I may have a chance to pick up an '80 280zx motor to swap into my '73 240. The only way I can do this project at all is to keep the costs way down. I have a few questions as I plan this out:

1. Should I keep the existing FI for the new motor, or put my 72 round top carbs on it? I like the idea of no smog with the carbs. FWIW, this is a weekend car, not a daily driver, and I am very comfortable working on the carbs. What sort of difference in top-end HP might there be?

2. Can I bolt my existing 240 clutch parts on to the new motor? They are relatively new and in good shape. For now, I don't plan to do a 5 speed swap.

3. Can my existing 240 radiator handle the load? I had a few cracks fixed last summer and the shop said it was otherwise very clean. Will my existing hoses bolt up to the new motor?

4. Can I keep my existing radiator fan and shroud?

5. What about motor mounts?

6. What else should I be thinking about?

Thanks in advance!

Daniel

1. I am doing the same swap. In fact even my Z is a '73 . I am using my SUs but I have SM needles to handel the added CCs and I also have some head work and a after market cam . The SUs will handel the 280 no problem and the performance will be vary close to the injection . Just low tec, you will need to use the choke when the engine is cold. That kind of thing. Yes to all the other questions. You will need to add a electric fuel pump if you are not already running one. The later head is not set up for the manual pump. If you need one, find a RX-7 that is carbed at the bone yard NOT a injected car. This pump will work great on the Z and mine was $15.00 at the u-pull-it. It is quiet also. It mounts by the fuel tank. #6 you might think of replacing the rear main seal. this can be done without droping the pan just remove by prying it out carefully . enjoy the ride Gary

2. Can I bolt my existing 240 clutch parts on to the new motor? They are relatively new and in good shape. For now, I don't plan to do a 5 speed swap.

3. Can my existing 240 radiator handle the load? I had a few cracks fixed last summer and the shop said it was otherwise very clean. Will my existing hoses bolt up to the new motor?

4. Can I keep my existing radiator fan and shroud?

5. What about motor mounts?

Thanks in advance!

Daniel

2. Yes, but USE EVERYTHING from the 240Z, and NOTHING from the ZX. Don't mix clutch/trans parts!!

3. Yes, if it is a 3 row radiator. If it's only a 2 row (stock 240Z), you will likely have problems as the radiator was marginal for a 2.4L engine in the first place.

4. Yes to fan, Yes to Shroud. If you end up changing to a ZX Radiator, you may need to modify the shroud to fit

5. Yes, Use same Engine mount brackets and motor mounts

6. How much fun you'll have when the job is done.

Hey Daniel, the 280ZX motor has a different flange on the exhaust manifold where the first exhaust pipe bolts on. You'll have to have an exhaust shop fix that. You could get a down pipe from VB or Motorsport and have the shop tie that in to the 240Z exhaust. Unless you're going to run headers, then you'll need exhaust all the way back.

The bigger engine in the 240Z really wakes the car up. The stock motor has more torque at low RPM's but doesnt wind out as good as the 240Z motor. But it can made to run really well with mods when you can afford them!

Chris

If the zx is a standard trans, you might as well put the 5 speed in it. you will have them out anyway.

And it would give that much more.

I just installed a '77 L28 with the 5 speed into my '73 240z. Fit nicely. I am running my '71 SU and headers. I still have to connect the exhaust from the 280z car into my 240z.

I can't wait.