Michael

The first law of thermodynamics deals with work and energy. It's the principle of conservation of energy. It has nothing to do with horsepower. The second law of thermodynamics deals with heat, work and entropy. It's the principle that heat can't be 100%converted into work, without some other change taking place. It has nothing to do with horsepower. Mathematically, horsepower is the time-derivative of work. For a system in rotation, such as an automotive crankshaft, work is the integral with respect to angular displacement of the torque. So, alternatively, power is the dot-product of torque and angular velocity - hence our "layman's" formula relating power and torque. Torque is the cross-product of the force vector is the position vector of said force, with respect to the point of rotation. In other words, a force times a moment arm. That's a real, physical quantity, isn't it? Dynomometers measure torque, NOT horsepower. Horsepower is inferred by multiplying torque by rpm, times a proportionality constant. So, physically, torque is real, and horsepower is "mathematical" - Grumpy is exactly right.

Some one please remind me, why is that such scams originate so often specifically from Nigeria?

whatever happened to that Cobra? And how much did it weigh?

The magnitude of such a project is unbelievably high. 100 hours? Try 1000!

Some point to consider… 1. Given the weight penalties of a big block, and the wide availability of 383+ cubic inch small blocks, a 396 BBC is probably not worth rebuilding, unless it’s a numbers-matching collector car. Start with a 454 block (or larger). 2. As the enthusiast market for BBCs is declining, the remaining BBC market is increasingly racing-oriented. This means big cams, huge-port heads, Dominator carbs, 2 ¼-primary headers, 12:1 compression dome pistons, and that sort of thing. So, maintain a critical eye; lots of the engine-building advice out there is race-oriented, not street-oriented – and the resulting combo could be unstreetable, especially in a relatively small-displacement engine and a heavy car. 3. One advantage of big blocks over small blocks is that stock parts, like cast cranks and 2-bolt-main blocks, will reliably survive at higher hp levels than would the analogous parts for small blocks. To some extent this can help save money. 4. The biggest cost difference between BBC and SBC is in the cylinder heads. Good aftermarket aluminum heads for the SBC are around $900; excellent SBC heads are around $1200. Good BBC heads are $2000+, and nice CNC-ported heads can reach beyond $3000. But again, note the tendency towards racing-parts, vs. street parts. The BBC cylinder head market is currently in flux; wait a few months for things to shake out. 5. Machining costs will add up. I started with a 454 from a 1978 Suburban. I recycled the block, mains, crank, rods, and damper. But the cost of machining and balancing, plus “minor†parts (pistons, pins, rings, bearings, rod bolts) was something like $1400. And make sure to get good (such as ARP) rod bolts, especially if you have 3/8â€-bolt rods.

bastaad525, you’re absolutely right – those 0-60 and 1/4-mile numbers are mutually inconsistent. The “literature†(coffee table books) suggests that a 1970 240Z should be capable of mid-16’s. 280Z’s, however, are indeed probably in the 17’s or maybe low 18’s. Also note that the BMW convertible is easily 200 lbs heavier than the coupe/sedan. Did he have a passenger? And one other possibility: the BMW might have been running 87-octane gasoline, in which case the engine management computer probably was pulling out timing to avoid detonation at high load.

It’s the old “why worry about it, if you’ve got nothing to hide†argument. Reasons to worry: * Guilty or innocent, I resent my even being asked the question. * Behaviors that theoretically are “against the law†are often nevertheless justifiable, depending on circumstances. The “black box†data is very black and white; no gray area, no room for mitigating circumstances * I resent having a device that I paid for, a device that I bought voluntarily (my car), being used against me * I reserve the right to be “guilty†of victimless “crimesâ€, without any punishment whatsoever.

