Yet another N52 -> E30 swap thread

[LukeJ]

More header pictures.

[LukeJ]

As mentioned above: Header collectors. What an interesting challenge. I spent way too many hours thinking about how to accomplish bringing three 1.625" dia. tubes to one 2" tube. I wasn't able to find anything online that was the right size or correct number of runners. I explored trying to make a metal cone and then form it in some way, but I would have had to invest a lot of time and materials into tooling and I'm not sure my 20 ton press could handle it anyway. Ultimately, I ended up making a couple smaller tools and using some bits and pieces I had laying around from years of collecting stuff. I machined a 120 degree press tool so I could form the feature where the tubes meet in the middle of the collector. Once I had the end formed, I used my bandsaw and cut the 120 degree feature away at an angle, leaving enough material to be 1/3 of a 2"dia. circumference on the other end. Once I had that going, I concocted a bending fixture on the press which allowed me to bend the tube segment about 10 degrees to give a better shape for the collector. Just flying by the seat of my pants at this point.

So now I had a couple sets of three pieces to start to play with and see how I could join them. The geometry of everything going on here is complicated. Arcs and angles. I made another fixture which allowed me to mount these pieces in the mill vise and cut them at an exact angle. I cut, and re-cut, adjusted, re-cut, making them smaller and smaller. It seemed I couldn't find the right combination of conditions to get everything to come together enough to be tacked for welding. The whole thing stalled out here for a week or so while I tried to figure out a better way. Ultimately, on the suggestion of my 9 year old daughter, I used some stainless rod to fill the gap internally. Sometimes, even a little girl can see a problem from the 'outside' and offer a simple solution. Not sure if this is 'how it's done' in the 'header building world', but it's what I did. The stainless rods gave me some structure and made it much easier to fine tune the shape of the outer pieces.

[spiDmang]

this is phenomenal! subb'd

[LukeJ]

Thank you for the complements. I'm definitely grateful to be able to accomplish a few of these 'bucket list' items. I've been wanting to do a 'project' like this for a long time now.

[Panici]

Great fab work!
I look forward to seeing your progress.

[mjweimer]

This is outstanding work. Much respect for the thought put into the design and the skill shown in the execution of the fabrication. Absolute next level DIY.

Subscribed for future updates.

[LukeJ]

So the first thing I did was mock up using the S54 headers. After cutting the flanges off the runners, I added an inch (25mm) of tubing to achieve the spacing I wanted. I used a piece of plywood to replicate the frame rail to insure clearance going forward. Initially, I was trying to replicate the S54 headers, but the bends I purchased didn't have quite as tight a bend radius After a few days of messing around with it, geometry won, and I went a different route. The header pictured with the number 1 runner turning 90 and going behind the other two was the design I developed. The very first set of runners I welded were never completely finished because I discovered an issue that would have prevented me from doing the final welding. I adjusted the shape of the 1st runner so it could be removed from the fixture to facilitate the welding of the 2nd and 3rd runners to the flange. This 'second' header would be the one I used in developing the collector building process.

[LukeJ]

Okay. As mentioned above, headers. Some of the earlier N52 swaps used 'AA' style headers and from what it seems, they work 'just fine'. I bought a pair of Ebay 'AA' headers as a place to start. The headers I bought were from a company in Germany. The welding was very nice, but they still would have needed 'adjustments' if I were to use them. The ID of the runners seemed a little small too. The main reason I chose not to use them was they were not equal length. There is about a 5 inch difference in length between the first and third cylinders. At least one, recent, N52 swap was able to utilize S54 headers with some modifications. In that particular instance, A/C was removed so compressor clearance was not an issue. In my case, A/C is a must and I needed to figure out a way to have 'M3ish' equal length headers and A/C for Az. So I spent a few weeks developing a 'system' and taught myself how to build a set of headers.

