Rock Pistons
Car Name: Nissan
Model: KA24E (1990-1995)
Size: P610.20
Obviously a bit confusing, says the ka24e, but then the years dont match up since the ka24e was only in the 240's in 89/90, 91 Changed to the twin cam.
Now if they're are ka24e pistons I would assume they're around the 8.6:1 compression, since that was stock in the late 89 and all 90 models:
KA24e Wikipedia: Compression ratio: 8.6:1 (9.1:1 for early 1989 240SX)
Heres where i'm a bit confused, the site also lists the stock compression of the ka24de 9.5:1, but looking at the pistons the twin cam pistons are dished, these rock auto pistons arent domed but they aren't dished...kinda flat across the top, so I dont see how they would have a lower compression rating than the dished pistons...unless im completely misinterpreting this lol. This is my first go around for an engine rebuild.
Im really trying to figure this out because I do plan to boost as soon as I break the motor in properly, but I want to figure out the compression ratio before I do that. If I cant figure this out i'm just going to reuse my OEM pistons, forged is out of the question...both for price and I never intend to go up that high in HP to need forged internals.
Heres some pics of the pistons:
