Hi Z fans!

It is with great pleasure that I open this topic! Acquisition of the 240Z on last August 14 was a dream come true!

I was looking for one Z long ago, even before the 510 SSS (1600) that I own too! These years I saw some, but for some reason or another never materialized! It was now!

The car is a 1973 Datsun 240Z . The historical level and by what I could say the was from Nissan dealership near Oporto. It as "just" 64000 km!!

The idea is to restore it in the future , but for now , I'll just some minor improvements and enjoy the car like it is!

We have performed a mechanical overhaul, normal, such as:

- Change engine oil and filter (carter was cleaned)

- Valve adjustment

- Change spark-plugs

- Change ignition cables

- Change gear box and differential oils

- Check the brakes ( are great )

- Check wheel bearings

- The tires are new

- General tunings

I have to thanks my brother because he is the " mechanic specialist"!

Here some pictures and a video from a Portuguese TVshow (sorry I don't have subtitles!) :lick:

Edited November 17, 201311 yr by Guga

Some more:

The main problem resided in the engine tuning. After all revised, car denoted a mixture too rich ... After several attempts to tune it without success (note that my brother is very good on it!), we decided to disassemble the carbs and check piece by piece. There was no need to go far to realize that the needles were poorly assembled and furthermore denote excessive wear. In Portugal it is difficult to get the original needles (N54 or N27) , so we installed the SM needles (much used in Z 's). It improved a lot, but after some test drives we think that we can improved a little more! So we start thinking about a solution for nozzles!

My brother designed a repair kit for "old" nozzles! It is a kit that opens a lot of possibilities nozzles/needles, because we can change nozzle diameter and choose the better needle for it! Sounds easy, but in practice it is not!

Here are the photos:

Old Nozzles

New Nozzles

Final Result:

We proceeded to the installation of needle SM, with appropriate centering with the "nozzle". Operation that proves time consuming and requires a lot of patience and thoroughness! This procedure makes all the difference!

Here is a photo of the SM needles that were used:

Float level:

After several checks, engine starts running very smoothly with a almost perfect tune! We made ​​some adjustments and now we are doing more kms and check the behavior!

For now we are very pleased with the innovation in nozzles! We look forward to your comments!

This type of change is possible also in other Hitachi SU type carbs....

Results:

Cool Jet Mod! I like it.

Nice Z too.

I was in Lisbon in May... I hope to return. Wonderful people, food and buildings!

So it appears you cut the end off the jet tubes and threaded them. What did you use for jets to thread into the modified tube?

Charles

That's a smart modification ! I like the idea..

I have been wrestling with my carbs also, in the end a rebuilded set from Ztherapy made it running perfect, without fouling the plugs everytime.

Have you noticed the main mixture screw raises or lowers the nozzle height to lean or richen the mixture ?

It looks your Z is a European one right ? You have the 5 speed manual ?

Edited November 18, 201311 yr by bartsscooterservice

Cool Jet Mod! I like it.

Nice Z too.

I was in Lisbon in May... I hope to return. Wonderful people, food and buildings!

Thanks, Blue!

Yes, Portugal is a small country, but indeed we are good people, we have great food, beautiful weather and wonderful cars!!

Return any time! You are always welcome!

So it appears you cut the end off the jet tubes and threaded them. What did you use for jets to thread into the modified tube?

Charles

Patcon,

We need to cut in order to install the thread (small piece with an hole, that we call jet) in the threaded jet tube. At the end the height it's same than the original jet tube (nozzle)!

Jet has 2,55 mm or 0,100 in (like original), but we can customize for other applications!

Edited November 18, 201311 yr by Guga

That's a smart modification ! I like the idea..

I have been wrestling with my carbs also, in the end a rebuilded set from Ztherapy made it running perfect, without fouling the plugs everytime.

Have you noticed the main mixture screw raises or lowers the nozzle height to lean or richen the mixture ?

It looks your Z is a European one right ? You have the 5 speed manual ?

Hi!

Nozzles slide smoothly on carbs body! No problem! Choke works well also! We have tune it with 2 complete turns in the main mixture screw (nut).

Yes, my 240z was sell in the european market (Portugal). It has a 5 speed manual gearbox! And an original rear spoiler!

@Gugat.

 

I'll be in Portugal in a couple of weeks.  Please PM if you wish to connect. I'll be in Lisbon area.