CU Zcar

I have a set of Beck-Arnley rings for my '83 Turbo engine I'm building and the end gaps are all at about 0.0200", where the specification is 0.0075" - 0.0130" (from Haynes manual). Those are just the top rings, I haven't measured the second or oil rings yet. I put the rings about 3" down the bore, squaring them with a piston. My knee-jerk reaction was to say "hm they're a bad set" and ran to Nissan to order a set, but the $120+ they'll cost, especially if they're off the same amount, is $120 I really don't want to be spending...but if they're right it would be worth it to me. What are your opinions? Is 0.0200" excessive? Have any of you gotten away with, or even had, this problem? I know of one guy who had this very problem with Beck rings, but he hasn't completed his motor yet (though he decided to use them). Since I've spent the money on most of the other "good" parts I'd kind of hate to handicap this motor at this point from being cheap...but at the same time it'll never get done if I keep spending $ like this do you suppose maybe it's just that the bores are worn from a couple of instances of honing (I think this motor was rebuilt in the past)... [sigh] so many questions, sorry. But thanks for any input. After I decide on a course of action here, I get to go back into my overly-preloaded R200 LSD rearend, to figure out whether to modify the pinion shim, get new shims, then see if the pinion height and then backlash are anywhere in the ballpark...guuuuuuuuuuuh.....

At this point, doing a tapered cut was what I figured would be best as well. I was talking with my dad about using epoxy of some sort and he didn't like the idea either. I'll probably grind it out tapered for now and if for some reason in the future I find myself feeling like it's a constriction, perhps then I'll have it welded and bored straight. I feel you're probably right though and the taper won't hurt much. If anyone else has suggestions/different ways they did it, it would still be helpful to me to share thanks!

I was intending to put a Weber 60mm TB onto a 1983 280ZXT when my partner-in-crime who was going to set it up on a milling machine for me noted that the casting gets very thin right behind the TB flange. He suggested that the "right" way to do it would be to weld some extra metal into that area, and I see that as a good option. However I was wondering if epoxy of some sort would be able to withstand the vacuum/pressure forces involved. The worry here I think would be heat cycling, with the epoxy expanding at a different rate than the aluminum. When others of you who have bored out their TB openings for 60mm+ throttle bodies, how do you avoid cutting through your castings? Maybe I should just not cut that far on the thin parts? Thanks,

You can try to find yourself a copy of the "Lseries Engine Builder" program, I know it's available at http://www.upstatezclub.com/lengine.zip You can mix and match parts to your heart's content. According to the program, an L28 with its stock bore, rods, head gasket, Turbo pistons and P90 head makes 7.4:1 CR.

I just had another idea, are you running Turbo injectors? If so, it would make sense that your car is running rich, cause the '77 ECU is calibrated for much smaller injectors, i.e. Turbo injectors will flow more fuel than stock '77 injectors would given the same amount of time "open". Playing with the AFM may give you enough adjustment to make the ECU "think" it doesn't need to open the injectors as much...if you tighten the spring on the air flap, the AFM will have less deflection for the same amount of air, but the ECU will think that less air is coming in, and hence it will not open the injectors as long. If this isn't making sense let me know (bear in mind though that I've never opened up an AFM to play with it, only read about it), and if you're not running Turbo injectors with the '77 ECU just disregard this. If you do get the '83 ECU wired in, that should run Turbo injectors - and the rest of the '83's injection system - properly.

Is the smoke really black, or blueish and oily-smelling? I think I understand you to be saying black, which should be from running too much fuel which matches the symptom of the fouled plugs... Could one of your injectors be stuck open? or your fuel pressure way too high? or your AFM or temperature sender connections be dirty or the sensors bad? As for the timing, I forget which way too, but if you can get a timing light you could figure it out quickly. Or, note which way the rotor turns when the engine cranks over, and turn the distributor assembly in the opposite direction to advance timing. Seems to me that with the rotor staying in the same position relative to the crank, turning the housing in the direction opposite of rotor rotation would make the rotor trigger ignition events "earlier" relative to the crank. It sounds simple enough to me but then again I'm also tired so make sure I'm not thinking backwards, and good luck! What wiring harness are you swapping in, just out of curiosity?

