thehelix112

Datto-Zed, I'll assume you're talking to me, sorry for the hi-jack everyone. Manifold is stock, no match porting, no internal deburring, that being said, it looks pretty clean in there to me. All it has had done is bead blasting because it was very dirty (and full of crap) when it came off the 280zx. Engine is internally stock. Cam is a baby Crow 58643 (http://www.crowcams.com.au/templates/Catalogue-Datsun-OHC.shtml) I have no idea on power output, but most HP calculators give me around 320fwhp on 10psi assuming 1115kg weight (very optimistic). Calculated from 115mph trap speed. Dave

^^^^^^^^^^^^ What he said. Also, website says they are steel? Steel is heavy. Get someone who can fab them in alu. Also, direct port is not necessarily a good thing. The longer the fuel has to atomise the better. Injectors want to be up the runners I think. Dave

One is DIN, one is SAE I believe. Dave

Actually I just realised that the gearbox that will be going into it is geared very tall, so the 4.4:1 will probably go in for a little while at least. We'll see. Wish it wasn't so damn hard to change the ratios. Dave

Yep. I've got a 3.54:1 R180 locker that will be going in as a temporary measure. Until I can get a different ratio for the R200. Dave

Thanks boostedz, The exhaust manifold was fabricated by Ian Rowlerson who used to run a TIG welding business in Warburton, Victoria, Australia. I'm running a base-level Autronic SMC. Wouldn't do that again. Its a good enough computer for a basic engine, but there are things I want to do that I can't, great for the price though. Dave

Brian, Depends what you want to do I suppose. I used a non-turbo intake manifold as I couldn't find one and plan on making a custom one anyway. I cut off the valve on the very end, then cleaned out the copious amounts of crap in the gallery that runs next to the plenum on the underside. I also discovered holes that go through this and into the runners! I tapped these and plugged them. I also converted to cable throttle and cut off the ugly towers. Hope this helps, Dave

A point of clarification, those tokico shocks aren't 5-way adjustable, they're two-way-fixed-rate adjustable. You are only changing bump and rebound, and simultaneously at that. Not meaning to rain on your parade, just got all excited then disappointed when I read more about them. Hope she handles like a dream! Dave

MikeZCar, Can you give us the proper specs on the cam, advertised duration is about as useful as clothes for women. What is 0.05" duration? Dave

Ron, Definitely going to take you up on that It'll be great to catch up with some fellow datsun enthusiasts. Looking forward to it. Dave

See you guys there. I'll be the one without a car. :S Dave

Curtis, Nice flares, may I ask if they were a custom fab or did you get them from somewhere? Dave

Jon, I don't make any decision about what to do on my car based on what people say on an internet forum. For me its a place to maybe learn a little. If you are taking peoples on internet forums' words at to what is best for your zed you're in strife IMHO. The topic posed many questions, the main one (as per subject line) is a broad scoped question which I interpretted differently to you. Not to worry. There is no question in my mind that a N/A V8 (almost any) will kane a N/A L6 (almost any). So if you don't have the budget to go forced induction, the choice is relatively clear, if less than optimal. Whats a VK56 worth these days and will it fit? But I don't know why you'd muck around with N/A stuff as I mentioned earlier. And as soon as you got forced induction (turbocharged especially) there is not as strong a case to go V8 unless you are chasing 1000hp+. Anyway, I think I'm repeating myself so I'll sign off this topic. Enjoy Dave

Jon, Are you capable of comprehending the HYPOTHETICAL? I'm not talking about ANY engine. When I say `everything else being equal', I mean, everything else being equal. Imagine an L6 with an OHV design, and then a standard OHC L6. Which do you think would rev higher, and which do you think would make more power? I have no idea why you keep comparing I6 to V8 in conjunction with OHC and OHV. And then where did this comparison involving a 6 valve per cylinder V8 (48 valves), or are you talking about a 4 valve per cylinder V12 now? Would make about as much sense. Dave

