Happy Birthday to me (280z build)

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drummingpariah
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Happy Birthday to me (280z build)

Post by drummingpariah »

Today's my 30th birthday, and I wanted to make it a good one.

The Fenton race 240z that was up for sale got me thinking about alternative ways to meet my goal of racing next season. After spending far too long building a pile of parts that I call my 240z, I realized that it'd be much easier to pick up a parts car to finish it than keep sourcing and buying parts piecemeal. I came across a few over the past couple of months that the owners obviously had no intention of selling. This past week, one Craigslist listing (ugh, Craigslist) for a '75 280z with crappy cellphone pics caught my eye as a parts donor, and I went down to look at it after work on Friday.

280z vs 240z
Looking at it in the dark, I realized that it's far closer to completion than I had thought. It's also a bit heavier than the 240z in ways that make it slightly less deadly and should put it in a more competitive class. To top it off, the entire drivetrain is much more robust (r200 instead of long-nose r180 differential, better axles, stronger driveshaft).

Engines
The Datsun inline 6's aren't technologically advanced, but they hold a special place in my heart. Beautifully internally balanced components, a fully counterweighted forged crankshaft and rods, and cast pistons are all housed in a rugged steel block. A single overhead cam with 4 valves per piston manage it, foregoing fancy features like variable valve timing and multiple camshafts. I could send any of the n/a Datsun inline 6's out to Rebello or Spirit and have a 200whp powertrain delivered back before spring. Heavy head work can certainly go higher, but reliability becomes a concern at that point. They're also non-crossflow, meaning that the intake and exhaust manifolds are on the same side of the engine. It makes spark plug changes extremely easy, but plagues the engine with cooling issues in high-power builds They're known for their rugged reliability, a broad powerband, and ease of maintenance while making modest power.

The 240z came with a SU-equipped, carb'd 2.4liter inline 6 (l24). It was a decent enough power plant, but they're getting a bit pricey and slow in their old age. The 280z came with a fuel-injected 2.8liter inline 6 (l28e). The fuel injection was certainly nothing to write home about, but it's a great building block. I've always loved carbs, so I picked up a pair of n42 l28 engines (280z engines) and plopped round-top SU carbs on them (from the 240z, the 260z came with hateful flat-top Hitachi carbs). Unfortunately, combining the 2.8liter carb engine in the 240z puts it in a higher class than I'm comfortable trying to be competitive in for my first season.

Under the hood of this 280z isn't just another l28e, it's a (non-running) l28et. The l28et was a low-compression l28 with slightly less terrible fuel/ignition management and a modest t3 turbo bolted to it. They're incredibly reliable, especially considering the fact that it had no o2 sensor, no intercooler, no real blow-off valve, used a rising rate fuel pressure regulator to adjust for boost, had a labyrinthine downpipe design, and somehow managed to screw up the Borg Warner T5 design. With all that in mind, the l28et is a great way to make 200hp.

Immediate Plans
For now, the goal is to get the thing running and driving. That means service the brakes, replace/grease the wheel bearings, replace the tires, replace all the bushings, flush/replace all the fluids, removing the silly wing and side skirts (and probably that strange-looking bumper), and carefully inspecting for any hidden rot/rust areas. It's still down in Mass, and I'll have to register it this week so I can have it towed up to a friend's house for a weekend of serious thrashing. I've assembled a small 'crew' of friends that I can feed beer and pizza to get together this weekend in hopes that I'll be able to drive it home on Sunday. There will be many more photos of the work over the weekend.

Long-term Plans
The 240z gets the classification hit regardless of which 2.8liter engine I plop in, so I think it makes more sense to put the l28et in that than a n/a carb motor. The 280z will probably get one of the carb motors, since that'll fall into a stock classification. Looking at the worksheet, it looks like the 280z with the l28et and 14x7 wheels would end up in SP2 (corrected, I typo'd the engine displacement and thought it would be SP4), which would be pretty awesome! Putting an n/a l28 motor back in may allow me to stay in Unprepared, which would be a blast too. The firm long-term plan I have is to drive one of my Datsuns up all the hills in 2014. Whatever I need to do to make that happen is going to happen.

