DAW

Check to confirm, but I believe the L28ET pistons are drilled under the oil-ring and the L28E pistons are slotted (i.e., weaker). DAW

I think you did a good thing. I just go by my gut feeling when sizing these people up. One thing I really enjoyed when I lived in downtown Chicago was going to a nice restaurant and getting a "doggie bag" for whatever meal wasn't consumed. Then I'd walk around and when my gut feeling told me that I found a person truly down & out, I'd give them the food. One reason I liked the food idea was that with cash, it might go to drugs or booze, but with food I knew it was going to nourishment. DAW

I've identified a criteria that is fairly reliable in sizing up the authenicity of a curbside beggar: If their sign says "God Bless" at the end of their message they are most often a fraud and using that phrase to give the impression that they are legitimate, possibly even endorsed by God. I don't give a thing to these theives. There are times, though, when you just know the situation is real. I recently gave money to a guy on the side of the road standing in the rain with a sign which read: Stranded, please help me, I need to get back home to Ft. Collins, CO. And no "God Bless". The clincher was that he kept holding his sign up to hide his eyes because he was embarassed that he was crying. Through my travels, good people have helped me when I was in a jam, I am eternally grateful, and I do the same good thing for others...but I hate the low-lifes that have found an angle there to exploit and bilk good decent people out of money. DAW

Smelling a lot of fuel is significant. I think the '76 had a cold start valve. Use the manual to locate the valve and unplug it, or better yet, pinch off the hose to it as it may be stuck open and dumping fuel. Check other things that would cause excess richness: on some engines around this vintage it is possible to cross-up the wires/connectors to the water temp sensor with other sensors which share the harness running along the intake manifold side of the valve cover. If the water temp sensor wire(s) are disconnected or crossed to another sensor, the message to the computer is that the engine is being started and run at sub-zero temps and the computer will send maximum fuel to the injectors, flooding it out. The wires I'm talking about are dark green and the one with a white stripe may be crossed with the one with a yellow stripe. The AFM with the silicone sealer suggests it's been tampered with. Check the action of the flap/door: can it stick or is it stuck? The spring tension may have been fooled with and that will directly affect the mixture the engine sees. Check the TPS per manual. Check the fuel pressure regulator...at least plug a test vacuum line to it, suck on the line and plug it with your tongue, and see if it holds vacuum pressure. If it doesn't, the diaphram is ruptured, and it will allow fuel fuel pressure at idle; flooding it out. Good luck and follow through with feedback. DAW

What makes more sense than improperly paired cylinders with triple SUs is six smaller SUs (like from a small British 4cyl or a large motorcycle cyl). The small SUs should be mounted fairly close to the head (like each one onto an individual runner of a triple weber intake manifold). The inlet tubes to each carb would be paired by cyl ignition interval (1-6, 2-5, 3-4)and are equal in length. No throttle plates in the carbs, as all air regulation will be done by a single 60mm throttle body upstream. No major synchronization or throttle linkage issues and individual cylinders can be tuned for mixture if needed. So, there are long equal length runners that carry only air, not air/fuel, and these are configured as six-into-three-into-one plenum with a single throttle body and provide a high velocity, balanced flow at low and midrange rpms. The system is a staged induction design as there is a short path/high flow/large plenum secondary manifold incorporated as follows: just upstream from the individual carbs the runners have a Y-junction plumbed into the primary runner tubes. On the short secondary side of the Ys sits a log-type plenum with large inlet at one end. The secondary manifold system is a dynamic unit. The plenum has an outer shell with six ports connected to the Y's. An inner insert is a slip-fit into the shell. The insert has six same-sized port-holes and when rotated, these ports align with the outer shell ports and permit flow, when insert is rotated back; flow is regulated back. Rotation/regulation is actuated by a vacuum actuator taking its signal from a flow-sensing carb venturi source (vs manifold vacuum). Actuator rod connects to lever attached to inner shell, shells have O-ring seals. Secondary plenum large inlet is plumbed to main primary central plenum with an air valve proximal to it which isolates the primary airflow from the secondary. The "airvalve" is a large single SU (no throttle plate or fuel supply, just a heavy piston) this eliminates resonance into the secondary plenum, preserving low speed throttle response, and opens in response to flow when the secondary (staged) manifold system comes into play at mid to high rpm range, when insert is rotated. The transition between pri and sec systems is essentially self-modulating and directly linked to engine speed needs. This staged intake design would work equally well with multiport f.i. as with the 6 SU carb model. The f.i. model with a turbo would provide excellent off boost performance This induction system may or may not be worthwhile, but functionally it is similar to the state-of-the-art staged manifolds on many new engines. DAW

