Bringing a 1977 Z back life

[Captain Obvious]

I'm back and had a few cycles to look into the EGR systems.

Well guess what! They made a change in the thermal vacuum valve between 77 and 78. Short story is that (I would claim) they are interchangeable. Longer detailed story goes like this:

The 77 TVV is a bang-bang digital switching device. Should be closed up to about 120F and stay open at any temp above that.  (EC-11 and EC-12 of the 1977 FSM)

The 78 TVV, on the other hand, is a more gradual opening device and it should also be closed up to about 120F and open above that, but there is a THIRD state for the 78 TVV where it will close again if it gets too hot. The 78 TVV will close at temps above about 200F, while the 77 version will stay open. (EC-11 of the 1978 FSM)

Note, however, that in normal operation and a 180 degree F thermostat, the TVV should never see temps that high. This an overheated state. It seems that for whatever reason, they decided it was a good idea to cut off the EGR system if the engine got too hot.

So as long as you don't overheat your engine, the 77 and 78 thermal vacuum valves should operate pretty much the same and be interchangeable.

[Av8ferg]

Capt Obvious that was some impressive research on the TVV.  You are a true lover of these cars....thanks for that. 

So I got my fuel tank back today ($350 later) they had to redo the entire boiling and sealing process.  Will install when I return to Memphis on Sunday.  I’ve debated pulling the rear bumper off now with the tank out but I’ll still have that drip edge that welded that might look odd.  You guys think I should pull the bumper now or wait and pull the tank at a future date. 

I’m hoping the car starts with a fresh tank and clean fuel.  If it doesn’t I’ll need to serious help as what to do next. 

[siteunseen]

I run the oe rear bumper for safety and the 240 bumper up front for looks with a xenon front spoiler. Kinda bass ackwards as I drive my 240 with thin bumpers front and rear more than than the 280.

I always think of those old Pinto public safety commercials. 

$350 for a boil out and recoat!?! I may start a side business for the busy, 'cause I'm not too busy and enjoy pouring the muratic acid on all these damn ant beds on my property. 

[rcb280z]

 If I had it to do over I would get the bumper from the late 260z or the 76 280z and install them on my 77. They look better than the 77-78 ones. Then I would shave them getting them closer to the body. I like that look. There is a member here with that done IIRC.

John, it really depends on what you are wanting for rear bumpers. If your not convinced one way or another then wait til later. Dont jump just because the tank is out. Pulling the tank a second time will be easier because you will done it already. 

[S30Driver]

John,  if you are intending to remove the rear bumper fairly soon.... there are 3 bolts for the bumper shocks on each side that secure them to the cars underside.  Only the middle bolts on each side are only accessible by lowering the tank for enough clearance.   You could remove just the middle bolt on each shock mount prior to mounting your refreshed fuel tank,  allowing you to completely remove the shocks in the near future without dealing with the tank.  

The rear finisher is spot welded on and can be removed with a proper drill bit for those numerous welds.

[Captain Obvious]

3 hours ago, Av8ferg said:

 You are a true lover of these cars....thanks for that.

Glad to help. All that research done, however, I have little confidence of exactly what style (year) will arrive when you order from rockauto.     The most important takeaway is that it probably doesn't matter.

So, about the gas tank... Didn't you already have the tank done? Why is it costing you more money?

[Av8ferg]

So the tank didn't cost me extra $$ but its been a hassle.  It took three tries for them to get it right. First time they didn’t repaint the outside and just did a primer, so I said please finish the job.  2nd time I went to pick it up the filler pipe was still rusty inside and they lost the drain plug.  3rd time I went to pick it up and shined a flash light inside they missed a 4”x4” spot in the tank on the top.  They then reboiled and stripped it all one more time and then rebaked the coating, and now it looks like new.   This porcess took about 5 weeks because they’d “finish” the job and I would have to wait to get back to TN.  See pics.  I dont have the before pics because my iphone went tits up and I hadn't synced it...hint sync your phone every 2 weeks.  My phone was only 4 months old,   Needless to say the tank was really bad inside. 

On the bumpers.  I like the 260 bumpers too.  Cliff, i watched a vid of removing the rear bumper shocks and it seem they need to come out by pushing them and the tank would be in the way. Maybe there is a way  but seems like a tight space.   I don't really want to repull the tank bit it might be the right plan. I think these 77 bumpers looks like crap but wanted to focus my limited time to geting the functional aspects of the car done.  

[Av8ferg]

I need a favor.  I forgot to mention the when I pulled my brake master cylinder there were no lines connected to it.  I appears the PO forgot to put them back in and I never noticed it because they connect under the master cylinder.  I’m sure its next to impossible to order these two specific lines individually so I was think a flex line possibly.  Since I’m now headed back to NC I cant measure the lengh I need.  

[EuroDat]

I measured mine by running a piece of electrical wire along the lines.

The line going from the front mastre cylinder to rear underdside of brake switch is 300mm.

The other line going from the rear of the master cylinder to the front underside of the switch is 310mm. These measurements are give or take a couple of mm and the bends are fairly tight going to the switch.

I would look for a shop that can make two straight sections and when back home bend them to suit. If you gl with flexables, make surd they are not to close to the exhaust and limit their movement.

After all it is your brakes.

[siteunseen]

11 hours ago, Av8ferg said:

So the tank didn't cost me extra $$ but its been a hassle.  It took three tries for them to get it right. First time they didn’t repaint the outside and just did a primer, so I said please finish the job.  2nd time I went to pick it up the filler pipe was still rusty inside and they lost the drain plug.  3rd time I went to pick it up and shined a flash light inside they missed a 4”x4” spot in the tank on the top.  They then reboiled and stripped it all one more time and then rebaked the coating, and now it looks like new.   This porcess took about 5 weeks because they’d “finish” the job and I would have to wait to get back to TN.  See pics.  I dont have the before pics because my iphone went tits up and I hadn't synced it...hint sync your phone every 2 weeks.  My phone was only 4 months old,   Needless to say the tank was really bad inside. 

On the bumpers.  I like the 260 bumpers too.  Cliff, i watched a vid of removing the rear bumper shocks and it seem they need to come out by pushing them and the tank would be in the way. Maybe there is a way  but seems like a tight space.   I don't really want to repull the tank bit it might be the right plan. I think these 77 bumpers looks like crap but wanted to focus my limited time to geting the functional aspects of the car done.  

Tank looks good!

You say they baked it to cure the liner?  I learned, after a lot of reading, to not put fuel in until the smell of the Red-Kote is completely gone.  

[Av8ferg]

It will sit in a hot garage for 5 days.  Hopefully that will suffice. Break....break

EuroDat, thanks for the measurements.  I tried to pull the line of the Z’s in the yard today but the fitting were rusted and I would have stripped them out.  Will bring PB blaster next time and a proper fitting wrench and try again otherwise will try a diffferent approach. 

Lastly will this driver’s side window fit in my 77?  I know they made some door changes that year but not sure if it effected window attachment or figment. 

[siteunseen]

If you've installed the tank pull the fill cap off so it can breath the fumes out. Looks really good inside and out.