC timing, from the factory is to comply to
(before C.A.R.B. like stuff) was to meat a smog compliance
& if you have an aftermarket intake, carb & headers or free flowing exhaust
it can certainly take more timing...

"not any one timing setting/s fits all engines
there's no one set in stone, "timing #s"
even on 2 identical engines can be different

Each specific engine will like a lil' different timing
a bunch of different factor are in play,
what type of ignition system & how hot a spark, or is it multi spark/CDI
the combustion chamber size, valve size, cam timing/camshaft size & duration
how far the pistons are down in the hole/or zero deck, or domed
what fuel you run

you may have found the sweet spot for your specific combo
may not be right, but it works

But;

I really depends on the "actual" compression of the engine
& what mods have been done, like thicker head gaskets, stock is 0.020" shim
that's a bit different than the newer replacement head gaskets are
newer replacements are usually 0.039" compressed, (like FelPro, Perma Torque)
they also have a bigger diameter bore size in the newer gaskets
all that can affect compression too, lowers it if it's thicker & bigger diameter
(nice to get them a lil' closer to the bore size & not have any hangover into
the combustion chamber)
unless specifically ordered different, from someone like "Cometic Gaskets"
or
It's maybe a rebuild with lesser compression ration,
lower compression pistons with a
"less compression height", that's where the wrist pin sits in the pistons
in relation to the pistons down in the hole farther, or not up nearer the deck surface
(as in zero deck, top of the pistons up flush with the block deck,
more compression, less timing will be needed)

usually when it likes more ignition timing, it's just a band-aid for something else

But my 383/479cid 0.040" over & 4.15" stroke, really like 38*'s, total
& I have no pinging or detonation issues, at all

I do live at altitude too, it likes a bit more advance, it starts with 21*s initial timing
it is cam is installed advanced at 2*s my camshaft is a Hydr. roller
cut a 112* intake & 114* exhaust, so it's camshaft is installed at 110*

"not all advance curves are the same"
not all engine need the same advance curve either
1 doesn't fit all, no matter what magazine all say

depends on what heads what material the heads are, what kind of cam
(what the final compression is)
a lot depends on where the cam was set in (degree it to know)
& if it is advanced or retarded at top dead center
at #1 cylinder firing already,
a lot of it is ground into the camshaft advance
or ***even camshaft is installed retarded to begin with
'it may be retarded' or the camshaft actually ground that way
***that scenario would like more initial timing too
or the timing chain sprocket/keys it was installed that way
(many "better timing chain sets" have multiple keyways,
from 0*- 8* advanced or retarded)
Or that many times, cams installed are in the wrong place/degree wise,
installed wrong, ground different & never degreed in...

good luck

 

[Markie]

You didn't say if it or was stock or modified, rebuilt engine etc.

what fuel do you run ? 87, 89, 91 even 93 oct, if they have that in Hawaii ?

the Octane rating can make a difference too
Or if it's a high level of Ethanol % (Corn based or Methanol Alcohol)
it will resist pinging, & you can run more timing then too, & it will like it too

Not sure the gas mixture you guys have there in Hawaii now...

(*** edited, added) Or whether you have a 4 speed & low gears
or a high geared set up that, puts a load on it early
or a stock Torque converter & 3.23:1 or 3.55:1, less tolerant to advanced timing
verses like a 2800-3200 stall with 3.91:1+ to like a 4.10:1 or steeper gears
where the load is applied in high gear can make or break it, under load
steep/er gears you can get away with more timing under a load***
***loosen the distributor, so it can be moved, but not loose
set the idle up to like 2000+ rpm
***disconnect the vacuum advance, plug it
then turn/advance the distributer, to it's highest RPM afterwards,
shown on a tach, not touching the throttle
back it off maybe 1* & then go road test it, under a load in high gear
like up a slight grade
if it pings under a load, then back it off, a 1*- 2*'s at a time
until it won't ping under a hard load
& that's about the place your engine wants the timing to be...


40*s isn't that uncommon
but with todays crap swill fuels/crappy gas, it's not the norm
head designs on a stock 440
are like the heads on a SBC on a big block
(I know sacrilegious) they are a pinch point, not the best design for a 400+ cid engine
& the engine can't get the needed flow it wants
hence the added/needed timing, to band-aid/make up for it short comings
in a too small design for that many cubes (even on a 383/400 etc.)
a factory 375hp hyd. FT cam is like advertised 268*/284* (ish)
228*-241*@ 0.050" lift & 0.450" in./0.458"ex. (ish) gross valve lift, with stock rockers
the moderate 10-12* ATDC timing, from the factory is to comply to
(before C.A.R.B. like stuff) was to meat a smog compliance
& if you have an aftermarket intake, carb & headers or free flowing exhaust
it can certainly take more timing...

"not any one timing setting/s fits all engines
there's no one set in stone, "timing #s"
even on 2 identical engines can be different

Each specific engine will like a lil' different timing
a bunch of different factor are in play,
what type of ignition system & how hot a spark, or is it multi spark/CDI
the combustion chamber size, valve size, cam timing/camshaft size & duration
how far the pistons are down in the hole/or zero deck, or domed
what fuel you run

you may have found the sweet spot for your specific combo
may not be right, but it works

But;

I really depends on the "actual" compression of the engine
& what mods have been done, like thicker head gaskets, stock is 0.020" shim
that's a bit different than the newer replacement head gaskets are
newer replacements are usually 0.039" compressed, (like FelPro, Perma Torque)
they also have a bigger diameter bore size in the newer gaskets
all that can affect compression too, lowers it if it's thicker & bigger diameter
(nice to get them a lil' closer to the bore size & not have any hangover into
the combustion chamber)
unless specifically ordered different, from someone like "Cometic Gaskets"
or
It's maybe a rebuild with lesser compression ration,
lower compression pistons with a
"less compression height", that's where the wrist pin sits in the pistons
in relation to the pistons down in the hole farther, or not up nearer the deck surface
(as in zero deck, top of the pistons up flush with the block deck,
more compression, less timing will be needed)

usually when it likes more ignition timing, it's just a band-aid for something else

But my 383/479cid 0.040" over & 4.15" stroke, really like 38*'s, total
& I have no pinging or detonation issues, at all

I do live at altitude too, it likes a bit more advance, it starts with 21*s initial timing
it is cam is installed advanced at 2*s my camshaft is a Hydr. roller
cut a 112* intake & 114* exhaust, so it's camshaft is installed at 110*

"not all advance curves are the same"
not all engine need the same advance curve either
1 doesn't fit all, no matter what magazine all say

depends on what heads what material the heads are, what kind of cam
(what the final compression is)
a lot depends on where the cam was set in (degree it to know)
& if it is advanced or retarded at top dead center
at #1 cylinder firing already,
a lot of it is ground into the camshaft advance
or ***even camshaft is installed retarded to begin with
'it may be retarded' or the camshaft actually ground that way
***that scenario would like more initial timing too
or the timing chain sprocket/keys it was installed that way
(many "better timing chain sets" have multiple keyways,
from 0*- 8* advanced or retarded)
Or that many times, cams installed are in the wrong place/degree wise,
installed wrong, ground different & never degreed in...

good luck

View attachment 1706391

Budnicks
Thanks for all the info on different set ups. I haven’t tested for pinging up a hill. I will try that and get back to you.
Aloha