Engine Compression Numbers

[Midlifecrisis42]

The guys working on the resto of my 1970 T got these compression numbers from my engine,

1 - 90

2 - 90

3 - 90

4 - 130

5 - 90

6 - 90

They also said

Scoping the bores shows cleaner edges to the piston tops meaning oil ring issues. the numbers say compression rings as well.

I would say this motor needs a "Top-End" meaning, everything from the rings out (rings, valve guides, valves, rebuild carbs etc.)

Can anyone recommend a thread I can read so I can learn more about this as I'm a newbie. I don't doubt the advice given is 100% correct as I trust them completely (well known in Porsche circles) I would just like to learn more and broaden my understanding of the topic. I would also like to understand about the compression numbers.

Thanks

[fred cook]

Buy a copy of Wayne's 911 engine rebuild book. It contains just about anything you would need to know about these engines. If I remember correctly, any compression variation from cylinder to cylinder of more than about 5% should be checked out. The 130 number is probably closer to what they all should be.

[Midlifecrisis42]

Thanks Fred, I will ask the wife to get it for me for Christmas!

[JJ 911SC]

Originally Posted by Midlifecrisis42

Thanks Fred, I will ask the wife to get it for me for Christmas!

No, you get the book and ask the wife for the Top End parts for Xmas

[HawgRyder]

This is a test....just how far can a man push the envelope in asking his wife for parts for the Porsche?
We are standing by! ..... LOL
Bob