Engine rebuild

[Dieschelan]

Hi

I have disasamble the engine from my s3 and the pistons are in good condition. The pistons are 0.30 and are printed the number 18950. Anyone knows wich type of piston is? I need a new piston ring set.
Where can I find the rings?
In the cylinder head is stamped 26e 311. Someone knows the type of cylinder head?

Cheers

[nmauduit]

I source most of my engine part from QED (no affiliation) ...

[Dieschelan]

I have another doubt. The pistons have small valve cuts. Can I use these pistons with a big valve conversion?

Cheers

Diego

[pharriso]

18950 are AE / Hepolite part numbers for Cast pistons.

[2cams70]

I have another doubt. The pistons have small valve cuts. Can I use these pistons with a big valve conversion?

Cheers

Diego

These pistons are fine for anything up to Sprint size valves and cams. Anything larger and you'll require deeper pockets. In fact it's best not to have pockets any deeper than required. Combustion is more efficient without lumps and bumps all over the pistons. This is why Lotus themselves went from large pockets on the pistons to small pockets on these engines. You can check them for clearance during a trial build of the engine in any case.

[nmauduit]

I have another doubt. The pistons have small valve cuts. Can I use these pistons with a big valve conversion?

if you are keeping the original camshafts you should be fine - in case of any doubt, you can always do a dry fit with plasticine to check actual piston clearance...

[Chrispy]

I believe I have the same pistons, except mine were 0.040" over. Standard piston rings from Burton's is what I used.