ol doc gully

With my seating position, my small-diameter fat-ring steering wheel is blocking my tach view right in the key areas. OK for DD but already at the first autox I had to keep hunching over and was undesireably encumbered. So I'm looking to make a shift light/indicator for my 72 240Z. Still in the concept stages and any suggestions/resources/corrections are greatly appreciated; I've found a surprising lack of any information of this kind. Im aiming at passive electronics, but may consider Arduino. I'm comfortable with either but mostly just would like to figure out how such a shift light indicator would work when fitted to distributor ignitions - ie what that signal looks like coming off the coil, or similarly even just how a tachometer works in that sense. So really the key is confirming that it is a 12V square wave with frequency reflecting that of all spark plugs firing. I have a multimeter but no data collection hardware at my house. I presume its 12V at the positive terminal where the tach connects. I have a 3 ohm coil, no ballast resistor. I have an electronic dizzy but thinking about it as points seems viable and simpler, so my thinking that I'd like to verify (please correct if wrong): voltage builds in coil when the contact is closed then releases into plug when it opens. so i would think there would be 12V at the input terminal when the contactor is closed and goes to zero when it fires - thus spark signal could be considered a falling edge triggered event. Although necessary to make sure I'm thinking correctly, that level of detail isn't really functionally necessary as all we need is frequency of this signal. I could just determine the RPM I would like the light to go off at, then correct to 'revolutions per second' then multiply by 3 (inline 6 = 3 ignitions per revolution) and we have target cutoff frequency to design circuit for. Right? I havent thought through the circuitry too much yet but generally seems like it would just be: high pass filter (tweaked to frequency) --> inverter --> light (?) Arduino may have the advantage of multiple RPM set points without having to reassemble the circuit. Then just use whatever kind of light - maybe even under the windshield vents as a HUD As I said any recommendation / correction / resouce is welcomed. Thanks in advance. Ben

autox went fantastic. car was set up beautifully, felt very well balanced. a little understeery, but mostly from driving/course mistakes and dropping front tire pressures actually still helped a lot. undecided at whether i still see sway bars as necessary as i thought i did. pesky rear toe in was likely keeping the rear a bit more planted than i wanted so will probably get after that first and go from there. engine did great. i accidentally started off the first pass colder than i had intended and was burning a good bit of oil, but had it at right temp for second and third and performed flawlessly without the james bond some screen. the carb setup is pretty dead below 3000 which i thought would be a problem but was not at all. really impressed at how well the car did for its first time out all around. friend showed up with a camera after the first lap and got some great burst shots through the big corner before the first big straight. stance/alignment/balance seems to look as good as it felt . same corner lap 3 . . . . also was super excited to find this bad boy in the pits and get to talk to the owner/builder. a factory five 33 hot rod was to be my build if i could have afforded it and i have a huge soft spot for daytona coupes. made a great day greater. .

I sweat it wasnt even giving me that when i was trying! maybe i had a now non-existant home page defaulted. ah well, just glad it hasnt gone anywhere. thanks!

Is my browser/cache messing with me or is the site down? I've always used it to reference engine/head codes and specs - now wishing i had saved the info to a document on my hard drive!

thanks - murder chamber is actually still intact haha. besides some suspension and alignment tweaks im hoping we are 99% of the way there for this year. working on convincing the girlfriend to wrap the steering wheel, as that would really be the last piece

Drove the stank out of it the other day. little bit of seepage from valve cover but i bought a new gasket for the old engine that i can just put on, everything else seems solid as hell. got a clunk from passenger rear strut thats been going on forever, i think the gland nut doesnt have the right spacer, so going to put it on jackstands to dis/reassemble it and also make some other suspension adjustments; need to do some grinding to clearance the damper adjuster knob and get more camber in the front. Going to hit an autox first, but there are 2 SCCA events and 1 NASA at mid ohio coming up. Thinking im going to aim for NASA. i think my car as it stands falls into TTD, and surprised to see some 240Zs winning those chapters around. I know i dont have the power (classed with 300ZX, E36 M3s, 350Z, WRX etc) but will give me something to aim for, i'll only be doing HPDE for at least a year anyway.

