Round tops: Update and questions!

[g9m3c]

Yet another thread on my swap. I've done some searching, and haven't found clear cut answers to these questions. I was hoping some of you more experienced members could shed some light on this for me.

Late '74 260Z with a 100% stock L26 (currently converting to Ztherapy round tops)

My carbs will be here tomorrow, so I'm trying to button up some last minute things before they get here.

First of all, I got rid of the coolant lines and hoses that ran through the original intake, carbs, and balance tube.

Can someone verify that the way I have my coolant routed through the heater hoses and everything is correct?

Reducer from 3/4" hose down to 5/8" going to the heater core. I still need to make a bracket to hold the hose close to the block there.

There was originally a 3 outlet pipe screwed in here that routed coolant either to or from the carbs and intake. I have it plugged. I'm guessing this is ok?

I cleaned and wire brushed the outside of my manifolds (N36) and balance tube as well as cleaned all the hardware and painted the freeze plugs. Can anyone tell me what fittings and screw-in doo dads I'm going to need to keep? Will the PCV valve stay located in the balance tube? What about the idle air adjustment screw and fitting directly above the PCV valve outlet that was factory on the L26? Also, will the center linkage and everything that comes with my 3 screws from Ztherapy bolt/slide into place on the 260Z balance tube? Will I need to retain the idle linkage adjustment bracket mounted to the stock EGR base that you can see painted black in this pic?

I also painted my heat shield with high temp paint. Turned out very nicely. (pic sucks)

Just a general shot to show where I'm at. :classic:

Sorry for all the questions! They're kind of spread through my post, so I'll post them all together for ya. Thanks a ton if you can even answer one of them for me!

Can someone verify that the way I have my coolant routed through the heater hoses and everything is correct?

There was originally a 3 outlet pipe screwed into the t-stat housing that routed coolant either to or from the carbs and intake. I have it plugged. I'm guessing this is ok?

I cleaned and wire brushed the out side of my manifolds (N36) and balance tube as well as cleaning all the hardware and painting the freeze plugs. Can anyone tell me what fittings and screw-in doo dads I'm going to need to keep?

Will the PCV valve stay located in the balance tube?

What about the idle air adjustment screw and fitting directly above the PCV valve outlet that was factory on the L26?

Also, will the center linkage and everything that comes with my 3 screws from Ztherapy bolt/slide into place on the 260Z balance tube?

Will I need to retain the idle linkage adjustment bracket and screw that is mounted to the side of the stock EGR base?

Edited July 31, 2009 by g9m3c

[Alan O]

I am at the same exact point as you. I also found that when I went to mount the 74 Air box to the carbs, that the choke cables are exactly where one of the hoses comes off the back plate. I found a used 71 air box on Ebay. Anxiously awaiting its arrival.

So far I pretty much have the same hose routing as you do. I made some caps for the 3 port tee as I was a little nervous about the 35 year old plumbing.

Also I would like to see the answers you get to the question.

Alan

74 260Z 2+2

[Weasel73240Z]

When I eliminated the warming lines when I installed my ZTherapy carbs I ran my coolant lines exactly the same as you, works fine.

I plugged the 3rd line in the T-stat housing, works fine.

I attached a pic of my balance tube, I eliminated just about everything.

The screw on top of the balance tube is not idle adjustment, its for running up the rpm's to balance the carbs. Only used when the carbs are being tuned.

I'm not sure if your linkage will work. I bought a set of donor carbs on eBay when I bought my ZTherapy carbs to use as a core. I used the linkages from the core set.

Hope this helps.

[Bruce Palmer]

That flat top balance tube is sure a pretty thing isn't it? It ought to go sailing over the fence into the neighbor's back yard along with the carbs.

[g9m3c]

That flat top balance tube is sure a pretty thing isn't it? It ought to go sailing over the fence into the neighbor's back yard along with the carbs.

Hahaha, I know, right? I plan on making my own sheet metal balance tube eventually.

Can anyone tell me if the thin carb spacers I have now will work for the round tops? They're about 1/3 the thickness of the ones shown in Weasel's pic above.

Thanks a lot for the pic, Weasel. I'm off to the parts store to buy some brass plugs.

[g9m3c]

Alright, I got my plugs installed and everything into my fugly balance tube. :laugh: The only holes that remain open are for the brake booster vacuum fitting and the PCV valve. I guess I'll reuse one of the press-fitted nipples on the front manifold (see the pic in the first post) for the distributor vacuum advance signal unless someone has a better idea.

