nissan2ner831

from what I understand from carb'd Porsche's, this isn't quite correct. If I'm not mistaken, there's actually a point where much longer air horns are better for high rpm applications....I'd have to pull out the book again to find out for sure though. and no, I don't think it should cause any serious problems for a short while.

Well I'm not sure on either of those, I'll have to leave the answer to those questions to someone more experienced with the 240Z that me =P I can't find anything on it, most people use the Z31 brakes when upgrading versus the Z32. I'm not sure if that is because you can get Z31 stuff cheaper or what, I'll leave it to someone who knows these cars better than me to answer.

Well I'm not sure about being able to do a 5-lug conversion with the Z32's hubs, but I know there are some people using the rear end off of the Z32....problem is it is much more difficult to get it to work than using an R200 rear diff. The R230 rear diff is stronger, but unless you are building a very high output motor, it shouldn't be necessary. In all likeliness, it will just be easier to get an R200 rear differential. You should be able to find information on this through searching by the way. I can't find anything on using the Z32 hubs, so I'm thinking it hasn't been done before (someone can correct me if I'm wrong in this case).

Yeah I happened to read that thread right after I posted *doh* I hope he get's this to work though, it could open up some interesting possibilities in the future if it doesn't cost too much money. Then again, with the amount of money people spend on maximizing the L-series heads, I'm thinking this would probably be pretty cost effective if you can do a lot of work on your own (minus some of the stuff that pretty much has to be done at a shop unless you happen to own your own shop =P)

hey Mag, any updates? Just curious, this thread idea interests me greatly =P

haha well I understand the hybrid thing =P I'm not trying to put down V8 swaps or nothin, they make for some serious fast Z's. It may just be I like the idea of doing things a little more uniquely, like sticking with an L-series engine (hey, putting a LD28 block is as much of a hybrid as swapping in a V8) or doing something else that is unique. Part of the reason why I want to do a Datsun is to make myself "different" from all my friends who are crazy about Camaros and Mustangs and such....besides I was always into japanese cars =P

haha why is the recommendation to everyone just swap in a V8?? =P I understand that power to cost is something you always are looking at, but like I've said before, if I wanted a V8 I'd just buy an american muscle car XD. Though I admit having a V8 in a chasis as light as a 240Z would be nice =P I'd rather stick with a Chevy Nova to be honest though =P

Must.....look...away...can't afford...a rust free car...much less dream over something like this XD.......damn college (you may make me a college drop out yet =P) Great job, I hope you get everything working together. Who knows, maybe this would be a somewhat attainable way for people to get DOHC heads on the L-engines...then suddenly all the arguments about building up a L6 is pointless because its a "non-crossflow head" would suddenly become null and void XD. Good luck!

haha alright, I'm used to many other forums where I do get yelled at for asking questions like this =P Good to know that as long as I don't ask something like "Can I swap an L28ET into a 240Z?" I won't get flamed =P And as a side note, if I wanted a V8, I would probably get a Chevy Nova and swap in an LS6 XD. Part of the reason I wanna stick with an L6 is because all my friends are into the Chevy Camaros, Ford Mustangs, Chevy Chevelles, ect. As cheesy as it may be, I have always been into the Japanese import scene since I saw The Fast and the Furious as a kid =P. I know the movies are way different than reality of course, but that is just the generation I grew up with...though for some reason Honda Civic's never appealed to me XD

haha Josh, like I said earlier, this is more out of curiousity than anything. In reality for the next several years, I'm plan on working on the car with a very tight budget. I'm hoping to get it turbocharged within a year of getting the car, but I'm not expecting to make the "dream" build for quite some time, if I ever do. I'm not foolish or trying to be unrealistic, I just ask a lot of questions. If I can't find the information through most of my searches, I figure I might as well ask. Even if it is something that I never end up doing, if I don't find out an answer, I go crazy =P. Sure I would love to just build an LD28 right now, put ITB on it with a nice turbo and the block off plate from a company that escapes my memory right now (essentially it closes off half the turbo on the exhaust side until a certain RPM is reached, at which point it opens allowing full flow, but speeds up spool), somehow get a crossflow head for the L-series, do a full suspension swap from an S13 into a front tube chasis 240Z, but I don't have the skills, knowledge, experience or money necessary. But I would love to learn how to do this, and even if that dream never becomes a reality, I would find any of the skills I gain valuable. I'm not trying to annoy anyone, just gain some knowledge on what I would like to know. I don't pretend I am capable of this, but is there really any harm in asking?? (and yes...I would love to have that car, though I doubt I ever will XD).

