Well,
Out of the things to do, I managed to complete all but fitting the mtech1 skirts.
For anyone following this thread, the next events won't be a surprise.
All was good until the time for an oil change came upon us.
One shiny and sparkly thing ...
Lead to another
Expecting to see bearing carnage, I immediately took the head off.
Apart from the weird combustion pattern due to flat top pistons with 885 head chamber, nothing wrong was apparent.
The bearings show SOME minor wear, especially the axial one but that's kind of to be expected and would not sparkle up the oil that much, keeping in mind this is the 5th oil change on that engine and no signs of glitter were previously visible.
The connecting rod bearings looked the same - some wear, but in the expected area.
I was baffled and turned my attention to the head.
Needless to say - same thing as before had happened. Destroyed rocker arms and chewed up camshaft. It couldn't have been oiling anymore, that was sorted AND verified with running the engine without the head cover. So what was it???
In the end, I figured it out. The guy who did the head work had assured me he had checked for valve spring binding and everything was fine. Silly me, I took that statement as true and didn't verify that.
Below is a picture of a OEM spring on the right and the ones I use on the left.
So what went wrong is the VAC motorsport spring retainers. They are a generic part instead of a M20 specific part. I got those USED from a friend and he never had such issues with these. So ... WHAT THE HELL HAPPENED???
Answer- he used the retainers with KATCAMS springs, which have one coil less and were never binding because of that. Using them with my Schrick springs however ...
So ... at least I think I can do it right this time around.
Actually, disassembling the engine was good, because the piston rings showed some premature wear. Talking to some other guys, turns out Goetze piston rings aren't what they used to be any more. Same pattern was observed on 3 other engines.
Anyhow, when life gives you lemons, you order custom forged pistons
Huge thanks to Steve from Top End Performance, I made a huge mess out of that order, but he kept a cool head and helped me out big time.
Def recommend.
Currently I am in the early stages of swapping my e28, so this engine build will be somewhat slow. I expect that to happen within this year, so updates will be slow ... as usual.
Until then and stay cool
Out of the things to do, I managed to complete all but fitting the mtech1 skirts.
For anyone following this thread, the next events won't be a surprise.
All was good until the time for an oil change came upon us.
One shiny and sparkly thing ...
Lead to another
Expecting to see bearing carnage, I immediately took the head off.
Apart from the weird combustion pattern due to flat top pistons with 885 head chamber, nothing wrong was apparent.
The bearings show SOME minor wear, especially the axial one but that's kind of to be expected and would not sparkle up the oil that much, keeping in mind this is the 5th oil change on that engine and no signs of glitter were previously visible.
The connecting rod bearings looked the same - some wear, but in the expected area.
I was baffled and turned my attention to the head.
Needless to say - same thing as before had happened. Destroyed rocker arms and chewed up camshaft. It couldn't have been oiling anymore, that was sorted AND verified with running the engine without the head cover. So what was it???
In the end, I figured it out. The guy who did the head work had assured me he had checked for valve spring binding and everything was fine. Silly me, I took that statement as true and didn't verify that.
Below is a picture of a OEM spring on the right and the ones I use on the left.
So what went wrong is the VAC motorsport spring retainers. They are a generic part instead of a M20 specific part. I got those USED from a friend and he never had such issues with these. So ... WHAT THE HELL HAPPENED???
Answer- he used the retainers with KATCAMS springs, which have one coil less and were never binding because of that. Using them with my Schrick springs however ...
So ... at least I think I can do it right this time around.
Actually, disassembling the engine was good, because the piston rings showed some premature wear. Talking to some other guys, turns out Goetze piston rings aren't what they used to be any more. Same pattern was observed on 3 other engines.
Anyhow, when life gives you lemons, you order custom forged pistons
Huge thanks to Steve from Top End Performance, I made a huge mess out of that order, but he kept a cool head and helped me out big time.
Def recommend.
Currently I am in the early stages of swapping my e28, so this engine build will be somewhat slow. I expect that to happen within this year, so updates will be slow ... as usual.
Until then and stay cool
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