280 to 240 swap confirmation plz

[Guest Anonymous]

I have been looking around here, at classic z, and the other resources and have come to a couple conclusions and I would appreciate it if someone could verify that my conclusions are valid

 

I have a L28 out of a 76 280z, and I would like to put it in a 240z. The main problem that I see is the fuel issue.

 

Option 1: Pull the head off the L24 and place it on the L28, swap dizzys and maybe a couple of other minor things and then I should be able to swap it in. Pros, simple, cheap, and I should have a higher CR (from what I understand the older heads had small combustion areas) Cons, the engine might run a little lean, won't have the fuel economy and perhaps the smoothness of injection, and I might hit valves due to the longer stroke of the L28 (I need to look into that issue a bit more before the swap.)

Option 2: Keep the L28 intact and yank all the EFI stuff out of my 280z and stuff it into the 240z. Pros, still have the injection, economy, smoothness, and everything on the engine is still stock. Cons, probably a pain to locate and remove everything out of the 280, the old rusty 280 would then officially be junk or a parts car, couldn't put an engine back into it.

 

The purpose of the swap is to create a straight rust free car with a decent motor. The L28 is in decent shape, and the 240z body is in great shape, just need to merge the two somehow.

 

What option would be preferable?

 

Does anyone have another suggestion as to another way to do the swap.

 

BTW, the search function on the board works just fine, it would be nice to be able to search all the forums on the board at once instead of haveing to do the same search multiple times for each different forum

 

Thanks for the help

 

-frozen

[texasz]

Not knowing what head you have to put on the L28 that part is hard to comment on. It is possible that you would have a combination that would give you a lower CR. Another thing to keep in mind is that unless the 240Z head has been rebuild it may likely not have hardened steel seats threrfore you would have to run a lead additive (these were originally designed to run on regular gas not unleaded) or replace them, costing you money there.

 

Just putting the L28 with the EFI and all in the 240Z is some work but it has been done many times over by people through the years so that is a good option.

 

If you do not want to hassle with the EFI wiring and all you could always convert the L28 to carbs when you put it in the 240Z and then that problem is solved (this is what I'm doing). You already seem to know the pros and cons of carbs vs. EFI so I won't go there.

[Drax240z]

I'm fairly certain all Z's had hardened valve seats...no?

 

First off, take a look at both engines and tell us what casting numbers are on the head. (between #1 & #2 sparkplug) Should be E31, E88, N42, etc.

 

This will sortof determine what way to go.

 

On one hand you can have good fuel economy, decent power, and EFI cold starts.

 

On the other hand you can have simplicity, a bit less economy, a bit more power and a choke.

 

In the end, you can't go wrong with either setup really. If you are planning on driving the car a lot, I would say EFI should be chosen. If its a weekend fun car, the SU's are just fine for that.

[texasz]

I'm fairly certain all Z's had hardened valve seats...no?

 

Not so, the N42 head had brass/bronze (depends upon who you listen to) seats. As for the others I understand that some had soft steel seats instead of the hardened steel seats. If you have the brass seats replace them with hardened steel ones, if you have the softer steal ones check the condition and go from there.

 

If you're wanting power with minimal effort you can go with a non-turbo F54 block which will have flat top pistons (these came in '80-'83 280Z's), a rebuilt N42 head with hardened steel seats and carbs. The block/head combo is said to provide a 10:1 CR; and this is without any other mods. From here you can do things like headers and exhaust work, or other mods to get more gains. Another popular head alternative is to put a P90 on the above setup but to get the same type of results it has to be shaved down and depending upon how far it is taken you may then have to shim the cam towers (this becomes a bit more expensive and more work). It's really all up to you depending upon what you want from your Z and how much money and time you have/want to spend.

 

The possibilities are nearly endless! I've seen 5.0 Cobra engines in a 240Z, even an LT1 and the accompanying 6-speed tranny in one (and that one MOVES!!).