Michael

All sorts of potential opinions on this topic.... my preference would be for an aftermarket upgrade to the T5, if your current gear set is to your liking. But that's a $2500 adventure. There are cheaper options, but they might require modifications to the clutch/hydraulics. A new blowproof bellhousing, clutch pressplate/disk, throwout bearing and plumbing --> another $1000; but you might be able to recycle most of these components with an upgraded T5.

Off topic, but it's been almost exactly 5 years since JMortensen's statement that it would take "5 years to sort out" his car. Any updates? And speaking of 5 years ago, back then the "traditional" small block vs. LS-series was still somewhat of a serious debate. Today that hardly seems to be the case. Where has all the time gone?

1/2" x 1" piece of office printer paper, folded to form a 1/4" x 1" strip. The carb is a Holley 4160-style vacuum secondary, 750 CFM, bought new from Summit Racing in 1998. "Mods" are removal of the choke plate and filing of the throttle blade shafts/screws for some nominal increase in flow. I am now contemplating a Race Demon 750 or 850. The intake manifold, by the way, is an Edelbrock Performer RPM oval-port, stock except for minor port-matching to the heads.

As with nearly every other activity, the 20/80 rule applies: 20% of the club membership do 80% of the work. That means, for all of you math enthusiasts, that some people are 16X busier than others.... which explains why some feel overburdened, while others feel ignored. The main benefit of a club is social interaction outside of work. You college guys might find this to be odd, but in the so-called "real world", it is comparatively rare for adults unrelated to each other to gather outside of work, except for church, golf, or babysitting each others' children. So a car club is an excellent venue for guys to just interact with like-minded persons. Unfortunately, as with nearly every other leisure activity, people tend to disappear during the family-formation phase of life (age 25 or so), not to reappear until their kids are grown and launched from the house - meaning, not until they (the parents) are over 50. Ergo, the usual car club friction: the "kids" (<25) vs. the "geezers" (>50, and often >65). The generation gap is enough to defeat any impetus towards camaraderie, and unless those special 20% of the club can continue holding it together, the club dies. And it's especially tough to maintain a pricey leisure activity in this economy. Check the stock market lately? Tony - WTF happened in Europe today, and are the "tiger countries" of Asia next... or are they immune?

Did the paper-test... Drove the car at moderate speeds (up to 50 mph), mostly doing burnouts in various gears (first through fourth), up to 5500 rpm or so. Result: wad of paper stuffed adjacent to one of the secondary throttle blades is completely intact. One other result: with the secondary thus (slightly) open, idle jumped from it usual ~1000 rpm to 1300 rpm. I now have around 12 miles on the odometer since my most recent rebuild. These are mostly burnouts in my driveway. Today I drove around the neighborhood, venturing onto public roads. The car is uncomfortably loud, but is otherwise fairly settled and responsive (and that's driving on only the primaries, ha ha!). It still spews oil past the timing cover - likely culprit is the front crank oil seal. As a bonus, the bouts of sporadic hard braking seems to have loosened the front-right caliper, so that now the car brakes evenly, without dragging severely to the left. More observations on the Doug Nash 5-speed: aggressive upshifts with clutch-dumps are actually pretty smooth, as if the transmission were built specifically for such driving in mind. Intentionally brutal driving results in smoother response than if one tries to drive this like a normal street car; that is to say, leisurely shifts cause bogging and requires the operator to "hunt" for the proper gear, while wantonly abusive gear-banging is rewarded with crisp, precise engagement. Reverse is still a problem - the shifter loves to pop out of reverse, especially if blipping the throttle.

Is the hypothesis that oil is being driven up through the non-baffle in the valve cover, through the PCV valve and, well, somewhere else (not back into the intake manifold?)? Could there be another source of oil leak, too small to notice as a loss of oil volume in the sump, but large enough to splatter onto something hot (headers, for example), resulting in fumes?

I recommend trusting your local engine builder, sourcing another used block, going through the various machining steps, and reinstalling your components. All other options will be more expensive. That said, prepping a used block will likely require... - wash/clean $50 - crack-check (pressurize) $50 - bore/hone $200 - decking $150 - align-bore mains $200 - cam bearings $50 - freeze plugs $50 - ARP mains $100 Total is $850. These are rough numbers, and are likely to be low. I'm assuming that the main caps can be reused, and the lifter bores are fine (in the new block). Then there are the main/rod bearings, polishing the crank, maybe new rod bolts and resizing, maybe new balancing. After a decade, it is quite easy to have $10K "invested" in a $5K engine. Ask me how I know....

