Jetaway

An update: To collaborate the working figures in my head, I measured the resistance of the functioning defogger grid on my other car. Measured out as .8 ohms, working out to 15 amps, which falls into my working range. I'm going to show my work here because I'm not 100% (or even 95%) confident in my electrical circuit abilities. The PERMATEX repair product datasheet lists the minimum electrical resistance of the applied product as .001 ohms / cm. My 1972 240Z has the pre-1972 vertical grid which consists of 20 traces, each 26.5 inches long. For applying the formula to calculate resistance in a parallel circuit, I concluded that electrically it consisted of 10 traces, each 53 inches long (and assumed 0 ohms for the thick connector across the bottom) or 135 centimeters. So each run would have .001 X 135 = .135 ohms. Plugging and chugging with: RTOT = 1 / (1/R1 + 1/R2 + ...) = 1 / (7.4 X (10)) = 1 / 74 = .0135 ohms. Indicating a current of: Amps = 12 / .0135 = 888.8 = Ain't going to work. The FROSTFIGHTER defroster kit may be a viable alternative. If I do go this route, I will definitely contact their technical staff. My own preference regarding modifying my Z is to do so in a way that it could be changed back to its original state. For best results, FROSTFIGHTER recommends removing the old grid, noting that it is likely that a red line, now part of the glass will remain despite any reasonable attempts at removal. So, in the oft-chance that a miracle repair kit is invented, I'd rather keep the existing grid in place. Running the FROSTFIGHTER grid as intended, that is horizontally, would make a checkerboard pattern -- definitely not desirable. An alternative, which I would think would work, would be to run the replacement grid bars parallel and right next to the existing grid lines. It might look a little odd, but not as odd as a checkerboard pattern. I suspect to keep the current draw reasonable you'd need to replicate the existing electrical layout (i.e., ten 53 inch traces) and not simply rotate one of their kits 90 degrees (creating twenty 26 and 1/2 inch traces). Which is why I would contact their technical staff. Just BLOWING AIR on the rear window. In the earlier post I wrote that I hooked up a computer fan to blow on the rear window. A few days later I was able to give it a good defogging test. Two people, 40 miles to get it nice and toasty inside, then a stop for groceries on a 42 degree, 100% humidity afternoon. Complete fog-out upon return to the car. Using only the smaller fan, the results were ... better than nothing, but not that good. In the five miles / 12 minutes back to home it was able to clear about 1/3rd of the window, but at least it was a useful part of the window. I managed to find a second, larger fan, and installed it. Haven't had an opportunity to test it yet, but I am very optimistic that with the much greater airflow and cross-firing pattern of the fans that I will be able to drive fog-free this winter. I wouldn't expect them to be of great use in deicing, but that is not currently a concern. Very quiet too, not even noticeable with the engine running. I've attached a pair of photos of the fans, the smaller is a little less than 2 and 1/2 inch square and the larger 3 and 3/4 inch on the square. For the wiring, I simply used the existing defogger connections. I've attached them to my speakers, a simple box or even just a panel set-up mounted on the shock towers should work just about as well. Have a happy New, all. Chris

Thanks for the replies. I think I'll try to find some information on what is the resistance per foot of a repair product and use that to calculate to estimate the resistance of a renewed defroster grid. In the meantime it was relatively easy to hook up a computer fan I had lying around and mount it to blow on the back window. I suspect it won't be strong enough, but haven't been able to test it as I am apparently living in the only spot in California not being hit regularly with rain. Merry Christmas! Chris

