DAW

I hear ya Dead Roman, not only doomed to be an A/T; it'll never haul balls.

I see your point, Yasin, and I'm in no way claiming that my cars meet emissions. However, there are some items that not only affect emission control but aesthetics as well, and they have no effect on performance... to keep them is part of the art of building cars. Why would your girlfriend or wife or anyone else around the car want to inhale fuel fumes if they don't have to? It makes no sense unless they are a "huffer". You're not a huffer are you Yasin? Put the damn canister back on. When someone asks you why you still have the thing on, you can ask "why do you and your car always smell like ****?" Or better yet, why is your car's olphactory like an 'ole factory? My cars aren't pristine but I hate following someone whose unburned hydrocarbons are so excessive that they're wafting into my vents and my family's bloodstreams and brains, and we certainly don't need the odorless CO that's bound to be there with it. DAW

That's cool. I overreacted, and I didn't mean to look like I was singling you out. Mea culpa. I do think it's essential that we try to maintain an image a cut above some of the other hot-rodders out there. When it comes to something like chucking charcoal canisters, we can either be informed and conscientious, or we can be pariahs of the car enthusiast world. We can tune our early Zcars, regardless of hybridized powertrain, for far more power than they were originally configured while meeting or bettering the emission standards of their era by using our heads (so to speak) and applying state-of-the-art technology available, like f.i., O2 sensor feedbacks, knock sensors, catalytic convertors, etc. DAW

Bravisimo Henrik! Your artwork is so amazing. The attention to detail is just staggering. I could not believe what I was seeing in the pics, the craftmanship level is like some old-world clockmaker or something. You've got some genuine talent there. DAW

PROject datsun, if you decide to go the route I suggested, here's some valuable info: you want to only consider L24 rod sources from engine # L24-096181-on as these have the 9mm rod bolts. Forget anything earlier as they would have the useless 8mm rod bolts. DAW.

Oh, sorry slow & rusty if I stepped on your toes. Donate something and we'll talk. DAW

Yeah, same situation. My '75 280Z A/C car with '81 L28ET, I ended up just chucking the entire A/C and installing a donor non-A/C control system, including the OEM firewall plug for the intake/output lines of the evaporator. Although, the whole thing is easier than taking a non-A/C car and converting it to look like a factory A/C car. DAW

Unless you're going to turbocharge, the dished pistons are worthless for making power. Even with a shaved E31 head you don't make significant compression and you've got those tiny valves to deal with. If you are building a n/a engine do yourself a huge favor and use flattop pistons, whether from an '80-'83 280ZX L28E bought as loose pistons or just find a shortblock from a 280ZX (F54) of those years. There's one other approach which makes sense: Take out your piston/rods; remove pistons from rods; have a machinist turn down the edge of the dish-top until it's just gone and you barely have a flattop (with reduced pin ht.); reassemble pistons to rods but don't use the L28 rods, use L24 rods with 9mm bolts (2.6 mm longer rod than L28, makes up for lost pin ht.). You can bench-balance rod/piston matches in the process and the net result is that you've increased your baseline compression and have a simple choice of stock larger-valved heads (vs E88, E31 small valves) to use. P79/90 now gives you 8.8:1 and N42/47 gives around 10.0:1 on an engine that has an improved rod length/stoke length ratio than an L28E. For the highest hp/buck ratio and greatest fun factor/ headache ratio, this is the way to go. Hint: you can probably pick up a L24 shortblock for free if you haul it, or a set of L24 pistons (with rods) for less than you could for a set of rods on e-Bay (from someone who knows what they have). I've tried every approach you're considering and this one makes the most sense. DAW