A hybrid swap (cross-manufacturer) is NEVER the economical route to getting a wounded project car back on the street. Do a swap to increase performance, at your leisure, when everything else is settled and you have acquired the time, the tools, the skills and the contacts. Best option would be to park the thing while you mull over your options, and look for closer Craigslist deals. Second best option would be to have a shop rebuild your engine. There is no shame in having a professional do a job that you are presently just not equipped to readily do. Just make sure that the professional is trustworthy.

For a while there I was wavering, but now I've mustered resolve: I'm going to convert my Z to FWD. I'll use the reverse of the JTR mounts to position the engine maximally forward, for better loading of the front tires.

It's especially hilarious when they pass under the banner ads for "Mother's"!

Mike - is your Z now running more or less to your satisfaction? Did you finish the 383, or have your switched to an LS-family engine? I performed some more fiddling. Checked static compression; it's 167 psi to 172 psi across all cylinders. In the process I discovered that one of the ignition wires had a short, so for the past 2 months I had a V7. Then I realized that the #2 and #4 ignition wires were crossed - so really I had a V5! For good measure, I added 10 more degrees of timing by rotating the distributor, following Pyro's suggestion. Now the car definitely feels better. The backfiring is gone, the engine feels smoother and power has of course improved. The carb is OK, though I still have no proof that the vacuum secondaries are opening under load. Best method for burnouts is to start in 3rd gear, rev the engine to all of 1500 rpm, dump the clutch and then punch the throttle. This leaves a satisfying cloud of tire smoke. In fairness, the result is not entirely due to prodigious engine torque... the tires are around 20 years old. I almost never leave my own driveway, preferring to avoid the risks of public roads (having a long paved driveway helps). Now I'm searching for a better ignition control system... and a helmet! The driver's head is surrounded by roll cage tubing, and I mistrust even the most sophisticated padding. One panicked swerve to avoid an Ohio groundhog or raccoon, and I'd get a nasty left-brain indentation. We need to have a Datsun reunion, maybe at the geographic halfway point. Get AAA to tow 200 miles, then drive the remaining 50 miles. The Miata might be getting a used Jackson Racing supercharger with "powercard", if the Craigslist gods listen to my supplications. Question for the cognoscenti: short of driving around with a mirror on a stick, or going to a chassis dyno, how does one determine whether the carburetor's vacuum secondaries are indeed opening under load?

It’s an amalgamation of many objective and subjective reasons. The S30’s have a more accommodating engine compartment. Fewer systems have to be removed/modified for the swap. A larger “support group†of fellow swappers improves the stream of advice. Subjectively, the S130 is viewed by many as aesthetically less appealing, and as “too softâ€. The core group of Datsun V8 swappers, which even today have extensive influence in the community, began several decades ago, when the S130 was still a fairly new car, and perceived as a symbol of the automotive malaise of the 1980s, whereas the S30 V8 swap was a kind of rosy nostalgia for what the 1970s ought to have produced, but didn’t. But the best swap is the one where the owner is most familiar with the component systems – chassis and engine. That is more important than choosing the “better†engine or chassis.

If "daily driver" means a 5-mile morning commute and a 5-mile evening commute, then a loud and bare interior shouldn't be too onerous. Long-distance driving is a different story. If you're in Montana, you may wish to consider keeping the heater/ventilation unit. My Z is a completely gutted tin can, except for the unmolested headliner; no dash, gauges bolted to the roll cage, no carpeting or sound-deadening, no center console.... just roll cage tubes. It's a weird feeling to stare at a bare firewall just sort-of connecting the floor with the windshield (firewall is set 6" back). The steering column just disappears into the firewall. The shifter sticks out from a hole in the transmission tunnel. The sensation is less of discomfort, than of a tingly feeling of driving a UPS package delivery truck, instead of a sports car.

