lz9 3900 V6 buildup

[Honest Don]

Must be close if the battery is making an appearance.

[The Dark Side of Will]

Indeed, it looks like it.

Distributor is still missing, though, and he needs to take the tape of the LIM.

[pmbrunelle]

Distributor is still missing

With the throttle body over on the left side, and the post-DIS coil pack assembly on the rear valve cover, I don't think we will be seeing a distributor! Looks like plans have changed.

Shaun, what kind of computer is going to run this engine?

[Shaun41178(2)]

Yep I decided to use a microsquirt ecm. Stock computer can be used but after careful consideration I felt I needed better control of my a/f and timing tables.

I am putting a vid together on its installation.

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[Honest Don]

Nice! Micros are a bargain for the functionality. And think of all the shop space you’ll gain by ditching the punchcards and paper tape!

[pmbrunelle]

Good choice!

Will you be firing injectors and coils once/revolution based on only the crank sensor, or are you also feeding a cam sensor into the MS?

[Shaun41178(2)]

I am just doing the crank sensor. Its essentially obd1 but with self tuning features, and more fuel and timing tables for better accuracy and adjustability at more rpms as well as the ability to run up to a 3 bar map sensor for boost if desired.

Crank sensor
Tps
Iac
Cts
Map

Thats all the sensors it uses.

[pmbrunelle]

Contrary to the GM batch fire which fires the injectors once per crank revolution, in batch-fire MS you can fire the injectors every other crank revolution.

So you can keep up the injector pulse widths this way... surely a concern for a "high power" project like this one.

I'd suggest 2 squirts/alternating.

[The Dark Side of Will]

It has the capability to do sequential, right? If so, it should just be a matter of wiring up the cam sensor that your engine already has. That sounds like an easy way to eliminate the vagueries of batch fire injection.

[FieroWanaBe1]

I'm interested to see how you handle the idle circuit.

[The Dark Side of Will]

I'm interested to see how you handle the idle circuit.

You mean since the LZ9 was only ever offered with throttle-by-wire? Pic with the UIM shows an adapter plate and throttle body from something else installed

[Honest Don]

I'm interested to see how you handle the idle circuit.

You mean since the LZ9 was only ever offered with throttle-by-wire? Pic with the UIM shows an adapter plate and throttle body from something else installed

The microsquirt doesn’t control a stepper valve out of the box. He’ll need a controller, swap to a PWM-style valve, or use one of a few other tricks. Or just deal with it; short of a/c idle up, it’s not a thing to keep your foot on the gas for the first warmup of the day.

[The Dark Side of Will]

Ahh, ok. Not even the weird ISM from a 4.9 or '93-'95 Northstar would satisfy that need... Not sure the last time GM used a throttle without an IAC boss.
Not sure if there's an adapter fitting out there for a Bosch style idle air valve or what.

[Honest Don]

Ahh, ok. Not even the weird ISM from a 4.9 or '93-'95 Northstar would satisfy that need... Not sure the last time GM used a throttle without an IAC boss.
Not sure if there's an adapter fitting out there for a Bosch style idle air valve or what.

It’s just a fancy vacuum leak. Slopeasy way is unscrew the stepper to closed position, then run the solenoid off a nipple somewhere

[pmbrunelle]

It could be possible to adjust the idle screw such that the engine will run following a cold start. Naturally, this will cause a high idle when the engine is warm.

There is a main spark_advance(RPM, MAP) table that determines the ignition advance in most situations, but the MS2/Extra firmware has "Idle Advance" settings which can be used to specify ignition timing for idle conditions (generally, TPS == 0).

"Idle Advance" in MS2/Extra can use coolant_temp > x as an entry condition.

So perhaps the main spark table could have a value of around 25° BTDC for idle (close to MBT), and then when the engine is warmed up, the idle advance settings could take effect, perhaps setting the timing to 5°. This should slow down the idle speed a fair amount.

The above was brainstorming to suggest a simple method to help manage idle without hardware modifications.

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I do love the crude idle air control of my 2007 Ford Ranger... it's an on/off device that keeps a high cold idle, then all of a sudden it drops down. How cool is that, especially considering the recent vintage of the vehicle.

Goes to show that you don't necessarily need sophisticated idle control schemes.

[Shaun41178(2)]

I'm interested to see how you handle the idle circuit.

This is an option if I cant get it to idle. Its an add on to the MS to allow the 4 wire stepper to work.

https://www.efisource.com/wp/shop/micro ... r-adapter/

As far as I know all lzs had drive by wire. This tb bolts on with an adapter and is from a GM truck. Earlys 2000s perhaps? I dont remember. Its 75mm however. Factory tb is around 62 or 65 if I am not mistaken. Upper plenum opening from the factory is 75mm.

GM purposely shrunk the tb to lower the hp rating.

[Shaun41178(2)]

Fuel system is setup. I still need to check for leaks but its roughed in.

Gotta wire the tach into the computer
Make throttle bracket
Hook up wideband
Run exhaust, already fabbed
Add oil
Bolt down upper intake
Add Fuel.

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[pmbrunelle]

How do you feel about aluminium fittings for fuel and oil lines?

I have a 90° -4 AN aluminium (Russell brand) hose end feeding oil into my turbo, and my dad looked at it and thought it was cheap... potentially a time bomb, whereby with enough fatigue (from engine vibration) the fitting could break and spray hot oil everywhere, leading to an engine fire.

My dad's comments are giving me second thoughts; I'm considering redoing that line to use steel or stainless steel hose ends this winter.

The turbo oil feed fitting may run at a higher temperature than other fittings, since it heated up via contact with the hot centre section of the turbo. This could degrade the material properties.

[Shaun41178(2)]

Been running aluminum for fuel for years. No issues I have found. They are aluminum and anodized. They should be ok.

My oil line fittings have been steel except for the aluminum anodized right at the turbo feed fitting at the oil filter. Looks fine too.

Remember the oil filter remote castings even from GM are made of aluminum. Oil temps dont get over 300 or 350F if you are having a really bad day. Nowhere near close enough to degrade the aluminum or the anodizing.

Imo you are fine. Periodic examination and inspection is always recommended.

[pmbrunelle]

I actually saw the black anodizing on my turbo oil feed fitting change to a dark golden bronze color.

My understanding is that the colour of an anodized surface can be done by impregnating the surface with dye. Supposing that the dye is some organic substance, I suppose that the dye could have slightly burnt, but the actual aluminium part underneath would be OK.

Anyway, thanks for your 2 cents.