Captain Obvious

Yeah, I didn't get away unscathed, but it could have been a whooooooooole lot worse. It was completely dark at the time and I never saw it coming. Huge BANG!!!! and a flash of brown, a couple big splashes of deer snot up on the windshield (I knocked the snot out of him), and then I saw him slide off across the oncoming lane into the brush. I was probably going 35-40 at the time. I went back today and took that pic. No fun at all for anything involved.

Last night I did this: I got off pretty easy. You should see the other guy: Say what you want about my park bench bumpers......

Ol' Blue!!!!

Agreed. Hopefully no revisit. I used an OEM Nissan gasket because after all the problems I had with my motor, the last thing I wanted to do was mess around with the head gasket again. Not saying that's any better or worse than what you used, but just that "if it's good enough for the dealer"... And there is a note in the FSM about re-torqueing, with the assumption that your using an OEM gasket of course. I figured what could possibly go wrong. Go wrong. Go wrong.

As mentioned prior, there's a whole lot modified on that system, and much of it done poorly. PCV connected, but valve cover vented to atmosphere. AFM mounted sideways. Static fuel pressure instead of varying with manifold vacuum. I don't think that's a stock throttle body. Looks like they threw an aftermarket one at the car because it's supposed to be "better". What's with the short stub of tubing that comes off the throttle body and goes to where the cold start valve used to be? Which side of that throttle butterfly does that tube come from??? It looks like the butterfly may be completely bypassed by that tube? Hopefully on that aftermarket TB, it comes from the high vacuum side, because if not... Sheesh! My humble opinion? The easiest route forward is to put most of it back to stock. Either that, or you will need an expert. Pay for one, or become one yourself. See if you can get the box of old parts the neighbor kid took off and put most of them back on. Someone threw a lot of time and effort at that engine, but I don't think they did it any good.

Excellent! Sounds like great progress. I don't know if it's really necessary, but I re-torqued my head bolts after about 100 miles or so.

I've only ever seen two length head bolts*, and the positions are pretty easy to figure out... Long ones go through the cam towers and the short ones go everywhere else. Five long ones for five cam towers. *I did see in the 1972 FSM where they referenced three bolt lengths. So that's either a feature of the early cars, or a typo. I've never worked on one that early, so I can't verify the lengths.

I suspect that the oil seeps down the shanks of some of the head bolts since the tops of the bolts are constantly bathed in a violent flying oil bath. The washers under the heads of the head bolts aren't made to seal. I suspect that some of them do, but some of them don't. Or... Depending on the head bolt in question, it could be leaking past the head gasket from one of the oil galleys. I had a couple exactly as you described on my engine, but the ones that were sludgy were nowhere near the oil galley holes, so I suspect the former.

I don't think any of the bolts go down into any other cavity, but some of them are drilled and tapped slightly deeper than others. And if you're really worried about the possibility of a tip of an old bolt being broken off down in the hole, you should be able to get a look down there with a good light. The bottom of the hole is cone shaped like the tip of the drill bit that created it. If you see a ragged flat bottom, you might want to do some more cleaning and investigating.

Oh crap... So when I said crank revolutions, I meant cam revolutions. I was spinning stuff and counting, but in all the excitement, I kinda lost track myself. I changed the original post to fix that mistake. Thanks for the help guys!

Oh, it's still there. I had the head work done by Dr. Marcus Nichols at Plexicorp.

If that doesn't work, then maybe you'll need to try a tap. Not denying that there are circumstances where it's necessary... Just saying that I think it's an overused and often unnecessary procedure.

It's a plan. You just need the correct brush. And I've found it most effective to stuff the brush all the way in and then rotate it in the direction that unscrews it. That tends to bring the gunk out instead of driving it deeper. And then at the very end, give it a couple blasts of carb cleaner. Stick the straw down the hole and cover the hole with a rag while blasting And don't get any in your eyes.

I have heard it said that the bright links of the timing chain will "line up with the timing marks ever now and then" when you spin the engine over. Well... I'm here to put a number on it and that number is eleven. I lined up my timing marks and then rotated the crank to see how long it would be until the marks lined up again, and the answer is that they line up every eleven rotations of the cam (twenty-two rotations of the crank). Not being satisfied with only experimental results, I counted teeth and links and stuff. There are 20 teeth on the crank gear. There are 40 teeth on the cam gear (makes sense since the cam spins at half the crank speed). There are 110 "teeth accepting holes" in the chain. The common multiple (modulus maybe?) of all of those numbers is 440 and it takes eleven cam rotations or twenty-two crank rotations to move 440 link holes. The links of the chain will line up in the same position every eleven rotations of the cam. And because everyone likes pics... Timing chain and pulleys:

LOL. Absolutely. Never a doubt.

