HizAndHerz

That's exactly what I have done on our Z's harnesses. Simple Green works well and won't cause the insulation to get brittle. Purple degreaser is a little stronger for nasty grease. It made sense to me to peel off the old wrap and inpect/repair the wires, put new connectors on and re-wrap. Non-adhesive wrap won't turn to goo like standard electrical tape.

From my research: standard bore, flattop pistons, Nissan headgasket the CR should come to around 10.8 or 10.9. No?

Rebird, its good to hear your having fun with it. It's great that pump gas is working well for you at that CR. I'm also curious what the bigger exhaust valves make. I'm in the process of putting together my F54 flattops/MN47/Mild cam/Custom intake/60mm TB/MegaSquirt engine. All it takes is lots of time and money.

Can the ring gear on a auto transmission flex plate be replaced? What kind of shop would do this? We're going to end up with another 280z with the L4N71B 4-speed autotomatic with lockup overdrive, but the flexplates have chewed up ring gears. The gear appears to be tack welded on so I'm assuming that it can be replaced by someone that can get the correct replacement gear and then rebalance after welding. Thanks!

Hey, Darrel. Yep, got everything for $50. I was only needing the flexplate since my wife's Z grinds occasionally when starting up. Since I had to pull the tranny to get the flexplate off, it made sense to just buy the whole thing. I'm thinking I'll rebuild this spare auto tranny and swap it in when I rebuild the engine. My understanding is that the clutch packs can be rebuilt to "turbo" specs. The 4N71B is a solid little transmission and has been used in various forms in a bunch of different cars over the years (Nissan trucks, vans, Pathfinder, Starion, Mazda RX-7, 929, Miata, MPV, ...) BTW, I never fixed the early shifting problem, but I have a couple of spare modulator pins of different lengths to try out. It shifts okay if you're heavy on the pedal. Probably not the same car. The yellow 84 Maxima I looked at arrived the last week of October and is heading to the crusher tomorrow. The camshaft didn't look too rusted but the car looked like someone had driven it with more oil on the outside of the engine than on the inside. Huge mess getting anything off that car.

Three-day half-price sale at the two Houston PAP locations. So, what cool things did you Houston area folks get? For me, it wasn't that great since I could only get to the NW location and they had just a three Nissans of interest, a 76 280Z, an 84 Maxima and an 82 ZX. I had a huge list with stuff like blower motors and wiper motors, 240SX TB, but wasted a lot of time Wed trying to pre-pull stuff. In the end I got a spare crank damper and crank washers, a spare T/C rod, a donut spare tire, and a spare L4N71B 4-speed overdrive auto tranny off an '84 Maxima (a steal at $50!). I wanted the head off that car but the engine had been abused. So, anybody got anything cool?

I sent just one of my dampers to Damper Doctor at http://www.damperdoctor.com. $139 plus shipping for a custom rebuild since he doesn't have these already rebuilt. Autozone says they can get new ones for the 280ZX made by Pioneer for $300. BTW, here's something that made it easy remove and to torque the damper bolt. It's a little bracket that bolts to the top starter bolt hole. The bevelled edge meshes with the ring gear on the flywheel. Took 10 minutes to make and saved lots of frustration.

Thanks for the input guys. I'm hoping I caught this in time. I was showing the Delco Remy alternator that I recently installed to a buddy when we noticed the crank pulley wobbling with the engine running. When I pulled the damper I noticed that someone put white paint on the timing mark and that the paint went across both pulleys indicating that the the two parts never fully separated. I didn't notice anything unusual except for the slight wobble of the alternator/water pump pulley. After reading the horror stories, I'm going to get the dampers rebuilt for all three of our Z's.

A few weeks back we bought a nicely restored 78 280z with a recently rebuilt engine. The previous owner paid out the nose for the rebuild, but I've found major problems that were ignored, including a blown up damper. I think we were lucky that the crank end wasn't mangled. I can't believe anyone would think it is okay to reuse this crank end bolt, key and washer. Most all the force of the washer was on the end of the crank not on the damper. The damper that separated is on the left. It is hard too see in the picture, but there is major separation in the rubber. I'm putting the one on the right on the car until I get the other rebuilt: Look what the front of the washer looks like compared to the nice one pulled from a 280ZX motor: You can see how the washer was bent compared to the nice flat ZX washer. I refused to to pull the radiator again so I made a quick and dirty puller. The threads in the puller were strange (6mm coarse?) and a 1/4" bolt fit almost perfectly except for the dirt in the threads. I chased the threads with a 1/4" tap. I screwed the crank bolt in about 3/4 of the way, then tighened the 1/4" bolts on the puller until the plate pushed the damper away from the crank bolt. Then loosened the puller bolts a few turns, backed out the crank bolt a little, then tighened the puller bolts again. Did this three or four times before the damper could be pulled off by hand. The trick was to make sure I didn't tighten the puller bolts so much that they protuded through the damper enough to dig into the front cover. I'll post when I get my dampers back from rebuilding.

