Originally Posted by nthach
Originally Posted by Gokhan
The camshaft is in the head, and the hydraulic flat tappet lifters ride on the cam, which push up directly on the rocker.
If I'm not mistaken, Nissan was using a variant of that design on the VG30s and Honda uses that basic configuration on their engines as well.
Those engines aren't picky about what you run. It'll be happy with most oils.
That's not my post.
OP's Z24 (or Z24i) SOHC engine has no tappets of any kind (flat or roller). It has sliding rocker arms directly on the camshaft. Yes, any modern oil is fine. If oil consumption is an issue, a 15W-40 HDEO would suit better in a warm climate like in California.
This is what I had written:
Originally Posted by Gokhan
Originally Posted by FordCapriDriver
Originally Posted by Cujet
Originally Posted by FordCapriDriver
SOHC doesn't mean it's not flat tappet.... i haveppen to have a SOHC flat tappet engine in my Escort.
The camshaft is in the head, and the hydraulic flat tappet lifters ride on the cam, which push up directly on the rocker.
Correct, those are flat tappet engines. Always liked the design. For a 2 valve engine, they seemed to run really well when properly tuned too.
I like them, but they are prone to cam wear and the press used to always complain that they were rough at high revs.
I run 15W-40 HDEO in mine to hopefully prevent that from happening.
OP's engine is Nissan Z24, which doesn't have tappets (flat or roller). It's an overhead-cam design with sliding rocker arms.
Here is his valvetrain and you can see the cam directly below the sliding rocker arms:
Nevertheless, 15W-40 (or 20W-50) is a good choice for engines prone to high valvetrain wear because of its thicker base oil.