Hi, all. The rear defogger on my early 1972 Z, which has the older vertical grid, doesn't work. The illuminated switch lights up and I measure 12 volts at the body side connector both between connectors and + to body ground. One of the grid lines has an obvious break, but that should only affect that one line. I measured the resistance between the cleaned the hell out of (i.e., shiny now) grid side connectors and come up with 25,000 ohms, give or take 1,000. If I've done the math right, that works out to a current of .0005 amps, which wouldn't provide much in the way of heating power. My working assumption is that while the grid appears intact (mostly, see above) to the naked eye, either abrasive wear from cleaning or close to 40 years of aging, or both, has deteriorated the gird, to the point that only an extremely tenuous electrical connection exists across the grid. Outright replacement of the window with a new one would be, if even possible, would be an expensive proposition. Which seems to leave me two options. The first, and less desirable, is to use an anti-fog product and rig up a fan to blow air across the window. The second is to recreate / renew the existing grid with an aftermarket repair product. I would prefer a functioning grid over the fan and anti-fog option, but am wondering about the practically of recreating the entire grid. The posts that I have read here on grid repair deal with filling in relatively short breaks in the grid, not, in effect filling in the entire grid. The aftermarket products that I've seen also appear to be designed as gap fillers, not OEM replacements. So, my questions are: 1) has anyone tried to recreate an old grid? If so, did it work and if yes, what product(s) did you use? 2) If you have experience with filling gaps, how much of the stuff would I need? I know, I'm asking for a guesstimate, but based on how much of the bottle you used for your repairs, how many bottles would I need? 3) Would it work? If no one has been successful recreating an old grid, I'm somewhat leery of spending a lot of time on what may be, in the end, an unsuccessful and possibly unattractive attempt. Why shouldn't it work? Well, my thought is that if the resistance of the repair product is significantly different from that of the original material, bridging short gaps may degrade performance somewhat compared to "new from the factory," but because it is used for only one, maybe two, percent of the grid, not be noticeable in use. However, this may not be the case when replacing, in effect, 100% of the original grid with the fix-it product. If, for example, the fix-it product has twice the resistance of the original, the current drops by half, which I suspect would reduce the heating power enough to be noticeable in daily use. OTOH, if the resistance is 1/2 the original, I'd get plenty of current, probably enough heating power and more than likely, one blown fuse after another. Chris

Yoshi, Elbow grease. I'm going to put a pitch in here against sanding it or mechanical buffing -- at least at first -- in favor of starting with less abrasive methods. Carl is absolutely correct about machine buffing being 300% faster than hand buffing, but: 1) if the paint is really shot, you've just dropped $200 for basically nothing and: 2) if you don't know what you are doing and get a little careless, you can easily cause serious damage to the finish. My suggestion: First, go buy cleaning pads, a bunch of microfiber cloths, rubbing compound, and scratch remover. Second, wash the hell out of it. Third, pick a larger piece of metal (hood, roof, or deck) and then, following the directions hit 1/2 of it with the rubbing compound. I'm guessing you will get a lot of dead paint on the cleaning pad, so be sure to rinse the sucker out regularly. Compare the rubbed vs. original paint. Good enough? If yes, then go on with the rubbing compound. If not, hit the other half with the scratch remover, then the rubbing compound. Is that good enough? If yes, well, there you go, and plan on a long day, don't be surprised if you've spent eight hours by the time your done. If no ... honestly, I'd drop back and just do the rubbing compound, followed up with a waxing. Then, seriously, repeat the process in a month or two. I mean, it's just going to get rained on anyway. If after hitting it with the scratch remover and rubbing compound the second time, it still doesn't do it for you, then consider the more extreme methods of mechanical buffing or taking sandpaper to it. Or, resign yourself to the fact that it's not going to look good until it's repainted. It wouldn't be a bad idea to find someone you trust who knows something about automotive finishes and ask them if mechanical buffing / sandpapering would do any good before going down that path. Mother's and Maquire's make good scratch remover and rubbing compounds (can't remember their brand specific -names) but I think the 3M stuff (cleverly called "scratch remover" and "rubbing compound") is a bit better. I've bought it at AutoZone and seen it elsewhere, it does, however, seem to come in and out of stock, so you may have to bug them to order some. Chris