Jon, When I say OHC will rev higher than an OHV, where did I mention 6 vs 8? They are two entirely seperate issues IMHO. An OHC engine WILL rev higher everything else being equal simply due to less reciprocating weight, not to mention it will make more power as there is less mass that the valve spring has to move hence lighter valve springs can be run, hence less parasitic losses. That is not an emotional argument. Dave

I'm not sure if you get what I'm saying Jon. I'm not saying, nor did I ever, that an L6 will make as much HP as a V8 (or any other engine that has around twice the displacement!) I also specifically said that whatever engine is a personal choice. Whether you want to make that on a purely rational basis or an emotional basis is entirely up to you because <MAIN POINT> You can get more hp from either an L6 or a V8 or a rotary or just about whatever you damn well want with enough work. </MAIN POINT> I should note that I'm completely and entirely pro forced-induction. N/A seems like trying to wizz out a house fire. A point that is entirely secondary to this is that an L6, due to its OHC design, will (with the right modifications) have a higher rev limit than an OHV design. IMHO the only way to compare it is stock, once you start comparing race engines you reach the stage of making up arbitrary rules like, on you're not allowed to change the timing drive etc etc, where do you stop? FYI, thought this might interest you: http://nkondo-web.hp.infoseek.co.jp/Kameari_L6_2.htm using your favourite web translator if you want to read it, worldlingo.com works. Now I'm not going to say that means much as I've never seen any proof, but why would you advertise it as being 13000rpm capable if you hadn't tested it? Dave

Richard, Quite right. I've also added some ACL heat shielding between the exhaust and intake sides. Heat transferring between intake and exhaust is definitely bad and its definitely a weakness and not ideal. I'm not entirely sure how I'll go with dealing with that much heat in a track condition. Dave

My point was only that OHC engines (in general) have higher theoretical RPM limits than OHV engines (in general). That is all. BTW, I believe there are several issues with a L6, some of which were covered by phred in other topics. It makes me wonder if you are comparing apples to apples here. Sure maybe some big budget top fueler V8s will pull past 9500, is that the type of engine you are comparing an L6 to? Please be more specific because I'm not convinced yet. See previous comment. You have successfully compared stock to stock and the L limit is higher. And if we are going to compare race engines we should use those from a similar application as a drag engine that only has to live for 540 revolutions or so can't really be compared to a circuit race engine. I never said I was using an L24. I've always said L6 I think. And if you don't see the difference between that and a V8.. well.. thats your err.. decision I guess. Yes its a Nissan thing for me. But at the same time I'm not going to go to any effort for a reduction in power/potential. I suppose it depends by what you mean by `breed'. I consider Nissan a breed. Also I consider an L6 to be an L6 whether it has webbers or turbos or whatever. The induction system is distinct from the engine in my opinion. Look forward to your reply. Dave

It seems to me that we are all assuming that V8s are all OHV and that these are the only ones you would consider putting in a zed. To answer the question posed in the subject line: it depends what you mean by better. As has been mentioned by several people, OHV is cheaper and easier to make, and OHC is more efficient and allows higher RPM due to lower weight/inertia in the valvetrain. Does anyone want to discuss these two assertions? Now if we start talking about putting a V8 into a zed, then it really becomes a matter of, do whatever you feel like. Depending on how much power you want and the drivability characteristics you prefer there is no real answer as to what is `worthwile', and less of an answer as to what is `better'. People can *try* to justify their preferences based on cost, but really, not too many people who do up cars don't realise that its an expensive hobby (by my humble standards anyway). Personally I don't really care about cost, if it costs more, it just means it'll take a bit longer to get. I have made a few decisions for reasons other than cost, like keeping the L6 engine in an attempt to see how far it can be pushed reliably, and keeping the chassis and basic suspension design for the same reasons. Plus I love the way an L6 sounds on boost heading past 6500. Do whatever you want, but don't expect everyone to like it. I don't know how many times I've heard: ``You're a fool, you should've just put an RB26 in it.'' Personally, I don't like mongrel cars, and I don't see the need for it. Dave