Grumpy, thanks for another illuminating post! It’s good to hear some one with authority mentioned that port volume comes from cross-sectional area and runner length; so, two heads of different design from different engine families can have significantly different port volume, and yet very similar cross sectional area – and vice versa. Do you have a derivation of the formula, “Intake Runner Area = Cylinder Volume X Peak Torque RPM 88200� Is it from Jim McFarland’s web sites? Often one hears that 240 ft/s is a “good number†for speed of the intake charge going into the cylinder, at the max torque rpm. Let’s make a crude approximation that intake runner cross-sectional area is about equal to the product of the average effective valve curtain area and the discharge coefficient (the discharge coefficient is an attempt to account for aerodynamic losses in flow past the valve). Then, from the above formula and cylinder head flow data from a flow bench, we can approximate the speed of the intake charge. And here’s what happens. If we select 4500 RPM as the desired torque peak, and use 460 cubic inches for the typical BBC and 300 CFM for the typical BBC aftermarket head flow at max lift, the intake charge speed comes out to 244 ft/s. That’s good. But if we use a much lower torque peak, say 2500 RPM, the intake speed becomes 440 ft/s – this is too fast. Evidently, the heads need to flow LESS CFM to return to a more reasonable intake charge speed; for example, 175 CFM works nicely. And if we use 6500 RPM, the speed becomes 170 ft/s (too slow); but 400 CFM returns the intake charge velocity to a reasonable value. So, by using intake charge flow speed as a guide, the rule of thumb implies that we can “select†what head flow value to shoot for. Of course, if the apparent CFM value is too high, the solution is to open the valves by a lower amount. The solution is NOT so simple if the CFM value is too low. This, I think, is why “too large†of a cylinder head can be acceptable for low RPM applications. However, I would like to mention what I believe are some limitations of the rules of thumb: 1. The various equations and formulas that we use are just CRUDE APPROXIMATIONS! They can easily be off by 10% or 20%. And yet, the difference between a “small†SBC head (180 cc) and a “large†SBC head (say, 210 cc) is only about 17%. So, it’s entirely possible to be consistent with the rules of thumb, and yet end up with a selection of parts on either end of the extreme! The same thing holds for cam duration/overlap/whatever, carb flow rates, you name it. For my engine, the rules of thumb equally smile upon a 700 cfm carb and a 850 cfm. It’s all a matter of assumptions, guesses and mitigating circumstances. 2. The more unusual your application, the less reliable the rules of thumb! Meaning, that you have to GUESS – precisely in that circumstance, where experience is LEAST available and numerical predictions are most important!

Is the difference between LS6 and LS7 so enormous, that the latter justifies a > 100% price premium?

From the purely financial viewpoint the “keep it all BMW†school of thought is correct. But as a BMW owner, I can tell you that those engines are temperamental, seriously lacking in the torque department, and definitely more show than go. So if you plan on selling the car, restore the BMW engine. If you plan on keeping it, yank that kraut boat anchor and drop in something more user-friendly. That said, aren’t there better options than a 2.4L inline-4? Like some sort of V6 in the 3.0-3.5L range, ideally with aluminum block – should be lighter than the inline-4, should easy fit in the engine bay, and would provide more torque – something that BMW’s traditionally lack. So where do you get all those nice cars? That car lot of yours is amazing! And I thought that Texas had nothing but pickup trucks!

It's good to see that after the various site revamps and reorganizations, some of these older posts are still around! 1978 280Z, made older by 6 years (long story) 6.25" firewall aft relocation. semi-tube frame with all sorts of diagonals and such 1978 454 2-bolt block from Chevy Suburban, 0.030"-over cast 454 crank (stock) and rods (resized, ARP bolts) heads, cam, valvetrain: TBD! Performer RPM oval-port intake, 750cfm Holley Block-hugger headers into 2.5" dual exhaust, 3" mufflers stock suspension (new bushings and JTR crossmember mod) revised front end and hood no dash, no interior (except for headliner), gutted doors aluminum fuel cell in the trunk Kirkey aluminum seat, bolted to roll cage 5 years ago, in "roadworthy condition" with cast iron heads and prior to some gutting, the car weighed 2725 lbs, about 51/49 (the BBC makes the car noseheavy, even though it's set back far enough that the distributer is 2" ahead of the windshield lip). Future plans: * reassemble rear suspension (disassembled to fix the infamous toe/camber misalignment from bent castings) * finish front-end treatment * AFR 265cc oval-port heads * Cam Motion, 0.636/0.641", 239/242@0.050 mechanical roller cam * reassemble engine

For me, my most memorable posts, and participation in the most interesting discussions, were on politics, culture, current events - and NOT on Z's. There are about a half dozen guys on this site who help me get parts, who educate me on various issues of automotive mechanics and to whom I appeal for technical questions off-line. Why? Because at this stage in my Hybrid endeavor, my questions are too specific to have much appeal to a broader audience. Being a big-block guy doesn't help either, especially as it sometimes feels that the whole world is going Gen III SBC. Plus, as most of the canonical questions on suspension, brakes and the like have already been asked and answered multiple times, there's less and less reason to make additional technical posts. Pretty much the only technical posts that I make anymore are on roll cages, aerodynamics and BBC swaps.

The E46 BMW 3-series aren't particularly fast cars. The rumor is that acceleration suffered in going from E36 (1992-1998) to E46, and that even the 330i is slower than the E36 325i. Also, it's very true that the automatics are appreciably slower than the stick-shifts. My 1992 325is' owners manual says: 5.6s 0-60 for the stick-shift, and 7.0s 0-60 for the automatic; 15.8s 1/4 mile for the stick-shift, 17.0s 1/4-mile for the automatic. Seat-of-the-pants experience suggests that the 15.8 1/4 mile is reasonable, but the 0-60 time is too optimistic. By the way, today's typical V6 family sedan (Camry, Accord, Maxima, etc.) should be able to match or beat that 15.8 1/4 mile time. I only bought the BMW because it was RWD.

about 20 minutes, if the cam gets wiped.

