Captain Obvious

No, Not a Pun. It's a Palindrome! Glad to hear that the head condition didn't ruin your day. I guess I just take stuff like that harder. When I buy cheap used from a junkyard untested, I takes my chances. But when I pay good money for something that's supposed to be rebuilt, tested, and drop in ready? I expect more. Back to the job at hand... A question for the collective. What's the consensus of Felpro head gaskets for the Z? Are they a good choice, or are there better options?

Absolutely. With all that coil ringing being pushed back into the primary side! But do remember... My pic is in the quiet environment of my bench. I could do the same thing and take a pic of a points style distributor using a pull up resistor instead of a coil and I would get beautiful clean square waves. It's not until you put the distributor it in a car and get all that flyback noise from the coil that things get messy. In fact, I wouldn't be surprised if there was some coil noise that would show up in the electronic distributor as well. The ignition module would help isolate the pickup from the coil noise, but I bet $5 that it wouldn't get rid of all of it. In other words, I bet that same pic would look a lot dirtier when taken "as installed" with the engine running.

At the time I took that shot I didn't really care what direction it was spinning. I just wanted to see the wave shape. However... When you look down at the distributor as installed, it spins CCW. I used a drill on the distributor shaft to spin it, and I see no reason why I would have switched the drill to reverse for the pic. So that would mean that the shaft spinning CW as viewed from the bottom would result in the correct spinning direction as viewed from above? In other words, my pic could very well be the correct spinning direction. There's no reason why Datsun couldn't have used the falling edge to trigger. The best edge to trigger something like this is the steepest one with the greatest rate of change regardless of the direction (rising or falling). I'm sure the trigger point is the center of the pulse where the steepest section occurs by the zero crossing. I doubt the triggering is amplitude based, and I also doubt they are triggering on either of the curved lower sloped areas leading up to or trailing where the reluctor passes the pickup. But regardless of the true direction, it's easy to see how changing the polarity would mess with the timing. I might have a ZX distributor laying around... If I do, I'll snap a pic of that output. And I'll be sure to actually pay attention and verify the correct spin direction.

Sounds like good progress. Here's to hoping that everything works out as planned. What brand head gasket are you planning to use? And are you going to say anything to the head supplier about selling you a "rebuilt" head with three stripped out holes in it and a mangled stud? Personally, I'd be pissed.

"doh!" Glad it was that simple!! Don't remember if I was spinning this the correct direction or not, but here's what the reluctor pulses look like. Other direction would be mirror image about Y axis:

I've thought about what the grease does at high temps and spinning as well, and I've come to the same conclusion as John Coffey. I don't think it goes far and it certainly doesn't liquefy. When I took my old rear wheel bearings out, it was clear that the grease never left the immediate areas of the bearings. There wasn't a lot in there and it was all located by the bearings. I had to use mechanical means to remove it. When I put my bearings back together, I packed the entire recess completely full on the first one. Took about half a tub of grease. a strikingly large amount. After I got done with the assy, I tested the turning torque required to spin the hub, and it was too much. I didn't measure it, but clearly way more force than it should take to spin. Like the grease was trying to get out of the way of the balls, but just had no place to go. When I did the second hub, I packed the balls with grease and a little extra and put the thing together. Felt just like I would have expected it to. So based on those results, and because of where I found grease on the original bearings when I did the disassembly, I took the first side apart, scooped out most of the grease and put it back together again. Feels perfect and matched the other side.

Not really sure what you're asking, but here's another description of how the headlight system works... When you turn on the switch on the multi-function stalk on the right hand side of the steering wheel it allows current flow from the battery, through the headlight switch, and to the headlights. Out at the headlights, at any given time, only one of the two beam filaments is connected to anything. One of the filaments is hanging open (no-connect) and the other filament is connected to ground through the beam selector switch built into the turn signal switch on the left hand side of the steering wheel. The filament that will light is the one that is grounded. The one that is no-connect will not light. What your doing when you toggle HI/LO beams, is you toggle which of those two filaments is connected to ground and which one is hanging open.

Oh! I thought it was something functional that you didn't like. I lurk seat swap threads and I've seen some not so good reviews of the Miata seats. My interpretation of the consensus is that they look a lot better than they feel. Especially the first design. My own personal impressions after sitting in them is that the ones you have were undeserving of the bad press. Getting a little off topic now, but I shied away from the Miata seats because of the reputation and am going with Fiero seats instead. Thanks for the feedback and info!

That's a really neat idea.

Zedyone, Any details you can share on what you disliked about the Miata seats?

