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Michael

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Everything posted by Michael

  1. A very similar thing happened to me with my 454, when I installed a Comp Cams XE-262 flat-tappet hydraulic camshaft complete with the kit (springs, locks, retainers, timing chain set) on an otherwise stock engine from a 1978 Suburban. I used stock pushrods, stock rockers, ... - everything stock, basically. The cam was installed with the timing chain set dot to-dot (not degreed in). I did NOT check the spring pressure (open or closed), but I did check for coil bind and for sufficient length in the rocker slots (both passed the "paper clip test"). I didn't check the piston-to-valve clearance
  2. Folks, Somehow this whole high-performance in a big block thread left me with a jarring feeling of uncertainty. The reason that my post on big block heads may appear scatterbrained is that I have been pondering this issue for a very long time, and have long ago lost sight of the original “goals”. I’ve been through Staeffel’s book, and Currao’s, and various books by Vizard; and on the more technical side, C.F. Taylor’s engine “bible” and Lumley’s recent condensed version. But somehow that is of little help in choosing which brand of which component to buy. The trouble is theory
  3. Guys, Many thanks for the replies. When I got through writing my follow-up post, I realized that it ended up as more of a rant than a technical point, so I put it in a more appropriate place in the forum (the “I’m tellin’ ya” section). Please look at it if you get a chance, as it hopefully applies to a broader context than just big blocks. One quicky tech question though – has anyone tried "porting" an Edelbrock Performer RPM oval-port manifold to fit rectangle-port heads? This might not be as foolish as it sounds, because the Edelbrock oval manifold’s runner shape tends to be
  4. This one is long and loquacious…. For some time now I’ve been tossing around the idea of getting good aluminum cylinder heads for my 454 big block. Currently I have 346236 GM heads – standard equipment on 1970’s trucks. I have been following the various discussions about heads for small blocks, power vs. torque, the significance of cfm ratings, piston speed, etc. – and while the basics of course apply here as well, the particular choices are very different. Granted, it’s the full combo that matters, not the individual parts. But decent aluminum BBC heads are $2000 ($3000 with serious por
  5. I’ve made some front-end modifications to my ’78 280Z that preclude the reinstallation of the stock headlights in the stock location. The likely new location will be in the grill area, where 280Z’s normally have the front amber parking lights. Assuming, for the sake of argument, that such an installation is legal and all that, I still have to make the choice of whether to attempt to install the stock headlight assemblies, or to switch to a set of those compact headlights, such as the high intensity discharge units that have recently become popular (unfortunately, with rice boys). Does anyon
  6. NHRA won't approve a cage unless the main hoop is at least 0.120" thickness DOM mild steel. Chromoly is a different story, but if you're using 0.095 mild steel, the cage won't be legal. Unfortunately, most 0.120 mild steel DOM tubing is actually 0.118-0.119! Some NHRA tech inspectors will fail that! I can't claim first-hand knowledge, but I have heard of people spending $2000+ on custom cages with 0.120 tubing, only to get their cars failed. This is why it's something of an industry standard to use 0.134" tubing for the cage main members. My car has 0.134" for the main hoop and various o
  7. As with most things, yes, it has been done before. There are two drag Z's on this site with 454-based engines, and then there's my "street" Z with a 454 from a 1978 Chevy Suburban. All three cars have heavily modified frames. For pics of mine, see Pete Paraska's web page - there's a link to some information about my car. Weight distribution is the main issue. My solution was firewall setback. That may or may not be necessary, depending on the car's intended use and the driver's preferences. But one lesson that I have learned is that this is a difficult swap. Not impossible, by any
  8. It seems to me that the key to getting good weight distribution with a big block is chassis mods to set the engine further back – way, way back. Shameless self-promotion: see my car at http://members.home.net/pparaska1/MichaelOlsBBZ.htm. Of course, with that sort of approach, something like GN V6 would result in a combo with even more rear weight bias, even less loading on the front springs and even less need for upgrading the brakes. The “can I and/or should I use a big block” question comes up over and over again... I think that the reason for using a big block is low-end torque. N
  9. I second the observation that "front flexing" is a problem on the Z. When my roll cage was installed, before the front strut tower diagonals were in place, the car would still flex, as observed when it's abruptly lowered from a hydraulic lift. After the diagonals were installed, the flexing was significantly attenuated. The diagonals pierce the firewall and connect to a dash bar and "backbone" running down the middle of the passenger compartment. For pictures, see http://mywebpages.comcast.net/pparaska/MichaelOlsBBZ.htm
  10. This is sort-of off topic, but from reading this thread I suddenly get the impression that there are actually HybridZ people in Ohio!?! Especially in southwest Ohio? That’s it, we gotta have an Ohio HybridZ gathering! I live about 20 miles southeast of Dayton, almost straight down I-71 from Columbus. My car is currently engineless but I’d be glad to have people sit in it, and I’ll push the car around. You can make vroom-vroom noises.
