Finally finishing my project - LZ9 to RWD

[63a16p]

10 years ago, I brought an Opel Kadett back from Europe with intent to swap out the drivetrain for a little more go. Over the next few years, I swapped in a 3100 V6 (converted to RWD) and T5 transmission. The stock 3100 is from a 99 Grand Am with a OBD1 7727 computer from a 92 (or so) Lumina. My plan was to use this engine to get it put together but planning to build and swap in a better performing engine at a later time. I've been driving the car off and on over the last 10 years and am now ready to swap in a different engine. I'm looking at a wrecked but running 07 Impala with an LZ9 3900. The 3100 I have now has been converted to rwd by rotating the upper & lower intake 180 degrees, swapping the timing cover to the rwd setup and custom headers. The oil pan has also been sectioned for crossmember clearance. I don't need too much from the engine so will sacrifice some performance to keep it simple. I'll be searching and posting in the engine swap forums to get ideas and figure out how to actually make it work.

[SappySE107]

You will probably have to modify the engine mounts, and deal with the crank trigger or use a different computer. I swapped to a 3400 crank and custom pistons/forged rods for my future OBD1 engine swap, but I wanted simplicity and another comparison for the rod lengths in similar builds. Dan swapped an LZ4 into a FWD race car, so I know how that can be done but I don't think you need to deal with some of the things a FWD swap not using the VVT cover would. Not having coolant running through the intake might make a custom lower intake easier in the future as well. Post some pics of the car if you can. I looked some up on google, reminds me of a few different cars but not the Opel GT like I thought of when I was you had and Opel

[63a16p]

I wasn't sure about the engine mount differences between the 3100 and later blocks but my engine mounts are fabricated based on the various mounting holes cast in the block so making new mounts to fit the 3900 block isn't a problem. I've done some reading on the crank trigger and VVT issues and was thinking I could mount an external crank trigger to solve that issue and for the VVT, I was planning to lock the cam (not sure how/what degree is optimal) and remove the VVT mechanism to allow the swap the RWD timing cover. If possible, I'd like to use a 3400 or maybe 3500 (for better flow) lower and upper intake on the 3900 if that doesn't require extensive mods to do so. I like how the 3100 fits in the car so would like to keep external dimensions (timing cover/upper/lower intake) as close to the current 3100 as possible. Do you know if the 3100 and 3900 oilpans are the same?

[SappySE107]

That's a pretty nice size engine bay The oil pan is different, and holds less oil as well. I had spacers made to use the older style cam, but I also wanted a bigger cam. You can't use the older manifolds on the heads either. Its also going to need an adapter for a cable driven throttle body. The coolant will have to be routed from head to head above the timing cover. Im not sure if the stock crossover works with the RWD cover, or if you would have room to run coolant between the heads and the firewall/trans side.

The equinox cams are discontinued, but they would have been the drop in replacement for a non VVT setup. No need to lock anything if you can go that route.

[63a16p]

The oilpan has been sectioned to clear the front crossmember. I did lose some capacity but regained some via a remote large oil filter. I had n't thought much about the revised 3900 coolant issue - that could be a hassle. For the throttle body, I have access to a mill so building an adapter for a cable TB is no problem. The lure of 400 more CCs make the 3900 tempting but the LX9 3500 might be much simpler. From my understanding, the LX9 would just require an external crank trigger and cable TB to operate with the OBD1/7727 setup I have now. The LX9 would also open up options for a better cam. How aggressive can I go with a cam and still use the stock LX9 heads?

[SappySE107]

Depends on the valve springs and seat/seals but otherwise you can run any cam I have listed without machining the heads.

[63a16p]

Thanks - I'd probably be looking at the street/strip cam so would like to know what springs/pushrods are required to run that cam with LX9 heads. I've also looked at options for changing the LX9 to a 7x reluctor. The external route looks easier but since I plan to have the engine apart, swapping the internal reluctor to a 7X seems like the better way to go. Do you know if anyone is still making the 7X reluctor rings?

I have a Moates Autoprom that I bought years ago but never got around to using. Do you know of any Autoprom gurus who could offer some assist on getting started with the Autoprom when I swap to the LX9?

[SappySE107]

The stage 2 springs I have listed work with every cam I have had made. Only boost would maybe need something else. I don't know that anyone is making the internal or external triggers currently. I have a ring made, and the sensor holder, but not the hub/pin to weld up the timing ring to bolt to crank pulley. I have a 3500 swap chip for OBD1, using 28# injectors. It would be a good start. I don't know about autoprom specifically but I think I used it with BMWs a decade ago. I didn't have much luck with the GM computer.