My E36 S54 Swap Thread

[JunzieB]

Originally Posted by ZiMMie

My traction control is my right foot.

[Steve30]

man I need to stop looking at M3forum... that place is making me so paranoid about this engine lol. I'm thinking about picking up the VAC rod bearings and ARP bolts...

[Steve30]

Picking up new rod bearings and bolts tomorrow. Going to take a stab at it and do this myself. I spent the day getting all the necessary tools. Luckily I was able to find an angle torque attachment at the local part source! I'll post pics of the old rod bearings but I doubt we will see much wear.

[BmW1819]

it's easy to do just looks alot harder than it is

[Steve30]

Yeah..especially since the motor is out of the car, now is the time to do it. You just have to be really really really careful not to scratch the crank! I will report back when its done

[dcramer]

so why did it need rebuilding ?

[Steve30]

The original rod bearings and bolts in the 01-early 03 cars were not to spec or BMW quality standards and wore prematurely (or caused engine destruction). This issue is on ALL S54's though. I've seen 03.5-06 rod bearings that were completely down to the copper... I've read every thread/article on the net about rod bearings and even 03.5-06 cars are having this issue. The problem seems to be a mix of everything from long oil change intervals to consistently revving the engine to or over 8k. Apparently the engine was designed to safely rev to 7600 but BMW marketing just bumped it up to 8000. Most of the wear seems to occur on the top bearings which is a result of high rpms. The piston is being forced down with extreme pressure and the top bearings makes contact with the crank journal.

[dcramer]

Interesting, thanks for the info

[Dr. Flyview]

Originally Posted by Steve30

The original rod bearings and bolts in the 01-early 03 cars were not to spec or BMW quality standards and wore prematurely (or caused engine destruction). This issue is on ALL S54's though. I've seen 03.5-06 rod bearings that were completely down to the copper... I've read every thread/article on the net about rod bearings and even 03.5-06 cars are having this issue. The problem seems to be a mix of everything from long oil change intervals to consistently revving the engine to or over 8k. Apparently the engine was designed to safely rev to 7600 but BMW marketing just bumped it up to 8000. Most of the wear seems to occur on the top bearings which is a result of high rpms. The piston is being forced down with extreme pressure and the top bearings makes contact with the crank journal.

So can you get modified parts to make it safe to 8000 or are you going to keep it at under 7600?

[5style]

intedesting! did not know this

[Steve30]

The S54 is pretty much a race engine for the street so its going to wear like one if driven like one. Pretty much all race engines go through rod bearings in a season. You can still visit 8k on the street but if you hang up there all the time its going to wear out the bearings. There are kits out there that claim to reduce wear like VAC and Bimmerworld which offer treated and coated bearings. Its an inherent problem with all high revving engines because of the beating the rods take at redline. There are many other factors too though like having proper oil change intervals,and warming up the car properly before going to redline. I know Jay has original rod bearings in his roadster and they have over 200k miles but that car was maintained very well. I'm actually glad I have to do this. It will give me peace of mind and a chance to properly break in the motor and maintain it.

Originally Posted by Dr. Flyview

So can you get modified parts to make it safe to 8000 or are you going to keep it at under 7600?

[SiR]

you have an early engine?

probably good idea on the bearings anyways since the motor is out. Really a big issue was bmw spec'd the 5w30 early on for those engines... then changed to the 10w60 (which is a bit of a bandaid by bmw...but it works)

doing it yourself isnt hard. ive done that kind of work with the block in the car still. even then its not bad.

lol race engine. not really.

its a design problem that they missed(thanks to high revs and long stroke) but that oil helps deal with it.


its pretty much common sense you shouldnt thrash any engine before the fluids are up to temp...and mainly oil not just water. oil temp lags water temp by quite a bit so just because water comes up to temp doesnt mean your oil is up to temp.

[dcramer]

re race engine: it's only around 100hp/l hardly pushing the envelope. I also thought the problems came from poor bottom end bearings, which BMW recalled for the M3's

[Steve30]

It's going to be significantly over 100hp/L. With headers and tune it will be at 115hp/L. Just to put things into perspective the Mclaren F1 S70/2 produced 627hp from a 6.1 L block (102hp/L). Even at stock HP figures the S54 makes 107hp/L. I know its not a full blown super high compression monster but guys have built these things to well over 400whp NA so the potential is definitely there. Its closer to a race engine than anything else and has to be treated like on because of the tolerances.

The early engines were recalled due to out of spec rod bearings and rod bolts that stretch. I just picked everything up yesterday so I'll be installing the new bearings today.

[Steve30]

Just finished the bearings. Here are some pics.

Brand new updated bearings with rod bolts.



Oil pump removed for access to all rods.



Crank journal with a nice mirror finish. They were all very clean with no scoring or heat marks.



New vs. Old bearings



Angle torquing the rod bolts for their final torque. This took a while because you have to stretch each rod bolt which requires you to torque each bolt 9 times.



They were all pretty good showing very little wear except for cylinder 2 top. This one had a small area wearing through the first layer. None of these showed signs of spinning as they all sat in their original positions.



I know the pic is upside down but deal with it

Overall the process was very easy. The main thing is to stay clean!!!!