Hi Everyone- I have had this project going for quite a while now and wanted to try to get the details posted up here. A few years ago, I bought a 95 E320 wagon that was in fairly decent shape. I drove the car for a bit and realized that the head gasket was on its way out. My parts supplier and friend suggested that it would almost be a plug and play if I could get my hands on a 95-96 C36 AMG drivetrain. Lucky for me, I found a decent C36 engine locally. Rather than replacing the headgasket on the leaky 3.2 why not swap in the 3.6???
The C36 wiring harness was not used in our swap as it was cut and unusable. We reused the w124 3.2 wiring harness and swapped over the front pulleys and belt driven airpump from the old 3.2 onto the 3.6. The 3.6 engine came with a electric air pump. If you had a good C36 wiring harness everything would be a direct fit and could also use the C36 ECU- which I did not. The C36 wiring harnesses tend to be more pricey, complicated to find the correct one (three versions made), and difficult to find than the w124 ones. We reused the auto tranny that was already in the wagon. I had a receipt for the tranny being rebuilt fairly recently.
The swap went off fairly easily. I replaced a ton of stock parts while we were in there. Motor mounts, steering components, etc were all done with the engine pulled. I also took the time to POR15 some places that are known to rust on these cars- the battery tray and under the washer and coolant tanks.
The tricky part afterwards was finding someone to chip the 3.2 computer. I ran the stock 3.2 ecu until I found someone who could burn a chip to 3.6 specs. The car ran fine, but was really at stock 3.2 power level. After a long search, Speedtuning USA in MD was able to burn a chip for me. The power difference was significant and I finally got the full power advantage of the swap. I am still currently using the smaller 3.2 crossover pipe even though I have the 3.6 crossover tube. People have debated the power differences between the two, but I don't believe it to be very much. Obviously, having the one stamped 3.6 is infinitely cooler. I am going to be installing 3.6 crossover soon, but need to modify a later style valve cover in order to make it work. The channel inside the later style valve cover needs to be modified via a dremmel. The wiring from the injectors fits inside that channel. The valve cover gasket is currently shot so that will all be done in one shot along with install of a better wiring harness.
The wiring harness in the car is an early replacement harness. I have been chasing a erratic idle for a long time now. The throttle actuator was replaced, injectors cleaned, maf swapped, tune up done, and coolant temp sensor replaced. All of had no effect on the hunting idle. The car runs great other than this one hiccup.
Last year, the suspension was totally rebuilt. 500e sway bars were added front and rear. Early Sportline control arms were done up front. We dropped the rear subframe out in the rear and did those bushings as well. My suspension links were already newish so they stayed. H&R springs were added along with bilstein sports up front. Unfortunately, the drop with the H&R's is a bit up front even with the tallest bump pads. I ran a set of monoblocs with 225/45/17s for a while but got tired of beating up the passenger side inner fender. I have since switched to a set of 16" CLK lightweight wheels with 205/55/16 tires. I have not rubbed since switching and the car drives a 100 times better. The CLKs were something like 12-13lbs a corner lighter than the monoblocs. The drop is still annoyingly uneven. I don't have any options up front unless I swap in different springs. I can lower the rear a bit more with the self leveling control or by switching to smaller rear spring pads. I have a set of 500e springs available to use as well, but am not sure which direction I will end up going in. I really need to buy a mercedes spring compressor as it would make changing springs out far more easy to do.
I bought a bigger downpipe recently and will be installing it up soon. The pieces are all flanged and will make it easy to install. I sprung for a flanged high flow cat and flanged test pipe. Running no cat on the car makes a big power difference. The euro 3.2 engine makes 20 hp more than the US catted version. I found a shop to make me a flanged resonator delete pipe. It will lead into the stock rear muffler which has a 2.5" inlet. I should have this done in the next month and am anxious to feel/hear how it sounds/runs. I also have a second chipped ECU with the highest level of tune that Speedtuning made for the 3.6 engine. I have yet to try it out and am waiting to uncork the exhaust first.
I have left the interior alone aside from a 500e 390mm wheel. My friend donated a rough AMG gen 1 body kit to me. The skirts are fine, but the front and rear bumpers need a lot of fiberglass work. The kit's refurb work is a ways off.
The biggest letdown of the swap has been the old school auto tranny. It is poorly matched to the power band of the AMG engine. The engine really makes all of its power up in rev band and the auto always seems slow to react. In addition, I have a flare between the 2/3 shift that is super annoying. It became evident that the previous owner only had reverse gear fixed and not the entire trans overhauled. There is a K2 spring kit that you can install to help this 2/3 flare, but I have not done it. Last year, I found a untouched 86 300e 5 speed at a local wrecking yard. I was able to crib everything needed to swap things over to a manual. The key parts being the pedal box and shorter drive shaft. I traded my friend the overdrive 5 speed tranny out of the 86 300e for the 16v dogleg getrag close ratio 5 speed. I was able to get in on a group buy for a lightweight single mass flywheel online. It is very light and is great for my swap as I am able to bolt up the stock auto tranny ring gear. This important because the ring gear has the magnets/segments on it so that the car will idle properly and work with the computer. The early cars didn't need the magnets like the later 24v valve cars do. The custom clutch and pressure plate set up should be arriving in the next week.
The plan is to pull the entire drivetrain again. I need to do the wiring harness/valve cover/cross over tube repair. The EGR is a potential cause of the idle issue. It is easy to remove the EGR pipe with the engine out of the car, too. The oil pan gasket needs replacing which again is super easy with the engine out of the car. My friend may be renting some shop space locally so this engine/trans swapping may happen in the next couple months.
Sorry for the rambling and disjointed information. Here are some pics to check out. Cheers- Cory
Subframe out: With monoblocs after suspension redo: Elusive 3.6 crossover tube: These are the CLK wheels on the car before the suspension work: Pics of downpipe: Pics of custom flywheel for swap: