I'm not very familiar with this but what are good/bad timing #'s for our trucks. I've read that timing is important and prevents detonation. I will be porting the Eaton soon and want to keep the 6# lower on, so what should I be specifically asking my tuner when I send for a reburn? I want to keep everything as safe as possible any suggestions?

 

Oh, 'bout 40 degrees sounds good... if you are Rob_02 J/K

...but for us mere mortals, I think most guys run between 14 and 18, depending on what kind of octane you can get. For a 6#, I'd stay at 16 or lower, and use Ultra 94 if available.

 

16 DEGREES BARE BARE MINIMUM I LIKE MORE

You know what you all need right ???


























MORE TIMING



UB you don't say where you live ???? That WILL play a part,
and so will available Octane, (Bastards just took 94 away from LI)
If your in Cali, you may have prob's dialing in 6lbs of extra pulley
with any decent amount of timing. But here in NY at sea level,
MY LIGHTNING LOVES TIMING even on only 93 octane now.
(my street program is 18 degrees, and I run 6lbs and other Mods)

Ported Eaton will be here Mon/Tues

 

 

No and Yes
No

No + Yes on will I be running the 6lbs with Ported Eaton
I OFFICAILLY MAKE THE PORTED EATON --> "PE"
so I don't have to keep writing Ported Eaton a million times in
every post.

I will first run it with 4lbs and make sure it's detonation free
on the streets, and I will def "only run 4lbs" when I Juice it for
the first time on the PE

If all goes well, I'll switch to 6lbs for the street in the summer
"like I always do", but prob only run juice w/4lbs for now on in.

As for the more timing the safer, NO NO NO
The more timing the more chance of Detonation, but of course
the more timing the faster you go ""if properly tuned for it"".

In Texas, my guess is 14/15 degrees and a rich tune should be ok for the streets. If that works out simply have the tuner add
a degree or two with a free reburn afterwards .

I'm lucky cause my 16 Degree Nitrous Program is also the perfect program to use for extreme cold weather, long WOT, and better economy, so I always have that to fall back on in the event I hear detonation after the PE. A nitrous program has a little less RPM in the shift points, a def richer A/F, and of course Less timing.
(Mines 16 degrees, and thats def considered high for Juice)
HEY THATS LOW TIMING FOR ME

But for @ a full yr now I ran 6lbs on the streets 24/7 on 18 degrees of timing using pump gas and it's fine. (I DO NOT recommend that for you, and I doubt you could get away with it in TX)
Everytime but once, when I went to the track I ran 2 degrees less timing, plus 2lbs less boost, plus Racing Fuel, THERE IS NO WAY IN HELL I'M GOING TO DETONATE, AND NEVER HAVE.

This backwards way of thinking has worked amazing for me,
great ET's at the track, but the reason I do it is for safety and less stress on the Motor on the days I'm truly pushing it to it's limits. Schitt even my former 12.7's are using that exact 16 degree program @ 4lbs of Pulley and NO JUICE.

I just like to run the streets with more timing and more boost.

 

War and Peace was easier reading for me than the above quote

 

everywhere I go, I see Gators

 

Thats the ONLY time you'll be seeing the front of that truck

 

I get the impression you don't quite understand the concept of spark timing, i'll try to explain it the easiest I can. Like Rob said, timing varies for different trucks in different climates, and there's a very narrow 'timing window' that a given combo will run well with. A few degrees advanced or retarded from this window, and power drops off big time. When we say degrees, such as 16 or 18 degrees of timing, thats describing degrees in crankshaft movement BTDC (before top dead center). Top dead center is the point where the piston and rod are completely vertical on the crankshaft, and the piston is highest up in the bore and closest to the cylinder head.

When the spark ignites the air/fuel charge, it takes time for it to burn (duh!). The engine is actually accelerating faster than the a/f charge can burn, so the a/f charge needs a head start. The charge doesn't explode in the cylinder (like a nitro burning top fuel dragster), rather its similar to dropping a match in the center of a dry grassy field. It starts to burn slowly at the point closest to the plug (called lag angle), then the flame speed gets faster and faster as it burns in a circular patern away from the spark. Obviously there's going to be a point in the burning cycle with very little energy, and a point where lots of energy is released.

Different climates directly affect the flame speed. If its cold and dry, you need less timing because the flame burns faster. On the other hand, if you live in a warm and humid climate, the air/fuel charge will be less oxygenated and the flame speed will be slower...you'll need more spark advance. If you get the spark ignited too early (too much timing), the engine will detonate because you're releasing energy on the piston while its still moving up the bore on the compression stroke. If you get the spark ignited too late in the cycle (too little timing), you'll lose power because the burning a/f charge will be chasing the piston down the bore on the power stroke.

The trick is to time the spark so the point at which maximum energy is released corresponds to a favorable angle of the pistons/rods/crank (usually 7 or so degrees ATDC), so the engine can convert cylinder pressure to rotaional movement (torque). You want the air/fuel charge to be burning at a high rate when the piston is near TDC, because this is the point of maximum compression, quench, and heat. Despite what you may have read on the internet, once the intake valve closes you want maximum heat in the cylinder for maximum cylinder pressure. Again, you're trying to create maximum cylinder pressure. Cylinder pressure=horsepower, less pressure=less power, more pressure=more power. When you install a ported blower or pulley or chip or air filter, you're making more power because of more cylinder pressure.

The sign of a very well designed, highly efficient engine combo is it needs very little timing to make good power. That efficiency comes from a well designed combo of cam, heads, intake manifold and header tuning. If you want good examples, check out Honda. They have cars operating with 40:1 a/f ratio's, that only drop to around 20:1 when throttled and never detonate! Adding timing is actually negative work, because as the piston moves up the bore on the compression stroke it has to fight against a large, rapidly expanding cloud of gas when you've got lots of timing. This slows the piston down, which reduces power. Again, its a delicate balancing act. You can also do severe engine damage by running extremely low timing (6-9*). The exhaust valve is the absolute hottest point in your engine, and with low timing the a/f charge will still be burning as the exhaust valve opens. This overheats the valve very fast, and the first thing to get damaged will be the valve seat which is a very critical seal for making power. Also, you may have seen cars on dynoes before with headers glowing bright red. Thats caused from very low timing, because the a/f charge is actually still burning inside the header. Sorry for the long post. Hopefully it helps and doesn't confuse you any further!

 

@ rscoleman

You like my timing God after that awesome explanation

I'm gonna save that explanation and re-post it when people
ask timing questions