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Michael

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Everything posted by Michael

  1. Off-topic here, but it sounds like you've stumbled on a conversion-project which essentially does run, but which suffers from myriad problems, because it was done cheaply and without love. This happens often. Presently you have the fuel-pump/fan electrical problem. Once that's solved, other problems will present themselves. And so on, for several months. But on the bright side, you have a more or less functional conversion, which you probably bought for pennies on the dollar. Conceivably a not-too-distant project will be swapping the powertrain to a 350 or 383, with a T5 or similar 5-speed, or a 700R4. You already have the foundation for it, and if enough minor annoyances such as the fan/fuel-pump conspire against you, eventually you might decided to rid yourself of these problems with one concerted effort - namely, a full powertrain swap.
  2. The electric fan should have a heavy-gauge black wire to ground (say, 12 gauge or even 10 gauge), a heavy red wire going to a source of +12V (also probably 12 or 10 gauge), a "control" wire which goes to a switch that engages current-flow, and possibly a fourth wire connected to a water temperature gauge, which also goes to a switch of sorts. It sounds like the electric fan was miswired. Cooling fan companies such as Flex-a-lite (the brand that I happen to have, but others should be similar) should have wiring diagrams for free download.
  3. Good gas mileage is mainly about engine tuning and engine management. I don't wish to start a carburetor vs. fuel-injection debate here, but the preponderance of modern practice gives the nod to the tuning advantages of fuel injection. This, I think, is mainly why the LSx engines are delivering better mileage (in most cases) than the older small-blocks. My own example is atrocious: it gets single-digit mpg, but that's mostly because I am inept at tuning, and the carburetor is mismatched to the engine. The second variable is gear ratios and the rpm at which the engine achieves peak volumetric efficiency. Mismatch those two, or end up with too deep of a top-gear, and mpg will suffer. The worst case is a mild engine forced to rev high because of a deep rear-gear ratio and no overdrive. Boiling this down to a simplistic list: - everything sorted out, excellent tune: high 20s - modern fuel injection or very good carb tuning skills: low 20s - mild engine, mediocre tuning skills: high teens - aggressive engine, and/or tuning mistakes: low teens - incompetence: single-digits.
  4. My story doesn't involve serendipitous encounters with smashingly good deals, negotiations with parents, Craigslist scores or barnyard finds, or teenage infatuation. My foray into Z's began in my late 20s, after spending a decade driving various nondescript Toyotas. At the time I was living in Los Angeles, going through graduate school, and bemoaning my impending entry into the "professional world" without getting the sports-car bug out of my system. But I didn't want a "new car" - too expensive and too tame. I bought a Z because I was interested in a limber, attractive older sports-car with a large engine compartment that could seamlessly receive a V8 transplant. I never really wanted a muscle car or a classic sports car, but an eclectic blend of both. The choices were something English or nominally English (Shelby Cobra, Sunbeam Tiger); the Z; an Opel GT; and a handful of other 70s Japanese cars such as the Celica or RX-7. But I didn't want a convertible, which ruled out the British options. The Opel and RX-7 really had rather small engine bays (especially the Opel), and the Celica was too much like a generic coupe according to my tastes of the time. Plus, I always liked hatchbacks. The Z was a natural choice. My first attempt was a 1972, with awful rust problems, as it turned out. My second attempt was a reasonable rust-free 1978. My current car, bought at the twilight of the 20th century, is a combination of those two. It has been an on-again off-again romance. After many years of dead-end and angst-ridden tribulations, the car finally runs, albeit turning it into something genuinely enjoyable and reliable will require many more years and dedication of labor. The irony is that today, my daily driver is a Mazda Miata - a convertible, a lowly 4-cylinder lacking grunt or poise. But there is something endearingly charming about it, not the least of which is the remarkable reliability for a 20+ year-old car with sporting pretensions. Sometimes I fantasize about getting another Miata for a V8 swap, but it's so much more difficult in the Miata than in a Z, that a person of my lethargy and ignorance would be completely overwhelmed. You see, it takes decades of sports-car ownership to genuinely appreciate one's limits!
  5. Might be a worthwhile deal if negotiated down to $500, especially if it comes with the young lady in the 3rd photo in the Craigslist ad.
