3500 in a P'up

[Canyonero]

Well, I'll be picking up an LX9 for my Trooper tomorrow. This should be interesting.

[lilredtruck]

Basic question: What is the purpose of the water piping between the thermostat housing and the water pump on the LX9. Is it necessary?

[Joseph Upson]

I vaguely remember what it looks like but if it's anything like the 3900 in its purpose it's required to circulate hot coolant over the thermostat so that it limits how hot the engine gets before it opens. Without a recirculation of hot coolant from the outlet at the end of the heads back down to the water pump housing where the thermostat is located the 3900 would overheat and self destruct.

[lilredtruck]

Next question. I just purchased a crank pulley from a '94 Cavalier, expecting to see some kind of timing ring on the inside of the pulley something like what WOT sells, to trigger the crank sensor which mounts on the front cover. Nothing visible. Is it magnetic? I didn't get any response from a nail held close to the pulley as I moved around the inside face.

[lilredtruck]

Hi, Dave,
Didn't know of a shortcut to reach you so I am trying this.
I'm back on getting the LX9 ready for the swap. I have the drawing from V6Z24 of the connections to the ecm. On the ICM there are three ports, a 2 pin, 3 pin, and 7 pin. I found the 7 pin male with 5 wires, 4 are named on the drawing. But that leaves the other two ports not connected. Judging from cable connector for the CPS, there should be a cable directly from the ICM to the CPS. Is this true? The '94 Cav harness has the cable for the CPS bundled with the Fuel Injector harness, so how does that get to the ICM? Since you are an electrical Engineer, I figure you have already made schematics for the LX9 to the Cav harness. If so, are they for sale?
Thanks,
Brian

[Canyonero]

Do you have this engine physically installed yet?

I bought an LX9 years ago to put in my Trooper, but never did anything with it. I really should someday... Wondering what you did for motor mounts, manifolds and whatnot. Your P'up should have a similar layout to the Trooper.

I have a bunch of wiring diagrams somewhere. Are you going to be using the 1227727 (or 7730) ECU?

[lilredtruck]

No, I'm not ready to begin the swap, just getting everything ready to minimize the down time. I will be using the ECU from a 94 Cav - don't have it yet. Re: Exhaust;
I will get the header flanges from Ben or British Car, put on my cast iron manifolds that are on the present V6 - (GMPP '94 Camaro). The bolt pattern horizontally is the same; the LX9 is about 1/8" (total) taller/wider. A round file will fix that! I also have opted to keep as much of the LX9 appearance features as I can. So the A/C compressor is on the left side of the engine beneath the exhaust manifold. The Power Steering pump is on the right side with a remote tank. On the P'up I did not have enough room to mount the compressor (R4) or pump on the right so I made brackets for them. Using a Zexel compressor, much smaller. There are available bosses on both sides to mount either adapter plates or custom motor mounts. I have CAD drawings for both the A/C and PS pump, if you like. Also I can send you some pix via email if you like.

[Canyonero]

What are you going to do about the oil pan? Is your Pup 2wd?

I have a set of header flanges if you aren't able to find any.

[Canyonero]

I bought a set of S-10 headers thinking I could re-flange them to fit the LX9. I suppose it's possible, but the primary tube size is smaller, not sure how much I can flare them.

[lilredtruck]

The oil pan is a 'problem' since I have 4WD. When I pull the 3.4 out an take the pan off, I'll see what it takes to put the 3.4 pan on the LX9. That said, I can also raise the engine up an inch or so. Your Trooper uses the GM 3.4 V6? Then the resolution of the exhaust will be the same for you is as mine. I'm not building this for racing, just a daily driver, never run over 3K. I thought you would have Isuzu's 90 deg 3.2L V6, like I have in my '99, currently at 285 K.

[caffeine]

Using a 3.4 pan is a bad idea because the main bearing caps bolt through the stock oil pan.

[Canyonero]

Its kind of a big problem, the bottom end of the gen3 and gen4 is a lot different with cross bolted mains which use the oil pan structurally.

My 3.4 is from a 94 Camaro, its a gen1, so it was nearly a direct bolt-in replacement for the 2.8. No problems with exhaust or anything.

Sent from my XT1058 using Tapatalk

[Guest]

The genI/II oil pan will not bolt to the genIII block. the flange pattern is almost completely different. It's easier to modify the genIII oil pan, than it is to adapt the earlier pans to the block.

[Canyonero]

It's easier to modify the genIII oil pan, than it is to adapt the earlier pans to the block.

Is your Pup lifted? If you diff-drop the IFS, you'll have more clearance. I don't think you can chop enough off of the LX9 pan to clear. Somewhere around here I have pic of all the pans. Last thing I tried to do with my LX9 pan was imitate the RWD Camaro pan to use in my Opel Kadett, still needs a little work. But I ended up getting a Gen-II donor car so I'm just going to us the Camaro steel pan.

[lilredtruck]

Thanks, all. Very helpful. I will take some careful measurements and if need be, since I have to make engine mounts anyway, I can raise the engine a bit.
I am looking for the ECM for my '94 Cavalier harness. What is the number I should be looking for?