Head ID

[wayno]

I don't think that the W58 closed chamber head is that rare, I have two of them. I also heard from someone(i can't remember who), that the flow characteristics were worse if the liners were removed, can this be true?

[chester]

On the W58 peanut head, I have one and then I am pretty sure Skib had one on the 620

[lil89ram50]

ok itsconfirmed, they are not hard to find. either way, any thought on removing the linings? does it infact decrease flow?

[ggzilla]

I believe we already discussed that:

* It is a mod for high-RPM breathing

* It will decrease low-RPM flow & HP although as mike says "increasing or decreasing the exhaust ports has less effect than increasing or restricting the intake side"

[datzenmike]

Well the one I had was supposed to be from a 200sx.Now the 200sx was a sort of 'sporty' car and may have come with them for higher compression.

 

200sx

 

The '78-'79 was # W5880 ... this head is used on the '78-'79 620 truck and it is definitely open and a W58

The '77 head was # N5800SV... this head is used on some 710s after Nov. 76 but the L20B also used the U67 and the W58

 

The A10 (HL510) used the W5880 head and the 610 only used the U60 and U67 head. Maybe N5800SV means peanut???

[ggzilla]

SV i believe means it is service part, not a production line fitting.

 

In the late 70s nissan had closed chamber and small ports for A-series too. The open chamber head lowers NOx, but instead they used a lot of EGR to lower the NOx. At the same time they continued to open chamber/large port heads. Two different ways to do the same thing. Either rev it up or make it work at lower RPMs.