Well havent updated this in a while but after another overhaul its been back on teh streets for a couple months. going to hit an autox and then HPDE at mid ohio hopefully in october. Now running a holley 4bbl (390cfm), much more high-rpm than expected - nothing below 3k but over 5000 it pulls hard. Very fun, much more than i expected out of these engines on the top end. Rear toe looks a bit excessive but not sure what adjustments i can make to that anyway... offset bushings?

^ I really think it does too.

Very fair price. I think we can unanimously say it is awesome to see something like this coming together. Cant wait to see how the machining goes.

I'd certainly wager its better calibrated than mine when seated in a 240Z, ha Yeah tony i think youre right. at least that its something that makes enough sense that i need to double check. thanks again guys

fuel was one of my first thoughts. however there is no pinging sound when it maxes out and from what i understand most problems that are load dependent typically tend to correlate with timing issue. i have replaced the filter, but im not entirely ruling out a fuel issue yet. floats were set correctly but im thinking i may want to re-check them. also, on that note, i have the knurled jet adjusters on both carbs all the way out. i wouldnt have guessed they would need to be there but idle speed drops if they are screwed in any more. im attributing this to using original 2.4 needles on a 2.8 but figured i would mention it in case it seemed relevant. Jon, thank you, this should give me something to start troubleshooting, which is just what i was hoping for. did you notice any worse engine response on throttle tip-in without the vacuum? Arne's issues are definitely very similar to mine. i believe i have the condensor disconnected but i'll need to look back into that some more. one thing is I am using the BPR6ES-11 plugs (gapped to 0.04") and he said he had some success came from a fresh set of BP6ES. shouldnt be much difference but i might try a set of those just to see. ive already wired out the ballast resistor and have a 3ohm ignitor coil but i may just replace it too... also all in all sounds like its generally a symptom of not enough power getting to the distributor (?) thanks for the input guys, any ideas or suggestions are still welcome, i'll keep you posted

thats the only thing really keeping me from diving in on the valves is that i feel like the 3500 cutoff (as well as all the other inconsistencies) is indicative of a timing issue and id rather not introduce another variable by doing a valve job, unless of course it could be a reasonable cause. ALSO i meant to mention that with no load (ie just revving while sitting still) the engine revs much higher (5k+), another facet that seems to be point in the direction of a timing problem good call, im just going to disconnect vacuum for the next bit of troubleshooting. sounds like i definitely need to check in on cam timing, i will get on that, i should get a whole evening to work in the garage in the next couple days and actually the tang drive is 180deg off so my cyl 1 is at ~5:35. i only recently came to find this isnt how its supposed to be but i havent had an issue with running out of room for timing adjustment so havent felt the need to restab dizzy. it is definitely on the to do list

16x9.5et0, actually (I asked as I'm seriously considering a set of spinwerkes in future)

Oh man awesome - been wondering what that exact setup would look like, those are 15x9et0 right?

ahh good call, i have not taken off the timing chain as yet. i had checked the alignment according to the service manual, and it looked spot on, but in all honesty it was hard to make sure i was looking at the right marks relative to whats printed in the manual. i will definitely double check that as well (and/or take a picture and put it here) - thanks!

