Stock 440cu - Check my timing settings

[watermelon]

Hi All,

I installed an MSD Atomic EFI a few years back and set it up to control the engine timing. I used some baseline ignition numbers from an MSD Atomic install video which they set up on a Pontiac engine just to get the system running. I never went back in and adjusted settings for a 440cu.

I think engine may be running a little warm. Went out on a cool morning and temp got up to 207 after hot-dogging around. Im wondering if adjusting ignition settings can help.

Engine is a stock 440cu connected to a 727 auto. Ignition is MSD 6AL, MSD Coil, and MSD Pro Billet distributor. MSD Atomic EFI. Cooling is a Wizard Rad w/fan shroud, Flowkooler pump, and Milodon 180 thermostat(boil-tested good).

Can you take a look and recommend some ignition timing settings?

My settings:

Idle RPM 700
Total RPM 2500
Idle Advance 12.0
Total Advance 35.0
Vacuum Advance 10.0

I can change settings on MSD computer. Also, I can set Vacuum Advance to zero if it is not needed.

I’ll attach a pic of my settings and a pic off the MSD youtube vid.

Any help is appreciated.


watermelon

 

[lewtot184]

I have a 440 in my 69 r/t that always runs on the "warm" side. engine is stock and my advance curve is very similar to yours. I've played with advance curves in every direction possible and never found any cure for engine heat playing with the timing. my problem is a 22" radiator and all cast iron. the exhaust manifolds will run 700+f. i'd look for the cooling issue some place besides timing.

 

[Don Frelier]

A couple questions and suggestions:
1. Were you seeing 207 just driving around? Or stopped after driving at highway speeds?
- You really don't need a fan driving at 50 or 60 mph, I have an electric fan using Atomic and it stays off
2. Have the heads ever been off the motor? When I took my 383 apart years back the cooling passages through the head
had a layer of scale covering the holes.
3. Are you sure you set the initial distributor advance according to the MSD recommendations fixed at -20 degrees?

I would suggest a couple things:
1. Check that the fan blades are centered in the inward edge of the shroud. Too far in negates the fan functionality
by short circuiting the air in the shroud.
2. I've heard that high flow water pumps can possibly be worse since there is less residence time in the radiator.

Lastly a couple suggestions on the timing but these would be for starting, performance and economy:
1. Try initial timing at 20 degrees or so, it should start better. If the starter labors when warm and nearly stalls go back a few degrees.
2. Jack up the vacuum advance as far as you can and listen for predetonation. This will make it snappy.
3. I run total at 39 degrees, you might go up a couple here 906 heads with a big bore take a while to propagate the explosion.

 

[khryslerkid]

To try something simple,

If you're using antifreeze, try diluting it to around 0 degrees, the more water that you can get by with really helps with the cooling. (I'm not sure where you're from for your climate)

The Water Wetter product really helps. Even Kool-It will help.

 

[moparnation74]

So "hot dogging" it got up to 207....So I assume it came down appropriately? I take it your running pump gas with ethanol?

Your numbers seem fine if those are the actual numbers for timing.....If the temp goes up while sitting at a light or dogging it but quickly comes down when driving....Then Welcome to a BB....

As KK said improve on the cooling side of things.....

Also, is your gauge accurate? Use a temp gun at the water neck...

 

[Don Frelier]

The Atomic measures inlet air and cooling jacket temperature, if they are the same at ambient then it's working correctly.
I was surprised at how accurate my old gauge in the 66 was compared with the Atomic.

 

[watermelon]

1. Were you seeing 207 just driving around? Or stopped after driving at highway speeds?

3. Are you sure you set the initial distributor advance according to the MSD recommendations fixed at -20 degrees?

2. I've heard that high flow water pumps can possibly be worse since there is less residence time in the radiator.

1. Try initial timing at 20 degrees or so, it should start better. If the starter labors when warm and nearly stalls go back a few degrees.

2. Jack up the vacuum advance as far as you can and listen for predetonation. This will make it snappy.

3. I run total at 39 degrees, you might go up a couple here 906 heads with a big bore take a while to propagate the explosion.

Hi Don, good to hear another Atomic is riding atop a 440cu.

I do mainly see 200-204 at stop lights after driving. Otherwise, its 180's-190's. I have two electric fans the Atomic is controlling; Fan 1 set to come on at 195 and Fan 2 set to come on at 200; they both kick on at prescribed temps.