haha yeah that's the gist I'm getting. Like I said, I just tend to think about things a lot when I'm bored, and when I noticed the more more open head I just got thinking =P

I believe it was a picture like this that made me think about twin plugging the L6 engines: None of the race prepped heads or ones with the shapes show in this picture would benefit from it, but this combustion chamber is much more open =P

Yeah John, with all the pictures of these heads being posted of the L6 it doesn't seem like there would really be such a need as with the VW heads and Porsche heads I've seen. With the way all of those combustion chambers are shaped on the L6, it doesn't seem like twin plugging would be necessary. haha and yeah they can be a bit of a bandaid, but they do allow one to raise compression ratio's or increase boost (much more of a common thing on a Porsche flat 6 than found on the Porsche flat 4...and there is a reason why Porsche started twin plugging the Porsche 911 Turbo =P) or if nothing else, can help an engine continue working reliably. I know many people don't use it as a way to gain power by increasing the compression or upping the boost, but as more of a reliability thing...though that seems an awful expensive upgrade for some "reliability" to me =P

Here's a quick few things I found. There's a variety of VW Type IV engines, Porsche 6 cylinder engines and Porsche 4 cylinder engines: 4 Cylinder VW head (I believe) Porsche 911 with twin plug (whole engine bay of course, but notice the 12 wires running from the distributor. That engine cost a small fortune) Pic of a engine built by Jake Raby, one of the most knowledgeable people in building high performance 4 cylinder air cooled engines: Porsche 356/912 engine with twin plugging I'm short on pictues of the actual heads, but the first picture gives you the idea. And yeah, I can imagine it might be more difficult with our engines, but if people are rewelding up combustion chambers and redesigning them as it is, wouldn't it be an interesting option to explore? Granted, the actual design of the head may get in the way...but I've also wondered if you could just technically fill up say the exhaust port with metal, and then just reroute it to the opposite side of the head XD I'm thinking you would run into water jacket issues though, and that may indeed be a problem preventing twin plugging from being used on these heads. Just some musings of mine, something I was thinking about in my spare time =P

Yeah Daeron, and your information was informative, thank you =P It was mostly in response to Josh (not trying to go after him, just explaining my reasoning for asking some questions on very advanced builds on an L6). I know that it is way more cost effective to build a V8, I just like doing things that are a bit more unique (hence how I got into the world of Porsches...I currently own a Porsche 912 and was intending on sticking a VW Type 4 engine into it, but the costs were astronomical...8k at least for body restoration as my Porsche is in bad shape, and another 12k easily for the engine (not a stock Type 4 of course =P)...I have a serious bug for wanting to work on cars, and I just don't have those kind of resources to do it...besides I've always been more into Japanese cars than german cars =P). I ruled out the V8 conversion just because I know so many people have done it, and I can't deny it makes for a very nice car, but another thing is all my friends are into the whole "american muscle" thing, and in reality I've always been the one who was more interested in the Import scene, and I have liked the 240Z for a while. Just a personal decision to go with the stock L6, if I was going for the most efficient possibility I would have chosen a different enginen of course =P

haha I don't blame you for getting annoyed at the "cost is not a factor" threads, and I realize this is what this thread is. I'm not trying to say I know what I'm doing, or how it should be done. I'm just curious about many things, and in my spare time (which there is plenty of) I tend to think of many random things. I have a lot more knowledge concerning several different engines (including VG30DETT's and 4 cylinder VW and Porsche air cooled motors), but I'm fairly new to the L-series. I didn't figure there would be any harm in asking some questions about them =P Like I've mentioned, theres no way I'm going to afford anything like this anytime soon, I'm a college student barely scraping by as it is, but we all like to dream don't we?? =P

