Tennesseejed

Thanks TLOJDM.

The back half of my FS5W71S case needs to be replaced. The old case was damaged (bent/cracked) around the rear seal area. Just looking for the back half of the case. Jed ps. +100 cool points for anyone who can tell me what the rubber seal on the shift fork hole is called. Need to find/order one of those also.

ezzzzzzz, my original post wasn't intended to be a commentary picking sides on the merits of building a stroker v. staying stock. I hope it didn't come off that way. I was only adding that stroking the LD28 crank to 85mm results in an L6 engine that is almost perfectly square (87mm/85mm). IMO, I'd prefer an engine that is on the over-square side. I hadn't realize how square that engine design is until I was done researching it. Mack and I seem to have the same unanswered question: What is the maximum safe tolerance, if any, for undersized rod ends? The B16A rods are .79mm; Mack's Ford rods are .83mm. Maybe one of the many engine builders around here could chime in. Assuming the BE width in the B16A rods are not a problem, the original post seems a plausible design for a 85mm stroker for way less than the cost of the Kameari 85mm crank alone (assuming stock B16A rods over Carrillo). I'm not interested in building it, but maybe someone else can pick up where I left off and make it work.

I admit it, I'm a little smitten by the 3.1L stroker concept. Yesterday I was daydreaming around the Kameari site, mostly oogling the 85mm L6 crankshaft http://www.kameariusa.com/L6_l3_2_85mm_crankshaft.php) and other obscenely expensive parts. Then I recalled defrag010's thread on the the 3.4L LD28 block stroker (here: http://forums.hybridz.org/showthread.php?t=119072&highlight=forged+rods) which lead to some musings over offset grinding. Without dumping $4K+ into a Kameari crank, it seems a pretty comparable result can be had by offset grinding a LD28 crank to 48mm rod journals. If I understand it correctly, this would result in a 85m stroke (clearancing issues). Finding a compatible and reasonable cost rod and piston combination is a little more complicated. Sure, Carillo and JE will build you any rod/piston combination you want if your wallet is deep enough. But a few hours with How To Modify You Nissan, the L6 Engine Caluclator and Google lead me to the Acura/Honda B16A V-TEC rod (48mm, 21mm, 134.32mm) and the Mahle H22 piston (87mm bore, 22mm pin, 31mm pin height, 1cc dish). The above combination gives you are final deck height of 1.57. Maybe that's workable, maybe not. On the other hand, offset grinding the L28 crank to 48mm rod journals gives a stroke of 81mm and saves the cost of finding and buying a L28 crank. Using the B16A rods and the LZ22E (32.5mm pin) gives a deck height of .43mm. Kind of a mini-stroker with a better rod/stroke ratio. The Carrillo version of the B16A rod weighs 441 grams, the Mahle piston 319 grams. I was not able to find the weight of the stock 240Z rods and KA24 piston, but I think these weights are signifcantly less. The two biggest problems with this combo are (1) the BE Width on the B16A rod is .79mm v. 1mm for the Nissan rods and (2) the Mahle piston may not be suitable for long stroke automotive use. For all I know the Mahle H22 piston is a motorcycle piston or designed for some super-sized gas weedwhacker. Oddly enough, after crunching all these numbers I spent some time mulling over/under square engine design. The stock L28 is already moving pretty close to a square engine design (1.09 bore/stroke). Stroking to 83mm or 85mm is almost perfectly square and the rod/stroke ratio is low (1.54) even using the B16A rods. I know a lot of guys are making sick power out of 3.1L engines. There also seems to be two separate camps about whether the whole stroker concept is worth the $. Put me in the latter. I think I'll just bore 2mm-over and put the extra dough into a lightweight rotating assembly. I am by no means an authority on L6 engines compared to the brain trust here in HybridZ. Just thought I would post this in case it might be of some use to anyone else who is researching a stroker build. And if my ideas are junk, no feelings are going to be hurt if this ends up on the 'shed.

You'll find lots of information in the EFI bible which, I think, is stickied in the Help Me section. As for your problem, are you getting spark from your coil? Reason I ask is because Pin 1 of the ECU is connected to the negative side of the coil. As I understand it, when the ICU grounds to cause spark, the voltage change is sensed by the ECU through Pin 1. In short, if you are not getting spark, then your ECU is not recieving the proper signal from the ignition system to know when to fire the injectors. Disclaimer: I'm only familiar(ish) with '75-'78 280Zs and have no experience with ZXs. They could be different. If you do have spark, it sounds like you have ruled out a faulty ECU as the culprit. I'd do all the tests in the EFI bible and check the whole FI system for continuity.