I set the distributor to 15degs BTDC as outlined in the Atomic install instructions. Then set my ignition numbers as in previous post above.

Are you saying that your Idle Advance is set at 20 and your Total Advance is at 39?

Is the vacuum advance function needed? The MSD distributor has no vacuum port.

So "hot dogging" it got up to 207....So I assume it came down appropriately? I take it your running pump gas with ethanol?

Your numbers seem fine if those are the actual numbers for timing.....If the temp goes up while sitting at a light or dogging it but quickly comes down when driving....Then Welcome to a BB....

As KK said improve on the cooling side of things.....

Also, is your gauge accurate? Use a temp gun at the water neck...

Now that I think about it, I was banging the car around the neighborhood in an effort to drive off as much gas as I could; I was running it down to prep for a fuel sender replacement. I got the gauge down to Empty (not sure of old sender accuracy) then headed home. I wasnt able to get a long cool down lap in.

I used a temp gun at various places on the engine and radiator/radiator hoses and the numbers match what is being reported on the Atomic.


In regards to KK's comment: I am running 50/50 mix of Prestone & distilled water. I could modify this. Not sure I even need antifreeze in So Cal. And we do have 10% ethanol gas here.

lewtot184: I too have manifolds and all cast iron heads/block. I run a 1/4" Canton Racing phenolic spacer under the throttle body just in case.


Thanks for the input all.


watermelon

 

[Kern Dog]

207 is not a problem. New cars with aluminum heads run over 220. Keep in mind that the number could be artificially high. Stock gauges were merely "guidelines", not exactly precision instruments! Even some aftermarket gauges are not 100% accurate. A mix of water and anti=freeze raises the boiling point of the coolant. Once you go beyond 50% anti-freeze, the boiling point actually gets lower.
The higher the pressure in the system, the higher the boiling point too.

 

[Don Frelier]

Given your electric fan setup what you are seeing is exactly correct.
When you are driving the air from moving cools the radiator.
When you stop the built up heat in the system is still there, but no fans when you initially come to a stop.
The temperature rises and the fans kick in, but you have not been removing the heat for some period of time until the temperature rises above the setpoint. So even with the fans on the temperature will rise above the setpoint.
It's not a big deal as long as it comes back down in a couple minutes.
You can scroll and see if the fans are activated on the handheld.
As far as the timing:
1. Yes try initial at 20 degrees.
2. Try raising total advance 1 degree at a time.
3. The vacuum advance is controlled by the MSD it's electronic since it knows manifold pressure.
This is why they have you set the distributor up with 20 degrees advance. I think the Maximum is 42 degrees
which is unfortunate, because a big block can take up to 55 degrees depending on the engine configuration.
Try 15 or even 20 degrees of vacuum advance.
Again the timing recommendations are just for starting, performance and fuel economy.
Have fun.

 

[Don Frelier]

Sorry correction, you set the distributor timing to 15 degrees BTDC after you lock it out, not 20.
But you can actually cheat here and get more advance out the system.
You just have to keep track of how far you advance beyond 15 degrees and adjust your settings accordingly.
Rotor phasing can be an issue potentially.

 

[watermelon]

Now that I have reliable fuel level readings I can really go places with some confidence.

I'll adjust a couple of settings in small increments and let the system learn after some cruising. Will see how it goes.

The system has been great so far as I have not needed to touch it. I just knew there was more that could be brought out of it.


What does predetonation sound like? Or, will I know it when I hear it? I have exhaust cut right at mufflers just in front of rear axle so its a loud thing.


thanks again,

watermelon

 

[Don Frelier]

Usually predetonation occurs under partial throttle with a load like going up a grade at 30 - 40 mph.
If you have no exhaust you may not hear it, but you may feel it.
But the good thing about EFI is it is constantly controlling mixture.
If you have your AFR set to out of the box (13.5) for cruise with the stock cam selection it will likely not "ping" at all.
It sounds like someone panging on a steam pipe with a small hammer real fast, and it's a bad thing for an engine.

 

[watermelon]

thanks again

i took a 50 mile cruise saturday with settings as posted above. wanted to get a feel for how things stand now observe some parameters.

will hopefully get it out next week and play with the settings

watermelon