300tdi block damage advice

[bnoonan]

Hello all,

I have a 300tdi that had been, at some point in the past, redone by Turner.
It appears that bearings were replaced in the US. When I got the engine it knocked like hell.
Dropped the oil pan and found a thrust washer in the pan. The other was not to be found. The best guess at this point is that turner ground the crank to fit an oversized thrust washer but these were replaced with standard size when worked on stateside.

The end result is wear on the rear side of the block where the rear thrust washer sits. There remains a small lip where a thrust washer can be put and one path forward is to determine the exact oversize bearing required for a solid fit to the crank....but in my mind that leaves only the small lip on the block worth of play in crank movement before the thrust washer again comes loose and gets torn up.

Id appreciate advice from those experienced with the inner workings of these engines on how to move forward. Does it look as if oversize bearings will allow me to ignore the wear on the block (blue arrows)?

Thanks,
Brice

[Naplm00]

It's definitely savable. You can go to a good compliment engine machine shop and have that Raceway fly cut. And then you can get a custom bushing made, not going to be cheap though

[Mybluett]

Originally Posted by Naplm00

It's definitely savable. You can go to a good compliment engine machine shop and have that Raceway fly cut. And then you can get a custom bushing made, not going to be cheap though

Right on both points...

I just tossed a block that was in good condition, may have another couple in the shop for sale...

[bnoonan]

Originally Posted by Naplm00

It's definitely savable. You can go to a good compliment engine machine shop and have that Raceway fly cut. And then you can get a custom bushing made, not going to be cheap though

So by this, are you saying that simply putting in oversize thrust washers is not going to cut it? The only safe option is this Raceway Fly Cut? (I'm not familiar with this, but will get to Google right away).

[Naplm00]

Correct, can't just stick an oversized on in there because it will wear and then slip out since the shoulder has been ground down

[bnoonan]

Soooo....machinist looked at the block today, thinks it is toast.

My 2 questions are:
1) The short block came from Turner about 5 years ago. Richard Turner himself looked at the issue (super helpful) and told me: "What you are looking at is damage consistent with a high end loading of the crankshaft caused by maladjusted clutch (no free play) or an incorrectly fitted/assembled auto box which has caused high end loading. The bearings appear to be tin aluminium (light duty bearings) we fit lead copper heavy duty bearings only which suggests someone has been in there since supply. [I knew this to be true, that is what caused the problem] There is no dynamic within the operation of the engine that can cause this kind of damage without abnormal end loading."
Sooooo.....what is abnormal end loading? How does this happen?

2) He also noted that the short block left their shop with 020 oversized pistons. Forgive my ignorance, but would a replacement short block have to be expanded to the same oversize diameter?

Thanks again for the guidance.

[bnoonan]

Yeah, I'm 99.9% certain Q#2 is a duh, YES!

I ask because I'm wondering if I need to source only a block and have it machined or if it would be better to source a whole long block....ugh...

[sonoronos]

Originally Posted by bnoonan

Sooooo.....what is abnormal end loading? How does this happen?

1. Any force applied directly into the central axis of the crankshaft provides thrust loading on the crankshaft. Constant thrust loading on the crankshaft is undesirable.

2. A normally operating crankshaft has no thrust load during normal operation - only during clutch actuation. An auto transmission should have no thrust loading - or rather, the thrust loading is taken up by the gearbox's support bearings.

3. A manual transmission vehicle experiences thrust load on the crankshaft when the clutch is depressed, hence his statement, "maladjusted clutch (no free play)" which would provide the unexpected constant thrust on the crankshaft that is normally only applied during clutch actuation.

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If you are getting a short block, why would you need oversized pistons? A short block should have the pistons and piston rings already installed. Keep it stock bore.