clutchdust

For the most part I've been really happy with the way my car has been running even though I've felt it was running rich the whole time. Pulling plugs every couple hundred miles and they're coated with a pretty thick layer of black carbon. Not to mention puffs of black smoke just revving it in neutral Today, I finally got the O2 sensor connected, at least temporarily, so I can prove my theory. Sure enough, the sensor shows it just about pegged on the rich side under all conditions short of lifting off throttle. In neutral, when I lift off the throttle the meter comes way back, almost (but not all the way) to lean until it hits idle speed and then goes right back to rich. While in gear, lifting off (engine braking) will put it just about in the middle of the "stoch" range. The only other time it appears to come off full rich is right at throttle tip in and then it goes just to light side of rich. I'm thinking that tells me about the only thing that's right on this set up right now is the pump shot. So I just put #52 jets in it, it had #54, and that made almost no difference. I have the idle mixture screws turned almost all the way in. I mean literally, I think they're turned out maybe 1/8 turn. Any thoughts?

BTW Cam, your car is sick!

Granted this is a little old now but it's never too late to show off. So here are some pics from my build of my 2.4 block with 2.6 rotating assembly. My original 2.4 block was still in really good shape. #1 cylinder was right on the edge of needing to be bored but stayed inside limits even with a hone to clean up the wear. The rest of the cylinders were beautiful. I was given a 2.6 engine by a guy who builds and races Zs. That block was too worn and would need to be bored. So naturally, it just made sense to pull the rotating assembly from the 2.6 and marry it to the 2.4. Fresh bearings, rings, chain, tensioner, guides, oil pump and gaskets. Pretty much everything else is just reused. I had the cylinders honed, the crank turned just enough to polish the journals and .005 taken off the head, but otherwise very little done to the assembly. As usual, #1 cylinder (#2 was close behind it) had the most wear just due to the cooler water hitting it from the water pump. If this was supposed to be a long term engine rebuild or something, I might have bored it or at least sleeved the cylinder. But this engine will probably not hit 20000 miles in the next decade, and then will probably be rebuilt or replaced so I'm not real worried about the future wear. The car will just be a little weekend get-around-town toy for a while. Machine work, Pertronix, headers, intake and Holley, I think I'm still well under a grand. I'm pretty happy with the way it runs. I would like to bump the cam a bit but it's still strong even with the factory cam. So here goes. Just a basic 2.4 block. This is fresh out of the machine shop before I started any assembly. I primed and painted the block a "cast iron" engine enamel. You can pick it up in some of the later photos but it's close enough in color that it's hard to detect. I coated all the oiling surfaces of both the block and head with Glyptol. I've used this a couple times before and it works really well. It's a thick enamel that fills in pours in the metal and dries with a smoother finish than bare metal. I also knocked casting flash off the block that might slow down or capture oil in the return to the pan. You can also see the main caps installed. Dropping the pistons. I didn't upload a pic of the crank installed first just for bandwidth reasons, but it's already in there. So you can see I have the top ring in the empty cylinders. I squared them in the cylinders by dropping the piston inverted to the oil ring land and then measured the gap to make sure the gap was good. #1 was right on the outer limit which was no surprise but still good, but they got progressively tighter up to #3 and then maintained a pretty consistent gap well within tolerances. Notice using the correct tools to install both the rings and pistons. Piston #1 is already sunk. You might also be able to tell I polished the snot out of the piston tops. The idea is just to reduce the grooves and valleys that allow carbon build up to accumulate. Here's the crank installed with the rods being sunk. I plastigaged both the main and rod caps as I went. Everything was within specs but as you might expect, a little loose. Here's the head assembled. New valve seals but even the valves and guides were still well within tolerances. Like the piston tops, I polished the snot out of the chambers. Not only does it reduce the surface area for carbon build up but it also reduces the amount of heat transferred into the head. You can also see I did a mild port and polish on the intake and exhaust ports. Not really a true port and polish but more a clean up of casting imperfections and smoothing. I wanted to remove a lot of the imperfections on the intake side and smooth the exhaust. I also did a basic port match. New chain, tensioner and guides installed. Don't sweat the head and pan installed. The pan is just loosely bolted at this point as I stored the engine upside down when I wasn't working on it. Here everything is all put together and the engine is installed. That's an MSA 3-2 header and Arizona Z intake with a Holley 4bbl carb. I really hate that neither company offers both parts, because they don't fit together without modification. I had to dimple the #2 exhaust pipe and grind #3 intake port to get the clearance needed. It was not fun to take a hammer and/or grinder to brand new parts. Another thing about the intake, I like it and all and think it's a better (at least cheaper) solution than the triple carb set up, but it has a couple issues. First is the aforementioned fitment issues with the header. But the other is that the carb base isn't thick enough on the flange. When I first mounted the carb I had a good 1/8" gap on one side of the carb where the flanges didn't meet at all. There was NO sealing. I "solved" this problem by putting a 1/2" phenolic spacer between them, but that cut down on my cleaner clearance, hence the Edelbrock triangle filter. Not my first choice but better than nothing. Finally, here it is all installed and running. I thought the linkage would be a little more "trick" this way than simply running a simple cable to the throttle. Works great. I have about 600-800 miles on the engine so far and no problems with it. Can't explain why the audio doesn't match the video but this is also just running through a simple Cherry Bomb. I have since put a Dynomax on there too to quite it down some. I have also had the radiator refurbished and replaced the fuel pump you see in the video. I would like to put a little bit bigger cam in it but otherwise I think the engine is done. Thanks for looking.

