Mark Maras

Very very nice. We all wish we had one that good to start on.

I think I saw a little beetle in the garden that looked like that. Draw some legs on it.

I do think that's how it's supposed to work, in theory, but what if, when the engine isn't under a load and not using much fuel, the valve doesn't allow enough fuel to return. Now I wonder what, if any, change has anyone had when they removed the valve but kept the return line? Can anyone enlighten me on the purpose of the valve in the return line? Is it just a Miss Tilly's Orfice in the return line? I too am working on a slab of St Louis cut pork ribs. BTW, you left an o out of cooking, Freudian slip? Stay safe, in all ways.

I too, have pondered the why some do and some don't. The earlier the Z the less chance of heat soak, it would seem. Could it be that one of the larger puzzle pieces that is almost ignored is the fan. The heat soak problem happens in traffic (low to no speed), idling, and after shut-down, all in hot weather. It never happens at speed. At least if the engine is near stock. (the cooling system doesn't even need a fan at anything over about ten mph) So my line of thought is fan clutches. The resistance in them is all over the place, with varying ways of testing them. Personally, I've thought they sucked (definitely no pun intended) from the first time I owned one. I was never convinced that they were very efficient at pulling air, depending, of course, on how much resistance they had. A fan shroud would definitely help the alleviate the problem too, IMO. When the fan clutch froze up on my early 71 (metal fan), it sounded like a Cessna throttling up and it felt like the engine was down on power about 25%. Since I had a lousy opinion about the fan clutch to say nothing of the weight of that steel fan, I bought a flex fan with an extension. Previously I hadn't experienced drastic over heating. The temp would go up a bit in traffic. No heat soak problem. The flex fan did pull more air at idle. The temp didn't go up quite as high in traffic as before and it seemed like the engine revved faster. Probably because I dumped the boat anchor steel fan. The fan has to be a key element since it's job is not only to cool the internals of the engine but the externals too. BTW, If anyone with heat soak and is desperate enough, I have that flex fan set-up which could be borrowed to see what difference it makes, if any.

My G3 filter was never full and I never had a problem with the float levels or lack of fuel. I gave up wondering why, years ago. One can pull the chambers and pistons off of the carbs and check to see that the fuel is 1/16" below the top of the fuel nozzles. Easier than pulling the float chamber tops.

I believe you're correct up to a point. I don't, however, believe that the reason for the added pump was flat top carbs. The engines used the same amount of fuel regardless of which carbs they used and the mech. pump alone supplied enough fuel to run the engine at any speed. The elec. pump by the tank added pressure in the lines prior to the mech. pump, possibly raising the boiling point of the fuel or just compressing the fuel to try to prevent the fuel from vaporizing in the lines. At least, that's my theory.

The original Z's only had a mechanical pump. Nissan added the elec. pump (among other things) to try to cure the heat soak problem. I can't say for sure if it will help but it can't hurt.

No complaints from Oregon, we are the Beaver state.

This sounds like lack of fuel to me. I had a similar problem years ago when my Z wouldn't go over 45 MPH, in any gear. Engine revved freely to redline, in neutral. I limped it to my Dad's house. After explaining the symptoms, he explained that regardless of what gear you're in, it takes virtually the same amount of gas to go a specified speed. We went out, opened the hood, blew out the filter on the fire wall, started it up and the problem was gone. I drove it for a couple of days before replacing the filter. No problems. Easy thing to check before you get into things too deep. If the filter check doesn't solve the problem I'd check the other filters, and fuel pressure and volume flow.

Gorgeous carb set-up. And complete too. No Google necessary. The reference to Jalex's Z in Panama was because his Z is backfiring on deceleration. It's talking back at him more than he likes..

Well, Duh. I forgot which bumper we were talking about. Suddenly, I feel like Emily Littela. Never mind!

Since I've never bought a Z bumper, I don't have a recommendation. I believe there are a few different styles in the early Z bumpers using different length rubber strips with holes in different locations. You may need new rubber strips with a new bumper. Those can get expensive. Hopefully others who have bought aftermarket bumpers will chime in. Maybe I don't understand the chrome shop's process. I'm picturing cutting the bumper, plating the three pieces in their small tank then welding it back together. I understand the welds are covered by the bumperettes (guards) but what coating is on the welds? Am I missing something about the process? Have you seen any examples of their work?

Cutting the bumper is NOT an option IMO. Is there a chrome shop in Colombia or Costa Rica that has a larger tank?

Oh, I think it's talking, It just takes some time for owners to learn the language.

With the possible exception of Jalex's Z in Panama.

That would be a dream come true. Thought I could put a trip together for Austin but it didn't work out. Atlanta is farther but even more tempting.

I don't remember them on my early 71. but who knows, maybe the P.O. considered them extraneous B.S. Never had a problem with brake squeal.

Two down, and five to go.

Great pics Jim. Thanks for sharing. BTW, love your wheels.

Perfect explanation, as usual. Thanks for adding the other possible causes.

I can understand opening the float bowls if they thought the floats were stuck. Can't imagine why they would have adjusted them. Oh well, it's better now. Keep us posted on how it's running.

From the beginning his plugs were sooty, Ignition didn't seem to be the problem so mixture had to be the culprit. The popping started with the new exhaust. Something about the old smaller exhaust prevented the popping even with a rich mixture. How many turns down did you end up with yours and how accurate do you think the float levels are?

Yeah, we discussed the cleaned? plugs before. I agree it's gonna be difficult to get an accurate reading with those. On the plus side, the car is running much better now. Probably due to the floats now being set more accurately than they were. @jalexquijano Did someone try to readjust the floats after they came back from Ztherapy?

Keep in mind that bowl gaskets can be glued to the lids to prevent them from Pringling, per Cliff's suggestion. I understand your reluctance to open them up again but it usually takes me several tries to get them perfect. Probably just me. Anyway, CONGRATULATIONS, IT'S RUNNING GOOD. I'd drive it normally for a week or so and check the plugs again. Keep in mind that the Hitachi's are designed to run at 2 1/2 turns down + or - with the fuel level 1/16" below the top of the nozzle for best results. Keep us posted.

Sounds like we're on the right track. My gut feeling judging by your float setting pics, the number of turns down and the color of the plug is the float level is a bit too low. Are you going to double check the float level with the sight tubes you have? Remember, with the chambers and pistons removed and the nozzles 2 1/2 turns down the fuel should be 1/16" below the top of the nozzles. That is what your goal should be when setting the floats.