Anyone running a stand alone MSD 6A and OE fuel injection? I have a '75 280Z and decided to try and replace the stock transistor ignition unit with the MSD box. The MSD box wires up fine and gives spark, but here is the problem: The OE FI system takes an input off the of the coil (Pin 1). With the stock ignition unit, the coil terminals have 12VDC, and the transistor ignition until intermittently grounds the coil causing output on the coil secondary. With the MSD unit, there is no voltage on the coil terminals until the MSD box sends a voltage when triggered. The problem appears to be that the OE FI is not getting the right signal on Pin 1 and the injectors are not firing properly. The MSD forum has a admin post about the MSD 6A ignition only being used to "enhance" the stock ignition unit which is supposed to remain in place (not a z specific post). Right now, the car will crank, fire, and immediately die. I have power to relay, injectors and everything else that needs battery power. Is there a way to wire the MSD 6A to provide the proper signal to Pin 1 of the OE FI unit? Thanks. And, yes, I searched. Thansk

Thanks guys. I get around pretty well with electronics, but think I mostly got lucky to stumble on the solder joint solution. Really, the test and solution are very simple. And you don't have to do anything more than to remove the back cover of the brain. Remove all the wires/wiring harness and back panel on the ecu. Set your multimeter to ohms and test the resistance between the harness contacts and any point in the circuit beyond the solder joint where each wire connects to the PC board. If the resistance is more than a few ohms, the solder joint is not good. Visually, a bad or "cold" solder joint may have a brown bubbly/oxidized look to it. The fix is simply to apply a hot solder iron to melt the existing solder while wiggling the wire to ensure a good connection. I also resoldered the harness leads where they attached to the pc board. Even if you have no experience with electronics and soldering irons, if you are convinced a brain is bad and needs to be replaced, nothing is lost by trying to fix it yourself before you pay good money for a new one. Hey, it's going in the trash anyway. Not sure what I'm going to do with the car. It's not as clean as the pictures. I tried to check the timing yesterday and found the timing mark on the crank pulley is about 180 degrees out. Yikes! I'm in denial of shredded crank key syndrome for now. Engine has 20K on a rebuild and pulls strong. Hope to do valvle lash, check dash pot and distributor advance today. Yesterday, replaced diff fluid with syn and learned that the tranny fluind cannot be changed without having the car on a lift. (can it?) I'll probably just drive the car for a couple of months before I decide which way to go. I probably won't go the resto way. My gut tells me I'll likely probably strip it and turn it into a NA road racer. Glad I found this site. Tons of info and knowledgable people. Hope ya'll will let me jump on the Z-car bandwagon and ride along with you. TJ

Update: I pulled the brain and removed some transistors in hopes of finding a bad component. [Alaska is pretty much BFE for finding used Datsun parts]. Turns out all the transistors were good but several of the solder joints lacked continuity. So I resoldered all of the control unit leads as well as the connectors to the PC board. After reinstall, coil had no spark. Checked the coil wiring and moved two wires. Still wouldn't start. Checked the spark plug firing order and found all the wires one off. Changed the wires around and *drum roll* She started right up. Woot!!! Now the real work begins. Clearly needs a tune up. Runs fine but a little rough; idles at 1300rpm. Lots of obvious electrical issues too like fan motor not running and wipers not working. Once I get the tune up behind me all the fluids will be changed to syn. After that . . . hello money pit!

New guy here. I acquired a '75 280Z yesterday. Haven't owned a Z since a '73 240 back in my college days long ago. I was told the car needed a new transistor control unit. I searched these forums last night and didn't find what I needed so I figured I might ask for an opinion or two. With the ignition on, coil gets no voltage on the contacts. Using the trusty Haynes maual, I tested the leads to the transistor control unit and determined that 12VDC is getting to the black, black/white (x2) and blue wires at the control unit harness. (Car is the California verision without the brown wire) The only thing I can think to do before I buy a new control unit is test continuity between the control unit and the coil. I have read much about these fusible link things. Neither wiring diagram I have shows a fusible link in the ignition circuit, but one of the pictures I found linked on this site does. My questions are: 1. Which wires am I testing from the control unit to the coil for continuity? The blue wire appear to go from the unit to coil +. I don't know which black/white wire goes from the unit to resistor/coil -. 2. Are there any other checks or test I can do before I start buying parts which will confirm that the control unit is bad? Thanks in advance for any feedback. TJ