Hardway's Red Rocket 1972 240z Build Thread

[Captain Obvious]

10 hours ago, Hardway said:

Interestingly enough the two smaller carb feed lines were newer and were fuel injection hose

Not "interesting", but "telling". 

Those two newer lines were simply the ones that failed first! Good thing you addressed all of them before something bad happened!!

[240260280]

Nice routing!

It triggered me to think of another alternate dead-head routing:

1. Use Evap vent line with electric pump in back

2. Tap into this line at front of transmission tunnel.

3. Run rubber to FPR  on fire wall then to rear carb.

4. Some heat shield from exhaust may be needed.

 

 

[240260280]

btw here is an inexpensive higher temperature  duct tape available at Home Depot (212F).

I think John and the gang at ZCCNE liek the name:

 

http://www.homedepot.com/p/Nashua-Tape-1-89-in-x-30-yd-Dryer-Vent-Installation-Tape-1390801/207203955

 

 

And another from 3M (600F):

 

https://www.walmart.com/ip/3M-High-Temperature-Flue-Tape-1-5-x-15/21176959

 

Edited October 14, 2017 by 240260280

[sweatybetty]

On 10/14/2017 at 11:04 AM, 240260280 said:

Nice routing!

It triggered me to think of another alternate dead-head routing:

1. Use Evap vent line with electric pump in back

2. Tap into this line at front of transmission tunnel.

3. Run rubber to FPR  on fire wall then to rear carb.

4. Some heat shield from exhaust may be needed.

 

 

it does clean up the engine bay a bit

[240260280]

Convergent thinking

[Hardway]

I would like to re-route the fuel line at some point and move the regulator to the firewall.  Probably run a whole new feed line from the pump to the regulator and remove the old hard line.  For now, I just want to get thing running so I can drive it some.

[Hardway]

I have been putting in a lot of work on the Red Rocket over the past two weekends.  In addition to the Z, my shop space has received a fair amount of work as well.  The weekend before I got the Z I had a 3 ton AC unit and heat installed.  Weekend before last I replace the two 4ft shop lights with nine 4ft dual LED shop lights.  With the AC I can keep everything comfortable while I work, especially driving out the humidity.  The lights... it is like an operating room now!  I really love it and this kind of stuff is a true investment.  The sale of my series-1 Z helped make all this happen. Plus, a loving wife!

  

With the shop work all wrapped up I dove back in to the Z with the hopes of making it to Cars and Coffee.  I started with the transmission as previous experience has taught to check all fluids from end to end.  Removing the fill plug on the transmission I discovered I could not feel the fluid level.  Once I drained it, I am sure glad I did because there probably was not 4 tablespoons of fluid.

With the fluid drained I knew I wanted to change the rear transmission seal.  It was leaking and based on my research was not the correct seal even though a lot of places say it is.

With the driveshaft removed you can see just how deformed the top of the seal had become.  A little work with a pick and it literally fell out.  The correct replacement seal for this transmission is the SKF 13958.  As you can see it is worlds different than the old seal and should hopefully keep the fluid in the transmission instead of on the ground.

Installing the new seal was just a matter of using my 2 inch socket and a 3lb mini sledge to drive it in to place.  A little finesse to make sure it went in straight followed by a couple of taps from the sledge and everything was in place.  Before I installed the seal I gave the driveshaft seal a skim of fluid to lubricate it.

Since I was under the car and at the transmission I took the opportunity to pull out the speedo pinion to replace its seals.  It was looking about the same as the transmission seal.

I followed the write up below to install the new seals.  All in all it only took about 20 minutes.  http://www.nicoclub.com/archives/manual-transmission-leaking-speedometer-drive-lets-fix.html

When I had mine apart I noticed the speed gear was in a sad state so a new one will be ordered.

I went ahead and put everything back together and cleaned up the speed cable sheathing as best I could.  No pictures unfortunately but imagine a very clean speedo cable under the car!

Finally I filled up the transmission with new fluid.  I went with Dex/Merc aka Dexron III ATF.  This is the correct fluid for the transmission as it is a 280zx Turbo 5spd.  I have not had a chance to drive yet so I will post a report later on.  It took 2.25 quarts to fill it up.

Edited October 16, 2017 by Hardway

[Hardway]

Next up was the cooling system.  I knew when I originally looked at the car it had some odd bypassing done with various pieces of hardware.  Upon closer inspection I discovered that every end point had a bolt, lug nut, or random hardware and was under pressure.  I started on the driver side with the port what was originally used to run coolant through the manifolds of the SU carbs.

With the hose and brass barb removed I cleaned out the threads with a tap.  They are 1/2 - 20 fine thread in case you are wondering.  This is also the same size and thread pitch of most oil drain bolts and that is what I used to fill the hole.  A pipe plug would be a better alternative but finding one in 1/2 - 20 fine thread has been elusive so far.  You can see the bolt in another shot of the engine bay further down with the carbs off.

The passenger side was a bigger challenge and a decision had to be made whether to keep the heater core in the loop.  The hoses were not in the best shape, their grommets had deteriorated, and when I removed the lug nut from the outgoing hose I discovered the rubber had hardened and turned to plastic.  With this in mind I made the decision to bypass the heater core for now.