Jon, I have to differ there: I know of one L31 that goes to 8800, and I know of L16s that go to 10500 (http://workin4u.com/jhh/edwards.html). BTW, I believe the issue with Ls not being able to rev has SFA to do with the valvetrain (its pretty clear that a pushrod OHV setup has more valve train inertia than an OHC setup and therefore the theoretical rev limit is lower as more mass has to move, the fact that so many zillion people use SBCs etc and that you can get titanium everythings for them doesn't make them equal/better to a OHC setup). I'm not sure how we got onto the topic of RPM. But anyway, I fully agree that V8s have a lower CoG. My point was that you can get a great deal of usable hp from any engine in a zed including the original, and in a lot of cases more hp than the chassis can use without a great deal of work. I don't know what your point is about V8s at hotrod shows, I did say that some engines will do it easier, my point was that those V8s, and the Electromotive ZX aren't stock engines, and there was probably a fair bit of work and money went into both. Theoretically speaking, if you have the chassis to use 700hp, why wouldn't you use it? Need/shmeed. Dave

I don't have any overly good kill stores with my turbo L28, but as the body looks like a big piece of crap, its been underestimated a few times. I like approaching it via stealth. Each driver notes the other as they pull up at the lights, no more looks pass after that, then when they go green you take off at a moderate speed ensuring that your car is slightly in front of theirs or at the least, even with. Normally just after the other side of the traffic lights the game is on and the turbo/engine have had a chance to come up to speed and you can nail it. I've disposed of a few new Pontiac GTOs (read: Holden Monaro SS) in this fashion. They don't like getting beaten by a 30yo datsun with crappy paint. Dave

J, Granted that some engines will make power easier than others, but when I say serious, i'm thinking more like 700hp. Not too many engines will do that without a bit of work. Dave

Auxillary, You have a much better grasp of automotive history than I, I resind my remark that V8 OHV engines are dinosaurs. I will clarify what I meant. I consider the fact that the 240Z had an OHC engine during a time when they were often discarded for cheaper OHV engines to be indicative of the appeal and design philosophy of the car and thus, its not something I would *personally* alter. Way too much like going backwards for me. I also personally think that getting any serious amount of HP is both difficult and possible almost irrespective of what engine you choose to start with. Lets face it, mass-production engines aren't designed for power, they're designed to be cheap and go for a long time. If you start asking for more power, you are going to have to compromise on these two. So I personally don't consider power to be a valid motivation for an engine conversion. Weight distribution and centre of gravity issues however, well thats much more reasonable. I have heard tell that the longitudinal weight distribution of a zed is close to 50/50 as is, and given the engine has room to go back a bit in the engine bay (if you wanna get rid of the bonnet latch and potentially run into gearbox/tunnel fitting issues) I think this isn't as important as: Centre of gravity. This isn't a vehicle dynamics thread (and I'm not a vehicle dynamics expert) but as I understand it, the closer you get this to the roll centre (which in our cases is low) the less body roll issues you have to deal with, which is a good thing. I agree that a V8 is cheap power (and easy gearbox strength!). I don't agree that you should bite someones head off for getting excited about a very nice blue zed. So you've seen it before, so? Maybe someone hasn't. Dave

I'm sorry, I thought it was a fairly commonly understood thing that the L series was derivative of the Mercedes OHC design of the 1960s. Or are you arguing that over head cam engines are not an advancement/improvement over pushrods? Or that a 1960s Mercedes design is the same as a Ford 1920s design? Can I make a reservation for the party we're having in your engine bay with all that spare room? Dave

I have only briefly scanned this thread so I apologise if this has already been asked, but are you using the flat top `SU's or the genuine round tops? If you are using the flat tops, don't. Bin them. Dave