chaztg

I'm not concerned about smog. In California, 1975 and earlier model year vehicles are exempt. In any event, I couldn't use the SDS system on a registered motor vehicle if I had to comply with a visual inspection (talk about a waste of money if I had to, the EM4 system costs over a thousand bucks). I've never tried the bigger TWM throttle body on an FI-equipped Z car. I'm not trying to go to the moon, the part was basically free...if I gained anything from this, it would be the knowledge that this mod is probably not worth the money if the part was bought new, but at least it was fun experimenting with something different than stock (I was hoping for more torque). Based on the valuable opinions expressed here, I may hold off on this until I have the time to modify a stock manifold & cylinder head, add a cam & headers, a less restrictive muffler and exhaust, etc.

I'm planning on using this in my 280z. The car is fitted with SDS fuel injection management, stock injectors, stock cam, stock 280Z intake & exhaust manifolds, stock exhaust (no cat). I'm hoping that I will notice some difference in power, but I know gains will likely be marginal due to the restrictive stock equipment and non-modified intake & cylinder head. I'd like to install a set of OEM 280ZX turbo fuel injectors. If switched to the fatter injectors, the mixture can be adjusted with the SDS programmer based on the injector flow rate, so I'm not concerned about fuel/air ratio problems. Any advice...? Thanks

all for sale, by the way http://www.flickr.com/photos/90175897@N07/

goofy-lookin'

The box was labeled "240Z". They are blue, they are tagged F&R, their height is right for 240Z springs....what are they? They were found in a Datsun parts hoarde last weekend. I'm going back for more this Saturday. These springs have been stashed for quite a long time, they appear to be unused. The color suggests Tokico. I think a couple of older brands were "Turn Six" or "Dave Cook" that also were possibly blue. Are ther any more "seasoned" Z officianados out there who could wager a guess? Thanks

Well I got the two diffs apart & was able to change out the buttons and refit them into the spider gears in the 3.7:1 differential unit.The ring gear needs to come off the carrier in order to do this to allow the shaft holding the spider gears to slide out. I thought I'd need a press, but not so because the shaft is held in place with a roll pin, not a press-fit. Everything fit back together really easy just like you said. I replaced the side seals and refit the rear cover using a gasket & sealant. I filled it with some pricey Amsoil synthetic 75w90 (couldn't find Redline)...hopefully the end result will be NO LEAKS and NO WHINE!! Fingers crossed! I took the opportunity to also clean 30+ years of crud, oil residue, grime & whatnot off the rear transverse link & diff crossmember, painted them in a few coats of semi-gloss black (looks almost as good as powder coat). All I need to do now is replace the transmission, which makes a noisy knocking in 5th gear only. Weird problem. I have no idea what is causing it. After all this, I can finally enjoy driving my car again with a rear end ratio change which I'll notice and a fully functioning transmission.

Thanks guys. I already got the side seals & rear cover gasket, anticipating a full teardown of the diff. I'm thinking as long as it's put back together the same way, I won't experience any bearing issues. Carl, I'm just too proud to have a shop do it for me, so I'm trying it by myself. By the way Mike, how do you like the 4:11... Is it a noticeable rush to get that "hole shot" from the low gearing? I didn't get too extreme, so I went with a 3:7 ratio instead. Tony

I acquired a replacement R180 for my 73 240. It's a "K R180" later-type diff out of an 82 Maxima AT which was equipped with CV-joint halfshafts/axles and they do not interchange into the S30 for various reasons. Modern Motorsports offers companion flanges to use CV axles from a 280ZXt, but they only make flanges for 280Z style stub axles. Changing the wheel bearing stub axles to 280Z style means undoing the infamous axle nut...twice! And doing so, I'd better replace the bearings too. MM doesn't mention using other kinds of axles, like from the Maxima or maybe 200SX...? The 280ZXt axles are probably stouter...but the car's not a racer, so strength is not too critical as long as they fit. I measured the axles from the donor Maxima car and they appear to within 1/2" of the stock 240 halfshafts. It's a a big job to change those stub axles and I'm leaning toward just modifying the later diff to accept the 240 halfshafts, which means converting the K R180 to accept bolts (the CV axles are clip-in, not bolted). That means pulling the old & new differentials apart to swap over the threaded "buttons" and I'm thinking this is less labor & time overall (and less money). Another option is Beta Motorsport's modified axle flanges which require no diff dissasembly, just more money & down time for my vehicle. Any thoughts?

Hoods always get damaged in transit; they're big, bulky, awkward & they always get dropped. The corners are the first thing to get damaged. However, that's nothing compared to an ill-fitting part. That really sucks. I'm with ya on the Chinese-made junk....parts & tools....ALL JUUUNK! On another Z forum, someone said that they had already bought the "last" S30 OEM hood in North America.

The steel synchro gearboxes (later 2-piece housing type, for Z cars--we're not talking Roadsters) are distinctive due to the rear output is a flange (like the front of a differential) and the driveshaft is a 2-piece sliding unit like a 2000 Roadster). Internally they have the grey steel synchros (they look like rings with a small gap for expansion). They are not interchangeable with the Borg Warner brass type synchros which all US equipped Z's & ZX's (4&5 speed both) came with. I don't know if Les will tell you this--probably only if they are NLA--but the steel synchros are unique in that they can be reused....They can be "flipped". When I had a JDM 5-speed, we rebuilt it that way and it worked perfectly. You can check if the synchros have been flipped before by looking at the shoulder of the ring edge in profile and if one edge is rounded off more than the other, then the non-rounded side is the one that gets re-installed. It's hard to describe, but once you have them out it makes sense. The gearbox I obtained at first crashed in first thru third. After rebuild, it worked great. Put in a quart of 20w50 motor oil and this will smooth out the action. The steel synchro JDM standard & close-ratio "B" type transmissions have a different feel when they are shifted, not quite as notchy as a brass synchro box. Pretty cool.

