LS1 Conversion, A Retrospective Build Thread Options

[andys]

Here's the start of a retrospective build thread of my LS1 conversion. It took a few years to get it done mostly due to not wanting to be a slave to the project, and work on it for the enjoyment; and of course when family obligations allowed......teen daughter and high maintenance wife (IMG:style_emoticons/default/biggrin.gif)

What I started with was a local orignal owner '75 2.0 with 139K miles. The original owner "drove the heck out of it" until something died in the electrical system and he parked it in the garage for 14 years, as evidenced by the renewal tags. Only body damage was when he submarined the rear of a Mustang and creased the hood and flattened the left signal light pod. Otherwise, it was a good condition rust free (SoCal) car.

Brief specs are: '01 LS1 Z28 motor, Audi 01E 6 speed tranaxle, 911 front suspension, custom made rear trailing arms, Koni shocks, 993 wheels, and AC.

Below, are photos of what I started with, and what I ended-up with. I'll do my best to re-trace the build process, so if you have any questions along the way, please ask.

BTW, how does one place text between photos in the same post?

Andys

[andys]

Determining where the engine/transaxle assembly would best be located was driven by a couple of things. The motor has to fit in the hole (engine bay), and the transaxle drive flanges need to line up both front to back, and height wise to the wheel hubs at ride height. I was fortunate in that the 01E transaxle is shorter by 1" from the drive flange axis to the bellhousing than the 901. After adding in the adapter plate thickness stackup, I basically ended up with the drive flange axis very close to the original front to back location, and about 3/4" lower (the axles are angled slightly upward to meet the wheel hubs). I couldn't get the motor/transaxle any higher in the chassis, as the bellhousing would run into the trunk floor at a point where I prefered not to cut it due to structural concerns. The amount of axle angularity was acceptable to me.

With that info at hand, I set about designing the mounting scheme. What I decided on, was a cradle arrangement that would allow me to R&R the engine transaxle as a unit. You'll notice in the photo where the engine/transaxle is on the jack, that I fabricated a temporary engine mount bar so that I could experiment with the exact location. First, I had to fab a set of motor mount pedestals, since those neat aluminum Vette motor ones interfered with the AC compressor, as mentioned earlier. I decided on using the stock Vette hydro-elastic mounts. Being close to the header flanges, I decided to make some heat shields to guard against damage. I found some stainless cannisters at WalMart, cut them down, drilled holes, and welded in some re-inforcement; turned out kinda blingy. For the rear transaxle mounts, I fabbed up some trans mounts, and I used some Chevy Caprice transmission mounts.

Where the rear cradle bolts to the 914 chassis, I did a little re-inforcement around the chassis mounts just in case....they looked a bit whimpy to me. So the whole cradle stays bolted to the motor/transaxle assembly and mounts to the 914 chassis in the stock locations (6 bolts).