Zed Head

I think that the hub casting is slipped over the end of the tube then welded on. Maybe it's falling off. Worth a close look.

The super quick not much thought required test is to swap the wheels. The problem will follow the wheel or stay with the strut.

Woops. Didn't know "Kameari" referred to the whole list. The stock gear is adjustable. Also didn't realize there were so many Kameari parts. There's even a mustache bar. I seem to recall people having problems in the past with the Kameari ignition system because it has no instructions. Should be fun to get running once assembled. Motorsport is behind the times with their search results but if you put the right word in a lot of stuff comes up. http://www.thezstore.com

OR http://www.thezstore.com/page/TZS/PROD/classic12f02/10-2042

Has it ever rolled? Not clear what the history of the car is. If the wheels are the same and the hubs correctly assembled with bearings then the strut is bent or broken. Or you have mismatched wheels. Did you get one of your backs on the front and they have different offsets?

Did you forget to put the bearings in the hub? (I actually did that once on a different model of car). Something odd happening. That relationship is all tied to the strut alone.

The general thoughts about these engines, from the guys that have built a few, is that the big power increases are all released by work on the head. Apparently the intake ports are the main constriction. So the cam and the RPM potential won't be available unless you get the head ported. The fine details of squish and getting oddly specific pistons to work won't matter without head work. As I understand things. But, the standard 15% correction indicates that you'll need about 180 HP at the crankshaft. So, not terrible, seems achievable, from what I've read. Your path seems somewhat convoluted I guess, to me. It seems like flat tops, a worked head, some high RPM parts, and a cam might get you there. I don't really get the need for the domes and the crank offset work. Anyway, I think that Diseazd is the guy who destrokes his engines to get high RPM screamers. He has built several. He would know more, he can shoot me down. I'm just a words on the page guy at this point. Good luck. @Diseazd

Any dyno numbers yet? Read all of the pages. @Diseazd

This is the basic problem of "no paperwork". Can't tell where it came from. If you could get even some old letters or find some scribble marks in the engine bay, it would add a lot. Some rednecks do fine work too.

Ahhh...memories of beating a dent in the shock towers with a small sledge so the 351 Cleveland would fit in to the little Ford Futura engine bay. Good times... It was a barn though, not a shed.

You listed 240+240 crank, then L28 crank. E31 head then "worked head" with no casting numbers. Domed pistons and squish. Then you implied that I had not read what you wrote, like it was all clearly described. You have a big list of parts that might or might not work well together. You can't use all of the parts you listed in the same engine. That's what I meant by conflicting. I'm not really in to numbers matching that much, but a modified engine isn't really original, to me. It's either as it came from the factory or it's as it was modified twenty years ago. Time capsule style. I'd pull the numbers matching engine and hop up an L28. Then you achieve both goals.

That's a cheap gauge, with no damping. The needle bounce is amplified. Probably not a big deal to the carbs. Hard to tell what real pressure is, but it looks about 4.5 to 5 psi. An oil-filled gauge will give a smoother reading.

I read. You wrote a lot of conflicting things. Still seems like much work, getting all of the parts and operations to fit together properly, just to keep the numbers matching. If you modify the block is it really original? Good luck.

I'm not an engine builder by any means. But it seems like you're spending a lot of money on minor operations and odd parts just to create a fairly typical L6 engine. Looks like a common L6 with ~10:1 CR, and a Schneider 290F cam. And you're only getting 2.6 liters of displacement. Adding 0.5 mm of stroke (expensive machining operation), then decking the block (expensive machining operation) to get piston height right seems drastic for not much, doesn't it? How will these "domed" pistons (expensive) fit the combustion chamber? If they're not flat tops then you'll have to have the combustion chamber shaped exactly to the piston (expensive) to properly use "squish". An L28 might be a better starting point. Just another internet opinion.

The fancy named modules, like Accel and Pertronix, just pass more current and create more heat. Better spark at 7000 RPM, but if you're not going to be there it's a waste. I like the decent name brands from the parts stores. I have a BWD from OReilly Auto right now. Get on Rockauto and pick a Standard or BWD. You'll save some money and get a part that will work fine with a 0.7 primary circuit coil.

