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Michael

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Everything posted by Michael

  1. I have "X" bars in my car (one goes from where the "dead" pedal used to be in the footwell to where the B-pillar should have been; the other goes from where the seat belt retract used to be, to the upper door hinge area). Getting in the car is NOT that difficult. But I'm way way smaller than the 6+ footers that seem to dominate this club . The Z is a pretty big car if you're short. I think of the X-bars as a means of making the car more rigid, rather than side impact protection. Those bars are so close to my left shoulder, that even if they deflect just slightly, they will smas
  2. An important point implied in the previous post is that most Detroit 4-speeds tend to be externally shifted (the linkage rods are literally rods bolted to tabs on the outside of the transmission case), while 5 and 6 speeds tend to be internally shifted. This is one reason that the latter are physically longer. My Doug Nash 5-speed (fifth gear is 1:1 - this is basically an Muncie "rock crusher" with an extra deep first gear) is externally shifted. Installation required radical modification of the transmission tunnel. I would guess that if you install an Muncie, a Saginaw, etc., you wou
  3. In my case, the dashboard no longer fits, since a part of the roll cage currently sits where the dash used to be. With the mounts for the stock gauges gone, reusing the stock gauges was a lot less attractive. My brief experience taught me that mechanical gauges are generally preferrable to electrical ones; I bought a mechanical oil pressure/water temperature unit from Pep Boys for $30, and it works great. I could have used the stock tach, but that never worked right - the tach needle kept getting stuck. So I bought a $45 unit (with shift light) from Summit. I still use the stock spe
  4. Also, the big blocks and small blocks are two completely different families of castings. For example, in the Chevy line, the SBC as 4.4" cylinder bore spacing (centerline to centerline), while the BBC is 4.9" (I may have the exact numbers incorrect, but they're close). This is why there can not be a 4.5" bore small block - you just run out of block! There may, however, be aftermarket redesigns that allow nonstandard overbores. Companies like Merlin make "superblocks" - loosely based on the stock big block - that allow 700+ cubic inches. That's "two" 350's! Parts from one family do n
  5. As a big block Datsun adherent, here’s my brain dump on the issue.... Each of the “big three” Detroit manufacturers had basically two series of V8 engines – the small and the big blocks (specifically referring to pushrod V8s). Around 1954, the pushrod V8s started coming out (the first was from Cadillac (?) ), displacing around 300 cubic inches, and replacing their flathead precessors. Some 5 years later, new families of larger, beefier V8s came out; Ford had the FE series, Chevy had the W-motors (348 and 409). Ford kept changing their big block species, while Chevy settled on one bl
  6. The Chevy big blocks are probably the best choice for maximum cubic inches. The largest displacement possible with a "stock" block is on the order of 540 cubic inches, though the most common production size was 454. Beyond that, you can get a truck block (0.40" taller deck height) or one of the aftermarket blocks. The latter can be bored and stroked out to 800 cubic inches and beyond. I have a 454 in my '78 Z. Be advised that the big blocks take substantial extra work to fit into a Z. They do fit - but it takes things like notching of the frame to accommodate the exhaust. In my cas
  7. Now that my engine runs again, I noticed that it makes a fairly regular sharp popping sound once every revolution. The sound tends to go away when the engine is under load, and is especially apparent at moderate rpm with the engine unloaded. Unplugging the #4 spark plug wire makes the sound completely disappear. Witht the engine running and the passenger valve cover removed, it appears that the #4 exhaust lifter is not pumping up - despite very healthy oil pressure. These are hydraulic lifters for a flat-tappet hydraulic cam (Comp Cams, X-treme energy 262 series). Lifters, springs, cam an
  8. Well, my transmission tunnel was heavily reworked - with large swathes cut out and replaced with a sheet metal skirt, all in order to fit around that linkage assembly. It was interesting, to say the least, fitting the Kirkey aluminum seat into its cradle (anchored to the roll cage) alongside of the tranny tunnel. The shift rods were also reworked on my car, with various lengths and arrangements tried. Yet it's still notchy. Once the car is in motion, shifting is somewhat easier (that is, easier than it is sitting in the car with the engine off, just rowing through the gears with the c