Yea, I saw those Nakamoto pistons on eBay. Tempting, but a little googling reveals that they are a Taiwanese company that makes all sorts of cheap aftermarket parts. I could find no other information, no reviews, nothing. Too scary for me.

I've had no problems with "Master" branded pumps from Autozone. They are around $100. There may be better pumps for that price. I've got them on all four 280Z's, with a Fram G3 inline filter between the tank and the pump. You don't say if you checked for 12V at the fuel pump. Pumps don't seem to go bad near as often as fuse links (corrosion), bad AFM connectors, wiring and relays. See "Fuel Pump Control Information" on this page: http://www.atlanticz.ca/zclub/techtips/fuelpump/index.html

I've got several 280Z N47 heads and three L24E N47 heads. Both types are marked N47, but the L24E version has a thermal sensor below and between the #5 and #6 spark plugs. I think that's the most obvious difference. Edit: I recently read on another forum that N47 heads that came on early 280ZX motors had the thermal densor in the same location. It was 1_fast_z that wrote:

The electrical mods are a breeze on the later Z's and ZX's since they don't use an external voltage regulator like the 1977 and earlier do. The T-connector needs to be changed to a GM-style connector. The "+" and ground ring-terminals need to be a little larger to fit the studs on the alternator. That's it. If you have an earlier Z, there are articles on converting from an external voltage regulator to an internal one like on the 280ZX alternators. The only difference when using the GM alternator is that a different connector is used. Click here for info on the electrical mods needed to use an internally regulated alternator on Z's made previous to 1978. One thing I should mention is that the wiring harness that carries the wire from the alternator to the main battery wire is often fried on old Z's. The wire probably gets fried when the battery isn't tied down and the + terminal of the battery shorts against the chassis. I've had to rebuild this harness on three different 280Z's and I chose to run a new 8-gage wire in both cases. Even if you know your harness is in good shape, I think it is a good idea to run an extra wire from the alternator BAT stud to the alternator fuse or fuse link. It doesn't do much good to install an alternator rated at 94amps if the wiring won't support it. Here's a picture of the GM connector that replaces the Hitachi T-connector. Red -> White/Red White -> Blue I replaced the ground terminal with a larger one so that it would screw onto the back of the alternator: For reference, here are the connections for the GM alternator plug: Here are the connections for the Hitachi alternator T-plug.