Well I for one do not doubt your advice, and if I were planning on doing many serious mods I would go for a better head gasket. However I've not blown my FelPro NA gasket on my NA L28 even though I mistreat it from time to time, and it's cheap, so I'd trust it more than some other cheap HG. Also I know some aftermarket parts sellers tend to have NA parts cross-referenced for use on Turbo's (like having to watch out for getting an NA oil pump) but I now know the Turbo part number from FelPro, so I can feel reasonably certain that it'll have the right passages, etc. Sure, I could go down to Nissan and have the same certainty, but then I'd be asking myself "well why don't I just buy everything here?" but we're back to my cheapness I'm going to stop by my Nissan dealer and see what it would cost me to get everything there too, I just doubt I'll like the bottom line. We'll see though! Thanks for all the input guys,

I went to Federal-Mogul's site and they have an online catalog of their parts. They list a different part number for the L28ET head gasket set than for the regular L28E, so I guess that is where some people's coolant leak problems have stemmed from. My luck with Fel-Pro has been good so far so I'll probably stick with their gasket kit for now and I'll see if I do anything wrong enough to want something stronger. That said, having the head gasket be the weak link is preferable (to me) to melting/breaking pistons, or other more expensive items...

Two questions: -does the 280ZXT radiator bolt into a 280Z (1983 and 1978, respectively)? I measured and the width is the same, but haven't looked closely at the bolt placement on my 78 radiator lately. -I have my choice of manual or auto 280ZXT radiators, I'd rather use the automatic one since it's out but I wonder if the integrated tranny cooler (which won't be used anymore in my swap) would decrease the effectiveness of the radiator over the one in the manual car, since the tranny cooler section I'd think would have to take up some of the radiator's surface area. Which do you recommend?

I've read some posts to the effect that Felpro head gaskets are known to cause coolant leaks on L28ET's thanks to a missing coolant passage, while others say they work fine. I thought perhaps this could be due to there being different gaskets available, so I found some pics online of two different gaskets offered by FelPro: 1983 280ZX L28E and L28ET gasket: 1978 head set, for L24-L28E 1970-84 I think it said: Look closely (keep in mind that one of the gaskets is upside down) and you'll see differences in the number/size/shape of the coolant passages present. Anyone have a pic of a known good L28ET gasket for comparison?

I'm working on pulling all the important parts of the harness out of my car too, I understand that 81's are different but you may need to make sure you get the ignition harness too. Mine seems to have a sub-harness that is taped into the main one...I haven't checked to see if they all go to the ECU or not but I'd check yours to see where the wires go.

By problems, I meant does the ECU depend on any input from the transmission to work correctly? Apparently not, and I didn't think it would really. Just making sure, thanks!

Well the Perfect Power one is "supposed" to work with 280ZX ECU's, or so I think, since they have a wiring diagram for a 1980 280ZX listed on their site. There's a lot more research I'd do before spending $, though the more I think about it the more I'd probably go with a standalone for a little more. The Perfect Power piggyback is something like $2-300, vs. 2-3 times for something like a Microtech or PP's own standalone. It's just that the PP piggyback seems pretty advanced, and considering I am not looking for much more than, say, 250-300hp in the next year or two, a piggyback might get me by. Also, this particular one I think interfaces with a laptop, maybe datalogs (haven't even read the whole website...just have a friend with a turbo Miata that is nuts about them), can control extra injectors...it just seems like the easy way out plus it seems to be something nobody on this board has tried yet. If that's not the case I'd still love to hear how it works though.

I was wondering if anyone has run larger-than-stock injectors on an L28 using either wiring tricks (like resistors, etc. in sensor lines) or piggyback computers mated to the stock ECCS/ECU. I know standalone is the "right" way to do it and I may just save a little more and get one, but I'm also considering having something like a Perfect Power (http://www.perfectpower.com) unit sooner. I just wonder if such systems give enough adjustability to get something like RX-7 550cc injectors, or 300-something cc SVO injectors, etc. to run streetably. Thanks for input...

Essentially...you'll have the parts to do so supposing you had an R200 to begin with. The pinion flange and the rear cover must be swapped, but 280Z axles will pop in. To swap the flanges you need to put a good amount of torque on the nut, you'll need a big torque wrench.

