S20 air boxes

[RIP260Z]

While drooling at S20 engine pictures during those quiet time "having a look on the web", I notice the S20 air boxes on the Z432 and KGC10 (?) are different. The Z432 (PS30) has the air filter housing in front of the radiator, a longer pipe connecting to the car box (two rubber joiners), and the air enters the carb box at the front.  (Z432 image from Kat's thread, page 26)

The Skyline fitted with the S20, has the air filter housing behind the radiator and connect directly to the carb box, no pipe connector (1 rubber joiner). The air enters the carb box by a pipe coming in on the side.

I presume the obvious difference is red for Z432 and Skyline is blue?

I ask as I have an image of a red carb box, but the air pipe into this comes in from the side... was there a change during production of the Z432?

The way the air filter housing fits to the engine bay differs, my question is does the fixing point exist on other models (s30, Z-L for example), as some models have places to attach something that was not specifc to that model?

On the red airbox pictured not on the car, there is an indent at the back of the carb airbox, I take it this is space for the clutch master?

Any other documentation of differences (or correcting me-learning here) would I think make a great thread...

 

 

[HS30-H]

Hi Ian,

On the colour question, both the Skyline GT-R (PGC10 & KPGC10) and Fairlady Z432 (PS30) airbox and connecting tube were RED from the factory, with the 432's airfilter housing being BLACK (because it was mounted ahead of the radiator support) whilst the GT-R's were RED (because they were in the engine bay).

Factory replacement spare parts came in (manufacturer) Tsuchiya's factory blue colour, as per your photo.

The mounting holes for the 432's airfilter box are present on the radiator supports of all contemporary L-series engined S30-series Z models (both Domestic and Export), as are - of course - the holes for the duct and the (diverted) cabin fresh air inlet. The captive nuts for the mounting of the factory option S20 olil cooler are there too.

The 432's airbox fits on the car without any special accommodation/clearancing for the clutch master cylinder.

[HS30-H]

Here's the factory parts manual image for the 432 airbox and filter system:

 

[HS30-H]

Here's my factory replacement airbox on period Weber 45DCOE-9s and S20 inlet manifold, for shape reference:

[HS30-H]

The S20 airboxes have carburettor trumpets/funnels integral with the cover:

[RIP260Z]

Thanks Alan, very helpful as usual. They are just a lovely design.

I will carry on drooling with a little more info....

[kats]

Hi Ian , I am glad that you are interested in Z432 , how is your Silvia doing ? I saw a complete restored Silvia at Tokyo auto salon, that was so nice , I was thinking about you.

Alan , your Webber set up is so good ! I have heard at that time Nissan couldn’t afford to install Webber , while Mikuni provided a cheaper carburetor , so they took it. Toyota used it too , maybe the same reason? Anyway thanks Mikuni !

Z432 air box set up is superior to the GTR in terms of fresh air , thanks to the long nose , there is a room to position  the air cleaner outside of the engine room. 

GTR air box is always on sale at Japanese auction , but I have never seen Z432 air box on sale almost 10 years. Z432 were sold 400 and some more , while GTR(S20 engined) were sold 2000 and more , this is the reason why Z432 S20 parts are much difficult to obtain.

Kats

 

[xs10shl]

Kats, It's always interesting to speculate what happened to all those Z432 air boxes.  So many cars I've seen have them removed, so they must be sitting on garage shelves somewhere.  Or more likely thrown away 30 years ago during spring cleaning, along with the even-less-often-seen "Guide Assy air Intake" 62590-E4201 that Nissan made in order to route fresh cabin air around them.

 

(edit: apparently, you're not allowed to write "a-s-s-'-y", as it gets auto translated to "arse" by the message board. )

Edited January 27, 2022 by xs10shl

[HS30-H]

31 minutes ago, xs10shl said:

...along with the even-less-often-seen "Guide Assy air Intake" 62590-E4201 that Nissan made in order to route fresh cabin air around them.

Ah, the super elusive lesser spotted E42 'Guide Air Arrse'. Once seen, never forgotten... 

 

[kats]

15 hours ago, xs10shl said:

Kats, It's always interesting to speculate what happened to all those Z432 air boxes.  So many cars I've seen have them removed, so they must be sitting on garage shelves somewhere.  Or more likely thrown away 30 years ago during spring cleaning, along with the even-less-often-seen "Guide Assy air Intake" 62590-E4201 that Nissan made in order to route fresh cabin air around them.

 

(edit: apparently, you're not allowed to write "a-s-s-'-y", as it gets auto translated to "arse" by the message board. )

That is also true for the battery tray and cover , I have seen so many Zs have lost their covers and trays . I can say 99 % of cars which I saw in person or in magazines lost them . Nowadays cloth braided hoses , wire hose clamps , rubber pieces those are available on line , but the battery hardware is very rare to see especially for Fairlady Z cars.

Kats

Edited January 28, 2022 by kats

[kats]

Just a few references for understanding of the air box .Please enjoy the pictures.

Z432 and GTR , both S20 had same design change for the emission (pollution? ) from OCT 1970. Before that , blow-by air was released to atmospheric air pressure from the top of the valve cover , and the right side of the engine block . 
After OCT 1970 There are tubes which are connected from the air box to the valve cover , and the engine block oil separator.

You can see the oil pan and assorted parts difference on both S20 engine.

Kats

 

 

 

 

 

Edited January 29, 2022 by kats
Amendment date to OCT 1970

[kats]

Hi , I amend the month / year of  changes for the blow-by system . That was Oct 1970 .At that time for the Fairlady Z series , the automatic transmission began to be selected  and “ regular gasoline “ version which was lowered compression ratio , lowered ignition timing was able to be selected for both L20 and S20.

Kats