List of E-series cylinder heads - Page 7

b12brothers · Mar 27th, 2008, 03:40 PM

Now that we are at the heads what about the valve seats.
My E16I (we call them the german because the only few which are or were running here in Luxemburg are from Germany) runs with unleaded because of the cat.
So, my Nissan dealer told me it would not be recommendable to interchange the heads because they have different valve seats, even by changing timing the engine would not last very long.
As it seems, the seats of a E16I are harder than those of the E16S.
Is it the case everywhere or just here in Europe?

blownb310 · Mar 27th, 2008, 03:58 PM

That's not the case in the US. All of ours have the hardened seats for unleaded fuel.

b12brothers · Jun 11th, 2008, 01:36 PM

For the 33M head 24,5cc there is no need of valve reliefs and the pistons got 17,9cc, right?

The 15M head has only 17,9cc and for this head reliefs are needed because the valves are nearer to the piston top.

My question is, what did they do with the heads to keep the same shape? Itook a look at both and the only difference is the shape of the chamber (spherical and poly-spherical) the cam, rocker arms, valve springs and everything else is at the same place also valve angle is the same or else the rocker arms wouldn't fit. Valve lenght is also the same.

blownb310 · Jun 11th, 2008, 03:41 PM

I'm a bit rusty on E-series head tech, but I believe the valves are 1mm larger in diameter on the 15M heads and that has something to do with the necessary valve reliefs on the matching pistons for those heads too.

b12brothers · Jun 12th, 2008, 02:30 PM

Yeah, but what about the head?

I forgot a ? in the last post. So are the valves length different?

The valve reliefs in the pistons for larger valves that's o.k.

Valves must be shorter because combustion chamber is deeper.