These rubber pieces peel out and can be replaced. Might actually be under what I circled, those look bigger. Courtesy Nissan had the parts a few years ago. They'll give an extra 1/4" of lift. I think it's why old Z's tend to be tail droopy.

Your test procedure is correct. Discolored module is a sign of overheating. I think that the manufacturers actually include that in their instructions. Since it runs now, and ran well before, I'm guessing you'll see good results with new parts.

Be careful with those newly coated wheel flanges. The coating can get squishy and compress, allowing the lug nuts to loosen. There are stories. Mating surfaces are best metal to metal.

Primary is resistance to voltage passing through the coil and module. 0.2 is low and will cause the module and coil both to get hot. Heat can cause problems. If you're sure of that 0.2 number I'd get a new coil. I would not run that with my parts, and I run some weird stuff some times. You might even be able to feel the heat buildup by touch while the engine is running. Put a finger on the module and see if it hurts.

I realized after I posted that the center post does see voltage. Just across very high resistance. So the 12 volts wasn't wrong, but it was the wrong test. Your numbers don't look terrible but they might be a sign of a problem that gets worse with heat. They're not quite right. Where did you get your specs? 0.2 ohms is very low, even for a GM HEI module. Spec. is 0.6. That would create extra heat. The HEI module does put more work on the coil. If you have a spare coil it would be worth a swap. It's not uncommon for coils to fail when they get hot, then work when they cool off. Ignition modules do the same.

The common test for a short is to measure resistance from one of the terminals, + or -, to the center terminal. It should be in the thousands of ohms of resistance. Like 10,000 ohms.

If you really are getting 12 volts to the center electrode of the cap that would be a sign of a bad coil. Shorted internally. Might be your problem, it would probably get worse as the short caused heat. The distributor cap only sees voltage when spark happens. It will never see battery voltage. You might have found it.

720 is right. I edited my post.

Alright, so I've gone back to a known good spot, above. As I understand it, you eventually hooked up the blue wire and it started working. Maybe it's that temp sensor? Who knows. "Welp, I'm a dummy. I didn't have the blue wire hooked to the coil. It works great now. Perfect response. Now just to figure out this temp sensor. I bought a new one today. Hope it works." Then, some things happened. "Hey guys, so I'm back with more issues haha. So I've been wrenching on the Z for months. It's getting really close to driving condition. I'm just running into another spark issue now. The car cranks, runs, and is quite rev happy when the carb is dialed in. But I seem to have an issue where the car will start, then die maybe 3 seconds of running if the idle is anything under 1500RPM. After I tried all sorts of carb tuning, and idle adjustments, it still wont idle correctly. I pulled a plug wire and did a spark check. Very strong spark, but after a few seconds of running, it stops sparking, and dies." So, maybe the HEI module did get damaged. It's hard to say. You sound confident that you're losing spark, causing the engine to die. You might make sure that the module itself is not losing power. Put your meter on the B terminal of the module and see if it is getting lost before it does. It will show low current, like 10 volts, while the engine is running, but should jump to 12 when the engine dies, if it's not losing power. One other possibility is the pickup coil in the distributor. They have been known to have wiring problems. One odd one is that the vacuum advance moving the breaker plate causes the wires to shor out. Maybe disconnect your vacuum advance to be sure. Measure resistance of the red and green distributor wires also, not voltage. Should be about 720 ohms, per FSM. Sorry. Thought you had it back there in March.

When the engine is not running you'll get the same voltage on both sides of the coil. So that's correct. Seems like your ignition system might be okay and you have some other problem. There are a variety of possibilities. I went back through the thread and you have made progress. You have spark and it does run. But, I see that you have an E88 head, which means that you have carbs. So, that's a whole new twist for a 75 280Z. Do you know what type of fuel pump you're using? Electric or mechanical? Have you measured fuel pressure? What shape are the carbs in? Maybe start a new thread about carbs. People with carbs and Pertronix on a 240Z might not even look at this thread. But they'd have the answers.