Alusil and Nikasil in one engine, feasible?

[alniki]

Got a set of Alusil p/c and a set of Nikasil p/c, can I pick better ones from both sets and make a good engine?

Of course, the Alusil p/c would not be separated and re-ringed, just transplanted as a whole.

Your opinion or experience would be appreciated!

[OldTee]

Great question. Would be interested in the experts answer. Problems I would see would be a slight difference in expansion/contraction characteristics between the cylinders that might put pressure on the studs and cylinder base seals. Otherwise, to resurrect an engine for your own use (not for sale as a rebuilt engine to others) might have merit. This is certainly a short cut and I can't see any professional doing it.

[zweistein]

Maybe one side Alusil and other side Nikasil would work, as there a no thermal problems then.

Piston weigths?

[alniki]

Piston weight is a problem so I was thinking of pairing Alusil p/c, like cyl 1 & 4, or cyl 2 & 5. Alusil uses different rings but I don't know about the piston.

The difference between Alusil and Nikasil may be just inner surface plating, if so there probably would not be much thermal expansion problem if both kinds are put in the same bank.

[tom1394racing]

The biggest problem will be balance as the Nikasil and Alusil pistons are very different in weight.

Porsche specs call for a max spread of +/- 4 grams and most piston sets are within +/- 2 grams.

[Nuvolari]

bls