First, back to the discussion on Bush’s fiscal policy. Personally, I find all sorts of threads of socialist concepts in W’s policy. In my view, he’s the least fiscally conservative president since Johnson. Even his tax cuts are rife with social engineering (example: costly extra cuts for families with children; meaning, that the government wants to subsidize reproduction). We’re awash in ostensibly market-friendly legislation that’s actually concerned with a redistribution of wealth – in other words, principles essential to socialism. In Neoconservative ideology, the government has the right and the obligation to shape persons’ behavior, and one tool for accomplishing this is institutionalized financial penalties and rewards. Here’s an example: the home mortgage tax credit. The government says that home ownership is good, because it promotes stability and roots people into their communities. So, it offers a tax break – but not for the home purchase itself! Instead, it offers a tax break which promotes getting into debt. Pay off your mortgage, or buy a house for cash, and your deduction is zero. Why? Because the transfer of capital from cash to real estate isn’t necessarily what the government wants to reward per se; instead, it wants to reward people getting saddled with debt, since debtors are even more “rootedâ€. Plus, it’s a great boon for the banks and other lending institutions. Their profits benefit from more mortgages, encouraged by tax policy; another example of what might be termed corporate welfare. Unfortunately, the welfare state is here to stay; it’s a cancer that can’t be excised from modern life. What was once emergency relief for the destitute and the deprived, is now lard for anyone with enough political muscle to define themselves as a “disadvantaged†or “deserving†group. Like I mentioned in my previous post, if you spent 40 years working hard, only to “retire†to hunger and homelessness, society can and should lend a helping hand. This is the whole point of insurance. But how many people are genuinely in such dire need? BTW, livewire23’s assessment of the U.S. federal government’s contracting process is 100% accurate. Next, about public transportation… From fairly extensive travels in Europe, as well as to most of the major American cities that do have an underground subway-type public transportation system, I’d say that it’s less a matter of public transportation “working†in Europe and “not working†in America, than the simple fact that America is uniquely set up to function based on the automobile – and the rest of the world isn’t. For a mix of reasons – cultural, social, monetary, geographic, and maybe even accidental – mass transit just doesn’t work in America – and that would be the case even if the funding were efficiently spent. In most parts of western Europe, however, car ownership is a significant hassle and often more trouble than it’s worth. Hence, public transportation is unavoidable.

The original package containing the bolts is long gone; my car was first assembled 5 years ago, and is slowly undergoing reassembly (took 5 years to reassemble the shortblock, and might take another 2-3 to finish the engine).

Today’s elderly paid a disproportionately small amount of money into the Social Security system, compared to what today’s workers are having to pay. Essentially, the ratio of lifetime benefits to lifetime payments decreases with decreasing age; the later your birthday, the less you benefit from Social Security. Today, the Social Security tax is essentially a surcharge for being young. The modern welfare state has erased the distinction between assuaging the plight of the outright destitute and improving the standard of living of those who are merely “financially disadvantaged†– or, worse yet, of increasing the per capita income of everyone fortunate enough to claim membership in a particular group. Social programs do have value – in helping those who truly can not help themselves, either due to their having suffered some horrible tragedy, or to their having had no opportunity in the first place. But social programs that offload income “from those with the ability to those with the needs†are, well, you know – the C-word. Modern American capitalism is a curious animal. It’s capitalism at its purest, straight out of a Charles Dickens novel, when it comes to preserving the interests of certain well-connected businesses. But it’s a particularly perverse socialism when the so-called “needy†also happen to be a powerful voting block (farm subsidies are an excellent example). Social Security definitely falls under the latter. I agree with GWB’s plan in principle, but I vehemently disagree with the implementation. The most pressing challenge is to contain the federal debt – and his plan, with its “transition costsâ€, will make the federal debt only worse. To contain the Social Security monster, the only solution is to cut benefits. Maybe the answer is to raise the retirement age, or to means-test benefits, or something else – but it MUST be a net reduction in benefits, a net reduction in the flux of money from the “able†to the “needyâ€. As Samuelson points out in the article cited by Pparaska, even if solvency of Social Security could be preserved indefinitely through various “reformsâ€, its burden on the nation’s economy will become unacceptably high, unless the basic concept of welfare – getting something for nothing – is excised from the program. We should help and we can help those who are truly in need. But that’s a very, small percentage of today’s elderly. The fact that social programs can be a legitimate and humane help to SOME does not imply that they should provide guaranteed benefits to ALL.