Under the dash I cut the hoses as there was no way I was going to be able to get to the hose clamp on the back side of the heater core.  Knowing there is still some coolant left in the core I used some rubber corks from Lowes and pressed them in to the remaining hose as hard as I could.  This should keep what little coolant that is in the core from sloshing out.  The dash will come out one day in the future.  When it does I will hopefully have a plan for what I want to do regarding AC and heat.

To cover up the holes in the firewall I used a pair of 1-1/4 inch plastic body plugs.  They took a fair amount of persuasion to get in to place but they eventually saw things my way.  The end result is as good as can be expected for  now.

The other heater hoses were fairly simple to address as a pair of 1/2 in pipe plugs were used to fill the holes.  Thankfully the old fittings came out with little drama.

 

Edited October 16, 2017 by Hardway

[Hardway]

My replacement fuel pressure gauge arrived so I installed it and a quick test confirmed it was working properly.  When I test drove the car and when I drove it home the power would break up and the carbs would cough really bad around 2700 - 3000 rpms.  This pointed to the need to go up on the idle jets of the Dellortos.  The previous owner gave me several bags of jets that were all labeled and we both felt confident moving up to the next size should do the trick.  So I decided to dive in to the carbs and see if I could cure the carb coughing and power break up.

I pulled the idle jet holders out and saw they were 65's.  A quick check of all the baggies revealed the biggest idle jets were already in the carbs.  Some online research showed the ability to drill the jets using micro drill bits.  A quick trip to Harbor Freight yielded two sets of bits.  I ended using the ones in the plastic case since they had a 1/8 shank.  I use an old school lunch tray to keep everything organized.

Using my variable speed rotary tool on LOW I drilled teh jets using the smallest bit that just bit in to the brass.

After re-installing them the car would not only idle well but I could smell raw fuel.  I think the drilling of the jets was too big of a leap for the carbs.  I went ahead and pulled the other two air cleaners away and could see the front and center carbs had fuel flowing out of their bores.

At first I thought it was a pressure issue and turned the pressure down from 3psi to 2psi but that did not help.  Since the front carb was leaking the worse I pulled the top cover and tested the needle valve.  Using a vacuum tested connected to the fuel port, under vacuum and at full upward pressure of the floats, it would seal and hold.  However, just the slightest drop would cause it to let go.  I tried cleaning the seal with some brake cleaner but to no avail.

 

Edited October 16, 2017 by Hardway

[Hardway]

Since the car has sat for some time and I had noticed while under the car that the center carb had fuel leaking from the accelerator pump, I figured a rebuild of all three carbs was in order along with some larger idle jets.  However, before ordering anything I wanted to take a full inventory of all the jets, tubes, valves, and other components in the carbs.  This will give me a baseline and keep me from ordering duplicates of what I already have.  Like any good project manager, you document everything.  An Excel spreadsheet would do nicely!

With the carbs off a visual inspection could begin.  Right away I noticed something odd on the #3 carb that could not be seen well when they were installed.  A flat head screw that does not exist on the other two.  I am still investigating why it is there before I try to remove it.

In the picture below you can see the oil pan drain plug installed in the side of the thermostat housing.

Next I disassembled one carb completely and left it as-is.  As I disassembled the other two I put some components back on so I would have a reference of how things go back together.  I also took a lot of pictures and I have Dellorto book at my side.  The good ol' interweb is a good reference too!

As the inspection went on I found a major issue.  On the left side bore of carbs 1 and 3, the pump jets were stuck in their holes.  The jets have a small flat that is easy to miss but should become evident as the jet will not drop in to place in the carb body and the small brass cover will not go on.  Some how, someone in the past screwed up here and managed to get the jet stuck.  To make matters worse, someone realized this and tried to get them out but only made matters worse but destroying the top of the jet.

I tried once or twice with some needle nose pliers but quickly determined that was not going to work so I walked away and posted up on my car club's Facebook site Capital Z of Texas and asked for help.  A member named Joseph Chotiros suggested that I pull the venturi and chokes out to see if I could access the jet from inside.  A quick turn of the wrench to remove the lock nut and screw and I could see the other side of the jet.

I placed the body of the carb in my vise and protected the bore with a wrag as I used a pry to push it out.  It took more force than I expected but it shot out and hit my peg board.

The other carb was easier as once I pulled the venturi out a little the jet just fell out.  Thankfully the holes in the body look okay but a new pair of jets will be on the parts list. 

Since these two jets were not facing the right way, this has probably added to or has possibly been the root cause of why the car had such high idle jets installed and still would not run right.  Conversations with other 3x carb setup owners indicate I should not need such a high idle jet in the first place.  I think a full clean and rebuild is in order along with two new pump jets installed correctly is a good place to start.  I have a set of 60 idle jets and may try those and work my way down.  If I discover I really need higher idle jets I will order some.  I put the car on some vehicle dollies to free up the lift in case I need to use it while I am sorting all of this out.

The findings and events of today were turned in to the spreadsheet below.

That's all for now!

 

Edited October 16, 2017 by Hardway

[240260280]

Excellent work!  You are brave to dive into the carbs like that!Good Stuff.

[240260280]

Here is a work in progress reference for Weber DCOE's: http://240260280.com/Tech/Carbs/Weber/DCOE Theory Operation and Tuning.html

 

A document link at the bottom has Dellorto information.