I like it. Don't get me wrong, but this is the hood to look over.

Just had to post again. Took the Z out this morning and had the muffler shop weld in an O2 bung. On the way back I got a little playful. Thing handles like a pig and is the slowest car I have, but the thing made me giggle like an idiot.

I'm a little conflicted on this one. I think you need to break "performance" down into different catagories. First, engine performance: in stock form, by comparison to modern cars, they're kind of sluggish, especially the non-turbo cars. Don't forget that the advertised horsepower for the 240/260 cars was only in the 150hp range. Not too bad for a car that weighs just over a ton. But give up any thoughts of a stock-ish 240 whuppin' up on one of those little hotrodded Civics. Suspension: I can't prove this yet because mine is still in stock form all the way down to the original 14" wheel/tire combo, but I think upgrading to modern rubber in a modern size will work wonders. This is pretty much a universal truth for any sports car over 30 years old. When I stepped up to 17 wheel/tires on my '81 Vette from the original 15" combo, it completely changed the car. After that, maybe some newer coils and struts would make it feel like something that could be sold today. Brakes: in factory form, they're adequate, but no more. It should out brake the minivan you're following, mainly because of the lightness of the car. But brakes are a place that you could spend good money. In my case, it's likely to be one of the last places just because the originals are "good enough". As for the overall driving impression, I increasingly get a kick out of this little car. It seems like every time I drive it I like it a little more. Unlike a couple other posters though, the car feels kind of high to me. The ride height is probably 3-4" higher than I would like and I find the doors a little high for my preference. But then again, I'm on the short side, and I'm used to shorter cars. My other car is a hotrodded, and lowered, Vette and by comparison the Z positively towers over it.

Robb, not calling you a liar, but I would really like to see that car. I mean I would really like to see that car. Especially with the suspension. Compared to my almost factory original slushbox, that thing looks positively like a gokart. Speaking of which, in factory form, these things pretty much handle like a wet bar of soap. I think a lot of that is due to the 14" tires (as is the case with virtually every so called "sports car" more than 30 years old). As for the performance, I am still a bit skeptical that a naturally aspirated sub-3 liter engine can put out the kind of power needed. Of course, you may be talking about something completely different but I'm assuming the combination you mentioned is still something like 2.8L and conventional 2v configuration? I'm sure the car's weight is also a major factor.

For one thing we need to understand exactly what happens with the turn/brake lights, especially the rear lights. The front turn lights are pretty much a straight shot off the signal switch (technically, so are the rear) but the difference is within the switch itself is an interrupter that opens the brake light circuit when the turn signal is turned on. So that what happens is when you press the brake pedal, both tail lights illuminate. However, when you select a turn signal, the interrupter breaks connection with the brake light on that side and switches that circuit through the flasher. This becomes a problem with age as all manner of things happen to the turn signal switch. Now it's been a while since I last had my switch apart so I can't remember exactly which wires are the culprit but I do seem to recall green with white or yellow tracers being involved. Anyway, back to the issue, if the interrupter doesn't break the connection with the brake light, when you turn on the signal it really screws things up. In mine, it was causing a short that actually melted the solder and the turn signal wire would come off the switch. I resoldered it a half dozen times before I finally figured out what was going on. So when you pull your switch apart you will see four contacts in an 'H' configuration on a central rocker point. These are the actual contacts for the turn signals. One side of the 'H' controls the left, the other the right. The reason there is an 'H' instead of a single contact for each side is because of the interrupter circuit. Now if you look off to the side of the 'H' you will see a pair of normally closed contacts (for the brake lights) mounted perpendicular. These should be closed when the switch is in the neutral position, but should open one side when a turn signal is selected. If it doesn't it wonks up the works and will often cause problems like the OP is describing. I am not sure of the method of failure, I suppose it's just age and heat. In my case, I just re-bent the contact so it remained in contact until the turn signal was switched. Ever since my signals have worked pretty much flawlessly. If it doesn't help the OP, I hope it helps some others.

