Willys Flathead Idle Timing

[wkuran]

Engine: Willys Super Hurrican L6-226 (modified - engine data here: https://www.willysutilitywagon.com/engine-data/)

The engine runs rich rich when idling (800 - 825 rpm, 13 - 15 inHG) The engine is supercharged but at idle the blow-off valve is open.
Fuel and timing are managed with a Holley Dominator ECU. At idle, I am looking at only 6 - 8 cells in the fuel, timing, and A/F Ratio tables.
In those cels, the A/F Ratio is 14.5, fuel is about 7 lbs/hour, and the timing is (was) 15°) EGTs are close to 1000°F.
Coolant temperature is 180 degrees.
A high-flow aluminum cylinder head is installed.

The high (higher than what I think they should be at idle) EGTs got me thinkng that there wasn't enough timing so I added some. So far I have added 9° for a total of 24 degrees. Idle rpm is unchanged but the EGTs are now in the 600 too 800 degree range. Coolant temperarure is still 180 degrees. There is no audible pinging to sugest detonation. The engine (looking at the exhaust) is running less rich.

Does this mean the engine "likes" the added timing?
Should I continue to add timing to see how much it can take before detonation?

Thanks . . .

[In-Tech]

Hiya's,
7 lbs/hour is wayyyyyy too much fuel for that engine at idle, probably at least 2x. Forget the wideband for now and use the MAP sensor reading as a vacuum gauge of sorts, keep pulling fuel in those cells 'till it gets happy.

[wkuran]

Hiya's,
7 lbs/hour is wayyyyyy too much fuel for that engine at idle, probably at least 2x. Forget the wideband for now and use the MAP sensor reading as a vacuum gauge of sorts, keep pulling fuel in those cells 'till it gets happy.

I will cut the fuel by one-half. Should I change the timing back to 15 degrees?

To ignore the wideband, I can disable closed loop learn or set the rpm (say 1200) at which closed loop learn is enabled - right?

What does get happy mean? Am I looking for a change in MAP?

Thanks . . .

[In-Tech]

I bet you end up in the 2's or high 1's at idle. You can leave the timing up, headers run cooler. Get happy means you are pulling more vacuum, MAP KPA number will lower numerically as vacuum increases. Setting the closed loop learn to 0 or 5% will show you trends as to whether it is lying or not.

[PackardV8]

You can leave the timing up, headers run cooler.

Yes, set the idle initial advance to the happy spot. However, that requires modifying the distributor centrifugal to limit the total. Flatheads do not like much total advance.

[wkuran]

At 4.0 lb/hr the engine quit. It is back at 5.5 lb/hr because that keeps the A/F between 16 and 18 (no sounds of detonation). MAP moved around from 57 to 52 KPa. EGTs are around 700 degress. Less smoke at the tailpipe but still smells rich.
Should I be concerned about the lean A/F readings?
Maybe with less fuel the timing needs to be different?
Did you look at the cam information? https://www.willysutilitywagon.com/valvetrain-data/

Thanks . . .

[PackardV8]

At 4.0 lb/hr the engine quit. It is back at 5.5 lb/hr because that keeps the A/F between 16 and 18 (no sounds of detonation). MAP moved around from 57 to 52 KPa. EGTs are around 700 degress. Less smoke at the tailpipe but still smells rich.
Should I be concerned about the lean A/F readings?
Maybe with less fuel the timing needs to be different?
Did you look at the cam information? https://www.willysutilitywagon.com/valvetrain-data/

Thanks . . .

First, congrats. In my wildest imagination, twin centrifugal superchargers on a Willys flathead would have been beyond my dreams. You've taken it to new heights of possibility. Love the challenges it presents and I'm going to ask some questions and speculate; don't take it as doubting your ideas, just thinking along with you.

But then, there's trying to make it work at idle. JMHO, but that relatively small flathead is never going to behave well at idle with that much cam timing.

Back to your timing "for a total of 24 degrees." That's more than what a twin supercharged flathead is probably going to tolerate at full boost. Have you considered a pressure retard system? And/or water injection?

You didn't ask, but that seems a ton of spring pressure for a low RPM light weight flathead valve. Did the cam grinder recommend that much?

[Tuner]

The post above is spot on in every aspect. I don't know about the Hurricane engine, but Hudson Hornet and some early Flathead Ford engines and a '51 Packard straight eight I recently repaired a distributor for only use about 17 degrees total. Some flatheads use near 25, but any flathead with the quench "Ricardo" style combustion chamber use much less WOT advance than 2V wedge chamber OHV engines, until the late 'fast burn' head advancements.

I think water injection would be a good idea no matter what else, timing or ? an intercooler to reduce inlet charge temperature would be good.

