70 Cam Guy

I like the idea, that stainless muffler will sound nice. Can't wait to see how it turns out

I like this idea better than mine

The time my car vapor locked on me and quit, I had to tow the car back home. Point being it was essentially out of gas and it took a good amount of cranking before it would start later that day/night. Not trying to say you vapor locked but it takes some time for the gas to make it back up the line and fill the bowls. When I was still getting my car going, I tested the inlet/suction side of my mechanical fuel pump with a vacuum gauge. It doesn't sound like it's necessary but if you're curious, you can try it

Thanks, Dave! Thankfully(?), I haven't gotten around to the harness/relay upgrades. Since I did find a socket that will work in the tach and speedo holes, I am less worried, though not thrilled about tackling that. I am trying to stay positive and be patient with this There are 3 inline bus fuses on the right side of the center console, 1 for the radio and 2 others that I don't know where they go. The 2A radio fuse was blown and the other 2 tested 0 resistance. Is there another fuse I'm missing that's over by the hazard flasher and the body harness connections (the right kick panel)? I pulled off the red lead to my blower motor to probe the harness side with my test light. With the key and heater switch on, I wasn't getting a light on my probe. The fuses in the panel had 12V with the key on. I was thinking the resistor pack failed but it looks like the heater switch is the blower control. I am also not seeing anything on full blast. I didn't think to check voltage on the other inline fuses. I tested my ground using the radio lead. Lots of things to check, and maybe check again. The big bummer is this car has 51K miles, and before this, the wiring was perfect. Nothing under the dash is dry or cracked. The heater ducting is even still squishy/springy. I'm no body builder but my arms aren't very skinny. I have mini bruises everywhere, the red scratch lines are starting to fade finally, and the cuts look to be healing already. My hands barely fit in this dash Everyone, thanks for your help!

Thanks, We were seeing 15-16 volts on the side of the road. When we revved it we saw it spike to 32 volts for a second :eek:. I don't think it was sustaining that but I am sure that will easily smoke some components. I wonder if a sustained 15-20 volts could gradually heat the wiring to the point of softening the insulation. I could only see one wire indenting the insulation of the power white/red. (couldn't reach it) Good call, I will verify the fuse values on my next work day. The fuses are all seeing 12 volts with the key on I just looked at the service manual and you're right, it doesn't look that difficult to remove the speedo and tach. They each have 2 nuts on the back side of the gauge. The actual bulb sockets in the tach are 1 wire, grounding on the gauge chassis so they won't be hard to replace. I might try an under dash solder on the single wire (face shield a must) but I'll see how I feel when I actually do it. still a good amount of work to do Incidentally, I discovered today we have a dimmer on our gauge lights as I was looking through the FSM today. I have never even noticed the knob till today!

I read that last thread about the zinc content and ordered the VR1 10W30 from JEGs. The engine is running very smooth and quiet. I think mileage will help dictate which weight you run. My car has low miles so I am sticking with 10W30 for a while. If I can't find a source for Swepco, I'll keep running the VR1 oil with the NAPA gold filter or a Nissan filter. Why are you considering moving to 20W50? Is it using oil? Oil pressure not quite right?

Thanks Sarah for the confirmation, too many charging problems with this car to want to take chances with voltage again. Today's findings: 1 blown fuse: radio's 2A bus fuse All turn signal/hazard bulbs were blown including brake bulbs. Dash bulbs that were 'on' at the time blew, and partially melted the sockets they are mounted in (both turn signal indicators and parking brake). That is not going to be fun. I'm not sure how to make more room for my hands (found new sockets at Pep Boys that fit the holes) I keyed on and turned the heater switch to 4. Using my test light, it looks like no voltage is getting to the blower motor (red lead). My next stop is to try and get the instrument control finisher removed to get to the heater switch. I have the (stock) radio knobs removed, radio face, heater switch knob removed and 4 mounting screws removed. The finisher is loose now but it doesn't want to come out for some reason. The FSM doesn't have explicit directions to remove this panel but the couple exploded views don't show anything else that might be holding it on, except maybe 1 screw from behind. Going to have to search on this I think unless someone knows? While I was looking from behind, it looks like a couple wires were starting to melt together. Doing wiring doesn't bother me too much but I really hate working under the dash, too many sharp edges :stupid:

Essentially the voltage regulator limits the charge voltage of the alternator. When the regulator fails as mine did, I was seeing 15+ volts at idle and even higher with the engine revving. Electric motors (fuel pumps, heater blower motors) will turn faster with more voltage, and bulbs will burn brighter like the headlights at higher rpm. There is a threshold though where the excessive voltage causes a failure (likely from heat in electric motors). I had been on the road for 120 miles already so all that time on the freeway overcharged the battery to a point that it probably discharged and no longer held a charge. It was showing 1 volt! Yes, I did have my multimeter with me Anyway, IIRC voltage is considered potential energy and current is the flow of those electrons. You might think of it like a large river with a very slow current (large voltage, small current (amps)). You can also have small streams from, say, snow runoff that are small in relation but flowing very fast. Current is what is really dangerous to us. Stun guns operate at 50K volts but very little current (probably less than a mA). 110 volts is small in comparison but a 20 amp circuit in our homes will pack a deadly punch. I hope this helps you somewhat, Electricity is hard for me to explain because what makes sense to me is sometimes hard to communicate. I know current pops fuses but I don't know if a high voltage across a fuse will create enough heat for it to fail. Thinking in terms of Ohm's law, DC Current = Voltage / Resistance, a voltage increase with no change in resistance will result in higher current. Was that enough to pop the fuse before part failure? I don't know tbh

