TheCrazySwede

Forgot to mention it, but Dave said the same thing about the P79, so yes you are correct. He mentioned that they've built hundreds of NA builds running on N42's and pump gas with no issues whatsoever.

So, I had another Juan-on-Juan with Dave, and (again) didn't recommend flat-tops with the P90 head, due to deck height issues. Mr. Rebello is either an L-Series wizard or extremely well at selling a product, because I am (at this point) on the edge of getting my motor built by his shop. I always thought his builds run close to the $10k mark, but he wrote me up an estimate for around $5k. At this point, I'm still doing my research. I'm not really in a hurry, so I'll take my time with it all.

I've baby'ed this motor since I've owned it, so I'm glad to see that it's still going strong. Once my new motor is up and going and I'm satisfied with it after a while, I'll use the old one for something else. The possibilities are endless!

Got my current (stock) L28 on the dyno. Not bad for the ol' Fairlady! 148rwhp @ 5,200 161ft/lbs @ 4,000

Hmm, interesting. Haven't heard of that head before. Also, not sure if this relevant, but I my motor is carburated. I wanted to eventually go with Triple Webers, but that's once I'm more experienced. Are there any issues involved with high compression/different head combos with the use of SU Carbs? According to OZDAT, I'll be sitting at around 10:1 (about) I've heard that is a safe number for P79's and P90's to dish out. Of course the cam and all other aspects come into play, as well. I'll be doing some research on the MN47, but as far as you know, is there a major cost-performance difference between the turbo heads and the MN47? I figure that every dollar I save will contribute to a different aspect of the motor. If it's a night/day difference, then it sounds like a no brainer. Thanks a lot for the input. I'll have some more homework to do tonight! (Never thought I'd say that with enthusiasm)

Actually, madkaw sent me a link to a very thorough. P79 build page. I suppose I can go with a P90, as well. At this point, it's whatever ends up in the garage. I've had many people recommend those heads, but when I spoke to Dave Rebello, he seemed pretty confident in the N42's operation, even though I specifically addressed my compression goals and fuel octane resources. So that stepped me back a bit. From what I've gathered, however, there seems to be a lot more non-pinging P90/P79 high compression L28's than N42/N47's, so I won't be trying to re-invent the wheel. So to put the project up to date. Got the crank polished and the block bored .20 I ordered a pair of flat top pistons, but they happen to be out of stock....tried purchasing from Clark's discounts. I figured I'd get them from ebay, so that's not too much of a worry. I also got new bearings when I got my crank back. My bottom end is where I want it, for now. At this point, I'm trying to do my research and find a head and go with it.

06/22/2014 UPDATE Block still getting bored. According to OZDAT, my setup will leave me with 9.1 compression, which sounds good to me for an NA motor. The build has been running a bit slower than usual due to financial reasons, but I hope it picks up soon.

Cool, thanks gents! Thanks for the link, Lazeum! I found that last night when I was looking around. Seems like a few others around the forum have had great results from Clark's, too. Thanks again for all the help! Now I can order in the pistons and the crank bearings

Looking at ITM Flat Tops, and judging by the part #, does this mean 0.020 overbored? http://www.ebay.com/itm/Engine-Piston-Set-w-Rings-ITM-RY6134-020-fits-81-83-Nissan-280ZX-2-8L-L6-/161298615025?pt=Motors_Car_Truck_Parts_Accessories&hash=item258e258af1&vxp=mtr

Oh shoot, 95mm! I must've misread what car it was from, but I think the ones I saw were 89mm. The ITM pistons look nice! As far as piston sizes go, is bigger always better? Aren't the bigger ones more heavy, thus increasing the mass?

So, just got a callback from the machine shop. My crank is healthy, just needs a polish. Stock size bearings will do. However, the block needs to be bored. As of now, I'm just looking around and seeing what type of pistons I should get, and just bore it to fit those measurements. I've heard people using the pistons from a 240sx and some people even using the 370 ones (They look massive when compared to the stock ones.) I'm still looking around, but are there any fan favorites I should know about? Thanks lads!

That's the conclusion I reached, too. I sent the block, crank w/ rods to a machine shop to get it checked out first. I bought the motor from someone on CL, and he didn't know much about the engine, himself. Just want to make sure the block is in good condition, and also what size bearings I'll need, and such. As I've mentioned before, I'm not really power hungry, but I would like a responsive motor, not a sluggish one. Working on the valvetrain and a lighter flywheel will already give me that, so I'm already set, so to speak. I already have a set of rebuilt SU Carbs and competition headers (6-2), so for now, I'm just taking pre-cautions to make sure the motor is built right. Proper balancing is also high on my priority list. All that mass adds up! Thanks for all the help guys! I'm hoping the machine shop gets back to me at the beginning of next week. Once I get the info back from them, and hopefully all the components are in good shape, I'll head north towards Rebello to see how we can build a nice head.