Photos
I really couldn't get any good photos since it was pitch black out, but I managed one at least:
Image
Last edited by drummingpariah on Wed Mar 26, 2014 1:01 pm, edited 1 time in total.
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sachilles
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Re: Happy Birthday to me

Post by sachilles »

Looks cool, eager to see more.
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Re: Happy Birthday to me

Post by Rabbit Farmer »

Twin turbo Supra or an LS1.... that should be enough to get you in trouble.

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Re: Happy Birthday to me

Post by drummingpariah »

Rabbit Farmer wrote:Twin turbo Supra or an LS1.... that should be enough to get you in trouble.

Steve
If there's one thing I've learned about racing, it's that the only time a car needs more power is when lack of power is the only thing keeping it from going faster. Right now, I'd say EVERYTHING is holding this car back.

This little guy's good for a solid, reliable 200whp without any complaints or engine component replacements.
Image
With good engine management (megasquirt 1, for instance) and injectors that actually flow, that bumps up to closer to 250whp. After that, the little t3 turbine becomes the power bottleneck, and it needs to be upsized a bit. This engine responds very well to hybrid t3/t04e turbos (I happen to be well equipped already), especially with a diesel crank to increase stroke and offer more pre-spool torque.
Image
At that point, it's making enough to grenade any of the transmissions Nissan released with these. There were several variations of the same 4speed, the only 'unique' variation was the dogleg 4speed that was VERY weak (but still cool). There were several variations of the same 5speed as well, that didn't see any major improvements until the s14 240sx when it became much more stout. Finally, there was a Borg-Warner t5 that SOUNDS like it should be awesome ... but is probably the worst application of a BW transmission I've ever seen. They have a habit of failing gloriously under any amount of power. I have one in the trunk, but don't plan to use it at all. The three 4speeds I have should get me through season 1 without too much complaint. I've seen a few 'reliable' 400whp builds and a pair of 600whp dyno queens, but my power goals are pretty tame.

Right now, the main bottleneck is that the engine isn't running, and that I haven't driven up a single mountain in anger. Ever. Give me PLENTY of time to sort the suspension, tires, seating arrangement, safety gear, and any cooling issues that come up, and I might start looking for more power.

Image

For the time being, my todo list is pretty short:
  • Attach passenger window to its track or fix the track
  • Re-align driver's door so it closes
  • Install new wheels (DONE!)
  • Wrap up wiring of the l28et engine (I'll have someone else do that, since I'm colorblind)
  • Find and install AFM
  • Figure out why a rusty c-clamp is holding the starter motor to the bellhousing
  • Run a full electrical diagnostic on all lights and sensors
  • Swap all fluids (there's no brake fluid to swap right now)
  • Remove wasps nests from various locations
  • Replace brake pads on the front, adjust rear drums
  • Adjust/repair ebrake linkage
  • Repair/replace rust/rot under the battery tray
  • Repair/replace crusty and cracked seats, steering wheel, and shifter
  • Remove and sell the ridiculous spoiler, side skirts, and front/rear bumper cover (to be replaced with wind-tunnel-proven aero solutions - see here)
  • Find out why the heater core was bypassed, then repair whatever was wrong
  • Fabricate an exhaust (not sure if this came with a cat, so I don't know if I need to add one yet ... it can't really hurt though)
  • Find out why it has corvette tail lights
Image
Image
Image

All told, I'll call it $1k well spent.
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hammer
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Re: Happy Birthday to me

Post by hammer »

I'm loving this already! Can't wait to see how it turns out.
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drummingpariah
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Re: Happy Birthday to me

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hammer wrote:I'm loving this already! Can't wait to see how it turns out.
So am I, I can't wait to start tearing stuff off this car!

