DavidBoren

I do sincerely apologize for any offense caused by my language. If I had taken the time to read what I had written before posting, I would have not used such a word. A lot of this build has just been day dreaming of what I could do. I get away from reality sometimes. And it was not right of me to get defensive and lash out at those of you whom where simply trying to give me a reality check. Now that I have my feet a little more firmly planted on reality, I do have a couple questions... I am absolutely okay with using premium fuel only in this car as it will not be a daily driver, so my target is somewhere around 10:1 compression... is there anything else I need to worry about raising the compression that high in this engine (assuming the engine is structurally sound enough to use at all)? Special head gasket? Head studs? Will zero-decking the block, or shaving the head, negate the use of larger valves? If I am not overboring to add displacement, and I just re-needle the SU carbs, would larger valves be worth the hassle? And cam...? Something with good street manners that will compliment a high-compression L24. Do I have to go aftermarket, or would simply using a different L-engine cam be a better choice?

Thank you all, once again, for the input. Believe me, I get it. I wont see 240rwhp. I already stated it was just a figure I manifested from the model number of the car. I thought it would be cool to have a 240hp 240z. Already stated I probably will not be able to achieve it. The square bore and stroke is simply something I wanted to try if it was possible. I know a lot of people swap L-engine parts and I saw that there was an L-engine with the same stroke as the L24 bore... thought it was worth asking about. I also already said that I know experience comes with its price. I know that having a specialist build my engine will probably produce a better engine than having a no-name shop rebuild it. I get it. I promise. Why people insist on replying to this topic without any useful information pretaining to the actual topic, I dont know. I dont know a lot of things. I do not know how much it costs to rebuild a motor. I do not know how to rebuild the engine myself. I do not know to swap in a different engine. Last I checked, I thought that was the purpose of asking questions. Of course I want an unreachable horsepower figure. What the hell is the point of dreaming if you arent going to dream big? I am speaking out my arse. I admitted my ignorance right off the bat. Thank you to the three, or so, of you that actually had something useful to say. The rest of you retards that jumped on the opportunity just to starting bashing my self-admitted ignorance should take a long walk off a short dock.

Rediculous may have been a bit out of line. I appologize to Dave, if he frequents these pages. I have priced rebuild kits and other various parts for a mild performance rebuild and considered the machining and assembly costs. And I still find the price steep. I do understand that there are a lot of things that can cost a lot of money that may come up unexpected. I know that little costs add up fast. I am just going to have what is in there checked and cleaned, ported, valve job, balanced, zero-decked, etc etc. Re-use everything that can be re-used. Pick up a quality bolt kit and gasket set. I will simply fix what is there, but I will fix it right. I am not going to pay anyone $5,000 to rebuild that motor. Im just not.

I know that experienced engine builders carry a bit of weight, but $5000 for rebuilding an L-series engine with OEM L-series parts, and some porting is ridiculous. I cannot get over that. I could put an LS1 in it for less than the cost of having Rebello rebuild the L24. I really like the idea of keeping it numbers matching, but screw the "Purist" build.

The "Purist" build is $5000. Plus carbs (I asked for the triple-double carbs) and dyno, Dave says its closer to $7500. $7500 is way out of my price range. For that kind of cash, I can forget the vanity of having a numbers matching car, grab a 2jz-gte with the transmission for $3000, sell the twin turbos, buy an ITB intake and six throttle bodies, and still afford any fab work required for the swap. $7500 to stroke an L24 using an OEM 280z crank and OEM 240z rods and a little port work on the head? Nope. Not me. I may be inexperienced, ignorant, naive, but I am not freaking stupid.

Alright, I just shot Rebello an email. I will let you know what he says in return. Thank you all for your input and advice.

Ok, it is a HLS30 8###, placing it as a 1970, Series 1 car. It has the Z-in-the-circle emblem on the sides (which I thought was a Series 2 thing), and the louvers on the back window. My phone is about as old as this car, so I cannot upload the pictures. No noticeable rust around the fenders, cannot get under it to check the frame-rails. Overall, the car is surprisingly rust-free in appearance. This is promising, but I am not holding my breath. I fully understand that getting a 40+ year old car to working order is going to cost quite a bit. That is why I do not want to spend an obnoxious amount on the engine. I also have looked for the V07/LD28 crank, and have seen how rare it is. The cheapest one I have found was $500. So I do appreciate how much this is going to cost, regardless of which route I choose to take. Either way, bushings need to be replaced, and will be replaced with polyurethane parts. Shocks and springs needs to be replaced, so high-rebound shocks and stiffer rate lowering springs will be installed. The parts that need to be replaced are going to be upgraded with performance being the goal. Getting the engine checked and cleaned, as well as having any porting and machining done will be done regardless of whether or not I end up stroking it square. The valve job, port-matching, new cam, new intake, new exhaust all have to happen, even if I get to re-use the numbers matching block/head.

