Thoughts on these P&C measurements

[jwasbury]

Helping a fellow pelican with their EFI turbo engine as documented in this thread:

engine drop

I realize after further study that I made some of my measurements in the incorrect locations, however I think they are probably still useful and indicative. I believe that the P&Cs are all junk.

#6, no need to measure here...we know this is junk


#1, I did measure this one, but visual inpection indicates a problem. What causes this wear? Heat? Interesting that the cylinder doesn't look all that bad (Nikasil plating is that tough?).


Other side of #1. It does look like the crown was melting/beginning to deform here too, but didn't get as far as #6 (my first photo)


Here's a chart of measurements. For reference, "A" axis is parallel with wristpin, "B" is perpendicular to wristpin.



Whadd'ya think?

[Steve@Rennsport]

Thats all damage from detonation.

[tom1394racing]

A few of the cylinders look to be out of round. The ovality limit is 0.04mm.

This is not unusual with the 1/2 finned cylinders.

[jwasbury]

Originally Posted by tom1394racing

A few of the cylinders look to be out of round. The ovality limit is 0.04mm.

This is not unusual with the 1/2 finned cylinders.

Agreed on them being outside of spec for ovality...

unfortunately, these are not the 1/2 finned 3.3 jugs...they are 3.4L Mahle motorsport "yellowbird" P&Cs ($$$$$$$)