Thanks! Unfortunately, everything that I had on when the car lost power is now what is not working (fuel pump that is on with the key, hazards as I pulled over, heater blower was on for fresh air, parking brake when I stopped). I am hoping the fuses are the culprit. I will definitely check the turn signal bulbs. Thinking out loud here, our bulbs are dual filament bulbs so I can see why the parking lights work when the flashers do not. I am not sure if the flasher unit will even work without any good bulbs (no load) Will update later today as I hopefully find more answers

Has anyone lost their voltage regulator allowing the alternator to run wild charging? Did it toast any of your components? I lost my regulator on the drive to JCCS down highway 5. Turns out it wiped out my week-old Facet fuel pump and yellow top optima. We diagnosed the regulator and battery on the side of the road. I didn't notice the fuel pump until I had time to start diagnosing the problem. It popped the fuse whenever I keyed on (no start). Figured out the relay was not to blame so now I have a new fuel pump installed. While I was working on it today, I installed a ZX alternator and Dave's alternator plug from MSA. As a small review, the conversion plug is well worth it, very clean and completely painless. From a cosmetic viewpoint, it made my soldered jumpers look mickey moused and lame. Voltage is not going above 14.5 but it seems high at idle.... still 14+... not sure if it's due to a slightly drained battery or something else. The alternator was just rebuilt by an auto-electric shop we've known for years. The amp meter in the dash looks very steady, a couple needle widths into the positive and holds steady with the headlights. As the cob webs were blown out of the exhaust and engine warmed up (it was sure nice to hear it rev freely again), I started checking the amp gauge and loading the electrical system. As I tried to load the alternator, I noticed more systems are inop. Apparently I have no turn signals, hazards, heater blower, or parking brake warning light. The head lights work. I haven't checked fuses with a meter yet but they 'look' ok. I'm worried the over-voltage didn't pop the fuses and took out some components. Anyone have experience with that? It was getting dark so I decided to call it a day. Tomorrow I will be checking fuses, and likely looking at things under the dash :stupid: /rant off

I actually got my Grids from my Honda dealer, they offered free rotations and matched Costco prices. My best advice is to keep them rotated. I missed a rotation at my oil change and the rears feathered like crazy. My Civic has -2 degrees rear camber from the factory, enough that they released revised control arms. They are especially noisy now because of the tire wear and is why I say rotate them . When they were first mounted, they were dead quiet. I am not blaming the tires for this because I wanted to stay with the aggressive alignment. They are fantastic in the rain too. I have about 20K miles on them now. btw, the tires look good on the Z

I'm also curious how it sounds. I wasn't sure if the fuel pump concentric could still spin on the cam with the pump out. When I think of bearing noise, I think of a squeal like an alternator bearing. Just thinking out loud here, you've already taken it apart and re assembled so it can't be a cam bearing spinning or a journal not seeing oil. When everything was assembled (either the 1st or 2nd time), did you plastigage the bearings? Did the cam spin easily when it was installed? I'm at a loss to be honest but too darn stubborn to give up

Welcome! I personally feel a 240 is a good choice for the simple fact that they are smog exempt and we don't need to worry about BAR stickers and ref tickets

Typically the performance motorcycle pipes (mufflers) that I've seen are more like the perforated tube style resonators. The Stainless pipe on my bike is that style. You might run a glass-wrap perforated tube style muffler, like a Dynomax Ultra-flo welded, or double up on the perforated tube glass packs. Those can arguably replicate the type of exhausts you see on the bike. I have no doubt it will sound great, however, you'll be lucky if you can make a 240Z sound like a CBX. It's a completely different engine, 6 carbs, cross-flow head, twin cams, probably a different firing order, less displacement, etc.

It can't be the fuel pump cam spinning on the camshaft can it? I've only looked at it in the FSM so I don't know if that is even possible. Nothing is rubbing or interfering on covers? All more shots in the dark...

It's possible you have crud in the tank that settles. Once the gas level gets low enough, the debris gets stirred up and plugs the pickup. When this happens have you checked your fuel pressure? It would be ideal to be able to watch your fuel pressure while all this happens. Just as an anecdote, my friend's Jeep was stalling and we weren't sure if it was her TPS or fuel pump starting to fail. Even though the code for TPS was stored, we couldn't replicate the fault with the volt meter. We connected the fuel pressure gauge for fuel injection with a long hose and watched the pressure while the engine fluttered and surged. We thought we might need to drive around with the gauge in hand but it stalled while we were standing in the street. The fuel pressure never changed more than a couple psi before the engine cut out. Some form of fuel pressure gauge, whether it's mounted or held in your hand, should help confirm or dismiss your fuel pump/tank as the culprit. My 240 has a drain on the bottom of the tank. Do the 280's have the same 'feature'? When I was thinking my tank was full of debris, I drained my gas into a clean catch tray. The gas was crystal clear and the tank looked clean from what I could see.