A follow-up: No problems for 2 weeks after my last post. Then it began to take a long time to start, particularly in the morning. 20, 30 seconds of turning over before firing up. Ran fine, though, and the ammeter, while spiking, understandably, early, descended to normal levels within a minute or so whatever the problem was wasn't putting a huge strain on the battery. A couple of days after the slow start problem showed up and after a long day at work (15 hours) I jumped in the Z, turned the key and "click." Click, click, click. Now we're getting somewhere (figuratively, not literally) as before nothing would happen when turning the key to start. Lights came on strong, barely dimmed when turning to start. Got out of the car to look for a couple of students to give me a push start, didn't see any, got back in and tried again. Kkkggh -uhh- rrrRRRR Uuummpph burble, burble, burble. I recognized that sound! Drove home, shut down, restarted no problem. Next morning: Click, click, then a clattering sound accompanied by an unusual vibration. Stopped, tried again and Kkkggh -uhh- rrrRRRR Uuummpph burble, burble, burble. I had Friday off so I pulled the starter, and having nothing better to do, took it to a chain auto store to have it tested. First time, tested fine, to the kid's credit, he went, hmmm, hold on, I saw something there. Retest, nothing, as in nothing, the solenoid didn't engage. He looks up a new starter, quotes me $30 bucks, and could have it by Tuesday. He then says, somewhat puzzled or amazed, "$30 bucks? That's the cheapest part I've seen this week." I said to, him, "Tuesday? Hmmm, let me take a look around town, don't really want to leave it jacked up all weekend." This gave me a graceful excuse to go to the local independent parts store where I was told: "30 bucks, get it here by Tuesday. ... Let me check this other place. ... I can get you a higher output Bosch starter at 3:00 this afternoon. $70.00 though." I thought it over for about two seconds and said: "Do it." Not only do I prefer throwing my money at the locals, but I really didn't want to leave the Z hanging all weekend. Picked it up that afternoon, a handsome looking starter, as starters go, installed it, reconnected the battery, jumped in, turned the key and: WWWWHHHHRRRR bmp bmp. I almost s(*$% my pants, sounded like it turned the engine over at 5000 rpm. Two year replacement _and_ a two year roadside towing package in case of failure included in the price. So, I think this little adventure had two causes: First, while no individual connection was particularly bad, a little crusty here, a little corrosion there, combined with a failing solenoid worked together to cause the mysterious nothing on start syndrome. Once that was cleaned up, the solenoid sped along its way to its death, finally exhibiting the behavior and sound that I've associated with a dying starter. Second: The frog in the pan effect. The long time to start problem that started a couple of days before the starter died was caused simply by the motor not being turned over quickly enough by the starter to fire. Maybe if I had a couple of Z's I would have noticed that one was turning over slower than the other a few months ago, but with nothing to compare it to, the slow loss of cranking speed went unnoticed. Chris

1/4 tank sounds about right for low enough, but since the only reason to be screwing around with the tank sender is that the gas gauge isn't correctly displaying how much gas is in the tank, determining when you have a 1/4 tank left is not all that easy because, well, the gauge ain't going to tell you. I don't know about the 3 gallons needed to reach the pick up tube. I drained and dropped the tank to get at the vent tubes and didn't put in more than 1 gallon, probably closer to 1/2 a gallon when I was done and had no problem starting up and running over for a fill-up. I have an electric pump (mechanical pump was removed) mounted by the tank on my '72. If you have only a mechanical pump, maybe it needs the extra pressure created by the extra gallons to get going. Chris

I'm just going to add this might be more common than many people suspect. I was lucky (haha!) enough to be pulled over by the local gendarmes for no taillights. "Really, just a fuse," I assured them. Pulled the console panel off to expose the fusebox and confidently searched -- to no avail -- for the blown fuse. Ended up having to put it in a parking lot a little over a mile from home and hoofing it home to cap off a 16-hour workday. Fetched the car in the morning, looked again for a blown fuse in daylight, again to no effect. Brought out the multimeter and sure enough, there was a no-short fuse, which I replaced and that fixed the taillights. I looked at the booger with a jeweler's loupe and sure enough, the wire had physically broken away from the end cap. Between this experience and the aging of my eyeballs, I don't even bother visually checking for blown fuses anymore, its faster just to check them for shorts. Chris

It had 160K on it when I bought it two and 1/2 years ago so I can't say whether or not it was abused up to that point. Compression was a little low (5-10 lbs) but even across the cylinders and there are odd scratch-like marks on the cam that can be seen but not felt by hand. Goes through a quart of oil every 500 - 800 miles, depending on season and type of driving. Speaking for myself, I'm pretty easy on cars. A mis-spent (or well-spent, take your choice) youth of nursing left-for-dead hulks around for months, even years, with no more than oil and grease taught me how to keep stress low on cars. Not that I don't know what the pedal on the right does. Chris

