Pitted 2.2 Cylinder - Opinions

[Al S]

Rebuilding a '70 2.2, and found one of the cylinders pitted as shown.
These are Mahle jugs with the iron sleeves.
The pit is just below the compression ring at TDC.

One local engine builder opined that it should not be a problem.
Looking for opinions on what my options are (other than oversize JE pistons and rebore).

Thanks

[porschetub]

Originally Posted by Al S

Rebuilding a '70 2.2, and found one of the cylinders pitted as shown.
These are Mahle jugs with the iron sleeves.
The pit is just below the compression ring at TDC.

One local engine builder opined that it should not be a problem.
Looking for opinions on what my options are (other than oversize JE pistons and rebore).

Thanks

I would be looking for a replacement barrel that up to spec still,IMO this pitting will cause blowby......sure the guru's will chime in on this ,good luck

[RedCoupe]

If I'm looking at the picture correctly, there looks to be a noticeable ridge at the top of the iron liner. If you can catch your fingernail on it, the ridges should be removed with a ridge reamer if the other cylinders also have ridges. I agree with porschetub, I wouldn't use this pitted cylinder.

[Steve@Rennsport]

Its not something I would ever use in any engine, as is.

Personally, I would look for a better cylinder that can be finish honed to suit, or bore the set oversize and fit some JE's.

[Lapkritis]

I've seen worse come from happily running engines.

Would it run and likely not be noticeable? Sure. Not going to find many builders who would give it a stamp of approval publicly though... It won't get any better that high in the cylinder where pressure is great.

[Henry Schmidt]

If the pistons are still usable, I would suggest having all your existing cylinders Nikasil coated. The coating will repair any surface anomalies, can be sized to each piston and offers better sealing and reduced friction making the cylinder better than new.
If the pistons are not within spec, I would look to bore the cylinders and replace the piston with an over-sized one.
Since the engine is apart and the cylinder shows issues, why use it as is?

[Al S]

Thanks for the feedback guys, particularly from our resident engine gurus Steve and Henry.
Much appreciated.
This is a budget rebuild so I will look at replacement with a used cylinder.

[Henry Schmidt]

Originally Posted by Al S

Thanks for the feedback guys, particularly from our resident engine gurus Steve and Henry.
Much appreciated.
This is a budget rebuild so I will look at replacement with a used cylinder.

Talk to Ken at 911 Vintage parts 760-731-4911
info@911vintageparts.com They have a huge selection of used air-cooled Porsche parts.