You can replicate the sound free revving it? I would grab the stethoscope (or equivalent vacuum hose/long screw driver) and start searching. If you have narrowed it to the top-end, pull the valve cover and check for complete oiling on your cam. I have never tried it on our L engines but when my friends were trying to chase down a noise on the dyno on a KA turbo, we removed the oil filler to find it got louder. I know you have experience with these cars but you're sure it's not a heat shield resonating at those frequencies/engine speeds?

The local guys I spoken to also speak pretty highly of Todd and Wolf Creek. I heard Mikuni guru at the dyno day over the weekend. I didn't run my car but another guy with a '73 with round tops pulled 112.2 at the wheels (exhaust with turbo muffler, stock exhaust manifold). The AFR showed in the 12s so for fun, we pulled off the air cleaner top to see if we could lean it out a hair. It pulled 114.2 but it looked like lost a little on the lower rpm. It did lean it out in the mid-range but it went rich again up top. This was on a Dynapack, sorry I don't have the printouts. Seeing over 110 at the wheels gave me some hope

He did tell us to get our dog good and drunk if it ever drank some of the coolant. Phd chemists are usually right but sometimes things sound too crazy to be true no matter how much sense it makes when they say it Oil leaking past the valve seals is a definite source of smoke if the vehicle has been sitting a while. Leaking valve seals can also be seen on decel as the high vacuum pulls the oil past the seals. Oil usually burns a bluish-gray though

HC and CO tells me you should try to lean it out to see if it helps. Where the load test takes place, the mixture adjustment does very little IIRC. The needles really take over when the vacuum pots rise. Also check the condition of your spark plugs/gap, cap, rotor, and wires. Your smog pump would help with your HC levels. Playing with your timing/advance may help too but I can't really say which direction you should go. They obviously aren't checking visual if everything is removed so there may be no spec they are checking. Too much fuel will destroy a cat in short order. The internals of the cat overheat when they try to catalyze the unburned fuel. This is why owner's manuals in newer cars tell you to pull off the road if your check engine light starts blinking at you. It is essentially telling you there is a fault severe enough to damage the cats. A hotter spark may also help but too much may raise the NOx levels a small amount. It's a good thing you don't have a visual test there... hope this helps you a little bit

If my water pump suddenly springs a leak, I'll likely call NAPA to see if they have one available. I'll probably shop around and see if my friends can get it from Worldpac or something equally reputable. I typically avoid Autozone, but if it's under warranty, and you still trust getting a warranty replacement from them, go with the free replacement. I'd probably call the Nissan dealer to satisfy my curiosity what an OE one might cost (if it's available). 9 times out of 10 I'll go with OE if it's close to the aftermarket price... it does happen sometimes

It sounds like it was condensation but if you're really concerned, a cooling system pressure test will help diagnose if there is any seepage. Incidentally, my intro to o-chem professor told us once that drinking vodka can help if you accidentally drink some ethylene glycol. He says that ethanol will displace the antifreeze in your liver so it isn't metabolized into the stuff that hurts us. Obviously I've never tried it and am skeptical that it's true but who knows. It's been a few years

Oh I don't know, I'm still learning these sidedrafts. I figured if the 45s typically come with 34mm chokes, an L28 that needs 37mm chokes has some good mods to it.:tapemouth I still have a lot to learn

Happy to share! I like the old Toyota's too. We drove down there with a couple of the 1st Gen Celica guys (their message board is 1stgencelica). The blue one at the end of my album was our last casualty of the weekend with a broken throttle cable. It has an F20C and 6-speed out of an S2000. That thing has power to spare, dyno'ed with a base fuel map at 220 whp Another guy the drove down with us has a '71 with a freshly built 18-RG. He's got Mikuni 44's, I love the sound of that car. My friend owns the green mango (corolla coupe) in the show, but also has a '69 Sprinter at his shop I think he's going to build. I never noticed how cool the grill is on the Sprinters till I saw the cars at the show

Wow 45's with 37mm chokes, must be a hot motor I read most run with 32mm chokes on the Weber 40's. IIRC, the Weber book does say 30mm chokes for the triple kit. Do the 30mm chokes compensate since you were running 45s? Throttle response must have been out of sight. It's interesting everyone seems to be getting good gas mileage with these carbs. I never though I'd see 20 mpg with my car, let alone the 25 I got on a mostly freeway tank of gas. I'll be happy if I can keep it over 20, and will likely be beside myself if I get better than the SU's. It sounds like if you're smart with the skinny peddle you can make them work for you in any situation I forgot about the rallyX car had the Weber's on it (owned by a friend of the shop owner). It ran like a top, what a fun car! http://smg.photobucket.com/albums/v283/70CamGuy/?action=view&current=ThunderCross.jpg