I didn't get up on the wrong side of the bed that day. I just think that members of this club should be held to a higher standard of owner/operator aesthetics than those with their obnoxious blue-smoke/black-smoke belching, muffler-dragging, toxic fumes-emitting pieces of **** on the road out there. There are a lot of very bright and talented members in this club. I noticed a few days ago in a post that one installed dual "cats" on his hybrid Z. Where I live it's not absolutely required to do so and you're not subject to inspections on the car, but to do so anyway bespeaks intelligence and class. Back to the matter at hand, I think the items circled in the last photo are magnet valves. One is F.I.C.D. and the other is vacuum source. The first signals the fast idle actuator and the second routes vacuum stored in the reservoir to the first. Once the A/C is gone you don't need the one connected to the fast idle actuator, but you may want to keep the second and the reservoir so that the control for the mode door actuator operates properly. Personally, I'd eliminate the F.I.C.D. magnet valve, bypass the vacuum source magnet valve, and see how your heater controls work. If they don't function well, then keep the vacuum source valve. Better yet, go to a JY and take the mechanical heater controls from a non-A/C Zcar and convert your car to an OEM setup, eliminating the entire A/C system and keeping it clean and simple. DAW

Yeah, rip that charcoal canister out so that you and your passenger and everyone within 10 ft of your car can smell and inhale hydrocarbons and gasoline vapors. Throw it away because you don't understand what it is. It actually improves the aesthetic experience of driving and protects the environment, while compromising virtually nothing in performance...but go ahead and tear it off and give us all a bad name. Read a book and find out for yourself what it is you're doing. It's your responsibility. Why do you think smog rules come around to threaten car enthusiasts? It's because of early Datsun Z cars at a stoplight that smell like **** because the driver doesn't know **** about cars. That's my $.02. DAW

I would not change to a bigger cam than you're using unless you increase your compression ratio. You're present ratio, unless you have overbored, is 8.8:1 because you have an F54 flat-top with a P90 (same cc as a P79), i.e., you have a stock 280ZX compression ratio. Unless you go to an N42/47 head, you would need to overbore to block oversized flat-tops), install Euro L28E pistons (pop-ups), or stroke it. I'd use the P90 head (it's already been reworked, overbore the block to 87mm and use +1mm oversized Euro pistons. Alternatively, especially on a budget, I'd just install std Euro pistons without disturbing the crank in the block and possibly not removing the engine from the car. If you do this, pull the head as an assembly with manifolds, etc., on it, using an engine hoist to make it easier and it becomes a weekend project if you just replace the pistons. Once you've increased the compression, your throttle response (and gas mileage) will increase and you could consider a bigger cam. I suspect Drax's performance gains were significant when he went from 8.56:1 to 10.2:1 on his L28/E31 engine, both with same triple sidedrafts, displacement and cam but a change in pistons to increase compression ratio. DAW

Snug the cam tower bolts down but don't torque them, rotate the cam while you smack the towers a few times with a rubber hammer, torque the bolts. If the cam still turns freely you're all set. DAW

I've noticed that not all head gaskets are created equal and some are more true to the combustion chamber shape of the head than others and would provide a better template than others. PS-Jon, I did something like you did but I was one my road bike in the mountains in Utah. I never have had any recollection of the accident itself, just heading out on my bike for the ride that morning. The police assumed it was a hit and run. I was conscious that night but didn't know who I was and I had no short-term memory either but over the next couple of days in the hospital I started to recall things about myself and it seemed to come back in "packages". I recovered my memory within a week and it turned out that I was a medical student from Chicago who was doing a clinical clerkship in Ophthalmology at Univ of Utah and realized that I was absent from work on a different floor in the hospital that I was a patient in. I never have recalled the accident itself but my bike and myself were mangled. What I'm faced with now is different and to most people who don't know me probably think I'm normal because my intellect is intact. Even though I'm not walking around mumbling and drooling, my "excutive function of cognition" specifically is wiped out and it's like I'm smart and stupid at the same time. Life goes on and I try to make the best of it because it's permanent. DAW

Take a look at an L26 block. Maybe the factory square-cut approach isn't so crude after all because it does remove a lot of material. It just seems like a bevel would outflow a squared-off pocket. DAW

