Has anyone stroke 260z's?

[motorheadwannab]

I think i'll just get the 260, i'm about to leave right now to guy buy it, it'll still be a fun car i'm sure i won't be disappointed. The clock says it has 84xxx on it...should I even rebuild the engine or just clean the carbs and go from there?? It does run, fired up pretty well actually but this being my first car with a choke i'm not sure if the white smoke puff is normal! Well i'm off

[jmortensen]

If you look up "oversquare" "undersquare" and "rod/stroke ratio" on Google, you'll find some reasons why you don't see many stroked L26's. Plus the L28 block is basically the same but with a larger bore as has been stated, they're dirt cheap, and it's a bigger displacement engine to start from, so why not?

[mars23z]

80000 miles is not a lot for an L series engine if it was cared for properly. If there is white smoke I think that means there is water in the exahust. Now it could be moisture or there is coolant leaking in some where. Make sure the block isnt cracked. If the engine runs fine then I would start with carbs and go from there. I paid $250 for my L28 with 70K on it and it runs great. Watch ebay there on there all the time. It only cost me $350 to have it swapped or you can it yourself. Here is one with a 5speed for $499.

http://cgi.ebay.com/ebaymotors/1979-Datsun-280ZX-Engine-and-Transmission_W0QQitemZ130135994432QQihZ003QQcategoryZ33615QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

[motorheadwannab]

how do I check to make sure the block isn't cracked? I am guessing compression check and checking to see if the oil is fowled with water? I think it has round carbs not flat tops...tho I am still trying to figure out the difference, do flat tops have the air filters horizontal (ie flat)? Because this one does not have that kind.

[mars23z]

Flat tops are still round but the top is flat. The round tops look similar but the tops are rounded on the top. There will be either 3 or 4 bolts holding them together on the round tops. Here if you dont have these and have the money place a bid they will be a huge improvment.

http://cgi.ebay.com/ebaymotors/Datsun-240Z-SU-Carburetors-3-screw_W0QQitemZ140141977597QQihZ004QQcategoryZ33550QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

[motorheadwannab]

Would you happen to have a picture of the flat top so i can compare, or is it pretty obvious? Thanks for the help i'll keep my eye on that ad! The ebay ad says it is a 3 screw, does it make a difference if say mine were 4 screw? Sorry for the dumb questions!!

[motorheadwannab]

edit: oops

[mars23z]

I think the 3 screw are from earlier 240zs and the 4 screw are later 240zs, but I dont think it matters either are better then flat tops. Do a search here on flat tops they are bigger around then the round tops if you look at the pic of the rounds you will be able to see the difference between the 2. If you are interested I have a complete fuel injection from a 75-76 280z. You would have to upgrade your fuel pump but I have everything else. I have the MAP sensor, manifold, all the wiring everything should be there if you want it let me know. Check around this site first to make sure its worth it to switch to EFI. This came off the L28 I put in my 260. I chose to keep my carbs because I am eventually putting the L26 back in and I just wanted to keep carbs on the car so it didnt make sense to modify for EFI .It was just a personal preference I know a little about carbs but know nothing about EFI . Chris

[motorheadwannab]

haha ya I'm the same way, the whole reason i'm buying a 260 not a 280 is because it has less electric stuff! But, I found a great help on ztherapy http://www.ztherapy.com/technical_stuff/spotterguides/zcar/240spotter.htm if anyone is confused about carbs as well it helped me a ton! I am going to stick with carbs, however after reading on that site, does it matter what year I get the 240 carbs from cause they seem all quite different! Do some perform better than others?

[mars23z]

I think as long as they are 72 or older your ok. Ztherapy is awesome get the video from them.

[sblake01]

As far as the 'electric stuff' goes, I like it and wouldn't have it any other way but that's my choice. I consider myself fairly adept at it. My advice, however, is don't attempt to install the 280Z EFI on a 240 or 260 unless you fully understand the system and have the skills. Even then I'd be against it. So many things have to be changed on the car virtually from the front bumper to the rear including the gas tank, fuel lines, etc. besides all the electronics which is a whole different story. I have 25+ years experience fiddling with 280Z EFI and I wouldn't attempt to install it on a pre EFI car. Keep the carbed cars carbed and the EFI cars EFI'd(?!). Well you get my drift.

[beandip]

The ''flat top'' carbs the dome looks like a soup can. the top is completely flat , the SUs are dome shaped. The 3 screw carbs are SUs from a '72 , 4 screw carbs are from '70-'71. As for performance there is no difference in them. Mostly just assembly differences . I am running a '82ZX 280 engine in my 240Z and running SUs. I gave the injection away to someone that needed it. The difference in performance with this engine compared to my old 240 engine is night and day. My car is intended for street use and the mods done to it were done with this in mind. Gary