Royce

Good question! I don't know the answer but found a great article that may help you decide. This article was written by D. Elgin of Elgin Cams, a cam guru in the SF peninsula. Check out: http://www.elgincams.com/campaper.html I have heard tales that the 260Z cam was a performance mod. But the question is in what situation and when in the 30+ years of Z cars this was applicable. It may rank in there with the N36 manifold. Either one may be better than stock 240Z stuff but you could probably achieve the same if not more from modifying what you have. In this example, I would think it would NOT be worth finding a good used 260Z cam at this point. I think you would probably be better off talking with a cam grinder and seeing what they have to say. Elgin used to have a online catalog that listed Z car cams, however, I couldn't find it this time around. Have fun!

I am curious about this since I will probably one day do this out of necessity! If you remove the air tubes but unthreading them what are you left with? Is there a female threaded metal sleve or is it female threads in the cast manifold. If it is the latter would it be possible/advisable to tap the new threads into the cast manifold? Also, I would think that the type of metal of the plug would be important as to its expansion characteristics so that it wouldn't leak or damage the exhaust manifold??? Hope that last one made sense! Thanks!!!

Sorry, don't know the size of the bolt. What a local Z friend did that seems to work well is take the exhaust manifold to a welder and have them cut off the metal tubes on inside and out. Then weld it closed! They said it was better/stronger to weld the metal sleve, what is left of the bolt/tube deal, than to weld to the cast material of the exhaust manifold. They were also concerned that removing the metal threads from the manifold would damage it! Has anyone had luck removing these? I believe it cost him about $30 at a local welding shop. I may try this if I ever remove all the smog stuff. In fact since I have a few extra manifolds laying around I'll probably prep one just in case! Or should I say, when my air pump stops working! Hope it helps!

Okay, yes they will fit but the mount points for the arm rests will be different. So it isn't just a bolt on change. You would either have to cut holes for your 240 arm rest and have holes visable from the old armrest. Or you would have to fabricate some mount points for the 280Z arm rest. Sure it can be done but it would take a little bit of work because the inside door skin (making this term up) is different. This is the metal interior door panel that has access holes and welded nuts to mount all the panel items (window crank, interior door latch, and arm rest. Hope it makes sense! Let me know if i have raised more questions than I have answered!

Daniel, Yes, you are right the '73 was the only 240Z heater control panel to have backlite heater controls. Otherwise the heater control panel looks the same! Smokey, If the '70 unibody and floorpan are in better condition and it has the original motor it "might" be a better choice for long term value. However, if this is a car you just want to drive and have fun pick the one that is the best overall condition! Besides the diff location the '72+ Z cars had a different, more durable transmission design. In the US no 260Z's had fuel injection. That started with the L28 N42 block/N42 head '75 280Z. Hope it helps!

A used 240 motor doesn't have a lot going for it, especially if it has been removed from a car. It is easiest to sell if the new owner can drive it and see how it runs. In my opinion, once it is taken out it is basically a core. I mean, I wouldn't go through all the work to put it in my car just to find out there is a problem and then take it out again. I would rather take it appart and check it over first and at least replace the bearings and the rings. A 240Z motor is most valuable with the matching serial number 240Z car. Second most valuable place is with a racer that is restricted to original engine specifications. But a motor is expensive to ship so it limits you to mostly local sales. If someone is going to swap to a different non-original motor they may as well go with a 280Z, 280ZX or 280ZX turbo motor. It is hard to beat cubic inches or turbo if you want a little more bang for the buck. I just recently gave away a L24 because I had it for sale for several years and got no takers. But there are a lot of Z's here in California. So where you are they may have more value!? The bottom line is if you have time you have a better chance of finding someone that will pay what you think it is worth. This is just my opinion! Sorry, I probably didn't help much.

Well I noticed the font color was different but didn't realize it was a link. Thanks!

DatsunZGuy, How about some contact information???

Zsled, Remember, that is $5 for a L24 or L28 with modified bottom end, head, and carbs. You are not talking about your basic rebuilt engine here. They can build you a standard L24 - L28 for less, it just depends on the condition of the parts they are starting with and whay you want to have done to them! A little machine work here and there and some upgraded parts can add up really quick. Sure a small block V8 might be cheaper in some respects, but if you get out of the standard build it will add up quick too! Besides, small block V8's are still in new production and race developement. The L6 hasn't been for a few decades, not to the same degree anyway! Hope it makes sense! Derk, Sorry, no clue what Britney has to do with this!?

