I have a '75 280Z, looks great, but handles okay. Okay is not punchy like I want or am used to from my 240Z. Yes, I know it is not a 240Z and, in fact, is heavier. This is all known to me. However I want something with a little more umph than my 280Z has now. It currently has the stock N42 head L28 and seems tired. It will get up to speed but takes awhile. Combined with the transmission (which I hate, it has this damn tiny shift pattern, my 240Z had a nice long shift pattern to it and I never mis-shifted), it is not the driving experience I want.

I went to the Datsun Z garage and read about the P90 heads, originally designed for turbo applications. However he mentioned it is a very free flowing head and mated with a F54 block gives great performance. It should even have the square exhaust ports so it would mate straight up to my headers. My question, however: Would I continue to use the existing FI setup and ECU? At first lookover it seems I would, it is already on the car and both engines are 2.8 liter, right? I know the compression ratio will be different and it will have another transmission (not that this matters), Will I need different injectors? I should probably change them anyway. I read you need to get a turbo oil pump for the P90 head, so I plan on it. This seems to be a straight rebuild-and-drop-in project. Any thoughts? Thanks in advance.

 

I would take it apart and change the piston to flat or dome top, get a mild cam and use you SU to feed the gas

 

The pistons in an F54 block are already flat top. I do not want to use SU carbs, I actualy got a '75 to get away from carbs. I want to use the FI setup, however my questions was if I should stick with the '75 Fuel Injection setup or if I need to get a Fuel Injection setup from a ZX, like a '83. I was wondering about the AFM, if I need to chnge this. I was wonderinging if I needed bigger injecters.

I already plan to rebuild a F54 block from a '81-'83 280ZX, mate it to a P90 turbo head, but avoid putting the turbo on it. I plan on having this be a close to stock in alot of ways, 6-2 ceramic cloated headers, square head exhaust to match to P90 head. I was going to install a turbo oil pump, turbo head bolts, FelPro gaskets all the way around, '81 ZX 5-speed, '81 ZX R200 3.90 gears.

 

No, only difference is O2 sensor. I ran 76 with 81 engine for awhile. like your set up, expect I use the P79 head. Use all the 75 EFI components and you'll be fine.

 

I'm planning the same thing, F54 block, P90a head though. It's got hydraulic lifters. However this will be a Bored and stroked motor using the Nissan Motorsports Stoker kit. Keep the fuel enjection it should work just fine. good luck.

Joey
1976 280Z 2+2
2+2s are not ugly