I'm soon going to pull an L28ET out of an '83 280ZXT to rebuild. I did a quick search about head gaskets since I considered using a metal head gasket (though don't plan on it since I don't think my goals & sticking with stock turbo merit getting one) but ran across some posts saying the Fel-Pro L6 head gasket lacks a passage and causes coolant leaks. You're telling me they don't make an L28ET gasket? That's too bad, I'm generally pleased with Fel-Pro gaskets. Besides stock Nissan gaskets and the Nismo or HKS metal head gaskets, what other brands will work? Also, I have a set of piston rings sitting around unused from my last rebuild, they're for an 83 N/A 280ZX, are they any different from Turbo rings? Lastly, are any of the rebuild sets with all the parts bundled together worth anything?

bump I'd also like to know, I have a manual and an auto car to pull parts from, I'll be using the manual but if there's any advantage to either ECU I'd like to know about it. At very least I'd like to be able to tell whoever I sell the auto ECU/engine to whether they'll have problems with a manual swap, since I doubt many people would go for an auto. turbo swap.

You might want to get a BOV that allows you to return the vented air back to before the compressor, otherwise the stock electronics will be giving you fuel for the air you're dumping to the atmosphere, since it has no way of knowing that it's gone...i.e. you might shoot some flames out your tailpipe when you shift the way I understand it though, a BOV that's meant to vent to atmosphere shouldn't hurt performance otherwise since it should only open when shifting or closing the throttle anyway. That said, I'll probably try setting mine up both ways (recirculating or vent to atmosphere) and see which one's better, having the "whsssssssshhht!" of a BOV would be cool Those aftermarket valves you pictured though will be $$$, you could go for a used 1st generation DSM (Talon/Eclipse/Laser) BOV, or a Bosch BOV as found on Saabs and Porsches -- those you can supposedly buy new for $40-50 from a dealer (haven't tried yet tho). Bosch valves are meant to return air to the intake however, you'd have to modify it to vent to atmosphere, like put a one-way valve on the end to keep it from opening under vacuum. If you haven't already seen this page, there's a little info on the Bosch BOV vs. atmospheric vent type valves: http://wwwrsphysse.anu.edu.au/~amh110/Technical_pages/blow_off_valve.htm

Oh yeah and another question...I can get about the same deal on a FC3S intercooler and BOV from a different seller. (i.e. first post was about parts from a 3rd-gen RX7, this post is about 2nd-gen RX7) Any of you have opinions on which is better? I'm under the impression they're about the same, the 2nd gen's IC has a little larger area while the 3rd gen's IC has less frontal area, but a thicker core. Also under the impression that they flow about the same.

I found a great (IMO) deal on some RX7 parts, notably the IC, BOV and piping. They guy says he's going to a salvage yard or something and can get me anything else off one I want, can anyone think of anything else that's useful for someone trying to intercool an L28ET in an early Z? I also asked for some silicone/rubber couplers to put it all together... FYI I'm choosing this intercooler for a couple reasons: it's really cheap supposedly, it flows pretty well (small pressure drop) I understand it's pretty small, perhaps it won't introduce too much lag I figure if it is enough for a 250hp RX7, it'll do for my sub-250hp L28 until I have the $ to buy other stuff to overwork it. If I have $ for that stuff, I have $ then for a bigger IC...

You seem to see what DAW and your BOV company is saying, but if you're still not clear this may help: http://wwwrsphysse.anu.edu.au/~amh110/Technical_pages/blow_off_valve.htm Yours sounds like the "Compressor Bypass Valve" type of BOV.

D'ooh the guy sold it to someone locally, guess I'll just look and see what else is out there...maybe I'll try to pick up a MegaSquirt...

I've found a possible deal on an old Haltech F3 fuel computer, comes with manual, harness and sensors for $200...I've heard that the older systems aren't that refined but compared to eventually trying to make the stock electronics work running upped boost, possibly larger injectors, getting rid of the flapper AFM, etc. on a turbo L28, would it be worth it? Is there anything terrible I should know about this system? Thanks,

Well it won't be driven on again in its present state, I stopped driving it ASAP when I put that diff in. After I check the gear mesh pattern I'll move on to the bearings, etc...just gotta put some time into this equation...while keeping up with everything else I've got to do!

Well damn! Guess I'll continue looking into what's wrong with mine. Or else find a 200SX 4.11 R200 to swap the LSD into...