I'm no expert, but I wouldn't chase the threads in the block with a tap unless you really really have to. I wouldn't want to remove any metal, and running a tap in there has the risk of cutting out metal that does not need to be. I would use carb cleaner and a small round metal wire brush first before you resort to a tap. If, after wire brushing, the head bolt threads in easily all the way to the bottom, then you're good to go and it doesn't need to be chased by anything more aggressive than that. IMHO.

I'm not going to get into which direction is right for your application, but those two wires... the red and the green... Are polarity dependent and can certainly have an effect if reversed. Most (if not all?) ignition module systems use the falling edge zero crossing as the trigger. It's the most reliable point of the pickup signal.

I dug into the FSM's for the various years a while ago and here's some excerpts from my notes... 79 - is the same as 77 and 78 - 5th gear ratio is .864 80 - is different than every other year. 5th gear ratio is 0.773. But an interesting thing to note is that they got that ratio change from the main drive and counter drive gears, not from by using a different 5th gear set. This means that all of the other gear ratios are different than the prior years as well. 81 - has a 5th gear ratio of .745. They got that ratio change by adjusting the 5th gear set. The main drive and counter gears are the same as 80 so other than 5th, the rest of the ratios are the same as a 80. 82 and 83 - are the same as 81. So the bottom line..... If you put the tranny in 5th gear and turn the input shaft ten times: 77-78-79 output shaft will turn about eight and a half times. 80 output shaft will turn about seven and three quarter times. 81-82-83 output shaft will turn about seven and a half times. That ought to be enough distinction to tell them apart.

Frankly I'm a little disappointed. The zKars I know would have spent an unreasonable number of hours filing and measuring the POS pot metal spacer until it was accurate.

LOL!! Missed it by this much! No big deal. You ought to be getting pretty good at adjusting it by now.

Sorry for the delay. ID of the spacer tube is 1.290 inches. My assumption is that the original target was 32.75 mm OD of the spacer tube is 1.685 inches. My assumption that the original target was 42.75 mm Anything close to that would be fine. The OD of the stub axle where the bearings reside is 1.250 inches. This means that the 1.290 ID of the spacer tube results in about .020 inch (0.5mm) gap per side if you get the spacer centered. So reverse engineering the design, I'm theorizing they picked the size something like this... "ID of the spacer to be 1 mm larger than the OD of the shaft, and it should have a 5.0 mm wall thickness."

I think I see the divot from the original lock washer dug out of the one washer. Something has to go through the middle. I'm thinking you misplaced some parts? BTW, that float valve does not have anything to do with the power valve, right? It's only in those pics to show scale size or something?

I don't have the dimensions written down, but I will get them. I can tell you, however, that (within wide limits), those two dimensions aren't really important. It has to be big enough on the ID to pass over the bearing surfaces without binding, and it has to be small enough on the OD so it doesn't interfere with grease flow into the balls. Other than that, it doesn't really matter.

Sorry, we're using too many vague references here to "regulators"... There is a "main" voltage regulator on the alternator output that controls the whole car's system voltage. It's job is to maintain the alternator output voltage relatively constant under all conditions. Then in addition to that "main" voltage regulator, there are also other regulators built into each of the bimetallic dash gauge that compensate for changes in ambient temperature. And it was those "secondary" regulators that Dave was talking about. The regulators built into the gauges pulse width modulate the current to the sensor(s) by opening and closing a (second) bimetallic strip driven switch inside the gauge. It's job is to switch the current to the gauge sensor on-and-off at whatever pulse width duty cycle is necessary to keep it's "regulator" strip at a constant temperature. My supposition is that since it's more of a "power" device designed to keep the temperature of it's strip at a constant temperature, it may account for both ambient temperature AND system voltage. If the system voltage is lower, it takes longer for the strip to warm up. If the system voltage is higher, the strip heats up faster. Same with changes in ambient temperature. I haven't thought it all through thoroughly with my notes in front of me, but that's my theory. Which is mine.

That regulator is to deal with ambient temperature variations, not system voltage. Since the needle deflection is based on temperature of the bimetallic strip, ambient temp is an issue. So they address that in the gauge. I'd have to go back over my notes to figure out if system voltage would be a factor as well. It's a voltage divider, so system voltage variations may come out in the wash.