Just to throw in: I printed out and brought in the description for MSAs Premium Exhaust System (For Stock Manifold) to the best of the local muffler shops and asked them what it would cost me for them to come up with something similar. They said it was a "super" price and that I should order it and they'd do in the install for $100. Having done enough exhaust systems to know that this seemingly trivially simple job is usually not, I agreed. Ordered it on Monday, arrived Wednesday via cheapest shipment option (to be fair, an in-state, maybe 350 mile ship), took the shop an hour to install. Sure sounds tougher, perhaps a bit tougher than my Z really is. It is definitely louder, even under low engine speed steady-state speed conditions, as my wife can hear me coming whereas before she could not. Adds a bit of a rumble at 70 mph (3000 rpm -- very long legged gearing on my beastie) but hardly objectionable. What I really love about it is the sound of killer bees that swarms in at 3000 rpm when accelerating flat-out. Power? Honestly, can't tell. I don't have a timing trap and didn't do a top speed before / after comparison at the time. Probably not much on my stock, no severe problems, but also understandably tired (200,000+ miles) engine, but this upgrade was made with an eye for the future (rebuild and headers) as well as the present. My only real knock is the shape of the muffler itself, as has been pointed out by others, a comparable round one would look and fit better. 2 months in, everything is still together, no bumps or creaks or leaks and I am one satisfied puppy. Chris

Thanks all for the replies. I think I can see where the "love em or hate em" aspect comes from. The design of the Grose Jets appears more resistant to clogging / jamming from debris or build-up, and possibly allow for a finer and more controlled flow of fuel into the chamber. But, man, trying to figure out an over-rich (or flaming!) condition that comes on at speed -- wheeew, that could produce an inventive vocabulary landing you one circle deeper in Hades. Chris

Saw this referred to over in the Help Me! forum. Didn't seem to be relevant to the thread and I have no emergency so I thought I'd ask here: What is a Grose Jet? And why is it apparently a better choice than a needle valve for carbs? Chris

This did cross my mind, but I've had mine out to repair a leak and couldn't imagine how it could possibly cause the described symptoms. Maybe if the float broke loose and became a ... a ... sink? a bean? ... and got sucked down into fuel line. Seems unlikely, is a good 7 or 8 on my own PIA meter to investigate, and would be shuffled down the list behind more likely suspects. If it does have something to do with the problem, my guess is that it was inadvertent, perhaps a wire, unintended and unnoticed, was pulled loose. Or some rust/gunk (or beans;)) was knocked loose when removing the unit and settled over the opening to the fuel line. I now await further clues. Chris

[some deletion of above for space.] By "fuel sending unit" do you mean the fuel pump? I'm drawing a blank otherwise. A fuel line pressure sensor that cycles the fuel pump on and off? The physical pick up unit in the tank itself? Remember, my car came from the factory with only a mechanical pump and its electric pump is an ad hoc modification of unknown origin, so a part whose function is self-obvious to you may not be to me. I'll press on best I can here. After replacing the fuel sending unit, it idled for 10 minutes and you made it a block or two at low speed before it died. At most, 2, maybe 3 minutes is the longest it will run with just the fuel in the floatbowls, so the pump must have been doing some replenishment for at least awhile. But now, assuming I have your sequence correct, the fuel lines are dry, and the pump produces no suction but does make a noise. Hmmmm. What problem prompted you to replace the fuel sending unit? Chris

Man, if this was happening to my car, I'd definitely be thinking electrical, not fuel. The first two replies to this thread had electrical-related suggestions w/ the added benefit of being downright inexpensive or free to solve. Does this cutting out occur regardless of whether the engine is warmed up or not? Does it occur in any weather? Rain/high humidity vs. dry, for instance. Does it occur regardless of whatever other electrical loads you are using? Wipers, lights, blower, radio, etc.? You don't have to answer these questions to solve an electrical problem, but anything that you can do to specify under what condition the problem occurs (or is more likely to occur) vs. not, or less likely to occur will help you narrow down the possible suspects. One more question: Do you have an electronic ignition or points? If the former, which one? It seems that distributors are pretty interchangable. My 1972, for instance, came from the factory with points but somewhere along the line it was replaced with an early 280ZX electronic distributor. And I replaced its E12-80 ignition module with a GM HEI when the E12-80 began a death spiral. Chris