  6. If I'm not mistaken, the mounting location on the tailshaft is different between the TH350 and TH400. That however should be a relatively minor issue. The larger issue, as MikeKZ pointed out, is the ratios in the TH350/400.
  7. It's probably not realistic because most drill presses are not designed to take lateral loads on the drill chuck. They will chatter, producing a rough and uneven cut. Also, the drill press frame is insufficiently rigid, and the connection between the work-table and the shaft supporting the drill motor/belts/chuck is too flimsy. A better choice is buying a used mainstream mill. Decent examples can be found for around $1000. In the long run, you'll spend more money on attachments (various cutters, end-mills and so forth) than on the machine.
  8. Indeed, ironies abound. Congratulations on a successful business and on severing the umbilical from corporate life. Personally, I prefer to say "no" to capitalism entirely, and have spent my so-called adult life working for the federal government. It oozes corporate-speak and the smarmy culture of management, but at the same time, the overall impotence of managers gives employees very wide freedom, especially if those employees are technical specialists and define their own job.
  9. Pondering this for a few days, maybe this thread is a good occasion to revisit the BBC vs. SBC debate. So I'm going to revise my recommendations posted earlier in this thread. Back in the mid 1990s, when first having come across the JTR book, my initial sentiment was towards the small block. This was before the LS series and before the explosion in aftermarket support such as mainstream aluminum heads. Then I met the fellow who ended up doing the roll cage and other fabrication for my swap. He was a die-hard BBC guy, coming from a 1970s drag racing background. He swayed my opinion to big blocks because stock vs. stock, they had a durability and torque advantage that was difficult for small blocks to match. And back then, advantages of stock engine architecture were important. Thus my build was based on a Mark IV 454 BBC. Now having lived with a BBC for a while, I have second thoughts. I did not realize how much of the engine components would eventually be replaced with aftermarket parts, rendering the stock engine's advantages or disadvantages moot. And technology has moved on, of course. For example, now aftermarket cylinder heads are reaching flow numbers that 10 years ago were impressive even for big blocks. In the proverbial "if I were doing it all over again" - in 2012 - I would probably go with the LS series, especially if I could find a donor engine in good condition. The only exception is if the goal was truly maximum HP. Then an aftermarket BBC-flavored block (well over 500 cubic inches) starts making sense. Today if I were doing the V8 Datsun swap, I'd probably first purchase a running F-body from 1998-2002, and use that as the donor.
  10. I would spend the $200 on sufficient quantities of intoxicating fluids, such that the paint job and condition of the body would begin to resemble that of a championship-winning hot rod. If genuine reality is intractably out of reach, compensate through solipsistic surrogates. The keenest satisfaction is not in the production of a beautiful machine, but in the reorientation of one's sensibilities to obviate the need for great effort towards ultimately unsatisfying pursuits.
  11. Big blocks have their advantages, and these are not merely originality or the appeal of exotica. However, don't bother with a 396, unless it's a mock-up for engine installation. Build at least an overbored 454 (ideally with a stroker crank), or go with an aftermarket block. The complexity and cost of a big-block swap are only borne by aggressive displacement and concomitant power levels. Definitely use high-end aftermarket heads, a mechanical roller cam, good bottom-end components and the appropriate intake and exhaust systems. Plan on $10K+ for a suitable engine, and driveline components to match.
  12. A mismatched combination with an unknown history sold by a neophyte (or cagy) seller... Maybe 5000 rpm usable redline and 5500 rpm never-exceed redline. Figure on 220 ft-lb torque and 170 hp.
  13. Try "Engineering Statics", by Merriam and Kraige. That was our textbook 20+ years ago - it was very clear, almost pedantically clear.
  14. Indeed, Problem 3.81 is incorrectly worded, and that would confuse students. But resolving vectors into their components, finding magnitudes and directions, etc., is essential for mechanical/aerospace engineers. Something else to note... as you become more senior as an engineer, you'll be doing far less calculation and far more writing and speaking. So after enough time on the job, the primary skill set is supplanted by more of a humanities-type of skill set. The math however continues to be important, not through direct calculation, but in understanding the equations and how to simplify them for making quick estimates. One route to consider is to switch to a "mechanical engineering technology" major at community-college. Get an associates degree that qualifies you to operate CNC machines and the like. Old-timer machinists are losing their jobs because they can't program the new machines. Get into that niche, get some practical experience, and a few years in the future you can decide whether to return to 4-year college for your BSE. Your employer might even offset the tuition.
