How to break in S54 after rebuild?

[RGlenn]

Hi All -

I purchased an 07 Z4M about 3 months ago that had valve on piston contact on cylinder #6 due to the Vanos exhaust hub failing. I ended up pulling the engine and since I had it down to the block, replaced a lot of parts to get it back to tip top shape. Here's the list of parts that I ended up replacing:

New JE Pistons at 87.50mm
King Racing Main Bearings
WPC Rod Bearings
Rebuild Vanos
Turbotoy's C300 Vanos Exhaust Hub
All Timing/Oil Pump Components (Chains, tensioner, guides, etc)
Set of stock Cams & followers (thanks to a forum member)

One area I'm hoping to get some advice on from the forum is the break in procedure. I spoke with JE pistons, but they did not have a break in procedure for their pistons and rings. After that, spoke with Lang Racing who recommended Driven 15w-50 Break in oil which I have ready to go into the engine. Hoping to find someone who has some knowledge on how to break in these motors. I don't have access to a dyno so it will be a street break in. Without opening up a can of worms , is there a consensus on the best way to pull/rev for the first few drives? Want to do the best I can do get the rings to seat properly. As fun as it's been rebuilding, I don't want to do it again any time soon .

Appreciate the help!
Ryan

[Eson]

I just finished breaking in my Dinan built motor - they recommend 1,000 miles of sub 4K RPM followed by an oil change.

[RGlenn]

Originally Posted by Eson

I just finished breaking in my Dinan built motor - they recommend 1,000 miles of sub 4K RPM followed by an oil change.

Oh boy I bet that's going to be a fun motor... Thanks for the quick reply. Right in line with what I've been hearing. Heard anywhere from 4-4,500 for first 1000-1200 miles so right in line.

[Beedub]

how many miles did the engine have when the hub failed ?? sorry to pry. I really need get the redrilled disk asap while my motor has so few miles to reduce the fatigue on the exhaust tabs.

[RGlenn]

Not at all! Has 51k on the clock. That seems a bit low for the hub to fail, but I’m not sure what type of oil change intervals the previous owner had gone by. Quite a bit of build up in the head which is why I tore it down completely to clean it all up. Dr.vanos does a nice job on drilling the disc if you are looking to go that route. He is who I got my rebuilt vanos from.

[mattfwalters]

Originally Posted by RGlenn

Hi All -

I purchased an 07 Z4M about 3 months ago that had valve on piston contact on cylinder #6 due to the Vanos exhaust hub failing. I ended up pulling the engine and since I had it down to the block, replaced a lot of parts to get it back to tip top shape. Here's the list of parts that I ended up replacing:

New JE Pistons at 87.50mm
King Racing Main Bearings
WPC Rod Bearings
Rebuild Vanos
Turbotoy's C300 Vanos Exhaust Hub
All Timing/Oil Pump Components (Chains, tensioner, guides, etc)
Set of stock Cams & followers (thanks to a forum member)

One area I'm hoping to get some advice on from the forum is the break in procedure. I spoke with JE pistons, but they did not have a break in procedure for their pistons and rings. After that, spoke with Lang Racing who recommended Driven 15w-50 Break in oil which I have ready to go into the engine. Hoping to find someone who has some knowledge on how to break in these motors. I don't have access to a dyno so it will be a street break in. Without opening up a can of worms , is there a consensus on the best way to pull/rev for the first few drives? Want to do the best I can do get the rings to seat properly. As fun as it's been rebuilding, I don't want to do it again any time soon .

Appreciate the help!
Ryan

My engine builder also recommended the Driven break-in oil. Who did your machine work? I would strongly advise that you follow whatever break-in procedure they recommend - otherwise you run the risk of having them wash their hands of a mistake because you "improperly" broke in the engine.

FWIW my builder and I spoke for about an hour about his preferred break-in process (tl;dr: "preoil; dyno; very, very careful"), and he will be either in the dyno cell with me or on the phone as we go through that process. Which will be in 2021 or so at my current rate of progress.

[RGlenn]

Originally Posted by mattfwalters

My engine builder also recommended the Driven break-in oil. Who did your machine work? I would strongly advise that you follow whatever break-in procedure they recommend - otherwise you run the risk of having them wash their hands of a mistake because you "improperly" broke in the engine.

FWIW my builder and I spoke for about an hour about his preferred break-in process (tl;dr: "preoil; dyno; very, very careful"), and he will be either in the dyno cell with me or on the phone as we go through that process. Which will be in 2021 or so at my current rate of progress.

Haha better to do it right once than the wrong way twice! Outside of the machine work on the head and boring the block, which I had a local shop do, I’ve done the rebuild myself. Fortunately for me my brother is a mechanic at BMW so he had all the tools we needed to time it, check tolerances, factory torque specs, etc. He has done the major work for me, I certainly won’t claim to be at the level he is He actually had found the car for me. Got most of the big ticket items from Lang Racing so I’ve been talking with them about the build process. At the rate I’m going it will be snowing up here in NY by the time it’s done .

[pokeybritches]

General advice would be to turn the engine over by hand before attempting a start, and to take things slowly - low rpm, low load.

I'd reference the factory recommendation regarding break-in. Even though some parts may have different physical properties, the forces acting upon the parts (and their directions/locations) are the same.