As the title said: Solved -- Hopefully. That's the thing with electrical issues. Assuming things don't get out of hand, a little smoke is often preferable to determining if you have solved an intermintent problem by tracking down every possible loose or corroded power or ground connection. I'll take a closer look at the wires and some of the other suggestions next weekend -- or sooner if it won't start. Following up: I cleaned up the engine / body side runs from the battery and checked the voltage across the battery. 13.0 volts. And everything still works! To answer another posters question: The head unit is ran through an ignition-keyed circuit in the fuse box. The amp, equalizer, and antenna are powered off a completely separate power circuit, namely a very large wire with an in-line fuse connected directly to the battery. When the head unit is turned on, either because it left on when I last turned the car off or turned on with the car running, it sends a triggering signal to the amp, equalizer, and antenna telling them to amplify, modify, or stand up proudly. Of possible use for future reference: The amp and it's power wire are 20 years old (and yes, the amp, a 14 watt Harmon-Kardon kicks today's 50 watters as easily as it kicked more expensive 50 watters two decades ago). They were unused for close to 10 years before I brought them back a year and a half ago. When I fired up the modified system (added drivers and the equalizer) the in-line fuse blew (with the volume control all the way down). I replaced the fuse with one of the same specifications and it didn't blow, and hasn't despite high-volume stress testing. This has happened to me several times in the past -- an "old" fuse blows when a change is made in its circuit, but its identically spec'ed replacement doesn't. I admit that I have no rational explanation for this and that as a young whippersnapper, I'd thought the old man crazy in the head for suggesting such a thing could occur. Well, i may well be crazy, but the "old" fuse observation isn't evidence of it. Chris

My 1972 uses only an electric pump by the tank. The stock mechanical unit had been replaced by a metal plate on the block. I have to admit that I am puzzled as to why the 1973s came with both mechanical and electric pumps. I can understand why fuel injection requires an electrical pump, but carbs should need only one or the other. I would think. Taking a step back here: Why have you seemingly ruled out electrical issues? Taking another step back: You wrote that it stops running at 40 mph. What do you mean by "stop?" Just, bam, goes from running to nothing? Such that if you quickly shifted to neutral, the engine would be stopped? Or stop as in hack, cough, rough running, losing power and rpms but if you quickly shifted to neutral, the engine would still be turning over, albeit roughly and losing rpms by the second? If the former, I'd strongly suspect electrical. If the later, fuel supply problems, though if after thoroughly going over the fuel system the problem persists, its back to suspecting an annoyingly pesky electrical problem. Writing that the problem starts at 40 mph isn't as helpful as it could be. There's a lot of ways to be going 40 mph in a Z: a Z can go 40 mph in any of 2nd, 3rd, 4th, or 5th (if so equipped) gears. More helpful is at what rpm the problem occurs. Or, if your tach is dead, what gear are you in when the engine cuts out at 40 mph? Chris