I agree with ShakotanLife. Miata seats, at least from the first generation ("NA", 1990-1997) are a recurrent source of complaint on the Miata forums. A so-called "foamectomy" is recommended to improve head room, and/or to improve lumbar support. I've noticed that many Z owners are unusually tall; something about the car's ergonomics attracts tall drivers. Well, tall Miata drivers are especially discomfited by the lumbar support issue. I'm relatively short, but even I find bothersome the lack of lumbar support in my Miata (a stock 1991). The other issue is side-bolsters. As with most "sporty" seats, Miata seats are tough on broad-shouldered people. The lateral bolsters dig into one's shoulder blades, leading to a sort of hunched seating position. I suppose that this is especially a problem if you are short and broad-shouldered. Tall, slender people are probably not bothered by it.

Higher compression ratio is more of an enabler for other power-adding modifications (such as a higher-lift, higher-duration cam, without sacrificing low-end torque), than a direct power booster itself. As the principal engine-savvy members on this forum keep reiterating to the rest of us, the route to horsepower gain is through a concerted combination of parts, and not through individual replacement of one or another component. There is no shame in replacing one set of OEM parts with another, if that's what budget considerations dictate, provided that the new set is properly engineering to work with the old. Having gone through a lengthy and circuitous vehicle modification campaign (in addition to just "the swap"), my suggestion would be to bring towards preliminary drivable condition whatever you have now, and reserve as many impending mods as possible for evolutionary improvement after the vehicle runs. This is better than shooting for a high-quality complete vehicle that awaits full attention to detail before making its maiden voyage. It is better to fix lurking surprises on a running work-in-progress, than to fret over how well your baby will perform once ready for the grand unveiling.

What's a "cupholer"?

Thanks to everyone for their encouragement and words of congratulation! To be sure, I'm less disappointed than disenchanted. If my current result were to have been obtained 1-2 years after starting, I would be fairly pleased. The reason for my jaded disaffection is that a dozen years is too long just to reach where I'm at. I don't mind having spent the money for my "lessons" on what I really want and what the engineering compromises entail. I do however mind the time spent and the opportunity-cost, in terms of other cars to hypothetically have tried, on account of the Datsun having monopolized my vehicular attention. video uploaded to You-Tube: Issues to which to attend in the immediate term: - compression test. Is the horse pulling the car with every leg? - more advance for ignition system (currently 16 BTDC at 850 rpm (vacuum disconnected), linearly increasing to 30 BTDC at 3000 rpm, and that's it). I might try a Megasquirt-type of setup with the distributor gutted to serve merely as a device connecting the camshaft to the oil pump. I am not impressed with MSD/Crane/Mallory/Accel/Pertronix topical fixes to the GM HEI. The current generation of MSD digital ignition is an intriguing alternative, but there has been too much derogatory evidence against MSD. - figure out why it's backfiring upon release of the gas pedal. Sounds as if lots of unburned hydrocarbons are going down the headers! - solve oil-seepage problem through intake cover bolt holes. - figure out why the carburetor firehoses fuel into the venturis upon the gentlest application of throttle... or get a new carburetor. I'm not even sure that the vacuum secondaries are opening on this carb... or why I have a carb with vacuum secondaries in the first place! Longer-term issues: - new tires (these are maybe 20 years old, if not older). - if all goes well, dyno tuning. - if all goes even better, G-force T5 transmission. It is amazing how much of the manners of an engine depend on seemingly superficial aspects of tuning... spark, fuel, and that sort of thing. I mean, I spent years and years worrying about combustion chamber design, dynamic compression ratio, head port geometry and intake charge speed, piston speed and rod/stroke ratio... but in the final analysis, that's all ancillary crap. Well, not outright crap, but the best cylinder head design in the world won't compensate for incorrect timing or a carburetor that pukes fuel. The Miata is a wimpy little hairdresser's car, as a local friend remarked. But I enjoy the smiles-per-gallon and am warming to the idea of turbocharging it via a turnkey kit (BEGI or Flyin' Miata).