  15. To be pedantic, this probably belongs in the "drivetrain" subforum. The "world class" T5 is probably adequate for most applications, as the limiting factor will likely first be rear-wheel traction, rather than driveline stresses. The disadvantage of most domestic 4-speeds is the narrow spread between 1st and 4th gear. For a torquey engine in a light car, all of that shifting will be superfluous. And the highest gear is still too deep for comfortable highway cruising. A good example is my own mistake: I went with a Doug Nash 5-speed. Yes, it's a 5-speed, but 5th gear is 1:1. First gear is 3.27:1. So the highest to lowest ratio, 3.27 to 1, is quite narrow. The 4-speeds are even worse... some of them have a 2.2:1 first gear and 1:1 fifth. Unfortunately manual transmission options have not been improving over the years with anything close to the vigor that we've seen on the engine side. When the JTR manual first became popular, in the late 1990s, the LS engine series was just starting to hit the market, and the Datsun swap of choice was the traditional carbureted 350. The manual transmission choices were T5, the then-cumbersome T56, and the 4-speeds. Well, the T56 is still cumbersome. Just about the only change in the past dozen+ years has been the aftermarket support for the T5 (Forte's, G-force) - which is substantial and very good, but also very pricey ($2500 for a G-Force T5 upgrade).
  16. Replacing the pistons likely means rebalancing the rotating assembly, and buying new rings. You'll need to confirm piston-valve clearance using a mockup installation with clay. Even if everything fits mechanically without interference, as Pyro and others have mentioned, the performance gain is incremental at best. And if you currently have a fairly well sorted combination, changing one component tends to trigger a cascade of requisite changes to keep the overall combination consistent. That of course raises costs and promotes risk. My recommendation would be to do nothing, assuming that you have a reasonably well-running engine, until you are ready for a significant upgrade in power. Then get the latest fancy aluminum heads, mechanical roller cam, forged pistons with the right compression ratio, rods, and so forth. The cost advantage of a Chevy small-block is in the low price of the as-is combo. Adding individual components to any engine, no matter how common, quickly gets to be expensive.
  17. I'm all in favor of lightweight 2-seater sports cars rolling on 14" or even 13" wheels... something like my 1991 Mazda, only even lighter due to use of modern materials and chassis engineering. Say 120 hp from a 1.6L 4-cylinder (perhaps horizontally-opposed) in a 1800-lb car... decent performance and good fuel economy simultaneously. I don't believe that crash standards would be a problem, if bumpers are properly integrated into the chassis and the proper analysis (validated by testing) is done on crumple-zones and the like. The problem is market acceptance. People who crave this type of car tend to be ones who buy >20-year-old cars, not the latest models.
  18. One possibility is to run bracing-tubes along the transmission tunnel. Triangulated bracing would be welded in between the front strut towers and the firewall (piercing the firewall), then continue along the transmission tunnel, and then kick up again to meet the bracing connecting the rear strut towers.
  19. It's going to be a tough sell, considering that even economy cars in the current market are leaving the factory floor with 15" wheels. About the only market for 14" wheels is muscle-car restorations - and those probably are more for appearance than for handling prowess. I recently had a similar problem with my 1991 Mazda Miata, which is still on its stock 14" aluminum wheels. Its factory tire size is 185-60R14, which is becoming quite rare. As with S30 Zs, most NA Miata owners are "upgrading" their wheels to larger size... and this is on a car with maybe 90 hp to the rear wheels! My solution was to "downgrade" to 185-55R14 tires (Yokohama S-drive), which are somewhat smaller diameter and therefore throw off the speedometer, but have excellent grip. The lighter weight of the smaller tire carcass is also a bonus. On a brighter note, 15" wheel diameter is very popular for drag racing. So just a 1" increase greatly opens up the tire selection.