  9. Stay away from Richmond transmissions. I have a Richmond 5-speed, so I speak from experience. It has a 3.27 1st gear, and 1:1 5th. As some one already mentioned, these transmission are externally shifted. That's a plus if you are interested in custom shifter relocation, but a big minus in terms of (1) fitting the linkages inside the Z transmission tunnel, and (2) shifter feel. These things are NOTCHY! Downshifting is very difficult. But, according to rumor, they are obscenely strong - as in, the strongest clutch-engaged transmission available, period. The official input torque rati
  10. While pondering the next step in my efforts to make my car "streetable", I've had to make a painful admission: the simple things -like setting the correct timing, tuning the Holley carb, adjusting hydraulic lifters and telling apart noises made from spun rod bearings vs. malfunctioning mechanical fuel pumps - are not at all obvious! So, here is the question: what are folks using by way of a good, basic reference on working with Chevy engines? I don't mean "How to Hot Rod Your Small/Big Block", but something that tells you things like the cylinder head bolt torque settings. The ubiquito
  11. I second that. The Ford 4.6 is unbelievably wide - and width, not length, is the #1 enemy for Z V8 swaps. I have a Chevy big block in my Z. It does indeed take considerable work to get it right (example: even block hugger headers will not clear the frame rail on the passenger's side). It takes yet more work to get as good a weight distribution as you get with the JTR-type small block swap. But, if you do go big block, I suggest that you avoid the 396 in favor of at least a 454. With the weight and cost penalty of the BB, you might as well get as many cubic inches as possible.
  12. Talking about fuel lines, loss of pressure and pressure fluctuations, pumps cavitating, etc. ... I was wondering if folks' experiences are different for mechanical fuel pumps. My engine is mounted to the frame rails, rather than the steering crossmember. One advantage in doing this is that there is no interference with the stock mechanical fuel pump. Since the engine is presently not much different from stock, I left the stock mechanical fuel pump alone. I have a "Triangle Engineering" 20 gallon aluminum fuel cell with foam (not a wise decision, to say the least!), v
  13. 280Z's have a reinforcement bar inside the doors. If you can figure out how to mate the door and latch, a 280--> 240 retrofit is one option (the latch design changed in 1975, I think). For my car, I went all-out and had an X-bar welded into both sides of the car. Looking at the car from the driver's side, the top left of the X-bar is welded to the windshield valence panel/top door hinge mounting area, the bottom right is welded to the "pocket" where the seat belt retractor used to be (and also joins the rocker panel), the top right is welded just behind the lower front corner of the
  14. Since Pete invited a response, I shall oblige. It is rather awkward to attempt to “instruct†anyone, but I will try to share some thoughts I had about the Z’s aerodynamics. A proper explanation really requires a book. One such recent book is “Race Car Aerodynamics: Designing for Speedâ€, by Joseph Katz (Robert Bentley Publishers, 1995). And that is not an especially good book – but it is a good intro. Sadly, the 240-60-80Z has one of the worse shapes in terms of aerodynamics of cars in recent memory. It has small cross sectional area, which greatly helps. But apples-to-ap
  15. Michael

    ford 8.8 irs lsd

    I also think that the halfshafts would be the greatest problem. How wide is the 8.8" IRS pumpkin? Fabricating mounts for the differential is nontrivial but can be done with some basic machine tools. Custom-shortening and reflanging half shafts can not. It's the same problem with the Ford 9" rear. The Z's track is just too narrow for conventional applications. One suggestion to solve the halfshaft length problem was to alter the rear track width - for example, by sectioning and widening the transverse links. That of course alters the rear camber. The strut perches can also be moved
  16. My guess on the sidebar issue - specifically the bar that goes from the driver's left shoulder area down to the footwell (clutch dead-pedal area) - is that the ineffectiveness of the sidebar is due to the footwell being a non-structural area. That area is unsupported sheet metal, outboard of the frame rails. Without additional reinforcement, the sidebar has nothing rigid to anchor to. On my car, the clutch dead-pedal is cut out and the area is draped by a 1/4" sheet metal plate - actually two plates, one of which drapes over the rocker panel. And outside of the car, there is a bar f