Thanks for the replies, I'll do the battery voltage check this afternoon. This is what transpired. Took the battery into an auto parts store. To my surprise, tested out good, quite good as a matter of fact. Brought it home, and though the terminals didn't look dirty, took sandpaper to both of them. Connected the battery up, turned the key and fired right up. Leaving it on fast idle, I tracked the ammeter while programming in my two essential radio stations. The ammeter went up to 2, maybe almost 3 needle widths at first, then fell to its customary position of almost, but not quite a needle width to the positive. Normal, in other words. Turned the car off, waited 5, 10 seconds, flipped on the lights. Nothing. Lights off, turn key. Nothing. Turn key off, wait a few seconds, turn on lights. After a short delay, a second or so, lights came on. Lights off, turn key, fires right up. Puzzling to say the least. I had an appointment that I had to leave for in 20 minutes so I stopped futzing, got ready to leave and made the decision of death or glory. Turned the Z's key, started right up. No presets on the radio, however, so I wasn't imagining that the headlights hadn't turned on and it wouldn't turn over. Drove the 15 miles to the meeting, lasted about an hour, turn the key on the Z, fires right up. Drive home. Before I even got the garage door closed, a buddy stopped by to BS a bit. Maybe 10 minutes in, I said, heh, check out my new LED dome light. Whoa, he said, put blue and red plastic over that and people will think you are a cop. Not a minute later, he says Hey, look at the antenna. It was 1/3rd of the way up. "It wasn't like that before," he said. I wasn't sure, I would think I would have noticed if it were 1/3rd up, but it sure wouldn't have registered if it were fully retracted, so I'm not 100% positive that it wasn't partly up. I strongly suspect that he was right as in the 2 and 1/2 years that I've had the Z, the antenna has never failed to be either fully up or fully retracted. After he left I pulled the cables off the battery and sandpapered the clamps. It's worked for 3 or 4 starts and a half dozen light checks since then, but given the weird intermintent failures, I'm not declaring problem solved quite yet. Later this afternoon I'll pull the body and engine side connections, give them a cleaning, and then do the voltage check. Thanks again for the suggestions. Chris

Hi, all. Maybe a silly question. I've been meaning to have the battery checked on my 1972 240Z for a month now, kept forgetting, and yesterday morning it wouldn't turn over. Not as dead as a doornail, the headlights came on dimly, and the voltage-driven LED domelight shone brightly. I hooked up a multitester this morning and measured a current of .05 amps with the ignition off. That's about 6/10 ths of a watt, not much in other words, and presumably accounted for by the radio head units memory. However ... about a month ago (see where I'm going here?) I made some upgrades to my sound system. While I don't think the only new electronic piece (an equalizer) is the problem, I'm wondering if I either screwed up on the wiring of the trigger and power supplies or if I have created a partial short (like a strand of wire resting against metal). The system is wired as follows: Previously: The head unit trigger is sent to a power amp under the driver's seat. The power amp has a direct (fused), huge (could be 10 gauge, maybe even 8 gauge) and more than adequate line to the battery. The power and the trigger for the antenna are taken off the amps connections. The power amp does not have a power indicator, but the antenna served as an indicator. No problems in 18 months with this setup. A month ago I added: Four more drivers (no effect possible) and an equalizer. The equalizer trigger and power are taken off a splice in the run from the amp to the antenna. The equalizer does have lights and works as expected, i.e., lights off when head unit is off, lights on when head unit on. I'm going to pull the battery and have it tested, though I'm pretty resigned to replacing it. The battery came with the car, which I bought a little over 2 and 1/2 years ago and looked fine, which doesn't tell you much about a battery other than it not having been horribly physically abused. My concern is killing the new battery with a slow current drain. I haven't tested any other part of the charging system, nor other than replacing the belt about 8 weeks ago, made any changes to it. So, am I right to be unconcerned about the .05 amp "off" draw? Or, just thought of this, could this small current draw be artificially and misleadingly low due to the weakened condition of the battery? If so, what sort of ignition off current draw should be expected with a low-middle line, nothing fancy audio head unit? What size draw should compel me to pull out the driver's seat and investigate further? Chris

I'll bring 'em anyway. They are attached to a spare pair of taillights, not the ones on the car. Chris

I have 1 and 1/2 taillight seals. As you might guess, they are not NOS, in fact they are pretty hacked out but are still attached to a pair of taillights, which may be of some help in dimensioning. I'm still planning on the reunion in Sacramento next weekend, so I'll just bring'em along and let you decide if they are usable or not. Chris

Thanks for the info on the Rebello build. Chris

Rob, Thanks. I've marked the Sacramento reunion on the calendar and assuming the creeks don't rise or the valves burn, I look forward to meeting you and other Z - people two weeks, more or less, hence. Chris

Is the July 17th gathering for members of a club or can any Z-owner attend? Chris