  20. The fellow at in the link [http://www.dragtimes...slip-21234.html] is making his Hp numbers with 415 cubic inches, aftermarket heads and relatively sophisticated engine management, intake and exhaust. That engine has nearly a 1.5L displacement advantage over the 327. The point is not to disparage the 327 or to insinuate that the displacement is too small to be useful. That is not the case. Rather, the point is that more cubic inches offers a route that's likely to be simpler. Not guaranteed to be simpler, but widely regarded as likely. Alternatively, how about an incremental approach... shoot for a reliable car with no power-adders that comfortably runs 13.0 without breaking parts or displaying any ill manners. Establish that as a baseline. Then incrementally improve, experimenting with exhaust mods, cylinder head porting, and so forth. The advantage is the gaining of experience with a running vehicle, and the testament of personal evidence for what does and does not work.
  21. The trouble with Hp-weight-mph calculators is that they assume constant-power applied during the entire run, and then multiply by a fudge factor in attempt to account for aerodynamic drag, slippage, gear shifts and so forth. For a pro car with a pro driver, these assumptions are reasonable and the fudge factor is stable. But for an all-purpose car (street car, road-race car, and part-time drag car) the assumptions break down. I recall some advice from Marlin Davis, the tech-guru at Hot Rod Magazine, on much the same question. He said, if I remember correctly: for an amateur car intended to achieve a speed in the 10-second to 12-second range, go ahead and use the calculators, but calculate an Hp figure for a car that would be 1-second faster. In other words, if your goal is 11.00 seconds, then look up the Hp number for 10.00 seconds, given the estimated weight, and use that value for required Hp. My Z weighs in the neighborhood of 2600 lbs (completely stripped, lots of stock sheet metal removed, but heavy mild-steel roll cage and big block (aluminum heads etc.). It makes maybe 400 hp in present state of tune, but would be lucky to run 14s with the present suspension, tires, transmission etc.
  22. Randy - would it be possible for you to share the price and parts-list for the 555" big-block that you mentioned? There's another thread currently running, where there's a discussion on "price of a 800 hp big block". I'm curious about actual numbers for an actual engine.
  23. $2600 is an excellent price for that combo IF you have reliable evidence that it's complete, present-as-advertised, running, and properly assembled. Otherwise if could be a $2600 paperweight. It is emphatically not the case that a "600-800 hp big block" can be built for $2600! At that power level, you'll have $2600 in the cylinder heads alone. Stock rods would be questionable, and a decent aftermarket set of rods ($600) plus forged pistons ($500), balancing the rotating assembling ($250), and you've already blown more than half of your $2600 budget. Roller cam ($250+), good roller lifters ($400), pushrods ($100) and rockers ($300), high-quality timing chain ($100)... you get the picture. A properly assembled big block with the requisite machining and the components needed to reliably produce that level of power will run around $8000 using mail-order parts (Summit, Jegs) bought individually, if assembled at home, and if you already have a usable block. Crate engines will be cheaper, but components will be inferior and you have no control over tolerances or other details of assembly. A good crate big block from a reputable builder at the 600 hp level would run around $10000, with proper aluminum heads (AFR, Brodix) and mechanical roller camshaft. Adding another 200 hp means some serious CNC machining on the heads, probably an aftermarket forged crank and top-shelf valvetrain components... try $12000+. If I could interview the builder and have reliable information about that $2600 engine, I'd be all over it! Actually, even if I had no use for such an engine, at that price level, it would be a worthwhile acquisition just in case. But a few things bother me. For example, 0.630" lift in a 355 is an awful lot. What was done to the valvetrain to accommodate that much lift? How much valvespring pressure, and how will that affect camshaft life? Do we have dyno data... in other words, is that 485-500 hp an evanescent blip on the dyno at 6700 rpm? The big risk with "screaming deals" is truth-in-advertising. For peace of mind, and not for personal arrogance or cost-cutting, it is more attractive to build one's own engine.
  24. Some years ago I had the fortuitous experience of attending "professional military education" with a class full of USAF pilots. They were captains, most with 6-8 years of military experience, most from ROTC but a few from the USAF Academy and a few from Officer Training School. Very few were engineers! The most popular major was political science. Why? Evidently, what counted most was their GPA, and secondarily their extra-curricular activities and "leadership skills". If you kept a 3.9 majoring in English while captaining the lacrosse team and excelling in your ROTC unit, you were pilot material. While the poor schmuck who studied mechanical engineering, got similar grades but didn't play sports or "lead" any student groups - well, he ends up as Acquisition or Maintenance. In other words, knowledge does not matter; raw numerical outcomes (such as GPA) matter.
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