The seats are pretty much useless:
Image

I'm looking for replacements of some sort. I have an aluminum bucket, but that's currently in the 240z and I'm not really excited about daily-ing that seat. Since I'm hemorrhaging money right now, I'm trying to manage individual expenses so budget is definitely a concern. Maybe these FK fiberglass seats on Craigslist?
http://nh.craigslist.org/pts/4161565623.html
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Re: Happy Birthday to me

Post by Super1303 »

Sweet Dude. Happy Birthday! I don't care what it is, if it's old and has piston it's Sweet and that thing makes the list.
You got a point about those engines, they'll take quite a bit of abuse.
Had a friend back in the day who would run them old 240's on the line all the time flingin that rear out every where, good times good times.

Enjoy!
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Re: Happy Birthday to me

Post by Mopar 151w2 »

Frame those seats well, they'll do you good. Nuthin' wrong with fibergalss, as long as you consider it as a shell to hold the uphoulstery. This example from Day Motorsports:
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Re: Happy Birthday to me

Post by Chief Geek »

Best of luck, looks great.

Don't obsess about power. I don't have much, but any more would probably have helped me get into trouble. Plus, it really feels like the learning curve is very steep. Every little error is really obvious.

Before adding power, I need to find some of the 25 seconds I'm missing to the other Miata that competed. Dave V. has 1,000,000 times the experience I do and his car is setup much better, but 25 seconds is forever.

Whittling that gap down and trying to break-out (or more closely approach break-out) will keep me busy for another year, at least.

Paul
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Re: Happy Birthday to me

Post by drummingpariah »

Super1303 wrote:Sweet Dude. Happy Birthday! I don't care what it is, if it's old and has piston it's Sweet and that thing makes the list.
You got a point about those engines, they'll take quite a bit of abuse.
Had a friend back in the day who would run them old 240's on the line all the time flingin that rear out every where, good times good times.

Enjoy!
Thanks, and enjoying it is exactly what I plan to do!
Mopar 151w2 wrote:Frame those seats well, they'll do you good. Nuthin' wrong with fibergalss, as long as you consider it as a shell to hold the uphoulstery. This example from Day Motorsports:
Image
That sounds great, but those seats had sold by the time I contacted the seller. I'll keep my eyes open for more though. I suppose I could have these seats re-upholstered. It's less expensive than I had expected, but then I have 0 lumbar support, 0 harness capability, and I have to mess around with the ratcheting reclining mechanisms to get them to behave consistently. I don't have a lot of inherent love for original parts just because they're original, and have always felt more comfortable in fixed-back seats across the board. I really like that framed mount as well, it looks much more robust than the sheet-metal tabs that are welded to the thin un-framed floor of the 280z.
Chief Geek wrote:Best of luck, looks great.

Don't obsess about power. I don't have much, but any more would probably have helped me get into trouble. Plus, it really feels like the learning curve is very steep. Every little error is really obvious.

Before adding power, I need to find some of the 25 seconds I'm missing to the other Miata that competed. Dave V. has 1,000,000 times the experience I do and his car is setup much better, but 25 seconds is forever.

Whittling that gap down and trying to break-out (or more closely approach break-out) will keep me busy for another year, at least.

Paul
Power is the last thing on my mind right now. The goal is "as much power as the woo" ... so it doesn't really matter which engine I use. I AM concerned about reliability, which means managing temps on these engines, which requires a good fuel/ignition tune. See where this is going?

Once the engine is reliable, I'm going to have a lot of maintenance to catch up on (the last registration was apparently in 2006), and there are a lot of known 'evil parts' of the suspension that need to be worked out for them to handle consistently.

So, in order of importance:
  • Registered (done)
  • Running with brakes
  • Fire extinguisher installed
  • Air filter, fuel filter
  • Exhaust
  • Bushings
  • Alignment
  • State inspection
  • Seats that don't poke and prod
  • Running reliably, sensor outputs verified
  • Replace springs/struts (4-corner macpherson means all struts)
  • Megasquirt and wideband o2
  • Helmet
  • Confirm that everything will pass safety inspection
  • 2014 Autocross events for shakedown
  • 2014 Hillclimb
  • ???
  • Profit!
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