CA18ET pistons and rings in CA18DET block

[mulletmrt]

This might sound like a dumb question because they use the same block, but could you use CA18ET pistons and rings in a CA18DET? Are they the same pistons? I know the rods and crank are weaker on the ET, but wasn't sure about the pistons. Sorry was just thinking of a project idea. Thanks Mike

[NeedCAforS13]

nope... valve reliefs on the piston will be different! the SOHC is an 8V (???) while the twin cam is a 16V. With the SOHC there are 2 reliefs per cylinder whereas the twin cam as 4...

Sean

[mulletmrt]

I see, well it's time to blow up my sohc and get a DET or DE

[themadscientist]

got a dremel?;)

[Myetball]

The ET does have 4 valve reliefs per piston, looks just like the DET pistons. There's some pics I can't seem to find, I'll post them up if I find them.

Found one.



This particular CA18ET even has a CA18DET crank girdle installed. No modification needed, just the DET main bolts.

[NeedCAforS13]

really? I could have sworn I saw the inside of an ET at Nissan with only 2 reliefs in it! that just might work then:)

Sean

[themadscientist]

you are right, there are two releifs. Maybe this SOHC had the pistons swapped or something. New OE CA18DET pistons are cheap, like $200 a set and $150.00 for the rings.

[Myetball]

Took a while but I did find out that some time in '87, not sure of the month, Nissan started putting pistons with 4 reliefs into the CA18ET. So, if you have an early or pre-'87 CA18ET it will have 2 reliefs. If you have a late or post-'87 ET motor you should be good to go.

Now for some contrary information. Found a site where a guy is working with an '85 CA18ET. There's some pics for your enjoyment. Check HERE.

[undertaker]

I have seen some of the RB20 and RB30E's come with 4 relief pistons too, they look just like the DE ones

[boost_boy]

Unfortunately guys, the CA18ET's pistons will not work the CA DOHC heads. Even though the ETs have 4 valve reliefs, they are not in the proper location and are made to accomodate bigger valves. Either use the CA18DET pistons or get a set made to match the CA18DET's specifications. I'll say this again, the CA18ETs pistons will not work with the CA18DET's head because of valve relief spacing.

Dee