I will check it for rust when I go over there this weekend to check the VIN. I am pretty sure it has an L24, as that is what the American import 240's had in 1969 and 1970. This will be my first manual transmission vehicle, so I am mainly just going to play with it at autocross events to become a better driver. That being I am going to focus largely on upgrading the transmission and differential first, because it is going to take a beating with me pretty much learning how to drive a stick. Suspension and brakes will be a close second because autocross can be hard on these areas. Once I get the power it already has available firmly and efficiently hitting the ground, I will worry about upgrading the engine. Thank you all for your input, both negative and positive.

I will have to take a closer look at the car, but gramps said it was a 1969 240z. I didnt think they came stateside until 1970, so I assumed he was just a year off. To be honest, and to advertise my ignorance, I have just assumed Fairlady was a monicker associated with the 240z. I dont know if its a separate car. And if it is, I stand corrected. I appreciate the advice and criticism. I do not know much about these cars. It may not have an L24 in it. All I know is that I do not have the money to do an engine swap, so I want to have some fun with the engine that is in there. As far as making it square, it is just my preference. To each their own. Nobody thinks twice about stroking an engine, and that is all I was proposing with adding an LD28 crank to a L24. It just happens to make the bore and stroke match. And I just happen to like that. The 2jz is a square bore/stroke powerplant, and people do amazing things with that engine. I will get the VIN this weekend, and get back to you with some better details. Thank you for setting me straight.

Ok, hello everyone. As my username may suggest, I am David Boren. I am 28 years old. My daily driver is a 2005 Cadillac V6 CTS. I live in Portland, Oregon. My fiance's grandpa has a 1970 Fairlady just sitting in his backyard. I want to turn it into a my weekend cruiser. Just something to take out and have some fun in the sun with. I will probably use it in local autocross events just to become a better driver. And a 240z will do A LOT better job zigging and zagging between the cones than my Cadillac luxury sedan. I have no engine building experience, and am planning on making the Fairlady my first build. I am not trying to break the bank on this, and that is why I want to stick with the stock block and head. I will get everything professionally checked and cleaned. And any porting/machining will be at a shop, not by me. The 240rwhp goal is simply based on the fact that the car is a 240z. If it isnt feasible, then I will take what I can get from a high-compression "square" L24. The LD28 crank will give the L24 a square bore/stroke (83mm x 83mm). And if the 280 rods will work, they are probably pretty easy to source as well. I want a lightweight/balanced rotating assembly, so the rods and pistons will probably be the largest expense of this build. Having the block decked or the head shaved to up compression shouldnt be that expensive. And I am not doing anything too radical to the head as far as porting. Mainly just port-matching everything, and having larger valves installed if they will fit. Any word on whether or not I can fit any larger valves into a E31? As I plan on having the block zero-decked to the top of the pistons, I also need to know if larger valves would hit my pistons, or if high-ratio rockers and a lumpy cam would cause interference between valves and pistons. That is actually why I originally mentioned dished pistons. Also, speaking of lumpy cams... is there a L-series cam that is more aggressive that would be easier or cheaper to source, or should I just go aftermarket? Thank you for your replies thus far. PS. There are LOTS of 240+hp engines out there. I am not interested in an engine swap at this point. I am enjoying the vanity of having a numbers matching car, and just want to play with what I have available. If I was going to swap in anything, it would be an all aluminum 5.7L LS1 stroked to 372" with a 3.9" crankshaft (making it square with the 3.9" bore).

Has anyone done this? And what con-rods will I need? The square bore/stroke is just something I want to do. I know there is no replacement for displacement. I know the L28 strokers are more popular. I have a numbers matching 1970 240z, and want to use the block/head that it came with. I, personally, like the thought of a "square" engine, and thusly plan on building this one accordingly. Any insight or advice would be appreciated. My goal is 240rwhp, not sure its it possible, but thats what I am shooting for. Plans include: L24 block with stock 83mm bore, Ported stock head with bigger valves (if possible), LD28 83mm stroke crankshaft (knife edged), 11:1 compression ratio (91+ octane fuel only), Lightweight conrods (not sure of length), Lightweight dished pistons, New cam (not sure which), New valvetrain (lightweight, high ratio), Not sure of intake, 3x2 maybe, or ITB Might put a mild (75hp) shot of juice to it just for fun.