Well you got it bad, my friend. You know... That car guy thing that makes some of them do weird stuff? You got it bad. Not saying I'm any different. I'm just sad that I didn't think of that TIU mod first. :laugh:

Chas, Did you do that, or are you thinking of doing that? Did you take those pics?

What metal disk are you talking about? Is there a disk in your picture somewhere? Everything looks black... Can't make out any seams. Are you talking about the piston itself maybe? The part that the rubber seal slips onto?

Yup. Like that. You're having trouble finding HD-30? I've not had that problem. I've found that HD-30 is easy to find. What's hard to find is non-detergent 30W. At least in my area.

If your leaning out at throttle punch, then you're going the wrong way with the oil. Ditch the 20 weight and replace with 30 weight.

Yeah. What he said. (Only additional independent thought I can provide is that the piston max rise is NOT simply max RPM. You can easily run the engine up to max RPM by grabbing the throttle linkage while sitting still, and the pistons will not rise all the way to achieve that feat. They will reach max altitude when the engine sucks the most air. Might be at max torque, might be WOT at max RPM.)

Gotha. I just reread what you wrote before and just realized that you had not made any mods. You just thought about making mods but didn't actually make any.

Or: or a hat or a brooch or a pterodactyl.

Agreed. And that also falls in line with what I mentioned about the races being press fits, but not as tight of a tolerance as other bearing press fits I've messed with in the past. It's clear that they designed the system with the intention that you could do things your not normally supposed to do (like apply force through balls) without destruction. That said... When I put mine back together with my new bearings, I worked up this weird fixture contraption with custom ID tubings and drifts, etc. that allowed me to press the assy together and still follow traditional "don't put force through the balls" rules. Was it a pain in the arse? - Yes. Was it worth it? - I wouldn't if I was on the clock. I would just do it simple like they say in the manual. Would I do that again on my own car? - Probably not.

In theory, "No". Reason being, there's no way to get the outer bearing off the shaft without putting force on the balls. You see, when you install bearings, you're never supposed to use the balls as part of the force path to install them because you run the risk of damaging the balls or the race. You're supposed to only press against the race that is being forced into place so that no force goes through the balls. In other words... When you install that outer bearing onto the shaft, you're supposed to press only on the inner race as it slides against the shaft to it's fully seated position. Works fine for installation of that outer bearing, but you can't get around to the other side to grab the inner race when trying to disassemble. HOWEVER!! When you pull that stub shaft out of the housing, you'll be looking right at one side of the balls of that outer bearing. You should be able to get most of the old grease out replace with fresh without ever taking that bearing off the shaft. (And as a side note - At least on my car, that outer bearing is not an incredibly tight press fit against the shaft and mine came off easier than a lot of other bearings I've messed with in the past. With the relatively small amount of force I had to use to get it off the stub, I would have been willing to put it back into service without fear that I dented the races.)

So about your Miata seats... I can see the top of one of them in the background of your pic. Why did you hate them? At the last local import show, I went walking down "Miata Road" looking at the seats. Info was sketchy and hard to put together, but I believe there are (at this date) maybe four different styles? First - something like 90 to 98 Second - something like 99-00 Third - something like 01-05 Fourth - 05-present I think yours are the second generation. A couple generous Miata owners also offered me the opportunity to sit in their seats, so I have some seat of the pants impressions (get it?), but I want to hear yours.

Got any pics of what you did?

Sounds like something that would happen to me. Measure once, cut twice, I always say! In any event, glad you got it together. Another crisis averted. And I bet that after being compressed for a while, the next time you have to mess with the bar (if there is a next time) it'll be a lot easier since the bushings will take some compression set.

Seeing as how it was in the context of the strut work, I'm positive they meant collapsing one coil (to lower the car).

Yeah, I'd just get some longer bolts and call it a day. And I don't see any problem with that. I'm not a suspension guy, but I don't see it as a particularly strenuous application. The bushings will deform and limit the force on those bolts. You guys fighting and struggling to get the nut started and pre-squishing stuff with wood blocks and jacks... What's the point? Haha! Is it really worth the fight? Just get some longer bolts! My car came from my PO with new links. I have no idea where he got them, but the bolts are plenty long enough. I've got maybe a half inch of threads I have to traverse before the nut even contacts the back of the washer. Once the nut is tight, I've got maybe an inch of threaded length sticking out the back of the nut. And so what? As for the lengths front vs rear, I've had all mine off for suspension work, but I didn't compare lengths of anything between front and rear. I just kept everything with the end of the car they came from. I can tell you though that my rear bolts are plenty long as well.