It's ignition/spark. Check for spark when cranking the engine over.

I propose that we all watch the movie "Breaking Away" (late '70's, starring Dennis Christopher, Dennis Quaid & Daniel Stern). That will awaken the cyclist in us all.

I agree with the captain. As I was reading this, it didn't sound like fuel to me. It sounds like an ignition problem. My 73 Z has an annoying problem much like it. I've figured out different ways to get around it, but my car does it too (not starting seemingly with endless cranking). I've tracked it down to the ignition key switch, not the mechanical one where the actual key goes in and turns, but the electrical switch mechanism behind it which contains the plug leading to the wiring harness. Change that part. You can use the switch out of other early Z's, they are all the same--but like everything else with cars, it could be symptomatic of some other problem as well. Changing out the switch hasn't fully solved the issue in my car yet, but it helped.

the 2+2 will be the next "desireable undesireable" They don't have the appeal, but they are now rare enough to be that much more eccentric and insteresting. I'd own one if one came up for sale for the right price. Six bills seems pretty OK to me.

and a rear main seal for the motor if you're totally committed (as in insane).

that guy has humility, respect, class and good taste..., but he have better been wearing full-finger gloves so he didn't smudge the paint on "a very nice car."

Can I ask your source for the fiberglass 240Z style bumper? You mentioned front...what about the rear, are you changing that one too?

They may have done some work to the cylinder head, but if they did not remove the camshaft towers in order to resurface the head, then they may not have removed the valves & valve springs...which leads me to suppose if they did not remove the springs, then they most likely didn't replace the valve stem seals (a huge time-consuming job if the head is installed on the block). Oil smoking like you described is noticeable while driving especially when decelerating off-throttle when those stem seals are old, brittle & heat baked. New suppple seals will prevent oil in the rocker gallery from migrating down the valve stems into the combustion chambers. If it's smoking all the time & it's not a glycol leak, then it may be what I have suggested. Do you have any of the old parts the engine rebuilder could have replaced. Last cylinder head I had done, the machinist gave me a baggie containing the old stem seals. Proof, if you will.

Thank you for the replies and for your advice. I looked up the ring mfg website and it had just the info I was looking for. My initial presumptions were somewhat off and I also wanted to clarify that the motor has a .020" or .50mm overbore (Duh!). The cylinder head choice was due mainly to the fact that I have a rebuilt E88 sitting on the shelf, but the suggestion about the similar CR vs an N42 head including the advantage of bigger valves makes more sense I have to agree with. I do also have an extra N42 head I could rob the valves out of, but it's more machine shop cost to do it. However, the 280 head hasn't been rebuilt either, so I'm still weighing the options based on available funds. I've already spent hundreds so far for the junkyard L28 shortblock, the machining cost, new pistons, rings, bearings. It's all fun for me, and the money was spent over time not really on a budget per se. But if I have a ready to use part, like the E88 head for instance, then I should just use it since this won't be a race motor. I learned also that my word "chromoly" may be applicable to BMX bikes from my youth, but there are 3 distinct piston ring types: "chrome" and "moly"(short for molybdenum) are 2 of them and I have CHROME rings, which refers to the top ring only. The breaking in procedure involves setting the base adjustments on the motor, running it up to operating temp, checking oil psi, shutting it off then rechecking the settings (valves, timing, ign, carbs). The next step would be running it for a series of full throttle pulls from 30 to 50 mph. No lugging was expressly stated on the ring mfg guidelines. So I have indeed learned. I appreciate the everyones' help!

I neglected to remember that the carbs are DGVs, I'm not certain if they have inlet screens like the SU's...you'd better stick to using the additional filters just to be sure.

I've got all the parts to reassemble an L28 motor as part of an old school E88 head / L28 block combo project. I've got .040" bored over pistons on stock L28 rods and the rings my machine shop obtained for me are the chromoly type which I believe are standard for OEM. Does anyone have any suggestions on how to properly break in / or bed-in these kind of rings when the motor is first running? A friend of mine told me that he likes to lug a freshly built motor while driving up an incline or hill a few times to allow the rings to seat. Would this practice be okay for both cast iron and chromoly rings? Any feedback or opinions would be greatly appreciated!

Speedo gear pinion drive? Small enough to have a high-pitched sound & turns with the driveline; it's in the tunnel area. May have worn gear teeth, or a distinct wear pattern to make it whine only at certain RPM. I've seen ones that have become fused or tight to turn. Is the speedometer functioning normally?

Mazda RX7 pump...from a carbureted model of course. Use the stock wiring in the rear. If you have a pre-73 car, you'll need to find the unused plug inside the dash next to the radio & connect it with an inline fuse. Pump will activate when they key is in the "ON" position, and no regulator is needed. Try not to get roped into a discussion about fuel return lines, some folks around here get hyper-opinionated. Just leave everything stock, you don't need extra fuel filters, one's enough...the carbs have micro screens in the inlet pipes on the fuel bowls.

some threaded studs for the manifolds could have varying lengths depending on which part of the manifold flanges they fit through. This may make a big difference if you plan to use headers, but it may not matter if you are reinstalling the OEM exh manifold. When you're in there with a wrench head & clearances are tight, it could make all the difference. Mock up everything & test fit prior to reassembly as thoroughly as you can.

what year model patrol is it....2 wheel drive or 4WD?