L26 with 71-72 SU Carbs

[Framework]

Hi, I just got started on my first ever Z car, unfortunety it doesn't run for beans... yet. I was wondering though, would the carbs from a 71-72 240z run better on the L26 then it's stock carbs? I've got a 260z I'm swapping parts out of into a 240z. Is there a difference in the intake manifolds for the 240z and the 260z? I think I have the earlier model 260z if that makes a difference. Which would be best for power on the L26? I understand there is more displacement on the L26 but is it significantly heavier the the L24? I'm hoping to bring some life back to this L26 since it hasn't run in 10 years or so, and I figured changing out the carbs might be one of the things I might need to do. Any suggestions or comments would be most appreciated. Even if they are like many I get telling me I'm crazy to start this project! Thanks!

[Royce]

If the 260Z has the stock "flat top" carbs then the 240 carbs may be a good switch. There are those that claim they can get the flat tops to work well, I have never even seen a pair in person, but there is more collective information on working with the 240Z type SU carbs. I have a 260Z parts car that has a L26 with N36 manifold and 3 screw 240Z carbs. I drove it 100 miles when I got it and it ran well, although it has a bent frame so it wanted to change lanes all the time. The only problem seemed to be using the stock air cleaner. There are some adapters used to mate the round port carbs to the square port air cleaner. If you still need to smog the car than you may have to be creative to get all the hoses to connect to something but it can be done. If you don't have to use smog then it would be easiest to use the 240Z air cleaner or aftermarket air cleaner(s) and remove most the smog stuff.

The N36 manifolds are supposed to be a little better out of the box than the E88 manifolds. And the 260 head should have larger valves than the 240 head. This brings me to something I am not sure about, that is if the 260 has less compression than the 240 and if so is it in the head or the block?

I am not sure why you say the 260 motor would be heavier. Unless you are including all the smog and ignition stuff. The crank shouldn't add and "significant" weight.

I don't think it is crazy, use what you have. However, since it sounds like you are going to be rebuilding the engine anyway why not get a L28 block and/or N42 head? I would put my L26/E88/N36/240SU motor into a Z, but was running in a car less than 6 months ago.

One last bit is that the 240 & 260 may have different ignition systems? If your 260 has the electronic type, no points, it may require modification to work with a 240Z tach.

Sorry, I probably raised more questions than answers. Hope it helps! Have fun!