This may sound harsh, but V8 Z is a hobby car. It’s NOT a solution to a daily-driver problem. Some folks do drive their V8 Z’s every day, but they make that choice from the luxury of personal preference – and not from necessity. Also, do keep in mind that a V8 swap done under pressure is likely to have an unfavorable outcome. I started my V8 Z project in graduate school. Neither money nor time were particularly plentiful, but in a pinch I could commute by bicycle. So I did just that; my Z became a garage queen, and my only transportation (in Los Angeles) for six months was a bicycle. That was 1999 – and the Z still isn’t done. Oh yeah, and I had a qualified professional build my car’s chassis and do the actual swap. The point is, solve the issues of daily transportation first, then worry about the hobby car – because you might still be trying to get that hobby car back on the road, for several more decades.

I used to live in Pasadena – zip code 91106 (right next door to 91107, oddly enough). A good friend of mine is a local mechanic/businessman; he owns A and A Tire and Auto, intersection of Colorado Blvd and Sierre Madre, probably not more than a couple of miles from the 91107 post office. He could conceivably have a look at this engine and give a quick thumbs up/thumbs down (just visual inspection, of course). If you’re interested, I’ll give him a call.

Need info on correct torque for flywheel bolts; ARP bolts, 14" aluminum Hays flywheel (168 tooth), big block Chevy engine, Centerforce clutch. I couldn't find the spec on ARP's web site. BBC "how-to" sites generally quote 60 ft-lbs, but don't distinguish between ARP and stock bolts, or aluminum vs. steel flywheels. Elsewhere on HybridZ some one posted torque specs for L24-26-28 flywheels, but oddly enough there doesn't appear to be a post (at least, not one that survived the latest site revamp) quoting Chevy flywheel bolt torque specs. So, anyway, I'd appreciate it if some one could confirm the 60 ft-lbs number.

I remember that in the 1980's 87-octane gasoline was marketed as "unleaded", 89-octane gasoline was "regular" (meaning, leaded), and 91 or 92-octane gasoline was "premium", with the lead content ambiguous (probably it was unleaded). The 89-octane leaded gas was the cheapest. I cheerfully used it in my first car, a 1974 Toyota Corona (which went FWD and became the Camry in 1983). Sometime around the late 80's-early 90's leaded gasoline pretty much disappeared. The 87-89-91/92/93 ratings remained, but the 89-octane gasoline, having become unleaded, increased in price, so that now the cost per gallon progressed monotonically with increase in octane rating. My 1992 BMW 325is is supposed to be filled up exclusively with premium unleaded (91 or better); at least, that's what the owner's manual claims. However, I have been using 87-octane regular gasoline for several months, with no discernable ill effects. The same trick didn't work on my 1987 Toyota Supra turbo. When running on 87-octane, especially when the engine was still cold, it would very noticeably pull out the timing to reduce risk of detonation, with a very noticeably decline in acceleration.

I am disappointed that so many persons, on this site and elsewhere, who until recently were quite skeptical of Bush’s motives, methods and “visionâ€, have come to embrace his decisions as either the lesser of various competing evils, or as outright the best decisions. I still believe that Bush’s messianic zeal is more extreme, more naïve and ultimately more dangerous than that of any president in modern history, and his failure to discern shades of gray is the perfect mirror for absolutists that we today find amongst our enemies. To paraphrase Reagan: are we safer now than we were four years ago? Is the world more stable, or for that matter, more free? Is the Middle East more stable or more free? I do hope that the Iraqis will see better times ahead, that our troops can return with the pride of a mission truly accomplished. But I worry that far from confronting the proverbial evil, we have only contributed to its redistribution and entrenchment.

Congratulations! J.D. is a much better investment that Ph.D.

In my car the main hoop is butted against the roof support and welded to the sheet metal in several places, essentially in the manner as Johnc described. The seat is set back quite far, and actually the back of my head is only about 2†in front of the bar. Fortunately, the seatback is tall, and hopefully prevents contact between cranium and steel (it’s a Kirkey “pro street†seat). I thought about burying the hoop inside the roof support sheet metal, but one would have to weld the sheet metal “box†closed again, to retain structural integrity (otherwise it’s weak in shear, or twist). This would be impractically difficult. The “solution†to the interior panel problem was simply to delete them.

So, getting back to my earlier question (which, BTW, was rhetorical)... 1. Shared feelings of anti-Semitism result in a mutual understanding between Europe and the Middle East, which helps to diffuse what would otherwise have been cultural antagonism. 2. Extremists in the Muslim world prefer America as their enemy, rather than Western Europe, precisely because in modern times America is the global nexus of power, and is therefore the most convenient target for vilification. Well, so much for the “they hate us because we’re free, democratic and pluralistic†argument.