I had originally tagged this onto another thread but have completely rewritten it with updated information, hence the new thread... There are other posts on doing the Delco Remy (GM) alternator swap on an L6 engine, but I thought someone might want to see some pictures of what we did on all three of our 280Z's. Other alternator swaps have their advantages and this particular swap isn't for everyone. My reasons for going with the Delco alternator were: The exact Hitachi replacements for the 1976 280z or the 1978 280z's were not in stock. The old external voltage regulator could be eliminated on the '76 Z. A GM alternator can be had anywhere, anytime for cheap. One less thing to worry about on a long trip. Higher output rating. The Delco Remy 10si/12si comes in 63A, 78A and 94A ratings. Summit sells chromed 140A alternators (part SUM-810350) for around $120. (Of course, the higher rating doesn't mean much unless the wiring is up to snuff.) We saved about $20 and ended up with a high rated alternator. It was fairly easy to do with the tools I have. On two of our Z's, the bolts holes at the front of the mount were stripped and the bolts were missing. The swap solved that problem as well. Click here for a great website with info about the Delco Remy 10si/12si alternators. There are three methods of mounting the Delco 10si or 12si alternator that I am aware of: Mount the alternator upside down. The place on the alternator where the adjustment bolt normally goes will bolt right up to the existing mount with no modification. The trouble is that some people have said that the thin metal on the alternator eventually bends. Buy or fabricate a new alternator bracket. The mounts I've seen advertised were $80 to just over $100. Modify the existing bracket. This allows the alternator to mount to the engine much like it does in GM cars. We went with option #3 since it seems to be reliable, inexpensive and fairly easy to do. Here are some of the tools used: Reciprocating saw or hack saw Bench grinder Drill bits from 1/4" to 13/32" Parts used: Delco Remy 12si alternator rated at 94amps (Autozone Duralast Gold DL7294 at $70 with lifetime warranty or Valucraft 7294 at $50 with 1yr) M10x113 bolt (HELP! Part #45636) M10-1.5 hex flange nut (Dorman 982-010) M10 spring washer M10 flat washer 5/16"-20 bolt for ground strap GM alternator plug (Calterm 08602) Basic procedure: Remove Hitachi alternator and alternator mount. Shorten mount and drill a through-hole. Move the v-hub from the original alternator to the GM alternator. Install the modified mount and GM alternator. Change Field/Sense plug and put on larger ring-terminals. This is the third time I've done the swap. It takes between 2 and 3 hours to do the job if the parts and tools are all lined out. A picture of the new AC Delco alternator with modified mount next to the old Hitachi alternator with original mount: A picture of bolt and flanged nut: Now to the work. First, we removed the alternator mounting bracket from the side of the engine and cut about an inch off the front mounting surface. We didn't want to accidentally cut too much off so I left the bracket a little long and then mounted it to see how much more needed to be cut off. I started by cutting off 1.25". This placed the alternator pulley too far to the front. I used a bench grinder to do the fine adjusting. To get the alternator pulley was in perfect alignment, the bracket had to be ground so that it was exactly 1.7" deep. Next, the rear bolt hole needs to be enlarged and extended through the front of the bracket. The M8 threaded bolt hole needs to be enlarged to accept an M10 bolt. We used a 1/4" drill bit inserted into the rear bolt hole and drilled through the front. I worked up to larger drill bits and drilled the entire bolt hole until it was 13/32", which is just big enough for the knurled shaft of the M10 bolt. Actually, my drill set did not include a 13/32" drill bit, so I worked up to a 25/64" bit and hogged the hole out to make it large enough for the M10 bolt. For me, drilling the mount was the hardest part of this little project. Keeping the drill bit from grabbing while drilling straight is difficult without a drill press. Still, it only took about 20 minutes to get the mount modified. Here is the modified bracket mounted to the engine: Here's a picture showing the V-hubs (pulleys) of the AC Delco 12si and the Hitachi: The V-hub on the GM alternator is slightly more narrow than the one on the Hitachi. Even though the narrow hub seems okay, the belt rides higher in the groove and causes the alternator to turn too slow, so I decided to swap hubs. They came off easy with an impact wrench. The spindle is larger on the GM alternator so I mounted each half of the Hitachi hub in a vise and used a step drill to enlarge the center holes. Here is the Hitachi hub mounted on the 12si. Here is the final mechanical installation. This picture shows a cheaper 10si 78amp alternator without swapping out the hubs. I lost my picture of the 12si with the Hitachi hub. I’ll add some more info about the electrical hookups in a follow-up post. I hope this helps somebody out there.

Edit: I completely rewrote my lengthy post with pictures of the AC-Delco alternator swap that we did to all three of our 280Z's, so I moved the guts to a new thread. See http://forums.hybridz.org/showthread.php?t=115550

I'm about to do this on 280Z #4 tonight so I am just now coming back to read what I posted almost a year ago. I threaded the bracket so that the bolt would not wobble around. I suppose a nut could be used instead, but threading stills seems better to me. No, I'm 100% sure it is M10 X 100mm. I'll try to take pictures of the electrical part this time around.

From my somewhat limited experience, the things that go bad are typically in order of frequency: 1) Corroded connections (injectors, sensors, fuse links) 2) Leaky or clogged injectors 3) Worn out or clogged up fuel pump 4) Rust or varnished gas tank 5) Worn trace on AFM circuit board (usually easy to fix) 6) Bad temperature sensors 7) Bad relays 8) Previous owner's hacking The stock ECU seems to be very reliable. I've got a stack of good ones in my garage. I blew up the only one that is bad. A lot of the stuff in the list above has to be fixed even when changing FI systems. Even though I plan on "upgrading" at least one of our Z's to MegaSquirt in the future, I've found it valuable to test and then refurbish, rebuilt or replace all the components in the stock system. My Z's ran like crap or not at all when we got them, but have been completely reliable since going through the above list of components. If your engine isn't running right for some unknown reason or multiple problems, trying to get MegaSquirt running would probably be a major hassle. Don't expect MS to be able to diagnose fuel pressure or electrical problems. It will tell you about sensors and connections to some extent, but those things should be fixed first anyway. If you were certain it was the ECU that was toast, it might make sense to convert. But then again, working ECUs can be had for cheap. Just my $0.02

My 12-ton HF press would not touch the u-joints on any of the six 280z driveshafts I tried. Even with soaking in PB Blaster and heating with a MAPP torch didn't help. I had to beat the cups out with a sledgehammer. Not easy to do without bending the ears. The press has come in handy a quite few times, but I've been disappointed the times it couldn't cut it.