Finally drove the thing this afternoon. Main impressions... the power is fine, but lacks the impact of outright rocket thrust. Perhaps my standards are unrealistic. With the close-ratio gearbox, more time is wasted in shifting than in actual acceleration; best results are starting in second gear, and immediately shifting into 5th. RPMs rise so quickly that I almost certainly over-revved the engine on several occasions. With four over-stretched rod bolts, this does not bespeak a comforting feeling. The good news is that this time, my safety-wired rosette of bolts holding the adjustable timing-sprocket seems to be holding, and there is no embarrassment of said bolts backing out and grinding into the timing cover. Speaking of timing, the engine likes around 12 degrees at 900 rpm (with vacuum advanced plugged). It starts relatively easily in the warm weather that has finally visited us in Ohio. This (the easy starting, not the weather) is a welcome improvement over the trouble that I had circa 2006, when I last seriously worked on the engine. My colleague and I took video of the "first drive", or thought that we had; sadly, the camera was on the wrong mode, and instead of amateur video, we have amateur images of weeds growing along my driveway. In a few weeks we'll try again, and I'll try to upload something to a video hosting site. Bottom line - yes, it's nice to have finally overcome the vast plethora of seemingly trifling difficulties that plagued this effort for over a decade, combining in their vile cabal to quell whatever urge one musters to make progress. But as I posted some weeks ago, the completion is anticlimactic. When I was in my mid-20s, I wanted brutal acceleration at all costs, convenience, reliability and everything else be damned. Now, approaching 40, I'd prefer the easy litheness of my Miata combined with the unhurried thrust and poise of my M3, but instead what I have is a Japanese muscle car. It's basically a Chevelle 454SS, minus 1200 lbs. Where to next? For as long as I have garage space, the Z will remain parked within, to occasionally be trotted out for a mild day's tilting at windmills. Maybe some day I'll take it to a chassis dyno for the obligatory bragging rights (or plaintive consternation over making 100hp less than Desktop Dyno is predicting - few things are so depressing as a great theory, so long oblivious to practical criticism, defeated by a 10-minute experiment). My advice to prospective swappers: keep it mild. And any operation so extensive as to keep your car on jackstands for over a few weeks, is best delayed until you're a wizened old man, doting in retirement on empty acres, empty save for weeds and field-mice, silent save for mating calls of toads rejoicing in the incessant rains of languishing spring.

The most troublesome, labor-intensive, frustrating and incommodious part of the Datsun V8 swap is rust abatement and the related chassis-reinforcement. Rusty car ==> project will drag on for years. So spend the extra money on a reasonably “rust-free†chassis (there are no entirely rust-free Datsuns in the known universe). The second most troublesome portion of the swap is the engine build. If you go the Gen-1 or-2 SBC route (350, 383, 406, etc.), be prepared for a rebuild and cost outlay for aftermarket parts: heads, cam and valvetrain, intake/carb, and so forth. Likely the eventual cost will be comparable to the LSx series. Reasons for building a traditional small-block (or big-block): (1) this is where your expertise lies, or (2) you have an established supply-chain for the traditional engines but not for the newer ones. Otherwise, go with the newer family. I say this as some one who built a traditional engine, and now regrets it. The actual swap itself – engine mounts, cooling system, charging system, fuel routing, electrical, exhaust – while not trivial, is not particularly difficult, IF you have a decent host vehicle and a decent engine/transmission combination ready for the swap. My recommendation is to first find a suitable Datsun, that runs reasonably well, that can be registered as a street car. Drive it for a year or two. Worry about the rust, about the suspension, about the bodywork, the interior, whatever. And only then, once you are familiar with the car and aware of its weaknesses, would you be well-positioned to work towards a swap. Good swaps take years. Unsuccessful swaps take decades.

A 400 SBC from a 1977 Suburban will serve as reasonable foundation, but don't expect impressive hp. The top model for that year, a 454, would barely crack 200 hp. That said, resist the temptation to make even minor modifications. It is easy to ruin an otherwise serviceable combo by tinkering here and there. Example: installing new flat-tappet cam; excellent way to wipe the lobes and to send lobe/lifter material all through the oil gallery and into the bearing shells. So, buy the engine, keep it stock, get your car running, become familiar with it, and only subsequently entertain notions of modifications. BTW you mentioned that your Z went through a stint with a 454. What happened? Why was it removed?