I had some limited stainless steel Tig welding experience from the past. So I decided to take an online motorsports Tig welding course. Mostly to see what I already knew, and hopefully learn something new. It was a couple hundred bucks and I'd say it was money well spent. At the very least, it helped to build some confidence. There were stainless steel specific details that were quite valuable and definitely helped me achieve the quality of the result.

[LukeJ]

And some more pictures.

[LukeJ]

Thank you. Here's a few more pictures of the oil pan.

[lukeADE335i]

You should be proud of the sump - looks amazing Nice work on the swap so far!

[LukeJ]

Hello everyone. I've been slowly but steadily working towards completion of my swap project. It's been a couple years now since I got started. During the spring of 2020, I was able to pick up an engine and 6sp. from a wrecked 33k mile 2007 Z4. Everything I've seen inside the engine seems to confirm it's 'age'. Looking forward to reaching a point where I'll be able to turn it over and hopefully get it started with minimal issues. We'll see...

One of the main goals for my swap was to not make any major modifications to the car, subframe, suspension, etc. In order to do this, I had to make an oil pan and some headers. Once they were done, I was able to build a new exhaust system using cats, a 135i resonator, and an X3 muffler. I've been a machinist for a couple decades now. The welding and fabrication is more of a new skills development thing. I've been around and worked with some great welder/fabricators over the years, but I haven't had much opportunity to get hands on, until now. Fortunately, my FIL had an 80's Miller TIG welder he hadn't used for years so that was a good start in the right direction.

The first thing that needed to be done was to place the engine. I wanted to try to match the final drive pinon angle which I measured at 2.6 degrees using a digital level. The engine needed to be centered, obviously, and have 30 degrees of tilt. There needs to be enough room for the oil pan over the subframe and enough space to close the lid. There was talk in a previous thread of moving the engine towards the firewall 'an inch'. I started in that direction and found that the firewall prevents an inch, so after taking everything else into consideration, I settled on 13mm. I created some adaptors that allow the use of Garagistic 80A poly engine mounts and the original aluminum Z4 engine mount arms that came with my engine. The adaptors bolt to the subframe from the bottom and utilize both the original hole and the slot. It took me a few revisions to get all the geometry 'correct'. So from the original position of the E30 subframe, the adaptors move the unmodified Z4 engine mount arms toward the firewall 13mm. The engine mounts are only part of the solution, I needed a transmission mount too. I have the 'long' 6sp, so I planned to use the rear trans mounting slots on the belly of the car. I took some measurements and ended up machining an aluminum mount. With some aluminum spacers and more poly bushings, I was able to match the pinion angle. So hopefully, no driveshaft issues down the road.

After I got everything bolted in, I realized that my transmission mount would make it tight for the exhaust in that area. So a quick redesign and another part made, gave more clearance for the exhaust to turn the corner in that location.

With the engine and transmission in their final location, the real work on making the oil pan started. I wanted it to hold 6-7 quarts, it needed to have clearance from the rack and pinion, while remaining as 'tucked' as possible. Having the engine placed made it possible to shift things 1/8" here or there to make best use of the space and get the maximum volume while being low profile. I planned to use 1/8" aluminum sheet and make parts that could be laser cut, bent, and then welded into the final assembly. The front of the pan gave the most problems as far as design was concerned. There are various angles that come together, and there also needs to be clearance to get the socket on the bolt in a couple spots. I tried several versions of bent sheet metal, but all had drawbacks. One day, I was in the right mood and I got crazy with designing a machined billet front piece. By doing it this way, I was able to solve the issues and add some functionality and maybe a little 'bling'. To say I'm proud of how it turned out would be an understatement. I did all the welding/machining myself, with the exception of the internal weld around the inside sealing the flange to the pan. I started to have some issues while tacking the pan and flange together so once they were joined, I took them into work and had my boss run a nice bead in there. I know some of the welds don't look the best and the tacks around the flange are just ugly, but it doesn't leak. Maybe the 'next one' will be better?

I'm going to leave it here for now. Next, headers....