  17. Big block V8 Z conversions take lots of extra effort. While the block mounts the same as the small block, the fit is much tighter. The frame rails won't clear even block hugger headers without notching or relocating the rails. I don't think the engine will fit in the JTR setup - not enough clearance for the starter, the steering shaft, etc. Mine is set back 6.25" from the JTR setup by relocating the firewall and reworking the frame rails, among other things. You CAN get the car balanced and everything to clear, but by the time you're done, you might as well have built a complete tube-fram
  18. Mine is a rather extreme example, done in a friend's shop. The front clip (forward of the firewall) was cut off, then the firewall and floor were cut out. A cage was build on a jig, welded together, then raised into the shell of the car, and welded to the body. Then the floor and firewall were welded back in. The frame rails rebuilt with the front clip welded back in, with new sheet metal bent to accommodate the new location of the firewall. Then the front strut towers and tension/compression strut mounting points were connected back to the cage. The headliner is the only piece of interio
  19. In hot pursuit of the no start/no spark problem of my big-block (454 Chevy) 280Z, I've decided to do an overhaul of my distributor. That leads to the following questions: 1) since I won't be revving the engine above 5500 rpm, do I need to worry about the stock or stock-replacement HEI unit losing voltage at high rpm? 2) is it worth to buy a complete distributor package, or to just replace the "guts"? Mechanically, the distributor shaft looks good. 3) what's a good aftermarket brand? 4) I'd like both vaccuum and mechanical advance. But lots of otherwise good aftermark
  20. Once the 280 and 240 are stripped down to the shell, the difference in weight is very small - maybe 100-150 lbs. 280's weigh more mostly because of the added peripheral components, of which the bumpers are the most obvious (but probably not the most significant). My 280-based big block car weighs 2725 lbs, and that's with an engine that's 250 lbs heavier than the L6, 100+ lbs of roll cage material, 100lb transmission and 40 lb bellhousing. But it also has a lot of sheet metal removed. Stock weight for 280's is ~2850, not 3075.
  21. If the oil pressure problem occurs even while cruising at a steady rpm (and so, evidently at a steady speed), it might be a bearing problem, rather than an oil pickup problem. Does the oil pressure fluctuate when you rev the engine in neutral, with the car parked? Also, are there any deep rumbling noises that vary linearly with rpm?
  22. Yesterday morning I walk out to the parking lot, and see a sight that breaks my heart: a puddle of antifreeze on the asphalt under my V8 Z. The temperature was maybe 15 degrees, and the cooling system was filled ~50/50 with antifreeze. When I removed the cap from the filler unit, which sits on a section of hose, inside I found crunks of green ice, as if the antifreeze had itself frozen! There were two dripping streams of coolant: one from a clamped hose end (no biggy), and one from somewhere under the block (biggy). It's too cold to check closely, but I suspect that at best, a freeze
  23. Just some brief comments.... When taking pressure data, it is critical that we make note of dynamic vs. static pressure. If the mouth of the tube which acts as the pressure probe is flush with the surface of the hood (i.e the hood has a hole drilled in it, and the tube is inside that hole), it measures static pressure. If the tube opening faces the exact direction of the oncoming flow, and the other end of the manometer is connected to a static port near the same location, the measurement is the dynamic pressure. Any in-between orientation of the tube opening will give some mixed
  24. Is there a clever trick to successful connection of the stock 280Z tachometer to an HEI distributer? The ubiquitous JTR book mentions the connection of two wires from the ignition module in the passenger's footwell: (1) the blue wire going to the "tach" terminal (with a resistor in series) and the black-white wire going to the "bat" terminal. But that's with the ignition module removed! It seems to me that the blue wire would then be connected to nothing. I've starting the rewiring of my electrical system from scratch. The ignition works, as do most of the lights. Now I have a bare
  25. I've found that if you have significant hot rodding and mechanical experience, you develop a "nose" for low-tech, low-cost, yet perfectly sound solutions. But lacking that experience, one tends to saddle himself with unnecessarily "high tech" methods. Part of the learning curve, I suppose. For a 300hp V8 Z, my opinion is that the only unavoidable "high tech" part is the manual transmission. Detriot products rarely came with stick shifts - especially the high-powered ones. The typical stick shift transmission (T5) is generally regarded as being too weak for 300 hp. The Muncie 4-speed
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