Alright, I'm fairly new here (though I've been a lurker for over a year), and to the L-series engine in general (I'm young XD). Anyways, I have a lot more experience in my 20 years of life with air-cooled engines, in particular the VW Type 4 engine and the Porsche 912 4-cylinder engine, the same one found in the Porsche 356. Now I know (from all my various information gathering and some work experience on them) that almost all the air-cooled Porsche and VW engines can benefit greatly from twin-plugging the heads (not on its on, but what it can allow the engine to do...and expensive modification, but one I would have done had I continued with that world, though I plan on returning to it someday in the future, the costs for a college student were just too high). Anyways I was looking at some build ups of several L28 heads, and noticed the spark plug placement is very similar to that of a stock Type 4 or Porsche 912 engine, that is off to the side of the valves. So it piqued my interest if anyone had tried to twin plug the L28 engine, and I couldn't find anything on it. Is there a specific reason for this? Head design doesn't allow for a second plug to be drilled in on the other side of the valves? The cost unjustifiable? Just curious as I know it is quite common in the air-cooled world for high performance builds (it's limited to those due to the cost) and am wondering why it hasn't been explored with the L-series (or if it has, I may have just missed it).

Yeah 1 fast z again I was reading that somewhere else earlier today XD If I go to a 90mm bore I'd sleeve it, and hopefully have room for at least 1 rebuild if needed later. I'm liking the idea though, using a custom crankshaft, rod and pistons would leave around a 1.7 rod/stroke ratio and a displacement of 3.3589L (what would you guys say, should that be rounded up to 3.4L or no?? =P). Things may change, I'm still a far way off from building anything =P

Yeah I know that...for instance those very rev happy Honda motors like the B16 or B18 are not a "perfect" rod/stroke ratio either. I'm just aiming for around 1.7 (a little higher or a little lower, doesn't matter) just for keeping wear down on the pistons. I personally don't think I'd want the engine to rev over 7500 rpms anyways, I don't need a huge rpm band (and according to what I've read, both the standard L28 and the 83mm stroked L28 can both hit 7000 rpms, so I don't need a big improvement or anything). Anyways, from what I've figured, I may just bore out to 90mm on a LD28 block (not sure if this is "safe" for a boosted project, but I'll keep researching to find out If not...well I can either decide to sleeve the block or just drop my displacement down) with a custom SCAT crankshaft for a 88mm stroke, giving me 3.3589L of displacement...and with the higher deck height of a LD28 block, using custom rods and pistons would allow me to reach a decent rod/stroke ratio. Expensive to be sure, but it should hold up to almost anything you throw at it XD. Who knows, again these are all just ideas I am throwing around in my head right now, we'll see what happens when I can actually get working on a project =P

Yup, I'm well aware that there are height issues if you use an LD28 block in a S30. And I know it doesn't allow extra displacement (well, not in and of itself at least), it just allows you to use a longer rod with whatever stroke is used for a better rod/stroke ratio. Only way you can get "more" displacement out of the LD28 because of the deck height is to use a larger stroke, and the extra deck height allows the use of longer rods to keep a decent rod to stroke ratio. And yeah...if I go with a turbo motor, I've read a lot saying 90mm is too much off the block, but going with sleeves for at most an extra 2mm (from 89 to 91) doesn't really make much sense. I guess if I was finishing the project and was just going to spend a ridiculous amount of money on it I guess, but I can't really see justifying it for a 2mm overbore. I may consider it so I can do a 90mm bore, and have a rebuild still available for the sleeves. I'm kinda agreeing with you PanzerAce, I may have to go with a longer stroke to get the displacement I want. Again, I'm just mulling around different idea's in my head, it's what I do when I am bored XD (like how i decided to sit down and figure out what rod lengths are needed for 4 different strokes (88mm, 87mm, 86mm, 85mm) to have rod ratio's of 1.75, 1.7, 1.65 and 1.6 XD...oh I forgot to mention I did this by hand XD...and I did the same with several combinations of stroke and bore for displacements...again by hand. I get quite bored sometimes lol)