[wkuran]

First, congrats. In my wildest imagination, twin centrifugal superchargers on a Willys flathead would have been beyond my dreams. You've taken it to new heights of possibility. Love the challenges it presents and I'm going to ask some questions and speculate; don't take it as doubting your ideas, just thinking along with you.

Thanks and thanks for the questions.

But then, there's trying to make it work at idle. JMHO, but that relatively small flathead is never going to behave well at idle with that much cam timing.

The engine is designed to "be happy" between 3,000 and 5200 RPM. At 2800 to 3000 rpm the rate of accelleration increases - it feels like a different engine. It has always run rich at idle. I'm hoping to improve idle performance but maybe it is not possible. I'm thinking that someone with tuning experience can at least make it run better that than me. One of my favorite videos: https://youtu.be/RtkRVhDYCRk?si=uGZlQaArI4CNqlhp

Back to your timing "for a total of 24 degrees." That's more than what a twin supercharged flathead is probably going to tolerate at full boost. Have you considered a pressure retard system? And/or water injection?

The fuel, timing, and A/F table are used to add fuel, pull out timing and reduce the A/F ratio as boost and RPM increase. Twelve pounds of boost is probably possible but I have not seen more than nine. There is a water-methanol system but, other than testing, it has not been incorporated into the tune. A W-M injector is installed in each of the tubes connected to the blowers. https://www.willysutilitywagon.com/wp-c ... 8x1153.jpg

You didn't ask, but that seems a ton of spring pressure for a low RPM light weight flathead valve. Did the cam grinder recommend that much?

That's a good questions. No reccomendation from the cam grinder so here is what I did to come up with spring force: https://drive.google.com/file/d/1G5WDX1 ... wF_tz/view
The challenge was to find a spring with the correct spring constant that also fit.
[/quote]

[wkuran]

The post above is spot on in every aspect. I don't know about the Hurricane engine, but Hudson Hornet and some early Flathead Ford engines and a '51 Packard straight eight I recently repaired a distributor for only use about 17 degrees total. Some flatheads use near 25, but any flathead with the quench "Ricardo" style combustion chamber use much less WOT advance than 2V wedge chamber OHV engines, until the late 'fast burn' head advancements.

I think water injection would be a good idea no matter what else, timing or ? an intercooler to reduce inlet charge temperature would be good.

This engine/head combination has a 0.030" quench height. I agree, W-M is good.

[In-Tech]

Hiya's

Engine Control Module: Holley Dominator (Holley Part No: 554-114)

Distributor: Autolite PN: IAT 4206 1K modified to accept hall effect camshaft and crankshaft position sensors
Isn't this locked out so ECU controls timing once base and rotor phasing is correct? If not, why not? Then you can adjust timing anywhere on the fly via laptop software.
It must be, just noticed you have individual coils.

Fuel Injector: 8x36 lb/hr (Accel PN150136)
.5 BSFC = theoretical max 576hp
.6 BSFC = theoretical max 480hp
.7 BSFC = theoretical max 411hp

Does this have an IAC(Idle air control) valve?

[wkuran]

Hiya's

Isn't this locked out so ECU controls timing once base and rotor phasing is correct? If not, why not? Then you can adjust timing anywhere on the fly via laptop software.
It must be, just noticed you have individual coils.

Yes, once the rotor phasing is set the ECU controls timing. Timing and fuel can be adjested on the fly. The system ICF also allows individual cylinder timing (individual coils) and fuel (multi-port injection) corrections.

Does this have an IAC(Idle air control) valve?

Yes, Accel PN 74779.

[In-Tech]

All cool(BTW, I am very familiar with the Holley stuff as well as many aftermarket and OEM ecu's)

Ok, another little tip to aid in idle control tuning after adjusting tables to get highest map reading. Watch the IAC counts, as you get even closer on the tune in these areas(timing and fuel), the IAC counts will lower. Again, don't pay too much attention to the wideband as high overlap stuff can throw raw oxygen and tell you it is leaner than it actually is.
Good luck.

[wkuran]

I am very familiar with the Holley stuff as well as many aftermarket and OEM ecu's)

So . . . I put everything back the way it was. It starts well, runs down the road good, but still idles very rich. Pretty obvious that I kon't know what I'm doing.

Is there anyone on this forum that does remote tuning or, better yet, lives in the Washinging DC Metro Area that has experience with flatheads and the Holley Dominator ECU?

[PackardV8]

On a recent Engine Masters episode, Steve Brule gave up trying to tune a particular intake/carb/cam combination. He basically said, "I've spent hours just to make it less bad, but it will never be good."

Is it possible your combination of cam overlap and the intake plenum design just don't want to work together at idle?