I've been chasing this for a while but i think its time i get some input. the setup: I have a 72 240Z with a L28 (N42/N47) set up with round top SUs. compression was not great (bumped when tested wet so likely rings), have not retested since i got it running. I bought the car not running, among other things found the dizzy wasnt advancing so replaced it with a remanufactured '1979' 280ZX electronic dizzy - Cardone part number 31-619, just like this one. it was enough to get things going and drivable. carbs were recently rebuilt and came right off a buddy's race car, although one piston is leaking a bit more fluid than it probably should. the basic problem: i originally had the advance set to ~12 BTDC static but it wouldnt rev past 32-3300 rpms, higher gears would barely get to 3000. when it maxes out it has a very raucous sound, but is consistent, it will slowly increase speed until it maxes out. it wasnt pinging at all so i kept bumping advance, seemed to keep helping marginally. Now ive got the plate maxed out and, according to the 3 row crank pulley, static timing is at about 35 degrees - which seems high to me. still not pinging, even on throttle at low rpm. but it still wont rev past around 3500 rpms. potentially related issues: - spark is pretty inconsistent when i put a timing light on it. sometimes it is solid, but often after revving the engine when back at idle the light will indicate plug 1 firing but timing mark is nowhere to be seen, id say this can happen 1 out of every 3 shots. the advance is fairly consistent but once it adds around 10 degrees it seems to scatter and lose consistency completely. - i was having traffic overheating issues for a bit (fan, clutch replaced and shroud added so not as much of an issue now) and when it gets too hot i get definite hesitation on acceleration. i presume to be from vacuum advance which is kind of what i feel like is my problem here. - vacuum advance is connected to the port on the SU carb just outside the throttle plate. solutions: 1. did i buy the wrong distributor? maybe the cap is bunk (new at NAPA)? it is very consistent about when it loses power and something seems to be awry with the ignition system in general so i feel like its a distributor issue. how can or should i troubleshoot it? was goinig to try to get my hands on a vacuum gauge next. 3. the only thing i havent done is check valve lash, which i need to do. is this something that could be causing these type of issues? valve noise is minimal so i feel like its set well (probably never been touched) and id rather try to isolate one variable at a time 4. i currently have the gas tank evap and vacuum (the T fitting by the coil) just open, i dont see why this might be affecting anything but i thought it was worth mention sorry that is long but i figured it was better (less annoying) than not giving enough info. im at a loss and being able to rev to redline is the only thing keeping me from some track/autox before the seasons over - any advice or insight is greatly appreciated

^ i like that

im actually using a Kirkey Intermediate Road Race seat right now although the shoulder wings have been cut off. im borrowing it from the guy i mentioned as his street car is currently engineless. the side bolsters are a freakin pain though - they stick up too far and very much are in the way of elbows. im wondering if its a problem at all for you with the pro drag? luckily i picked up some corbeaus for cheeeap so im just going to recover them with something vintage-y

15x9 RKR?

I suppose I would argue that they are both effectively check valves, but that seems to be a matter of semantics. But yes, by 'recovery' I suppose I meant "hold a vacuum to pull the coolant back in" - do you have a recommendation for a radiator cap to perform this function and fit a stock 240Z radiator?

Is there a recommended 'recovery' type of radiator cap people use when adding a coolant overflow tank to the older models? Or can you just use the ones from 77+ Z models when they started using coolant recovery setups? ie. the stock cap (which I assume the one to be in my car) appears to only have the rubber seal and spring and not the extra valve to allow coolant back into the system when cooling after shutdown. Just wondering if there is one that people use that fits these radiators and has the right valve or seal positioning. I know its an old thread but it seemed to be the most relevant one I could find to the question I had - thanks in advance.

been in the garage for a year, had a couple trips around the block, but today was the first 'real' shakedown run. found some twisty roads and ended up pushing it a bit harder than expected, partly due to the encouragement of a GTi, but it handled great. seems to have a misfire so going to double check valves and timing

engine wasnt revving past about 2500-3000, turned out dizzy wasnt advancing at all. got a electronic 280zx distributor in, took for first 'real' drive, runs good. oil pressure was reading a little low and i know i have a small leak in the pan so i still havent pushed it to hard. replaced the oil pressure sender last night, so hopefully it reads fine and is ready for a real real drive also finally put the hood on; it had never fully latched before. so after fiddling with it for a few hours i got it reworked and all lined up.. and then couldnt get it back open hahah. finally did yesterday, the release cable is junk so im just going to replace it before it snaps on me.. new ones are $160!?!?! oh well, should be getting here today also got in a temporary seat. think i am going to just put in the corbeaus once i can get some brackets welded up. then make fancy covers for them this winter

flares suit the car incredibly well - great vision