Yeah 1 fast z, I've read several threads where you have commented on this. I'm not thinking of this as an idle whim or anything, I'm trying to do all the research I can on it before I even buy a 240Z and get started on it. In fact...I intended in my original post to saying something to the effect that I understand that sleeves in adjacent cylinder cannot just be dropped in, they must be welded in...like I said, I am trying to do all the research I can on this.

haha yeah I know it costs a lot, I'm not expecting it to be cheap I'm not currently saying I have many concrete plans for a Z, mainly because 1) I don't have a Z XD 2) I'm still learning the skills I want to learn to work on my own Z 3) I don't have the money required for any project right now (gotta pay for schooling). Though I do have some general ideas and some ideas I'm considering, like a bigger than 3.1L L series (I'm leaning towards an LD28 right now for the extra deck height), turbo, possibly a front tube frame...nothing concrete right now, and it's all a far ways off. Gotta get my schooling taken care of, and gotta learn the skills I'd need to get this project rolling (mainly starting with welding classes right now) It's just all getting thrown around in my head, pretty much just a dream right now This is really more of a curiosity question, I'm really in the planning stages of what I would like to do with a 240Z. So essentially...with either the LD28 or L28, you can only go about 2mm over the max bore with sleeves compared to a block without sleeves?? I know you can hit 89 with a L28, so 91mm would pretty much be the max if you sleeved the engine?? I'm interested in the LD28 too...mainly because you can fit a longer rod in there for a better rod/stroke ratio. But yeah...an extra 2mm doesn't seem like it's worth it...I know it's expensive, but I was hoping for at least 93mm out of a wet sleeved block XD

Out of curiosity, what would you guys say is the maximum bore possible in a wet sleeved L28 or LD28? I searched and couldn't find much, but if its been answered before I guess I just didn't look hard enough.

yeah I know rust is one of the big things (I learned that with the car I currently have, a 1966 Porsche 912...the carpeting hid all the rust...as in in entire floor pan, rear seat area and even the deck behind the rear seats is all rusted out....thankfully the parts that came worth the car make up for what I paid for the car, and is how I am getting the money to work on a Datsun. But yes I know very well to make sure about rust with older cars). And yeah, I know the backfiring issues could be many things, I'm just hoping that it isn't some serious problem that would cost thousands to fix. I'll be giving him a call later today, and from what I can tell in the pictures of the car, it doesn't appear to have many issues with rust (though im expecting some in the normal places, especially the battery tray).

I don't personally own the car, so details are going to be thin right now (I'm going to try to give the guy a call tomorow to try and find more out about the car, so I should have some more details then). I'm lookin to get a S30 to drive around for a few months until I can afford a down payment on a newer car as a daily driver, at which point my S30 will become a project car (that is another thread of course lol). Unfortunatly, the one I am looking at (I only have 2000 dollars to spend on the car right now, so I'm not looking for a pristine condition car) has a pretty serious backfiring issue. Like I said, I need to get some information on exactly what is going on with the car, but aparantly the carb and intake manifold have been replaced, and thats not helping aparantly. He hasn't identified what is wrong with the car (he thinks the distributor is the issue, but who knows). My question is, is the car worth it for $1200?? It's got a black primer paint job (which is ok, being I plan on painting the car myself eventually) and the interior is in at least decent shape. Should the extra $800 be enough to get the car up and runnin again (I should have more than that if need be, but I'd prefer not to spend too much money tryin to get the car in decent running condition). Any opinions would be great =) *edit* and sorry about my name...im not sure what I was thinking when I chose it (its too....idk i dont like it lol) I usually go by mike831 (if there is any way to change this, let me know please =P)