Sorta jumping in here. Some people find my writing style annoying. Hell, I find it annoying sometimes as well. So they stop reading. If you find yourself annoyed, but would like to contribute, scroll to the bottom where I have a very brief summary. I hope to have the scratch to have my engine rebuilt by the end of August / early September. It's a 1972 240Z that had so many mods when bought (cross-drilled and, grooved in the front rotors, a 5-spd tranny and electronic ignition from, I believe a 280ZX, redone but not stock interior) that it won't be entering a concours anytime soon. It's engine does, however, match the chassis and I want to keep them together. The mileage is a bit north of 200,000 and have no reason to suspect that the engine has any less. Compression runs a trifle low, but is consistent across the cylinders, doesn't smoke regularly but will go through a quart of 10-30 in 400 miles in the summer, putting in 10-50 put a stop to that nonsense. Spark plugs generally are good now that I have about 1 and 1/2 clues about adjusting the carbs. But I replace the spark plugs roughly every 3000 -- 4000 miles just for the heck of it anyway. Strictly by eye the cam has some noticeable discoloration / not a uniform appearance that I can't feel but I suspect .001 inch is well beyond my ability to detect by touch anyway. Within the last 2000 -- 3000 miles a "knock," sometimes louder, sometimes softer and related directly to engine speed has developed. I've heard it before in other cars I've owned, a mechanic friend of mine suspects -- hell, I' forgot what he said -- I think he said it sounded like a connecting rod getting a bit loose and that it probably could go on another 30,000 miles w/o great concern. In short, its tired. Given the tremendous increase in horsepower across the board, but especially at the lower end of the market during the last ten years (and hooray for that, I say) I feel that to be right with the world, and to uphold the traditions of the original 240Z owners, and to be true to the 240Z itself, a few more than the stock 150 horses is justified. 240 horses would nice, but I think I could live with a solid 200 give or take, more give, I guess, than take. Is that realistic: 1) without increasing the displacement; 2) keeping my present externals (i.e., exhaust, carbs, and ignition) but; 3) internal modifications (cam, porting, other?)? Of some importance is cost -- getting an extra 50 horses, I'm confident of swinging, but at some point the $ per power gain increment will bend towards the vertical. Although I haven't called for an estimate yet, I admit the Rebello 2.7 "Purist" rebuild interests me. Claims 240 HP using the original engine, though obviously bored and stroked. A concern I have is the durability of the rebuilt engine. The thrill of leaving engine or driveline parts on the ground hole-shotting off the line is well in my past, I'm afraid, and in normal day-to-day driving I'm probably guilty of upshifting too soon. Still -- that developing gap your eyeing on the climbing S-curves at the end of the straight off the Sunol UH-UH, that's mine, buddy, that's mine. And as I often find myself screaming (to no avail) at M/B AMG drivers "That pedal on the right -- push it down -- its OK to clear out. Idiots!" Since Rebello is mainly known for racing motors, which are rebuilt on a regular basis, is it realistic of me to expect 100,000 miles out of Rebello? Is turbocharging a realistic alternative to a semi-race motor? I've read that the best time to add a turbo is when the engine is new, or, as in the case, rebuilt. 15 lbs should produce close to 300 HP (based on doubling of atmospheric pressure), drop that to 10lbs, low to mid 200's? Is it cost-effective to turbo for a relatively mild power increase or does it only make sense for all-out street / drag monsters? 240 horses would nice, but I think I could live with a solid 200 give or take, more give, I guess, than take. Is that realistic: 1) without increasing the displacement; 2) keeping my present externals (i.e., exhaust, carbs, and ignition) but; 3) internal modifications (cam, porting, other?)? Of some importance is cost -- getting an extra 50 horses, I'm confident of swinging, but at some point the $ per power gain increment will bend towards the vertical. I live in the Central Valley, work in San Jose. So, I guess I'm lucky in that none of the garages recommended in this string really seem that far away. Forty-five miles north of Sac-Town? Hell, I'm barely conscious the first 30 miles of my commute (kidding -- kinda). Summary: No engine swap -- stay with installed engine. Nothing "wrong" with the engine, just tired. More power than stock, please. I'm a gentle driver -- most of the time. And always courteous. Really. You want over? Just signal, that's all I ask. At what point does the cost per additional unit gain in output head north? Want to get 100,000+ miles out of the rebuild. Huge possible service area. Thanks for reading! Chris

I have a 1972 240Z and if that would be of any help and you haven't completed your project, I could come by. Not tomorrow, not even this week, but soon enough after. Chris