My 3B project (ongoing)

[Dobby84]

Had a successful day in the garage today
Fully stripped the engine down.

All looking fairly good although a bit of wear on the cams.

The pistons and valves are black. Should I be concerned? What's the best way to clean these up?

Cylinder head to be stripped still

To any of you with more knowledge than me please let me know if there is anything I need to look at? I'm going to be buying new bearing, rings and gaskets all round.

[Dobby84]

Few more photos.

Looking at Glyco bearings. Are there any good?
Will replace the rings too

[Antsa]

I'd say some carbon buildup is normal on these engines, soda or vapor blasting would be a way to go for cleaning these. Some say oven cleaner works too but I've not tried that myself.

Glyco bearings are OE quality so they are a good choice.

Before rebuilding I would take the block to be measured and then decide what to do. At minimum it would need to be honed before fitting new rings. If the block is worn it should be bored to oversize and then new pistons.

[Dobby84]

I'm planning to take the block to get measured and honed. Just trying to find somewhere local to me.

[Tractor Dave]

I got all my bearings and rings from C S parts in Germany. Tell them what engine you have and they will put together a complete kit for you and also a discount. Don't forget to replace the cam chain while you are in there. The soot might just be from cold starts on the last few short runs?

[Dobby84]

Thanks, I'll check them out.
Really hoping I don't need new pistons

[Tractor Dave]

I think thats very unlikely. My Nothelle was on nearly 180k when i rebuilt the engine and the bores were still within tolerance. From what i can see in your pics, the piston skirts look good. What do the bores feel like?

[Dobby84]

Really smooth to be fair.
The engine has done 116k and doesn't look like ithe bottom end has ever been apart!
I'll find somewhere to eat it measured and honed and go from there

[Dobby84]

Well I have had the bores measured and have been told that if I hone them they will be on max tolerance so save bet is to get it bored and go for oversize pistons.

I may as well get new rods whilst I am there then I shouldn't have to think about it again in the future.

I am looking at this kit from Wossner.
Audi 5cyl Low Comp Forged Piston & H-Beam Steel Con Rod Package | Wossner UK

Anyone have any advise on these? Should I just go for 81.5 or 82.5?

[Crasher]

With forged pistons they will not be offset, nor will the rods so combined with their higher expansion rate clearancing, you do have to put up with some slap whist cold.

[Antsa]

If you are not looking for major power increase, I would stick with stock pistons. You can use standard piston to wall clearances and should not have to worry about increased oil consumption or piston slap with cold engine. This might be an issue with forged pistons. Also, lower compression ratio is needed only for high power applications.

I just checked mahle online parts catalogue and 81.51mm oversize pistons should be available.

[Dobby84]

I assumed that I could not use standard pistons if I need to bore the cylinders.
Any idea where I can buy the Mahle pistons? I cant seem to find anywhere.

Not running major power at the moment but will be looking for 400-450 is in the future

[Antsa]

Pretty much every online spare parts store shows out of stock. I purchased mine from local supplier and they told me it was a factory order but available. The price was pretty high, nearly as much as custom piston set, but I wanted to stay stock.

Maybe you could ask your local spare parts place? Mahle partnumber for 81.51mm oversize piston is 034 92 02.

Your target hp is pretty much the same I have, and based on what I've read, those are safe numbers for oe pistons.