You're right and I screwed up by relying on my memory instead of confirming by looking it up. I had a false memory of 35mm L24 and 38mm L28, when it's actually 33mm L24 and 35mm L28. I have to discipline myself that my memory is impaired because it just doesn't feel like it is to me. I was poisoned by CO due to a faulty furnace in a rental home back in '98 which resulted in permanent cognitive impairment due to toxic encephalopathy. Lawsuit against Prudential Property Management is taking forever but it's out there. Meanwhile, my career is trashed and I'm on disability. I've been a Zcar enthusiast for a long time and bought my first 240-280 back in '85 when I was in medical school. I guess I'm sharing this so that while I'm more often than not accurate, those who read my posts should take this as a disclaimer. I've known details about cars for decades with reliable recall and it still feels the same to me (I don't feel like my memory is bad but it is), but sometimes the recall is flawed since the CO poisoning. This is way more info than I should probably share here, but I want you all to know that you should double check info you get from any source before you treat it as fact. BTW, the concept is the same whether it's 35mm valves in an 83mm bore or 38mm valves in an 86mm bore, you have to make room for both the valve and the flow at the top of the bore and this is much easier to do on an engine that's been run (vs fresh hone or overbore) because the upper travel of the top ring is demarcated in the bore. If you go too deep down the bore the ring will flutter and fracture. Use the head gasket and ring mark as your guide. DAW

Since you "threw in" 38mm valves it implies that your engine had 35mm valves which came only on L24 engines (83mm bore). 38mm valves will crash into the tops of the cylinder walls on an 83mm bore unless you grind reliefs in the block to accommodate them. Nissan did provide a crude relief at the top of the L26 bores to accommodate the 38mm exhaust valves intefacing with the 83mm bore, but L24s didn't have this. I would assume L24E blocks have factory reliefs since they are 83mm bore and 38mm exhaust valves. Anyway, you can create a far better-flowing relief with a grinder creating a rounded relief than the factory does with their industrial/agricultural looking squared-off relief that they flycut into the top of the bore. DAW

I started watching cycling races when I lived in Boulder, CO where we had the Celestial Seasonings "Red Zinger" Classic. It was like a miniature tour because it had a couple of road stages, a criterium, some mountain stages, etc., and most of the finishes were in front of the Boulderado Hotel with all late 1800s era architecture all around (not old France, but old USA). Eric Heiden and his sister (Becky?), Connie Carpenter, Davis Phinney...this race grew to evolve into the Coors Classic which became one of the largest cycling events in the US. I look forward to July each year for the Tour de France and I like to watch the stages live (get up at 5 or so PT = live action in Europe). When I lived in Italy from '90-'92 it was really cool because cycling is a bigger sport over there, and watching a stage on TV live made it feel even more current and closer. I think I'm going to have to go over there within the next couple of years. Bike around some and see some of the Tour. One reason I asked about it was because I think it has some stong links to the essence of the mindset of members here. In the tour, the greatest possible power is generated by individuals who tune their bodies and their bikes using the most current technology and innovations (including aerodynamics, state-of-the-art materials (carbon fiber, etc.,) with the goal of creating the lightest, fastest, and most durable vehicle using a motor and computer made of meat. It's like Formula 1 engineering and competition level, with the world's best drivers and a risk of crashing, etc. Americans on French teams, Australians on Italian teams, Russians and Italians on US teams, etc. Politics can't dictate whether a team from a particular country will win, or if the top rider will even be from the same country as his team is. Performance wins the race. No points for best looking bike, just for the bike and rider who cross the line in the least amount of time. I'm hoping we're all the type who give wide berth to keep cyclists safe and recognize that their power-to-weight/fossil fuel consumption ratio compared to a car's is infinitely greater, and garner some respect for that. Although, when an 18-wheeler goes by and doesn't change lanes, the suction from its slipsteam is significant, it's like little shots of nitro boost when you're riding out in the middle of nowhere and want to go as fast as you can. DAW

I'm just curious, do any of you watch the Tour de France, and if so, how many years have you watched it and have you ever gotten up at 5 a.m. to watch a live stage race? DAW