Also, judging from Weasel's pic (thanks again!), the 260Z connecting linkage that mounts through the bushings on the balance tube will work fine with the round tops. I was originally worried about this, but I'm pretty sure that will work out fine now.

The only thing that slightly has my attention now is the carb insulators (spacers). I hope with the carbs being 1/4" to 3/8" closer to the manifolds that it doesn't cause a binding issue with the "tie rod" that connects the balnce tube linkage to the carb center linkage. Maybe not. Here's hoping.

I'm also assuming that the 260Z PCV valve to crankcase hose will work fine as well. Hopefully no float bowl interference there.

My carbs chould be here anytime now!

-Grant

[rtaylor]

Grant. If it is a problem let me know. I think I have a spare set of used spacers from my 240 that are in good shape. I need to dig for them. I can mail them to you if you need them.

Edited July 31, 2009 by rtaylor

[g9m3c]

Grant. If it is a problem let me know. I think I have a spare set of used spacers from my 240 that are in good shape. I need to dig for them. I can mail them to you if you need them.

Ok, thanks! I should know here pretty soon. Whenever UPS decides to be kind to me.

[g9m3c]

Still waiting on the carbs! Urgh!!! It's 7:10 PM local time, and the truck hasn't been by today, and the tracking info still says out for delivery. I'm gonna be livid if they don't come tonight. :mad:

Anyway, I got the manifolds and balance tube on and mostly hooked up. All I have to do now is hook up the linkage and the next step will be to install carbs that I don't have yet.

Edited August 1, 2009 by g9m3c

[g9m3c]

IT'S ALIVE!!!!!!!!!!!!!!

....................only after I corrected a stupid mistake. I should have known I was gonna forget something. I put the carbs on, hooked everything up, turned the pump on, and checked for fuel leaks. Everything was looking great, so I tried to start it. Nothing. Wouldn't hit a lick.

I verified that there was at least some residual fuel in the mouths of the carbs and that the chokes were working properly. That was fine. I sprayed a touch of starter fluid in there............still nothing.

I went back in the garage to put the starter fluid back up and then I saw it........................my rotor...........laying on the workbench. Holy crap I was excited. I stuck it back in the distributor and she fired right off like a dream! It even idled pretty well without adjusting a thing.

I've still got some tweaking to do and a dead battery to take care of. I had to jump start it and then I let it run for quite a while, but it still didn't have enough juice to turn it over again. Hopefully my alternator's still charging. If not, I guess the GM alternator swap will come a tad sooner. I'm gonna take my battery to work tomorrow and charge/test it as well. I haven't driven it yet, but I'm planning to in the morning.

Anyway, I'm gonna post answers to some questions I had to maybe help you other guys out who are in the same boat.

"I cleaned and wire brushed the out side of my manifolds (N36) and balance tube as well as cleaning all the hardware and painting the freeze plugs. Can anyone tell me what fittings and screw-in doo dads I'm going to need to keep?"

I was originally going to run the distributor advance hose to the front manifold like the stock configuration was, but I decided to take Ztherapy's advice and use the nipple on the front carb. Seems to be working so far, although I haven't driven it yet. I'm sure it could work on either port, though. I also kept the PCV valve and brake booster fittings in the factory location. The stock PCV hose and everything worked out fine.

"Also, will the center linkage and everything that comes with my 3 screws from Ztherapy bolt/slide into place on the 260Z balance tube?"

The throttle linkage worked out easily. Everything from the center linkage between the carbs all the way to the firewall worked like it did with the flat-tops. The thin L26 carb insulators seem to be fine. No binding or issues there. The "tie rod" that goes from the balance tube linkage down to the carb linkage worked as well. The only thing I had to do was drill a couple of holes into my heat shield for the throttle return springs.

Here's to hoping everything goes smoothly tomorrow!

-Grant

Edited August 1, 2009 by g9m3c

[Alan O]

I would suggest that you not put the throttle springs right through the heat shield. Use S hooks or the way I did it was drill two 1/8" holes get two cotter pins 1/8" and put those in the holes. Then put your throttle springs into the eye of the cotter pin. Looks nice and will save the loop on the spring.

[g9m3c]

I would suggest that you not put the throttle springs right through the heat shield. Use S hooks or the way I did it was drill two 1/8" holes get two cotter pins 1/8" and put those in the holes. Then put your throttle springs into the eye of the cotter pin. Looks nice and will save the loop on the spring.

Good idea!