  11. After doing the bumpsteer crossmember mod, I discovered a weird wheel alignment problem with my V8 Z: in the front, the driver’s-side wheel appears to stick further outboard than the passenger’s-side wheel. But in the back, the situation is reversed. The car has 14x7 wheels with 225-60 tires, and stock suspension components, with the possible exception of the springs (courtesy of the previous owner). Making reasonably accurate measurements in the rear, I found that the left vs. right control arms do not measurably differ in length, and the distance from the control arm outer pivot (t
  12. I have a big-block Z. Well, sort-of. Some old but reasonably illustrative pictures can be found on Pete Paraska's site; look under "Michael OL's big block Z". I said that I sort-of have a big block Z. That is because my engine is apart and won't come back together until a long, long session of soul-searching, book learning and hands-on trial and error. Why? Because, as the guys have already mentioned, big blocks are big potential but also big bucks and big effort. Yup, it's all big. I have a 454. 454 is the natural big block. A 632 all-aluminum jewel box is nice, but let's
  13. I'm the BBC dilettante that Pete was referring to. Things are a bit hectic now, but I'll post with pictures of my setup in a couple of weeks. That's a promise - sort-of. Here's the summary of the project: The car was basically built by a buddy of mine, though I can take blame for most of the design. The front end was cut off, the firewall and floor cut out, a roll cage welded into the car, then the floor was shortened by 6.25", floor and firewall welded back in, front reattached with frame-rail doublers and lots of sheet metal in compound curves. The transmission is a Doug Nash 5-
  14. Well, I'm one of the bigblockers, though currently my Z is in a state of suspended animation while I work up the courage to spend $$$ on getting the engine rebuilt. It's a 1978 280Z with a 454 BBC, originally from a Chevy Suburban. 90% of the metal work on my car was done by a buddy of mine - not by me. The BBC vs. SBC thing has been kicked around a number of times; a search under "big block" will hit most of those threads. Basically, by going with a BBC you are committing yourself to a project well beyond the framework of the so-called JTR type of swap. It CAN be done, and it can be
  15. These discussions invariably come down to some trite but true saying, like "Speed costs money; how fast do you want to go"? Some experience with Chevy big blocks suggests that the Mopar Hemi (426-based) will indeed fit - but not with the stock sheet metal. With the right exhaust headers you can probably clear the stock frame rails. Plan on setting the engine so far back that the motor mounts anchor on the frame rails right about over the area where the tension/compression strut mounts currently sit. And you will probably need to relocate the brake vacuum booster to clear the driver's
  16. I have a Richmond 5-speed behind the Chevy big block in my '78 280Z. pros: incredibly strong (reputed to be the strongest shaft-gear manual transmissions, bar none); deep first gear; external shifter can be moved around for customized relocation; fit standard GM stuff, like Lakewood bellhousings and the GM 26-spline tranny shaft. cons: very notchy and heavy shifter, if the shifting linkages are professionally assembled - and impossible to shift otherwise, due to (among other things) manufacturing defects; no overdrive in the 5-speed, relatively deep overdrive in the 6-speed; exp
  17. Just out of curiosity, does the one-piece front clip include the "valence panel" and inspection lids? I've found that most fiberglass hoods terminate at the same aft location as the stock hood. For my car, the valence panel and inspection lids are riveted to the stock hood, and the whole thing lifts up. Also, how do the "fenders" of the one-piece clip wrap around the rocker panels, behind the wheel wells? Are the fenders somehow split, like on a C4 Corvette?
  18. Folks, Regarding the very start of this discussion – I would opine that going 200 mph in ANY car is risking your life – that is not a risk specific to the Z. The main problem with car aerodynamics is that the car’s shape is not “smooth”, so it’s very hard to predict what the air flow will do. Most of our methods, from the hardcore theory down to handbook-style approximations, assume that whatever the vehicles does to the air, those changes actually differ at most modestly from the undisturbed flow. Airplanes are, as a rule, “smooth” – and so, much easier to analyze. A go
  19. 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
  20. 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
  21. 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
  22. 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
  23. 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
  24. 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
  25. 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
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