Info needed: Block brackets

[ensys]

 

At the risk of exposing more of my considerable ignorance, I would pose the following:

Working with the well-known on-line parts manual, I have come up against an issue of production timing that has me confused, and I am hoping for some enlightenment from this forum.

My puzzlement is centered around the period between the start of A/C in Aug ’73 and the end of the Air Pump in Aug. ’74 (dates as per diagrams… are these good?).

Part I: Since both apparently occupied the same space (the front lower left side of the block), how were there Air Pump equipped cars provided with A/C?

Part II: It is not apparent from the diagram for the Air Pump just how the 3-point bracket shown is attached to the 4-point mounting provided by the block.

Part III: The bracket shown for that corner on the (L24-L26) block diagram, looks neither like that shown on the A/C compressor diagram, nor like it would accommodate the A/P bracket, nor like it would mount any kind of compressor. What was its function and when?

My thanks for your attention.

 

 

 

 

[esmit208]

The air pump was a factory installed part for emissions. The A/C was dealer or aftermarket installed and the air/smog pump was removed to facilitate A/C installation. It just took until the late 1973 before these systems were developed. There was an additional banana shaped bracket on the air pump somewhat like the alternator as that allowed belt tensioning. The air pump probably had matching connecting points to the bracket. The last time a saw a car with the air pump functioning and attached was back in the 70's. If you are considering installing A/C the kit you buy will have vehicle specific hardware to make the installation as seamless as possible. Look at Vintage Air. They seem to be the most popular vendor for these cars. Good luck!

[HS30-H]

On 2/15/2018 at 4:10 AM, ensys said:

My puzzlement is centered around the period between the start of A/C in Aug ’73 and the end of the Air Pump in Aug. ’74 (dates as per diagrams… are these good?).

Part III: The bracket shown for that corner on the (L24-L26) block diagram, looks neither like that shown on the A/C compressor diagram, nor like it would accommodate the A/P bracket, nor like it would mount any kind of compressor. What was its function and when?

It's worth knowing that Nissan was providing a fully developed and fully integrated air conditioning system for the S30-series Z as an extra cost showroom option from early 1970. It just wasn't offered on North American market cars, that's all.

Provision for the compressor mount bracketry and etc seen on the L20/L20A, L23 and L24 engine block castings before 1973 was because the engines were also fitted to other models, most of which were offered (in Japan) with factory air conditioning. There were several different designs of compressor mount bracket, depending on model.

What particular bracket diagram are you referencing?

[ensys]

Well, Gentlemen, it's my pesky curiosity that keeps buggin' me about that transition period between the (presumable) intro of A/C in '73 and the end of the Air Pump in '74, not to mention the curious assortment of brackets thru this period.

First, there is the bracket shown on the L24-26 block diag. (fig.1, hopefully... first time trying to integrate images... fingers crossed)

Then there is the bracket shown in the diag. with the Air Pump to '74 (fig. 2)...

And then there is the bracket shown in the diag. with the A/C from '73 (fig. 3), which would seem to indicate a pulley for the Air Pump shown above the compressor (part no. 173)...

Now, if Mr.esmit208 is correct, it would mean that for a year, A/C equipped cars would not pass Fed and Calif. smog tests, a condition I can't help finding untenable. As noted above, fig.3 seems to indicate that A/P and A/C co-existed, tho I haven't the foggiest where the A/P bracket was spudded onto the block.

And I still don't get what/how the odd "orig." bracket in fig. 1 was used.

Perhaps my confusion is the price of geezerhood....

 

Edited February 17, 2018 by ensys

[HS30-H]

From the USA & Canada factory parts manual:

*14840-E4600 BRACKET - AIR PUMP

*14839-E4600 BRACKET - AIR PUMP FRONT FOR PLUS COOLER

*14840-E4601 BRACKET - AIR PUMP REAR FOR PLUS COOLER

The 'plus cooler' version brackets are not actually illustrated in the parts manual.

[esmit208]

Good research. If I look vigilantly enough I think I have the triangular bracket shown in the second diagram. I am going out on a limb saying this only because my 2002 Passat wagon has something similar to the air pump which blows fresh air into the exhaust so the vehicle can pass emissions. My guess is this was Datsuns' solution to the same problem. Because carburetors have an imperfect mix of air and fuel there is probably no real way to keep harmful emissions from spewing into the environment. But man are they SEXY!

[ensys]

 

Mr.HS30-H:

Probably a glitch in my less-than-cutting-edge browser, but as your references are neither illustrated nor active, I can only regret missing the potential enlightenment.

So, it would seem that between '73 and '74 one could have both an Air Pump (per regs) and A/C. Of course, this still begs the question about where/how the A/P bracket attached to the block, with or without A/C.

Does anyone have something to offer about the square bracket in my fig.1? This doesn't look like it could mount any kind of compressor that I've seen, and it doesn't look as if it could accommodate the A/P's triangular bracket either.

 

 

 

[HS30-H]

As I mentioned, the 14839-E4600 and 14840-E4601 do not appear to have been illustrated in any of the factory parts manuals. You'll probably need to find a real life example in the metal for your reference.

About the square bracket, maybe you need a better illustration or two?

[ensys]

 

Mr.HS30-H:

Aren't those fine illustrations; makes one wonder what Futu-whoever used to make the copies found on their website.... carved wood blocks perhaps.

As a bonus, your first fig. also introduces a third config of the lower-left block A/C bracket that while different from that in my fig.3, both diag. share the same tensioner pulley location (but not pulley brackets(!)) high on the right side, just above the water pump. Curiously, the bracket in my fig. looks the most (tho not identical) like the one in my 280, which mounts, as near as I can tell, the very same tension pulley bracket (as in my fig.3) below the distributor on the left side.

The curious thing is that the block bracket in my fig.3 looks to be the only one that might mount the A/P bracket by its two lower lugs (tho I haven't a clue where its top third lug attaches... besides the lack of a threaded boss, seems like the breather pipe is in the way), tho its anbody's guess if it (the A/P bracket) would fit between the A/C compressor's top two mounting lugs.

Mean while, I have no idea how the very early block bracket (shown in my fig.1 and your fig.2) "figures" into this at all.

It seems to be getting murkier instead of clearer.

Theories, anyone?

PS: Does anyone out there have a foto of the A/P mounted to the block?