ZXatlast

I'm thinking about different cam grinds, so I need to know what I'm starting with. It may already be close enough to what I'm designing, but it's likely it isn't.

Greetings All, Can I ask a different cam shaft question, please? I've looked up and down and either I'm missing the obvious or the specs are well hidden.... can anyone tell me, in terms of TDC and BDC, the inlet and exhaust open and close timings (angles) for the factory standard camshaft for a 1979 8.3:1 compression non-turbo L28e, please?? Best regards, Steve

Thank you Sir, for that, very much.

Guy and Jon, thank you very much indeed. I do appreciate your concern Guy, seriously. Obviously I gave the impression of a 19year old with his first 'proper' car, but no... I'm not a novice, I'm a novice to Z's, but hardly my first car/engine. Before the Z there was the fully blue-printed BMW 4cyl sohc (gas-flowed, crack tested, everything oversized, 324degree monster cam, balanced to 1/1000th gram, etc., etc.) and the Rover V8. Concurrent with this Z is a Mercedes V8 and a Toyota (Le Mans homologated) 3S-GTE. God! I love that engine!! But I digress. The BMW 2002 and the Celica are going to be my extreme interpretations of street-going Le Mans racers. The Mercedes V8 and the 280ZX are more traditional, if that's the word, customising projects, the Rover P6B a little less so, but mainly in the engine. I am more than capable of designing an engine from scratch, starting with the castings; I just can't imagine why I'd bother when there's so much brilliant stuff already out there just 'needing' the appropriate (re)design tweaks. What I came here for, was to get ahead of the game in the sense of not falling into unexpected quirks that novices to this specific stuff might fall into. And both you have spent time and effort, with gentle consideration for a new member, and have ensured I wont. So to both of you, again, thank you very much, it is much appreciated. If it helps to understand my approach, I am a Research Analyst often by profession and by 'natural bent'. So I like to gather as much data on something new before I get 'dirty up to my elbows'. As opposed to a very good mate of mine who'll jump in and tweak and pull and take apart without any research up front. He often gets stuff done quicker than I do, but he sometimes breaks a few things along the way, which he then has to fix, and that isn't my natural way. Now, since you gentlemen have been so generous and forthcoming, perhaps I could get into a more interesting question...? I want to make the L28e 'right' so I can experience the 280ZX in its original intended form. It's about getting a sense of the car's character and a feel for the overall engineering quality and the 1979 'design intention'. This is discerned as much through the senses in the seat of my pants as it is through the logical engineering I can eye-ball. But even now, after this short time, I can see I wont be satisfied. So I've been playing with ideas. My first thought was that with 8.3:1 compression the L28e has to be perfect for some simple but effective non-radical supercharging. I'm still researching, but the time and agro and cost involved seems a bit counter productive when compared to another option that seems readily available; more or less. OK, the first thing is to point out is that I acknowledge the 'boulevard cruiser' and 'soft GT' design of the 280ZX. That is exactly what I like about it and why I wanted it and what I want to retain. I don't have an intention of turning this into my third interpretation of a Le Mans street-legal racer. I want to fill that GT-flavoured space with this 280ZX, I don't have another car that does. The limousine-sized Mercedes is sort of on the border but it isn't the same concept really. However, I do want to take it further towards the boundary that once crossed it becomes a racer -- approach the boundary, not cross it. Which brings us, perhaps, to the most logical, and apparently cheapest option. And that is to replace the L28e and 3-speed auto with an RB20DET and 5-speed auto. Now, all that background was to bring us to this question: So far I have gotten the (hopefully true) impression that unbolting the L28e and 3-speed and then bolting in an RB20DET and 5-speed is a relatively straight forward process. I'm not talking about the engineering required to make it all work, these things I understand already, and what I don't, I'll find out. What I'm asking you about is the physical fit. Apart from reworking the positions of ancillary components, in terms of specifically the engine lump and attached box, is it an easy refit? Apparently, even the tail/propeller shaft bolts straight up, I'm told. But, I'm asking you guys for confirmation, or not, as the case may be. The ultimate point of this research question is that if I have to cut and weld in a chassis to make it fit (I'm sure that isn't needed, that was a worst case conceptual example), then obviously I'd go looking for the next best option. I'd like to stick with Nissan rather than the apparently common Chevy small block, which also, apparently, slips in easily. Someone else's engine makes it not a Nissan anymore, and I do want to retain the Datsun/Nissan flavour, so the RB20DET is my current favourite. Oh! One more thing, if I may? Do you guys know how big a wheel tyre combination I can fit and with what offsets and still fit within the standard guards? I can fiddle and find out, but it strikes me that this is stuff you guys would know off the top of your heads. AND... another one, but more engineering critical: Can I re-torque the head bolts to the assembly specs with the engine hot? Or do I have to leave it to cool down first? I've never worked with hot engines for these processes in the way the factory manual for the L28 sometimes specifies; the 'Euro gear' I'm into is always specified cold. OK, that's probably a big enough mail for now, and on the assumption that you're still reading this, thank you for that too. All the best, Steve

Thank you Diseazd, very much. With great respect, though, the pic in the manual isn't overly informative; I've just gone back to the manual and it refers to a "Pivot Adjuster ST10640001". It is seemingly a torque wrench looking device and where you'd attach a socket it has a long-ish arrangement that ultimately fits around the pivot. Now, I haven't yet seen these pivots in the metal, so if they have a 'normal' hex-shaped surface to adjust them by, for instance, then all will be fine. But if the place you grab to adjust them is some strange other shape that a spanner never fits, then it becomes more, umm, interesting. But as I said, you guys never refer to it, so I'm hoping that the special tool just makes it easier than manipulating a standard spanner in there. Just for the record, it states that the clearances - adjusted hot, and it says operating temp hot(!!), as opposed to warm - is 0.25mm inlet and 0.30mm exhaust. And thank you for your welcome, I hope it'll be productive both ways. When I get my profile done, obviously I'll put a picture of my 280ZX up in it's current condition, which is pretty damn good for a $2250 outlay; fully usable and rego-ed til May. All the best, Steve

Greetings Guys! I am a just brand new, and first time 1979 280ZX owner. It's taken a while, but I'm 'here' now. New to Z's altogether, really. And just now joined this forum too, so I'm still finding my way about. A simple question, I hope, if I may.... The bloke I bought it from spent over a grand and a half having the head reconditioned for its still-in-place original L28e engine. All well and good. However, the tappets -- is that a term you use? I'm referring to valve clearance -- are a bit noisy. I am quite happy to get in there and make the adjustments as a first step (I say "first step" because I am hoping I'm not going to get the other issues being discussed here). However, adjusting those clearances, according to the factory manual, requires a special tool I didn't notice any of you referring to that tool, so I'm hoping it isn't needed. And I haven't taken the rocker cover off yet, which might make the answer to my question visually obvious, but, since I'm here, my question is, is that special tool mandatory? Just judging from the not-at-all-detailed pics in the manual, you should be able to do the same thing by manipulating an appropriately-sized standard spanner into the right place. I would be very grateful for advice.... All the best, Steve