Some of you have been following my progress since at least the 20th century. There – is that sufficiently pompous? After inveterate blunders, rebuilds, disassemblies and sallies at improvement, the 461 is now finally installed in my Z. As of 6 pm EST, 17 April 2011, the big-block roars back to life! Have not driven it yet – still need to bleed the clutch and to fill the gearbox with fluid. But after some fiddling with the carb, the engine achieved a stable idle at 850 rpm, without too much coughing or apoplectic shaking. A bittersweet achievement, as the lifters clank unpleasantly and the timing is troublesome to adjust. No great flaws, nothing that a little enlightened patience can’t fix. But the disappointment is that now having driven newer and more refined cars, I’ve lost the youthful urges for the visceral thumping of loud mufflers, large cam and so forth. However powerful it may be, there is less joy than disaffection. I find no elation, no relief, no self-satisfied feeling of achievement, even if this time the rockers really are oiling (they may not be), the freeze plugs are holding, and the exhaust is no longer brown. My next build, if there will be one, will not be a traditional American V8. Henceforth my enthusiasm for these engines will be purely passive. Perhaps I’ll attempt to turbocharge my Miata, or maybe swap in a silky fuel-injected V6. Something that gets more than 7 mpg and doesn’t require a helmet just to drive around the block. But now comes the pedestrian task of better tuning, sorting out the electricals. Don’t wire your kill switch to the battery positive cable – it does nothing while the alternator is charging. I know, because in a panic I had to kill the engine, and even outright removing the battery failed to achieve this. The only solution was to pull the ignition wires from the distributor!

First, be especially mindful of German car registration requirements, if your objective is to enjoy this car in Autobahn driving while stationed in Germany. I hear from an acquaintance who now works for Siemens in Germany, that registering a modified Datsun would not be an easy undertaking; much harder than say in California or other US locales known for automotive stringency. They have their own rules on roll cage design, bumper height , and many other factors. If you already have friends stationed in Germany, ask them about car registration and whether they were able to secure any sort of exemptions owing to their military status. Second, the lack of torque is not by itself an advantage, even for a high-rpm engine. Instead what happens is that an engine producing high volumetric efficiency at high rpm ends up being comparatively weak in low-rpm torque, because it has poor volumetric efficiency down there. It is self-defeating to intentionally reduce displacement in an attempt to bias in favor of high rpm power. Before you receive a barrage of links to books and web sites describing suggested builds, just consider the two main ingredients: the engine should breathe well at high rpm (carb, intake, valvetrain, heads, exhaust) and the rotating assembly (crank, rods, pistons, valvetrain) should remain robust at high rpm. That’s it. It’s not about rod-to-stroke ratio or bore-to-stroke-ratio or whatnot. Also note the gearing (tire diameter, rear axle ratio, transmission ratios) and what rpm range your desired cruising speed will place you. With a tall 5th gear (0.6 or whatnot) and a 3.54 rear, you may find that 7000 rpm is completely unnecessary. From my forays on Autobahns mostly in central Germany (general area from Darmstadt to Bonn and the Ruhr and west, up to Bremen, over to Braunschweig), it is quite rare to find an unlimited spot where you can buzz past around 240 kph; there’s too much traffic and too many curves in the road. Most “unlimited†stretches only allow getting up to around 200 kph before the next speed-limit warning sign looms ahead. There are a few satisfyingly wide, flat and comparatively empty stretches, such as south of Frankfurt airport, heading towards Darmstadt. But that’s only around 20 miles. So in reality, German vs. American driving (especially in Arizona) would not be tremendously different.

Did the original poster buy a transmission? There was mention of doing so in April... and now it's April. Spring, the time for unbridled acquisition. Reconnecting my Doug Nash 5-speed to my BBC has driven home the obvious points that a heavy transmission isn't a good thing, and lack of a steep overdrive isn't a good thing. For large-displacement engines with mild tune, what we need is a small number of gears, very broadly spaced, with a steep first (used only for drag racing) and a very tall nth gear (used only for lazy highway cruising). In "normal" conditions a 2-speed will suffice, with the lower gear for starting/puttering, and the higher gear for rural roads and highways. So how about these gear ratios: 4:1, 2:1, 1:1, and 1:2? Manufacturers, are you listening? Pete's right about the G-force T5; best compromise of weight, shifting, and strength. Actually, even their gear ratios are not too bad, for the real world.

Installed those brass freeze plugs (bought the kit from Jegs) last weekend, using Permatex #1 adhesive (brown, dries semi-hard, semi-ductile). So far, no leaks. Engine goes in next weekend, and might be fired up the weekend after. Bought a new HEI-style distributor (supposedly with some upgrades) and flushed the fuel system (has been sitting since fall of 2006). So, wish my luck - will this be the first "truly" successful firing of this engine since 1999?

1990-1997 Mazda Miata