1) Great video and really nice car. 2) Not even close to what you described above. I mean your buddy may have started with what you suggested, but that video is not reflective of that baseline. Now I've gotten into a lot of arguments with the Vette guys because I'm planning on something kinda sorta similar. But the car in that video is far more of a track car build than anything close to what Datsun released. For one thing, that car handles really flat (to that end, I would like to know how your buddy set up the suspension) and I'd be really surprised if the engine mods you listed above are all that's done to that car. On the straight-aways alone the Z06 would still pull on ANY naturally aspirated L6. I'm not knocking it at all. Like I said, I'm planning on a similar build for my '73, and for the same purpose. I have gotten into a lot of arguments with the Z06 guys about my challenge (that I can build a Z for around $10k that will run with a new Z06) and think the S30 is a good baseline platform. But to run like that, the only thing Datsun will be the chassis and the emblem on the hood. Oh, and for the record, I can post up a video of my pathetically underpowered 1981 Vette passing a Ferrari Testarossa. Doesn't mean it was faster. Just sayin'

Sounds like you've covered most of the things I would suggest. I am curious about the turn signal switch you switched out. Mine was a problem and took quite a bit of fiddling to get working. I'm betting that's the source. The other thing I would suggest, regardless of how everything else works, is splice in additional grounds directly at the rear where the light plugs in the housings.

Funny you posted this. Just yesterday I made exactly what you're talking about for my shifter. Bought a 5-speed knob from Jegs that came in M16 with an adaptor to M12. As you so keenly pointed out though, our shifter levers are threaded in M8. My first though was the helicoil, but I would have to stack 2, a M8 to M10 then an M10 to M12, to get that to work with my combination. If I could have found a single helicoil I would have done that, and I think that's your best option. In my case, I just bought the M8 tap and an M12 bolt, drilled it, tapped it and cut the head off to make my own adaptor. You may consider that as an option. The tap only cost me $4 and a pack of helicoils was $5. How often do you expect to need the helicoils?

Would like to see proof.

Checked out your gallery. Just Damn!

Great looking on the cover. Don't get the mag. You have a gallery I can peep somewhere?

Holy crap man, you've already made more progress than I have in the three years that I've had my '73. Going to build that into a track day car myself. Considering that I am fairly short, I have no issues with building a full cage.

Looks like a good start. You have quite a bit of work ahead of you. Worries me seeing just two lug nuts holding on that wheel. One of the first things you need to take care of. As for a track car, the rust in the wheel well may not be all that big a deal. If you're not worried about a restoration, just cut that section out and put sheetmetal there. You'll be running a fuel cell anyway (right?).

I second the vote for the headlight/combination switch. I didn't have any problems out of my headlights but it took quite a bit for me to get my tail lights working. Had to pull the turn signal switch apart several times before I finally got it figured out. The trickiest part to fixing this particular switch is the brake light interrupter contacts. If they don't break contact as the turn signals make, it can overheat the terminal and will melt the solder joint on the wire terminal. If you try to repair it yourself, just remember to never use an aggressive material to clean the contact surfaces. 1000 grit sandpaper at the most, but generally I like to use something like steel wool or even a scotch-brite pad. The contacts have a silver coating on them and if you remove that coating, it will create nothing but problems later on.

Hoping to go to the junkyard this weekend. I'll keep my eyes open. I have no stripping at all in my window channels. Thanks for the heads up.

Come on down. Just give me a few days notice. It's sitting out in Pahrump so I'd have to make a trip over there. But if you're willing to make the drive, you can have the thing.

The compressor is in the rear cargo compartment so I'm fairly sure there's no R-12 left in it. As for replacing it, I'm probably going to go with one of the Sanden units. They're designed for 134 and only weigh a couple pounds. I swear this factory compressor is the size of a Briggs and Stratton engine and weighs every bit as much as one!

I have an original AC compressor from one of our Z's. It's an old R12 compressor and must weigh like 400 pounds. I do plan on eventually putting AC in the car, but will probably go with a Vintage Air system instead. So can you imagine anyone that might want this thing? I'm thinking it is probably worth more to the scrap metal man than it would be to anybody else. Thoughts?

THIS. I have been running wheel adapters on my Vette for well over a decade. I have probably in excess of 500 track miles and countless road miles on adapters. You need to get those spacers off the car. They are NOT hub centric, well, at least they don't make the wheel hub centric and dangerous. I might even disagree with Nigel about the 1/4" ones. if your wheel hub doesn't extend beyond the spacer, don't use it. If I can't find the wheels I want for my Z with the correct fitment, I will have no problems using adapters.

I, too, would love an update. Not only on progress with the Z but also what ever happened with the Bimmer?

OK, so I picked them up a couple weeks back and took the time yesterday to pop them in. Can I just say publicly how much I hate McPherson struts? Anyway, the wire size and number of coils appear to be the same as original but you can certainly tell from the accompanying photos that if these are stock replacements, the original springs were sagging pretty badly. I took it around the block to load the suspension but did not notice any significant difference in ride height or quality. Here are the pair I found in the junk yard. Just about $23OTD by the time they taxed me and my $1 admission fee. Comparison of the "new" springs versus what came out. Both old springs were at the same height uncompressed.

I like the idea of cutting and welding around the window channel, but what about the inner fender portion? Mine is rusted in the inner sheetmetal also. Result of crappy repair years back.