1980 280zx engine into 1977 280z

yes, its a straight swap. Keep the 77 air flow meter if its still works, I think its bigger but I'm not sure. Dont scrap the old engine it has valuable parts. I also need so 80 zx parts.

Use the entire 1980 motor including the the electronics, sensors, and the air flow meter. The electronics were updated between 77 and 80. Check the clutch while it's apart; the haynes manual tells you the proper thicknesses for clutch discs and if yours is getting thin you will want to replace the clutch while you have it apart.

Agreed unless its an auto...

check the dual port vac advance on the 80 engine the port closest to the engine usually fails. Also look at the ported vacuum valves, people break the **** off them all the time

Can I swap the tranny as well?

Yes.

theghosttanker said:

Use the entire 1980 motor including the the electronics, sensors, and the air flow meter. The electronics were updated between 77 and 80. Check the clutch while it's apart; the haynes manual tells you the proper thicknesses for clutch discs and if yours is getting thin you will want to replace the clutch while you have it apart.

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I believe that he will need the ECU, and the FI wiring harness, plus some relays (fuel pump, fuel injection, etc) and some wiring workarounds to get the complete 1980 electronics system into his 1977. Probably worth it for a cleaner, better running engine, but not as simple as just bolting the 1977 electronics on to his 1980 hardware.

Just clarifying. If you don't like wiring, then just bolting the 1977 sensors, wires, etc. to the the 1980 hardware would be the way to go.

You might consider going with the '77 head on the '80 bottom end for a big bump in compression ratio (upwards of 10:1). You'll definitely want to use premium fuel with that though...

The '80 trans will have closer 1-4 ratios, and a taller 5th ratio. IMO, the '80 NA has the best ratios of all the Z's.
But you might think about swapping the diff as well. Should be a 3.70 or possibly even a 3.90, vs. the '77's 3.54.
If you swap the trans but not the diff, 1st and 2nd gear will be noticeably taller.

77, 78, 79 and 1980 z/zx engines are exactly the same engine (N42 block, N47 head, 8.3:1 cr, dished pistons).

zx changed to the P79 head and F54 block (flat top pistons) in the 81 to 83 model. and the P90 head for the turbo with dished pistons in the F54 block.

the air flow meters are different. the 75 to 78 air flow meter has 2 extra pins that turn on/off the fuel pump. You can use a zx air flow meter on a z but you will need to put in a jumper wire in the 77 plug.

I recommend to use the 77 stuff on the 80 engine.

Oops, Wangsman is right, should both be N42/N47.
Also, it's likely that your '80 ZX has a 3.54 diff, unless it's a 2+2 or GL model in which case it should be a 3.90

The '80 transmission might still be an improvement, but it depends on what you want. The '77 has lower 1st and 2nd gears, but an annoyingly giant chasm between 2nd and 3rd. 5th gear is relatively close to 4th.

The '80 trans has taller 1st and 2nd for fairly close ratios 1-4. But it has a bigger jump from 4th-5th (which may be desirable for lower-rpm hwy cruise).

My 80 manual deluxe with 3.545 is awesome at high speed cruising. A minor interchange mod is the 80 5 speed with 3.90 differental for take off

I think the 79 and 80's manual cars came with 3.70's. not 100% sure.

From what I've read, they completely rewired the ECU in 1978. For sure though, the 1980 and 1977 ECU pinouts are different.

For example, the air temperature sensor wire, which comes off the AFM, goes to pins 6 and 27 in 1977, but uses 25 and 34 in 1980. You could make work, I'm sure, but it's not plug'n'play.

For fun, I also checked the pinouts to the dropping resistors/injectors - 1977 is pins 15, 33, 32, 14, 14, 30 and 31 for 1 - 6, 1980 is 2, 6, 5, 7, 3, and 8 for the same.

That's why you would need the FI wiring harness to go with the ECU.

While I'm here I might as well say also, that the last year they used the AFM fuel pump contacts was 1977. !978 used the oil pressure switch and alternator rpm to power the fuel pump relay.

Not arguing, just clarifying. I just went through this same thought process between a 1978 setup and my current 1976, digging around in the wiring diagrams and FSMs. Things started changing a lot in 1978.

Huh thats wierd my 79 Zx had a n42 block but the p79 head as stock, at least as far as I know it was stock.

I don't think the n42 ever came stock with the p79, not on a US spec z at least. I'll look into it, but as far as I know all f54 blocks had flat tops and the higher quench heads (p heads). An n42 with stock dished pistons and a p79 head would have kinda low compression.


Edit: Datsunzgarage backs that up. According to the site the p79 only came on 81-83 f54 blocks (US at least). Just another thing to blame on the PO Skittle.
http://datsunzgarage.com/heads/index.htm

79 and 80 are mostly the same. Manual 79 and 80 280zx had 3.545 rear ends. The 80 trans has its own unique gear ratios. I can verify that by looking at my Deluxe. Ok, some tables say that an Manual 80 GL had 3.90, which I doubt. But I'll be working on my 80 GL, and I'll look if it has the r180 or r200. Autos were 3.70

skittle said:

Huh thats wierd my 79 Zx had a n42 block but the p79 head as stock, at least as far as I know it was stock.

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And that's a weird spelling of the word "weird"! P79 head never came on an N42 block. If you have an N42 block with the stock dished pistons and a stock P79 head, your compression ratio is somewhere down around 7.5:1. Candidate for 30 psi boost!