Smallest engine to swap into a Z32?

[Veganpotter]

I'm looking to do a project(maybe a car with a blown engine) that's totally out of the ordinary. I've always wanted a Z and will finally have the time and resources to own and modify one. Well, it'll probably take a year to finish once I find the car I want. I've really only done bodywork and a buddy of mine will handle the drivetrain.

Anyhow, I'm not one to gun it very often anymore and want to build a gas sipping 300zx 2+2. It will be boosted with a largeish turbo that won't be doing a thing when I don't want it to. I'm wanting roughly 130-140hp before the largeish turbo kicks in at 3500 or so(I'm planning to have a differential for cruising...maybe 2500rpm at 70mph). 280-320hp is really all I'm looking for and I'd rarely use that.

What engine should I be looking for that won't be hella spendy to fit to the car? I don't mind spending on the actual engine and engine mounts. I just don't want to have to run nothing from the original car.
Thanks!!!

[Veganpotter]

With the car's CDA, and mods I'm gonna do, I'm hoping for over 35mpg. I think it's doable

[evildky]

Welcome to NICO!
I'm gonna move this thread to the Z32 section where it might find more response but not before throwing my two cents in.

SR20DET, it's been done, loads of power potential, plenty of aftermarket.
CA18DET, to my knowledge has not been swapped into the Z32, smaller lighter and cheaper than the SR with potential well within your range.

[zxFarside]

LS2 or electric motors... or both.

[NolimitZ32]

Realistically the SR or a KA-T would probably be your best choice. Money no object I would go play with a TD series engine and see what I could make happen.

[Veganpotter]

Thanks for getting back to me. I was thinking SR20 but the CA18 is appealing too. Wondering if those two would need the same work to fit into a Z while keeping the stock transmission? I just wish I could get actual emissions readings from the two of them with a similar exhaust. The KA is bigger than I'd like but if I knew it was cleaner than the smaller nissan engines, that would be something to consider.

[NolimitZ32]

Check out the 240 section, and search around, there are enough folks running KA-Ts that there is a plethora of info on the interwebz. That said, just because an engine has 9 million cylinders (or 8 or 6) doesn't mean it runs dirtier than a 4-banger, actually quite the opposite in many cases. If you have proper tuning and complete combustion you're going to run cleaner than clean and depending on the quality of the air in your area (like the Houston coastline for example) your car could potentially be converting the crap in the atmosphere to less toxic crap. Mind you this is a very VERY broad statement and there are TONS of caveats.

[evildky]

None of these are going to bolt to the stock trans, you'll want to run the trans that comes with the engine. Mounting points for the trans might line right up or at least be pretty close. All Nissan/Datsun transmissions I've seen use the same input shaft splining, the majority use the same rear housing, the output has at least 3 variations so a custom driveshaft may be required. A custom driveshaft can be made at your local driveshaft shop.

As Nolimit said, smaller doesn't mean cleaner. a newer larger engine like the VQ35 should be cleaner at the exhaust while making as much power as the stock TT.

[Veganpotter]

I live in Salt Lake City so we have some of the worst air in the country. And yes, newer engines generally burn cleaner but its a give and take with gas mileage since gas itself is so dirty to produce. This would be way easier if there were a plethora of small, modern(within the last 10 years or less), RWD engines on the market. Also, higher octane fuel is more ecologically taxing than low octane fuel. I'll likely make this car flex fuel compatible and not really run e85 until that gets cleaner which it will in the future.

[Ace2cool]

As far as mileage goes, smaller isn't necessarily going to equate to more mileage. You're going to work that smaller engine harder in order to get up to speed.

[Veganpotter]

That's totally true but this car will be driven on the freeway 90% of the time, if not more than 90%. I'm not too worried of that smaller engine comes with a 6 speed that's geared for acceleration. I'm adapt with my differential.

[NolimitZ32]

If that's the case you need to look at small displacement diesels.

[Veganpotter]

I'm

[Veganpotter]

I'm looking for low emissions too. I don't think I can afford a bluetech drivetrain from a Benz. I'd do veggie oil if I lived somewhere warm all year.

As of now, I'd love a new Miata engine. I have a friend getting over 40mpg on the highway with theirs. But that'll be hard to come by with them being so new. I'm maybe thinking about a Subaru engine from a regular Impreza or a Forrester...PZEV generation. The BRZ would be easier but its not as clean

[NolimitZ32]

The problem for you will be that the miata and BRZ are both well below 3k lbs, the miata is 2300 something. the Z32 tips the scale at 3300 with the spare removed and cloth interior. If you are looking for an economy car the Z32 is a bad candidate, for a number of reasons.

[Veganpotter]

I know its a bad idea. That doesn't bother me. I've wanted this car from childhood. Its appearance still doesn't for my. Ethically? I can't drive a car that wouldn't meet modern emmisions standards and I want better. Even with the Miata engine, this car will be about as slow as my Matrix which doesn't bother me. Emissions bother me. I also like good handing and this car will drive really well with 200 lbs cut out of it. Most of my fun comes from coasting down canyons.

[NolimitZ32]

Careful with that statement, the VG is a heavy lump and putting a much lighter engine in will mess with the near perfect F/R weight distribution. Just another factor to think about. I'm excited to see what you come up with.

[Veganpotter]

If you've ever driven a Porsche, you'd see that 50/50 isn't that great. I'll be happy to have the car at 45/55 or even 40/60.

[NolimitZ32]

1. Depends on the Porsche
2. 50/50 is oversimplified. Rear engine Porsches (considered Rear-engine rear wheel drive), though they are near 50/50 are rear-engine vehicles where the majority of the engine's and transaxle's weight is hanging past the rear axle. This is a cause of hatred for MANY racers and enthusiasts alike because it makes the car very tricky to handle at the limit. The Z32 is a Front-Mid-Engine car which places the weight of the powertrain forward of the center of the car but behind the front axle, closer toward the center of the car making for MUCH more neutral handling.
3. If you want a car that does twisties well you want 50/50 with a bias to center of the body like the Z32. Place too much of the bias on the rear and you will get a formula for heavy-assness and a preclusion to step out which on a mountain-side road can spell disaster.
4. Fun fact: the Z32 in it's day came in middle of the pack for pretty much every standalone performance test when pitted against it's JDM rivals yet it holds by a huge margin the most motorsports wins in it's class, that said I think the engineers at Nissan knew what they were doing when they got spendy on the CRAY system used to design the Z32.

[Veganpotter]

The roughly 50/50 Porshe cars were slow through turns. The newer cars are 40/60 and some are even 38/62 other than the Cayman. My weight reduced Corvette was 50/50. It was fun but not nearly as fun as the one Porsche I drove and the few I've ridden in. Its obviously a great car as is. The 2+2 is also gonna have more weight out back. It could lose some in the nose. A lot of assumed things worked before but there is new tech. The z32 wouldn't have been tuned the way it was if modern tires were available. Now that tires are better, cars can be tuned differently.

[NolimitZ32]

Again, just looking at the weight distribution ratio is an oversimplified approach, lots more at play here and if you are going to compare a vehicle designed and built in the 80s and one designed and built today what do you expect Its not just about weight distribution, its about tires (like you said) suspension design, downforce, AWD vs RWD, traction control and electro-nannies. IN the case of the Z32 2+2 you are correct it 53/47 (vs 2+0 55/45) but I would be careful making an all encompassing statement because the point of reference (middle of the car between the axles) changes when you elongate it and the majority of the weight stays at the front. Also you are backing up my original point about the car becoming more tail heavy which would wreak havoc with how it handles because the engineering that went into it was done for a specific weight distribution. Its a chain reaction.