Thanks for the input 310z, I'll ask him about the cams! I ended up going to a machine shop first. Dropped off the block and crank (w/ rods) to get checked. I want to make sure the bottom end is ready before I start on the head.

So, I gave Rebello a call (Turns out they are about an 1 hour away from where I live!) I asked him what type of pistons he recommends. He said he hasn't faced many issues with the flat-tops in the N42 head, but if a higher compression isn't needed, he would recommend the dished ones. I also asked him about valvetrain improvements, and he recommended a mild cam with a rather low lift (about .448) but he said that the Cam produces great torque and works great for street use. He said that Z Car Garage (Another highly rated Z specialty team) prefers that Cam Kit over most, mainly due to its power delivery. I'm going to go over to Rebello (bring my head!) later this week, probably on Thursday, and see what can be done. They use ITM Pistons, by the way. Thanks a lot, gentlemen, for your help! I'll report back with what we talked about.

Thank you, gentlemen, for both of your inputs! I still have a bit more research to do before I go purchasing parts and start swapping things around. I contacted Rob Fuller of Z Car Garage, and he also recommended the 45's for the L28. I wanted the car to be responsive and snappy. Power figures isn't my top priority. I know properly tuned Weber's, Valvetrain (Cam, springs, etc.) and a lightweight flywheel will already get a more responsive motor, but I was wondering if there were any more swaps I should do. I am now dealing with an empty block, so I suppose I build the engine back up with a setup I'm more satisfied with. I would prefer to keep the bore the same (86mm), but I don't know if I can get lighter, flat-top pistons at that size. The L24 crank and rod setup is something that seems interesting, but I am kind of confused regarding the size and positioning of things....wouldn't the setup cause a much lower compression ratio? If boring it to 87mm and going with the flat-top ZX pistons (or even the 240sx ones) is the better way to go, I'll go that route. I just want a responsive motor that isn't afraid climb, rather than a powerhouse.

After reading up on Cams, I'm probably better off with an Isky cam, like you mentioned. Their State III Cam sounds very intriguing! There's a shop near where I live that have experience tuning Weber Carbs, so that'll definitely help a lot. Any tips on pistons? What type of flat top options would i have if I didn't want to bore the head? (86mm)

UPDATE: 2/14/15 After a rather long hiatus, the build returns with updates! As some of you may know, I decided to go with the professionals with this build. Looking at some local shops around my area, most notably Rebello Racing, and also some other shops across the country, I've decided to send my dear L28 out to Eiji Hosomi at Datsun Spirit Inc. (https://datsunspirit.com/) There are three main goals that I wanted my motor to achieve. 1. Speed > Power. I want my motor to run like a hot knife through butter. It needs to be quick and very responsive. Power is nice, but a quick revving motor is what I seek. 2. Character. My beloved Z will eventually be my weekend car. I don't want the motor inside of it to just be a fast engine. It needs personality and character. Something that sets it apart from, let's say, a Honda Civic. This is why I went for triple Weber 45's, a flywheel that weights less than 10lbs, and my desired cam (more info on those later.) There's a certain character I want this motor to display, and I believe this build fits the bill just right. 3. Reliability. It might seem like an oxymoron, having a fast and reliable sports car motor, but I've seen time and time again how these motors, when built by true artists of their trade, can withstand almost anything you throw at them. My new motor will be running on pump gas, will idle smoothly and will barely break a sweat with the granny-like driving I put my Z through. Engine Specs: Bore/Stroke: 89mm/79mm Pistons: 29mm Kameari (280g) Rods: 139.5mm Kameari (~575g) Crankshaft: Polished, Stock L28 Camshaft: .290 Duration / .490 Lift Valves: New valves (stock size) Upgraded springs and retainers CR: ~10.5 to 11:1 Now, time for some photographs! Here's an album with all the photos I've gotten from Eiji thus far. I'll update it as the build continues: http://imgur.com/a/Fyqtv ORIGINAL POST: Dear Forums, I've been a long time lurker of these forums (along with Classic Z Cars) and of the community, but just recently, I've decided it was time I popped my Z cherry and got involved. I own a '77 280z (Motor has EFI; Transmission has 4 Gears) I'm currently working on another L28 that I picked up (Carbed, N42 Head)) along with a 5-Speed, but due to my lack of knowledge regarding these motors (We are a family of Ford Mustang owners) I seek your help in order to make sure this build isn't a total disaster. To start off, hello; My name is Mike I am 20 years old and I'm a computer tech. This is my first engine rebuild, so experience is not really something I have in my corner. Luckily, my brother and my dad are both mechanics, but they decided to pretty much leave me to learn how to swim in the ocean with this build. My goals for this motor are pretty simple and straight forward, but I would still love to get some help from some of you more knowledgeable L-Series petrol heads. Let me start by saying that I am not power hungry. We have the pony cars for that. What I want is a responsive motor, not a powerful one. Engine Goals (Might get redefined as I learn more about these L-series motors) 1. I would like to hit 200HP at the crank (Although not necessary) 2. I want the motor to be naturally aspirated. 3. I love the look and sound of triple Weber carbs. 4. I don't think I need a stroker motor to produce a descent amount of power, so unless it's necessary, I'd rather not go there. Things that I am considering (Please correct me if I'm wrong!) 1. Balancing the Crank 2. Lighter, flat-top pistons (I would like to keep the stock 86mm size) 3. Stock valves look good enough! Probably just stay with those. 4. I've read a few posts where people mentioned using L24 rods. Why is that? Weight? 5. A Mild performance Cam with upgraded springs. As I mentioned above, I'm just learning about these motors, so your help is very much appreciated. I'm gonna need all the knowledge I can get. This is the motor: So it started with this Time to clean! So that's pretty much it so far. Cheers guys, and thanks a lot for the help! Not that it matters much, but here is the car:

Gotcha, thanks guys for the advice. Much appreciated! Looking into my build, I don't see it necessary to have bigger valves. The L28, thankfully, already has large valves, so I should be set. I wanted to make a post asking questions regarding an NA L28 build, but I know there a lot of them out there, although many of them have different circumstances and don't all have the answers I seek. I just don't want to be the guy who gets flamed with "Did you use the search engine??!!" haha. I'm hoping to hit 200HP+ at the crank (Not to the wheels. Although that would be nice, too!) Do you guys know any good posts out there? I've found a couple, but most of them are discussions and not posts that actually follow a blueprint. Thanks guys, cheers!

I don't understand the justification of the price, either. Things that I'm planning on my rebuild are mostly Cam (Including rockers, retainers, springs), new pistons and proper balancing (within 0.5 grams) The stock valves look big enough for any performance need. So basically, I should be good with the stock sized valves, right? Unless anyone knows an affordable upgrade to the stock valves. I already know of SI Valves, but not entirely sure why they are considered an improvement over the stock valves. Are they just lighter? How much so?

Dear Forums, I'm currently rebuilding a stock L28. I was looking at the DSI Big Valves ($408) but was questioning myself whether or not it's worth it. http://datsunspirit.com/?wpsc-product=dsi-big-valves The Intake is 1mm larger, and the exhaust is 1.5mm larger. Looking at my own head, I noticed that the stock valves are already pretty large, and was wondering if bigger valves are worth the extra dough and if they are safe. Also, on that website, it states that the valves are longer. What would I have to change to accommodate for the extra bit of length? I'm planning on running a higher lift cam, but it's still a mild cam and not some crazy .560 racing cam. What are your thoughts on this? Cheers!

Dear Forums, I'm currently working on a L28 rebuild and was seeking pistons. Has anyone had any experience with the Kameari Pistons? I wanted to use my stock L28 Rods (DSI sells 86mm Kameari Pistons that fit stock rods) but wanted to know what type of difference in performance people have experienced with them. Cheers!

If you let your car sit for 10-15 min after driving it, do you have any issues restarting? Meaning, are you getting less fuel than you should? Been learning about how these L-Series motors are notorious for this.

I have downloaded and read the FSM, but it only confuses me more, rather than help me answer the questions I have. I appreciate the help, though, thanks!

Dear HybridZ, I have a 1977 280z and I'm having some trouble getting it starting. I don't seem to get spark from any of my plugs. The car was working fine the other day, but suddenly decided not to work. I've had starting problems in the past, but I have been able to fix them with some good ol' starter fluid. That trick won't work this time. The engine cranks just fine (starter gets proper voltage, as well.) I've checked the battery and the connectors, all work fine. I replaced my ignition coil, and all of the wires (ignition wire and spark plug wires) and I've also replaced the plugs, themselves. Still, no spark. I checked the resistance of my distributor cap and I got around 0.9 to 1.2 ohms. I believe it is suppose to be near 0, but I don't know if my level of resistance is enough to prevent the car from starting. My main question is this; Are the possible issues in the distributor, the cap and the rotor? How could I accurately test each one? (I've searched Google, but I've fond a ton of different answers that are totally irrelevant. Maybe I'm not looking correctly.) What else could be causing this? Thanks guys, I really appreciate it. Cheers!

Got her running! Sprayed some starter fluid into the AFM and gave it some gas. Started right up! Thanks a lot, gentlemen!