Sounds interesting, how about some pictures?

I think either motor would range between $4k & $6k depending on what you have done, condition of head/block/etc. they start with and if you are going to give up your original motor or not. If you build your L28 right you could be in the range. My 2.9L Rebello motor, built in 1990, is basically a smaller bore version of there current 3L motor. Mine is a N42 L28 block with L24 rods and custom pistons. It has my E88 head with 280Z vavles and some machine work. These days they usually start with the F54 block and will use a N42 head if you don't supply one. I have never put my engine or car on a dyno but I am sure it is not there. I put in a stock cam with my stock intake, exhaust, and all the smog equipement (remeber this was 10 years ago). It has a lot of torque but needs some other modifications to get the power. I have talked to two members from North California that have purchases Rebello L28 motors recently who could probably tell you more.

It sounds like the gas tank vent lines might be crimped somewhere. There are several vent lines so I am surprised this would happen, but maybe someone has removed some of the vents in the past. It is common for the vent lines to deteriorate over time and cause gas smell to get into the passenger compartment. If someone plugged a couple of the lines and left only one, and now that one is damaged that could cause your problem. All the vent lines are routed to a vapor tank in the hatch area behind the passenger side interior plastic quarter panel. You could start here but it would be best to get a manual and check out the fuel system, specifically around the gas tank to see a diagram of the fuel tank vent hoses. I remember my friend had this problem with his VW bug and it would actually crush the tank slightly from the vacuum. Hmm, I suppose you may have problems if your fuel vapor return lines, that run from the carb fuel rail back to the gas tank may be plugged up. This is easy to test by removing the return line at the tank. I cannot remember how high the return line inlet goes up once in the tank so you might want to do this will fuel level is low. Disconnect the return line at the carb fuel rail. Blow compressed air back through the line and see if you get good air pressure out the other end. In order for gas to get removed from the tank by the fuel pump it needs to have a way to replace the space with air. Hope it helps!

If you are racing you should run the breather to a catch can w/ breather. Otherwise you could use just a breather but as lan240 says if there is a worn o-ring, gasket or seal somewhere on your firewall you can end up smelling fumes in your passenger compartment. I have also heard that having the fumes drawn out by vacuum from the carbs helps keep the oil cleaner. This theory suggests that you are getting vapor contaminants out of the engine. This may be true but I don't know if it is significant. Of course if you have that many vapor contaminants in your engine you may be due for a rebuild anyway. Hope it helps!

I think this person is confusing flat top pistons with flat top carbs. However, if someone wants to show their car in a stock category and has a '73 240 or 260Z at least they can get a spare set of carbs cheap. Because they are probably going to need all the spares they can get to keep the thing running. Then again, all it takes is one person to figure them out and win a race with them and everyone would probably start buying them up! My friend has a '73 with them and it still runs well. I don't think I would stay with them because there is not as much info or parts available. Especially if engine modifications are planned.

Oops!!! Sorry, I looked over you info too quickly and mistook the info as 240, 280, and 280ZX specs, instead of 240,260, and 280Z/ZX! I realize E30,E31 and P79,P90 have better combustion chamber design but I think this is further proof that you can do quite well on a budget when starting with the N42 head! My bad! Thanks for the quick correction!

Zsled, Depends on whether you want to win or just have fun at autocross. It is hard to beat cubic inches when it comes to making more power! I don't autocross (yet) but I would (and did) go the L28 route. But make sure and keep you L24 if it is the original motor for you car. Turbo's and tripple carbs would likely put you in a modified class that would require many $$$ of suspension and other modifications and developement to make the car competitive. Besides, as Dan said tripple carbs are not necessarily needed to get more performance. You can go a long way with SUs. From what I have heard Rebello Racing builds a 200HP L24 SCCA ITS spec motor using relatively stock bottom end and carbs and mild head work. For the same money they can build you a 250-275HP L28 using modified SU carbs, L28 block, and modified head (using 280ZX intake and exhaust valves). I do not work for Rebello or have any affiliation, they are just well know local Z motor builder that I had build my motor many years ago. Dan, I think that makes a good case for the N42! Any L6 head could use a cam and a little polish and port. With the N42 you do that and add the 280ZX intake valves and there you go! Thanks for the info! Mudge, Well that is almost a second off the R/T test times when the cars were new, ~16.6 if I remember correctly. Although, with modern tires you might be able to make that difference. It is hard to compare without knowing you entire setup. Engine spec, exhaust, intake, trans, diff, tires. Have fun!

