M52 Engine Build concerns

[joeblow]

I am building up an M52 Aluminum Block engine (323) 2.5 liter with Pelican Parts. It is going into an E36 Race Car for Road Racing use only and will be all stock except for slightly raised compression from a cut head and deck and open exhaust, 3.0 M3 cams, M50 intake etc... The block, pistons, rods, crank, head etc... are all original M50/M52 componants. The original engine had very low use as it was crashed with 20K on the clock and everything was standard.

I am concerned with the pistons and the rings mostly but now also the main bearings.

The pistons came back from the machine shop nice and clean but it looks like they used a mild abrasive like a scotch bright pad or similar to help remove carbon and such. What concerns me is that I remember reading that the pistons are plated with something to help keep them from galling the aluminum cylinders. The sides of the piston are no longer the dull gray color they were before, now they are more aluminum colored on the skirts. They did not remove much material as the original skirt grooving for oil control are still clearly visable. Are these pistons OK to use still or am I in trouble?

Next I bought the rings for a 323 with STD bore, when I checked the ring end gap they are not matching the specs I have. The book (Haynes) says .0008-.0016 from memory for the top and 2nd and .0008-.0018 for the oil ring. Out of the package these rings have .0018 for the top, .0016 for the second, and .0030 or so for the oil control. Obviously something is off here. My question is if I need to order different rings that I can file to fit? Being for a racing application perhaps a little more gap is not a bad idea?

One more item on the rings is that the package indicates it is for both 325 and 323 applications?? I would have thought that the aluminum block would need a different ring than the iron block? Do I need to be concerned with this? How can make sure I got the right ring type for this car from you guys?

Lastly I bought the Glyco main bearings from you and it looks like they are mis-packaged as all the bearing halves are tops with the center groove and they do not fit into the main caps that have the two bearing tabs. Am I just lucky or has this happened before? I am under the gun here with my race only days away. The oringinal bearings look very good to me. They have no brass/copper showing, no grooves, and all the grey coating is there except for lightly shinny sections here and there. Nothing thaat catches the fingernail or feels off. What is your take about just running the originals? The clearances are in the middle of the range. The rod bearings will be changed as those seem correct and have good gap.

Thanks a bunch for helping!!

[joeblow]

Pic for ya!

[2mAn]

bump!

I am in the process of building something VERY similar, but M52B28. Machine shop recommends new pistons, but Id like to keep the factory parts. Is there any piston rings that can work after its been rehoned?

joeblow- did you find a solution? I am trying to avoid spending $900 on wiseco pistons