The L28ET piston/rod assys are way too long if you use the LD28 crank in the L6 block. The L28 is 130.4 + 38.1mm from crank pin center to a zero deck ht. Putting in an LD28 crank means increasing stroke from 79 to 83mm which adds half of that increase at the top of the TDC distance from crankpin center to piston deck ht.; in this case, there would be 2mm of excess piston deck ht. Using an extra thick head gasket might compensate (if the rings aren't protruding out of the block at TDC), but the main drawback is the bad rod/stroke which would result. It would be worse that a stock L28, which is a compromise for a performance engine as it is. You'd be making it 130.4/83 = 1.57. Why even bother building an engine with that kind of geometry? DAW

You have to do the math. There's no way L28 turbo piston and rods will work. You'd be looking down into the bore saying, "anybody down there"? You could use the piston but you'd need a longer (e.g., L20B [= 145.9mm]) rod to bring it up to deck ht. B.T.W., 186.5mm is the magic LD28 deck ht. (46.5 + 140mm) from the center of the LD28 rod crank throw. L28ET piston (38.1mm) + L20B rod (145.9mm) = 184.0mm deck. Better to use the LZ22E rod = 148.6mm. That's the correct formula and it puts everything exactly to deck. I wrongly cited the L20B rod in an above post. I meant LZ22E; (note the LZ22S rod is 145.9, same as L20B; LZ22E is 2.7mm longer at 148.6mm, [and piston c.ht. adjusted accordingly]). DAW

You'd have to use a F54 block, fix the plate to the block for overboring both the block and plate, and drop in a sleeve. DAW

A plate is an excellent idea as long as the total block ht. without the top head gasket is equal to the LD28/L20B/LZ20/LZ22 blocks as you want to be able to use the L20B front cover (probably just forget about providing a top hole for the L20B cover, or put one into the end of the plate). Finding head bolts or studs 20mm longer than L6 bolts with same dia. and thread pitch is the quest. Slightly longer bolts are OK with doubled hardened washers, but not significanly shorter. Any metric source can be explored...you take a set of calipers to a JY and start the search. Ultimately this may make more sense as there are no front oil sump/pump issues and no machining the bolt holes of the L6 head to enlarge for larger dia. LD6 headbolts. DAW

My posts should be moved to the "six-cyinder" forum or "other engines" as they fit better there than in the "turbo" forum where they sprung up, but if the moderators could library articles or FAQs somehow, rather than defer to "search", I think it would benefit all as we look for answers to our questions. Anyway, Kenny, I just used an extremely unscientific and crude method to assess the cyl wall thickness of some L6 and LD6 blocks lying around and these are the relative values of comparative wall thickness, not in units, but as related to each other. Personally, I'd feel comfortable with a .120" overbore of a F54 block, 0.080" of an N42, and .120-.160" of an LD28 based on my crude approach. I doubt there are many machine shops that would overbore a Nissan block much more than .120" so I'd limit my overbore on my LD28 blocks to 87.5 to 88mm bore. I'd recommend that anyone boring a block more than 0.80" over, have it sonic-tested rather than using my assessment. I've worked up combinations with larger bores and longer rods which should work OK, but the greater the displacement, the greater the demands on piston dish volume and combustion chamber volume, especially if you want forced induction. DAW