I voted for "All the time", although occasional drives would be more like it. With two young ones around neither of us drive it as much as we would like. Plus at 5'4" she has a bit of a time reaching the peddles. She would like it a bit more if I actually cleaned the inside once in a while and if it had more than just the stock radio! She doesn't know that's why I leave it the way it is! (kidding!)

It would kinda fit under the Tech Documents, open, or misc. forums. Maybe, he could ad a historical reference forum for these topics? And maybe a new discussion should be started since this is drifting away from the E-30 topic.

Yes, I too would love to learn more about the non-USA Z cars from a non-USA perspective! I enjoy all the different personalities on this and other sites. Hey, if we were all the same with the same opinion life would be boring! And everyone would be driving Z's!!! Maybe that would be too much of a good thing! Nah!

Sure Bambikiller240, you Carl guys stick together!!! ;-) Actually, I agree to your statement exactly. Carl Beck worked in a US Datsun dealership and has a great amount of US Z knowledge. But like anyone his comments may be a little biased to his own experiences. Most of the information on Zhome was contributed by Z folks from around the world. I am certain he would be very happy to have more information on the different Z markets! HS30-H, Thanks for the info on the E30 head. I had heard it is not necessarily a good choice for the L24 - L28 because it has smaller valves than even the early L24 heads. Of course vavle sizes can always be changed, and often are. Sure Carl Beck or zhome.com can take your affectionate punches. He enjoy's talking Z as much as anyone and I am sure if he has argured with you about anything Z it was in the interested of learning more and challenging you to the point of disproving some other information he was convinced by another was fact! I post things on this site and other Z forums that I think are ture. I certainly don't want to send anyone down the wrong directions and apprieciate it when I am corrected! Go for it, challenge him, them, it, us! Take care!

Sure it will work in a 240, 260, 280Z, 280ZX or anything that currently takes an R160, R180, R190 or R200. From what I have heard the trick is getting the right output axles so that you can attach your Z/ZX half shafts or CV joints. Example, If you have the 4 bolt flange type diff now you would need Datsun 510 R160 flanges to bolt up to your R180 or R200 half shafts. Hope that makes sense!? Also, the bolt holes on the back of the R160 and R180's are smaller than the R200. So you should be okay here to swap with a R180 but if you swap with a larger diff you would need to modify or change your rear diff mount, mustache bar for us first generation Z folks. I have read that a LSD diff is stronger than the comparable open diff. And that a LSD R160 would be stronger than a open R180 diff. So which Subaru's come with 3.9 or 4.11 LSD??? Hope it helps!

All L6 Z/ZX heads have round intake ports. The N47 & P79 have round exhaust ports as well. It has been said that the square ports are more productive to flow but I have never seen any dyno results to say how much of a difference, if any, it makes. I have seen "the quest for the best Z/ZX cylinder head" conversation come up many times on many different forums. I have some questions that I have not seen discussed... What are the different int/exh valve sizes for the various US marked Z/ZX L6 heads (E31, 240Z E88, N42, P90)? I have heard often talk about putting 280Z or ZX valves in E31 or E88 heads. Does it require machining the head to use these larger valves? (What I mean is sometimes you can increase the valve sizes by just grinding the valve seat and not actually machining the head and putting in larger seats.) What about larger than 280Z/ZX valves in any L6 head. Has anyone done this? I would expect that all the above has been done but it may be helpful in determining how cost effective it is to modify different stock Z L6 heads. As a Z car person on a budget the best head to me is the one that gives the best bang for the buck. I have often thought if you have a head in good shape that is the best place to start. From there you can modify it to meet your performance goals. I have heard that the E31 and P90's have the "best" combustion chamber design. Sure you could put larger valves in a E31 but I would have a hard time justifying the work it would take to get a P90 head to work well on a non-Turbo Z motor. Of course to take advantage of head work mods (big cams and large valves) you also need higher than stock compression or you could actually see less power output. What do you folks think?

I have seen 34 years! Took my first ride in a Z when I was 2 years old. My father borrowed his friends brand new yellow '70 240Z and took the family for a ride. Those were the days, Mom and Dad up front and three kids in the back. I bought my silver 240Z from the original owner when I was 20.