Quick question. what is this? 1970 R1600

[Mspencer]

i dont know what this is ? i have a manual choke, it works well so what is this for? if it is smog related can i remove it?

i 

 

While i am asking, what are these "ports" for?

 

Thanks for the help.

[datzenmike]

I believe that is an early electric valve to allow air into the intake during hard high speed let off deceleration. Needs clutch and transmission switches to work properly. This would lower the extreme intake vacuum and draw less fuel in that wouldn't burn fully and go out the tail pipe and suck less oil down the intake valve guides. Mid '70s the L20B engines had an anti backfire valve that replaced this. It senses extreme vacuum over a set limit and bleeds air into the intake to lower it and automatically shuts off when it returnes to normal. Though it is an emissions device it does save gas and oil.

[Tedman]

Red circled items: Plugged air injection ports? Pipes from an air injection (smog) pump would connect there. I'm no Roadster guy, but that would be my guess. 

[datzenmike]

The R1600 was also used in the 411 SSS. (also the Silvia an the Homer but not used here) I think ]2eDeYe has a 411. Ask him if he has an air injection pump. That's going back into the mid '60s I doubt air pumps were used then but maybe planning for future use.. 

 

The '70 521 had an air pump. 510s had them.

[MikeRL411]

The circled bolt heads are indeed air injection ports.  The ports were introduced about 1970 and the replacement heads were shipped with the ports no matter what year you requested.  Later replacement heads had the bosses for the injectors and had no threading on all holes, thus fit SAE and Metric engines.  If air injection was required, you had to drill and tap for the injectors.  I have one of these "Universal" heads on my RL411.  If anyone is interested I could post the manufacturers part number for this late model head even though it is certainly NLA.

[datzenmike]

But was not the R1600 discontinued '70.5? Here in N America that is, when the Z240 came out?

[MikeRL411]

16 hours ago, datzenmike said:

But was not the R1600 discontinued '70.5? Here in N America that is, when the Z240 came out?

 Yes but the roadster continued as a race / endurance favorite for several years.  Nissan USA continued to support the R1600 as long as there was a demand for parts.  Then along came Renault.  Thousands [literaly] of parts were scraped because they were over 10 years old. 

 

Metric engine parts were listed as preferred but the older SAE parts were retained in stock at the Gardena warehouse.  Most counnter parts people were not aware of this.  I needed a cam shaft.  NLA on the metric newer part with no backorder or due date.  About a thousand older parts on the shelf.  One of the original shelf queens is in my RL411 today.

 

The head was very popular.  Eventually Nissan stocked a universal replacement.  Cast with bosses for air injection but not drilled.   All bolt holes drilled but untapped, do it yourself for SAE or metric. Perfect replacement, I have one in my RL411.

 

Gardena Nissan corporate parts department was a great source for parts including checking into the Yokohama Foreign Parts department on a regular basis for odd part support.  I used them frequently.  After all my car was obsolete by the 1970s.

[datzenmike]

1/ Did any production 311/411 R1600 have a smog pump????? or any Fairlady Roadster?? 'Cause I can't find any.

 

2/ Can't see any R1600 powered race car having to be retro fitted with a smog pump to comply with emissions.

[MikeRL411]

20 hours ago, datzenmike said:

1/ Did any production 311/411 R1600 have a smog pump????? or any Fairlady Roadster?? 'Cause I can't find any.

 

2/ Can't see any R1600 powered race car having to be retro fitted with a smog pump to comply with emissions.

 

1-  311 roadsters produced during the transition to the 240Z would have been registered as 1968 to 1970 models, had metric engines and would have had to comply with the registration year import car standards.  Shoulder belts and air injectors.  These would have by design had the metric engine.

 

2- If entered into production standard road racing events, the vehicle would have had to comply with production standards for the year of manufacture.  Like shoulder belts and smog requirements.  Many 1967 RL411 were registered as 1968 which complicates the scene due to late sales of dealer cars and idiosyncries of state registration rules [date of manufacture or date of first sale].

[datzenmike]

 OK found the smog pump.... (always easier when you know it is there somewhere)