Rering / cylinder - Needs Help

[SteveBorelli]

Dear all,

I'm from Italy, so sorry for my poor English.
After I purchased the best two Wayne's books "How to Rebuild Porsche 911 Engines" and "101 Projects", I opened my 2,4 E 165HP Engine to make a rebuild of it.
When I've took off one of the cylinders and measured it, I discovered it is out of Porsche tolerances.
So, I went on a Porsche mech. and asked for alternatives. These is what he suggest :

1 - Buy brand new 2.4 cylinders, change rings, use old pistons
2 - Machine my old biral cylinders (about .4mm), buy a new and right sized pistons set with new rings

Now, I red deep the forum and I have not truly understood if there are other options.
For examples it seems that there could be a way to use "over-sized" rings over the old pistons in the machined cylinders (.4mm bigger); I talked to my mech but he says this is an old technique that does not guarantee any result...

Who can give me a clear idea of what to do ?!? (of course this workarounds are intended to keep the budget as low as possible)

Thank you in advance.

Ciao.
Stefano

[Steve@Rennsport]

Hi Stefano:

There are several ways to repair your motor, but the RIGHT way would be to machine your Biral cylinders and install new, oversize pistons & rings.

That makes a good repair that will last a VERY long time,....

Ciao,

[Superman]

Using oversized rings on original pistons with bored cylinders would be, in my opinion, a bad decision.

[350HP930]

Go with the new oversized pistons.

If the old cylinders are out of spec your pistons are pretty shot too.