lz9 3900 V6 buildup

[Shaun41178(2)]

Turbo mounting is figured out.

20200516_104527.jpg (503.73 KiB) Viewed 2952 times

20200516_104506.jpg (183.33 KiB) Viewed 2952 times

[The Dark Side of Will]

Olive drab compressor housing... reusing the same turbo from last time?

[Shaun41178(2)]

Yes same turbo. Compressor housing matches the car

[ericjon262]

not really a fan of the trunk blowout, as it removes some street manners from the car. I think it would have been simple enough to split the stock crossover and put the turbo there. that would require some modification of the rear manifold, but I imagine they are cast steel like the LSX manifolds and easy enough to weld without cracking problems, but that's just a guess.

That being said, it's your car, do as you please.

[Shaun41178(2)]

Yea, I thought about it for months before I cut it. Also why I tried to cut so little. I looked for lz9 exh flanges to make my own trunk side manifold but had no luck finding a set. I too would have preferred to keep the turbo in the engine compartment.

Modifying the trunk side manifold with a block off plate to put the turbo on the crossover would work but the flow would be terrible. Big reversion problems. If the goal was only 350 hp no problem with doing that.

[pmbrunelle]

Someone who really wants the top fit/finish could build a doghouse for this, like on a van.

My uncle used to have an Econoline, and it was supposedly one of the easiest vehicles to change the spark plugs on (says my dad).

[ericjon262]

Someone who really wants the top fit/finish could build a doghouse for this, like on a van.

My uncle used to have an Econoline, and it was supposedly one of the easiest vehicles to change the spark plugs on (says my dad).

I think I would try flipping the turbo upside down first, that may bring the assembly below the flange that seperates the trunk halves, and he may be able to put a single flat piece in. That would provide a ton more function than a dog house IMO.

[Shaun41178(2)]

I did a mock up for yhose people that are gonna do a 7730 swap or a standalone engine swap of how the engine looks in the bay.

This is. A truck 75mm tb. Its 4" od. It clears the stock getrag shift cable.

20200526_152144.jpg (137.22 KiB) Viewed 2825 times

20200526_152127.jpg (166.03 KiB) Viewed 2825 times

20200526_152213.jpg (172.44 KiB) Viewed 2825 times

[ericjon262]

FWIW, the LS4 throttle is a direct bolt on to the LZ4 intake manifold. It is a DBW unit though, so it will require a stock ECU or something like the DBWX2 like I am using with my MS3.

[Shaun41178(2)]

I modified my stock fuel rail. Gm had the rail turned 180 from how I am running mine. The input to the rail was on the TB side. I flipped my rail to sit on the pass side like factory. I modded the rail. I cut off the portion that turns up, I used a -6an compression fitting for my input.

050113GM03-074.jpeg (78.68 KiB) Viewed 2798 times

20200528_231829.jpg (680.62 KiB) Viewed 2798 times

[Shaun41178(2)]

Here is how I am running my coolant. Two -12 to a fill tank. There is also a -8 that feeds the heater core.

20200529_000335.jpg (173.44 KiB) Viewed 2796 times

20200529_000348.jpg (592.02 KiB) Viewed 2796 times

[ericjon262]

Here is how I am running my coolant. Two -12 to a fill tank. There is also a -8 that feeds the heater core.

20200529_000335.jpg

20200529_000348.jpg

I'm having flashbacks of the stuff I did to my car! LOL.

on a more serious note, it's looking good. I think I would have made a coolant crossover pipe from one head to the other, then ran a single line to the tank, but that's me.

[Honest Don]

Should do twins now that you’ve opened up all that space.

With all the LS builds going on now, this is refreshing

[Shaun41178(2)]

Twin turbos would be tight, add complexity too but I think its not impossible. More than I wanted to tackle at this time however.

Coolant system is done.

-12 out of each head
-8 to the heater core.

I'll prob tackle the fuel lines next.

20200607_211804.jpg (202.97 KiB) Viewed 2733 times

20200607_211823.jpg (559.74 KiB) Viewed 2733 times

[pmbrunelle]

You still have a tank up front by the radiator, right?

This one you built looks to make for a convenient fill location, but too small to handle the expansion/contraction of the coolant.

[Shaun41178(2)]

Yea I still have the overflow up by the radiator. The rear is similar to the original thermostat fill point. This is the highest point in the system.

Working on the wiring. Nearly have it finished. Then I can loom it. It will almost be nearly hidden when its complete.

20200805_194943.jpg (573.61 KiB) Viewed 2572 times

[The Dark Side of Will]

Yea I still have the overflow up by the radiator. The rear is similar to the original thermostat fill point. This is the highest point in the system.

Looking good!

However, since the hoses from the heads to the tank are lower in the middle than the ends, you'll still need an air bleed on top of the engine in order to burp the cooling system.

[pmbrunelle]

While everyone is laughing at the computer + electronics you're putting on this engine, it does make for a slim wiring harness!

[The Dark Side of Will]

While everyone is laughing at the computer + electronics you're putting on this engine, it does make for a slim wiring harness!

Notice what's missing from the last photo, though...

[Shaun41178(2)]

Wiring is.pretty much done other than some clean up in the cabin.

Wiring routes next to the heads on the drivers side. Only bits visible is the loom to the tos, coilpacks, and map sensor on the back of the intake. Its a mini tuck I guess but its.clean.

20200818_180639.jpg (882.1 KiB) Viewed 2367 times

20200820_193838.jpg (648.61 KiB) Viewed 2367 times