DIY Engine Swap & Rebuild Progress

[rhodesman]

I cannot believe it's been since August that I last posted!! Man, time does move fast, sorry about that.

I have so many updates!

For starters, the car is back together! First start just so happened to fall on Easter morning, truly a resurrection LOL. But lets not get ahead of ourselves. To rebuild the engine, I first needed to clean everything, that was critical for the best seating of the valves and making sure the engine had the best chance for success. Step one was cleaning and then boring the block. Nothing crazy, just a simple 20 second boring making sure to keep my motions consistent and always moving. Once clean, I could start assembly!

Installing the crankshaft, which I have to admit was more stressful than I expected. BMW (as well as many other manufacturers) prints the clearance 'range' on the crankshaft and block. The crank was all 'r' while the crank case was a mix of 'A' and 'B'. I spent maybe a whole month going back and forth on this because I wanted to use upgraded ACR bearings but they basically only come in packs that are one size. I did a LOT of reading, measuring, asking various experts and came to the conclusion that the performance bearings actually are intended to give a little more play which allows for more oil to flow into the area. So I did just that, ACR performance bearings are in and I sent it.

Now for the head rebuild. This was a process, and took a hell of a lot of time to do. Was also quite nerve-racking as I was terrified I was going to shoot a lifter spring into my forehead, thankfully that didn't happen. I did seat the valves twice just because I wanted to make sure I had good seats in there and I braved the cold weather of winter to wash the seat compound off the head via the outside faucet, then I baked it in the oven to dry it out. My kids were very confused. Since I had two heads (the cracked one from the blown engine and the new one) I went through and took the best looking components from both to install into the one good head.

I used a 3D scan tool to scan the head and then 3D printed a "filler" that I used to hold the valves in place while I installed the springs. Most time consuming part.

Next was the pistons and rods. This was fun to do, I enjoyed the process and it was great to see them sitting in the block....even though I dropped one. But I'll give Manley props here, I called their support line, told them what I did and they overnighted me a new piston, for free! Now that is what I call customer support!!!

To Be Continued....

 

[rhodesman]

Here's the damaged piston:

And here's the replacement:

Fully Installed:

Getting the engine dialed in was not hard, but really scary. I didn't have the tool BMW suggests to hold the fly wheel in place (I had the pin to align it to TDC, just nothing to hold it so I could torque it down. Nothing some scrap metal and a wheel grinder can't fix:

I bought the cam alignment tool off Amazon and it worked great...funny enough, I now have the tools to rebuild any inline 6 engine that was offered in the E-chassis, maybe I should start a engine rebuilding shop....

More to come

 

[wheela]

Great update!! Wow, cylinder heads in the oven and on the dining table, you have a cool family!!

 

[rhodesman]

Great update!! Wow, cylinder heads in the oven and on the dining table, you have a cool family!!

haha! That's because I'm divorced and my kids have no say over what I put where. LOL

 

[rhodesman]

Installing and torquing the torsion damper and chain gears was a fascinating journey through the battle of engineering with physics. I truly am stumped at how BMW thought the best way to hold the gears which drive the chains to rotate the cams in time with the crank shaft was pure friction. No key or pattern that would help keep them from slipping. Just 100nm plus 360* is all that keeps the engine from eating itself. Needless to say, even my 3 ft torque wrench was no match and I just had to rely on a 4ft breaker bar plus a floor jack handle and a paint pen. I got it to about 5* of a full 360 and no matter what I did I could not get it to turn the extra few degrees. We'll see if that stays that way...

Once I got that torqued down, it was time to seal the block. I did not realize the block sealant had such a short shelf life! I bought it in December and I did this the last week of February. The sealant said it was good to February, so hopefully that's true. I will say, the little syringe it came with was useless. According to BMW, you stick the syringe into the little ballbearing and it's suppose to send the fluid through the narrow channel around the block but instead it just kept coming back out through the hole. I ended up taking off the syringe, sanding the plastic tip of the applicator and holding it on with force creating a sort of 'seal' forcing the liquid to travel down through the block. This was the qworst part of this entire process and do not EVER want to do it again. My hands hurt for days.

Just a cool garage upgrade I did, I ended up installing a raspberry pi with monitor in my garage which made looking up the instructions so much easier. I had printed out all the internal engine rebuild instructions into a 3-ring binder which was great as I had organized it by the chronological steps I needed to take but after that, most of what I needed the instructions for was to remember things like the proper fan belt routing or random torque settings and having quick easy access to it via a mounted screen in my garage was a plus. I have a whole server I run in my house that has all the BMW manuals, coding software, settings, backups, etc. on it so having a terminal I can quickly access it was a huge help.

I have a metal heat shield from one of the original aftermarket N54 turbo companies. I cannot remember who made it but I ended up making a few adjustments as the turbo outlet on the front turbo was super close to the manifold and I noticed the silicone hose had actually melted a small hole that I didn't know about until I was breaking the motor down. I ended up cutting the corner off and then using some sheetmetal and welded up an extension of the shield to cover it.

Next up was installing the new clutch. I really wish I could show it off installed because it's really a beautiful kit. Funny thing I learned, I now have to start moving my car similar to a Carrara GT, the twin disc is so aggressive that if I try to give it gas while engaging the clutch, the car will buck and go crazy. I hope that wears in over time but now my neighbors probably think I don't know how to drive a manual LOL.

The pilot bearing was a total PITA to replace. I probably didn't need to do it, but it was more piece of mind for me since this was a used transmission. I had to employ the help of my neighbor who is an actual mechanic and has a full garage with 2-post lift (I'm jealous). The plus side is if there's a tool I don't have, he'll have it.

 

[rhodesman]

Finally! Install time! I got the transmission married to the engine and the engine and trans installed in the car. Nothing really difficult with this part, pretty straight forward.

Since I had the whole engine and transmission out, I decided to instead of modify the automatic transmission wiring harness, I replaced the whole thing with the manual transmission wiring harness. I really want to make this conversion as OEM as possible and I have a strict rule to never splice a wiring harness so this was a must. I will say though, there were some gotcha's I missed at first. for one, removing the entire wiring harness does fully sever the CAN system. it's an easy fix as you just need to connect the CAN lines inside the DME box, took me 2 minutes once I realized my mistake. You just need to bridge the twisted pair red and blue-red wires to re-link the network connection.

Wiring up the clutch switch was a process. it's really not that hard but it took me a while to wrap my brain around how it all needed to connect and program it all correctly. The biggest help was this part of the wiring diagram:

To sum up how I wired up the clutch switch, I ran a wire from the DME pin-18 (blu/brn) to the footwell to connect the clutch switch pin-2. I made an adaptor harness for the footwell that connects CAS Pin-3 to Clutch Pin-3 and CAS Pin-41 to Clutch Pin-4. Clutch Pin-1 is grounded to the brake and clutch cassis.

I will say, being in my 40's now, if there is one 'hack' that is a necessity, if I'm going to be under the dash for any time longer than 1 minute, I''ll pull the seat out. My back could not thank me enough.

But in the end, nothing beats seeing this in the center console:

More to come!