Well, I tend to obsess over stuff. I just thought it was cool how well the hump for the exhaust pipe worked out. The original just didn't turn up enough to get out of the way of the exhaust. It also hit the passenger side of the tunnel so I'd either need to bash in the tunnel a bit or drill another hole in the crossmember so that the mount could be a little off-center. I really appreciate you giving me all the great info and allowing me to bounce ideas off you. I'm taking off of work tomorrow to try to finish this thing off. We could have 280Z #2 back on the road tomorrow! Of course, that will leave room in the garage for Z #1 to have the Maxima N-47 head swap. It never ends, does it?

Darrel, it looks like I'm doing a combination of things. I've been trying to avoid the hassle and expense of having the exhaust re-routed. Using the original crossmember and putting new brackets on the tunnel would get in the way of the exhaust. The second approach was to use a differential crossmember which has the bend for the exhaust pipe. I was going to try to extend the corssmember by bolting on "wings" and then bolt it all to the floorboard with reinforcement. What I'm doing now is cutting the differential corssmember so that it fits up into the tunnel. Then I'm going to make new brackets out of 1/4" thick angle iron (the only place I could get supplies from on a Sunday didn't have square channel). I'm going to butt two pieces of angle iron together with two or three big bolts through each to make the bracket. I cut a flange out of the exhaust pipe since it was right in the way. For now, I'm going to put a sleeve on and then have it welded up right when I'm all done. Here's what I have so far: Here's a bottom view. Note that there's plenty of room before the yoke bottoms out on the tranny case. Another thing. The tranny mount is in pretty bad shape, the rubber is about to let go. I'm probably going to rig up the crossmember so that I can use a GM-style transmission mount like this one: Please tell me what you think. Thanks!

Darrel, that's what I'm going to do. You know how it is, can't help but keep second guessing

Can anyone provide the measurements for the JTR crossmember so I can see if it will work for the Maxima auto tranny? I've looked at lots of pics of off the shelf and fabbed transmisssion mounts on the forum, but haven't come to a conclusion on how to handle a Maxima 4-speed auto in my 280Z. I'd like to avoid having to re-route the exhaust, and it looks like the JTR crossmember may be the easiest option. The Maxima has the mount about 6" behind where the 5-speed has them, so I cut the original brackets out of the tunnel. The tunnel is oddly shaped back there and it would be difficult to make new brackets that bolt or weld up to the tunnel like the originals. I've also looked at using the front differential crossmember, and I can make the work around the exhaust, but it hangs pretty low and is a bit kludgy. I don't weld so I'd like something that could bolt in. Any thoughts?

Which tranny? I know that drivetrain.com has Natco rebuild kits for 5-speed manuals and has TransStar rebuild kits for automatics. None of the rebuild kits I've include the clutch and throwout bearing. Those must be obtained in a separate kit.

Not sure I understand. By locking everything together aren't you disabling both the mechanical and vacuum advance? BTW, I don't pretend to understand all the ramifications of mechanical and vacuum advance. Edit: Ok, obviously you're only talking about locking the breaker plate to disable vacuum advance. Disabling mechanical advance will kill the high end.

Here's what I did to rebuild my distributors. First, I fabbed up some replacement breaker plate bearing keepers (that's what I call them anyway). The originals are thin plastic (upper right corner). I used a rotary tool to make four out of Lexan. It tricky getting all the holes for the bearings and holes so that the breaker plate screws would clear. The stopping pin was a pain since it can't stick up above the surface of the Lexan plate on one side. There's a Mitsubishi distributor that seems to have been only available for the Euro market that has a superior breaker plate. It has 16 bearings instead of the Hitachi's 3. A much better design. Good luck finding one of these. Here's a shot of the whole distributor: Here's a vacuum canister from an early 1980's Camero that I modifed to fit a Mitsubishi 280ZX distributor. The mounting would need to be different for the standard Hitachi distributors normally found on Z-cars. I bent the plunger to match the one on the ZX distributor. I cut the end off the plunger of the ZX canister and crimped and soft-soldered it to the end of the new one. This canister mounts to the dizzy above. The mount would need to change for the standard Hitachi distributors.