Part II. So the LD28 bottom-half/P90 top-half is the "budget" stage II project and both of these engines (stage I and II) have decent rod/stroke improvements over the L28, and far better than the 83mm stroke/133mm rod formula. The next stage is to optimize the performance capabilities through increasing displacement (bore) of the LD28 and selecting piston/rod combos to get the best rod/stroke that the taller LD6 block affords. Stage III is still budget-minded as it uses stock Nissan L4, L6 and LD6 components rather than custom pistons, rods, etc. It is an overbore from stock 84.5mm to 86mm (unlikely that this is the max overbore, discuss later), use L28ET pistons (38.1mm c.ht.), L20B rods (145.9mm, same pin size, 21mm), and the P90 top-half. The 10.9cc dished turbo pistons keep the c.r. reasonable when the displacement is increased by the overbore, and the rod/stroke is now 145.9/83mm = 1.76. I've heard a lot of hearesay about the hybrid engine I'm talking about (like it can't be done, the LDblock which is built for 22:1ish c.r. can't be overbored [right! makes sense to me]), but haven't compared notes to many fellow builder/users of this engine hybrid. I'd like to compare notes to others out there who have actually built and driven cars so equipped with LD28 bottom-half/L6 top-half. I discussed my plan with a NISMO tech-rep (Ron) over the phone back in '96 or so and he was helpful but told me it couldn't be done. I wouldn't have pursued it if I had unlimited access to custom forged pistons and rods in order to have a decent rod/stroke performance engine but since I don't, poverty is the mother of invention. You have to crunch all the numbers, measure and search for a part to fit what you need (BMW headbolts, L20B timing cover, etc.) to make this work. Hey, what about marketing a kit requiring a customer's good bare L6 head core to exchange for a bolt-on conversion bare head and Stage package of choice? Not difficult, but I don't have the time to do it. Better do it yourself before the LD28 blocks become valuable. Most are discarded when the crank is taken out. DAW

I've yet to transfer the LD28 bottom-end/N42 topped hybrid I put together in '96 or so from my '82 Maxima into the '72 240Z waiting for it but one of these days I'll get around to it. The front sump/oil pickup vs rear is not a big deal, but it is an issue in the transfer between cars. Meanwhile, I use the car as one of my family cars, running my kids around to school, soccer, getting groceries, etc. It's very reliable, starts instantly every time. This is my "mule" for setting up the LD6/L6 engine and it's the "budget" prototype with stock bore (84.5mm), rods (140mm, large floating pins), and pistons (46.5mm c.ht.) which yields just over 10.0:1 c.r. with the N42 head. Cranking pressures are 210-220 p.s.i. with the stock N42 cam. I've never heard it ping. I've just done some crude tweeking of the stock N42 e.f.i. by changing sensor resistance values, thermostat, AFM door spring tension, etc. I'm using 280ZX headers with long secondaries into a 280ZXT rear pipe & muffler. BTW, the chassis components have been substituted on the Maxima with 280ZXT components and I cut the diesel springs down all around (the nose was pointing up without the LD28 upper end on the LD28 bottom end). I'm using the LD28 torque convertor (the Maxima trans has a hydraulically-activated lock-up convertor that the 280Z/ZXs didn't get). The stall speed is lower than the gas engine convertor but with the stock cam it works fine. With the high compression ratio the throttle response is excellent and the power goes right to the ground. The car is just a daily driver and looks like a stock Maxima except it has Infinity 15x6.5" wheels with 205/55-15s, an Audi 4000S front air dam and later year Maxima trunk-lid spoiler, and it has a lower-than-stock stance. Basically, it makes a good "sleeper". The plan was to swap it straight across to the early Z which is an A/T car and substitute an '84 300ZXT 4LN71B trans for the L3N71B, sort it out, then put a mild cam in it and select the best final drive ratio with that combination. I guess that's still the plan for the first stage hybrid, but the Maxima makes a very practical vehicle as-is and too useful to take off the road right now. What I may do instead, is to remove the N42 top portion and modify and install a P90 L28ET top onto the stock LD28 bottom-end. I'm confident that the bottom-end, built for 22:1 or so c.r. can handle a significant static c.r. increase and boost increase vs L28ET. Since the LD28 pistons have a tiny dish vs the 10.9cc dish of the stock L28ET, with equivilant 2.8L displacements the P90 head yields an increased but manageable c.r. on the LD bottom-end. I don't foresee getting by with the LD28 torque convertor, but I may choose a n.a.-range convertor rather than a turbo-range since the static c.r. will be higher and throttle response good; turbo lag lower. Intermission. I'm not going to risk losing this book to some computer glich or crash, so I'll post part II separately. DAW