The chokes are the least of the problems and can be gotten around by a primer/squirt system. The end-pairs of intake ports can be covered by L4 SSS manifolds. The inner-most ports are more of a problem and that's where your fabrication skills would come in. You would need to take the L6 manifolds and cut the intake port flanges off then cut each manifold through the centerline (vertical) of the carb mounting face and plenum, weld the two inner halves together and switch orientation and weld the flanges on. This center manifold could now be bolted to the head with the other two. Alternatively, use the lower section of an LD28 intake and fabricate an upper triple SU manifold. You may need to have the center carb face the opposite direction from the other two to allow clearance for all three. With these two designs you might end up with triple SUs; but they do not incorporate paired cylinders by ignition interval which would provide the optimum charge flow and low-end torque. That is, ideally, cyls 1&6, 2&5, and 3&4 would share the same SUs (and all have equal length runners); not cyls 1&2, 3&4, and 5&6. It's easier designing an f.i. manifold because it's carrying primarily air and not air/fuel. One last thought, consider removing throttle plates from the SUs, plumb their inlets together, and use a throttle body and a single linkage to control the airflow. DAW

Get fresh gas in it first. Drain what's in there and replace with a full tank of fresh gas. History is very important in troubleshooting but you don't have that luxury with an impounded car. If there are plates on it you may be able to get an idea of just how long it has been sitting. There are many things that could cause the problems you are having but try to keep the process focused, e.g., sure, timing can cause a backfire and since it's easy to check, go ahead; but realistically, unless there are signs that the distributor had been moved around just before it was parked, it's not way up on the algorhythm and is below checking the strength of the spark, insuring all injectors are functioning, there's adequate fuel pressure, the plug wires are on the correct plugs, etc. Establish the basics first and then start refining your troubleshooting. Otherwise, it's easy to get all muddled up. When you hear hoofbeats, think horses; not zebras. DAW

Be very polite and don't talk over the judge, speak when asked to tell your story. You have never driven your Mom's car before that time and had no idea it was so touchy...you were just as surprised as the officer. DAW

I wouldn't pay over $40-$50 for the setup. You can get other mfgs to work also...RX7, Starion, etc. DAW

You can set the fast idle speed however you want it in relation to the choke (jet dropping) function by bending the small linkage piece in that system. Get an SU manual or a factory 240Z manual for details. 240Z chokes can be a PITA because sometimes they stick and one carb jet may not return to where it belongs when the chokes are released, creating havoc. I decided I didn't want the jets moving once I tuned my needles to them so I did away with the choke cables and fabricated a cold-start system using small dia metal tubing which sprays a shot of fuel into the center of the intake manifold when I activate a small electric fuel pump by pushing a button on the dash. DAW

I think you'll find the rod large ends are too narrow for the L6, but the pistons may prove useful. Look into Z22E (E not S) 148.6mm rods to use in the LD28 block, or Z20E 152.45 mm rods. DAW

I think it could be a good swap. The Conquest/Starion 2.6 turbo has a front sump pan but you could easily adapt a truck pan (if these are rear sump). The sore spots on these engines are the cyl heads which are prone to cracking between the in & ex valves, and the lack of multi-port injection (they have throttle body, 2 injector systems). There are aftermarket bare heads (without jet-valves) available that aren't crack-prone, and there are aftermarket MPI manifolds/systems available (search DSM websites). Granted, multivalve-head Mitsubishi engines would be a better choice, as would several other engines, but you already have the 2.6 so do the $math and decide which makes more sense for your situation. DAW

Are you talking about a 280Z N47 head or a Maxima N47? They are very different heads. With the availability of the Maxima N47 head, the E31 makes no sense on a stock 240Z shortblock; and the 280Z N47 head, while having bigger intake valves than the Maxima N47, has larger chambers which drop the c.r. lower to the point where performance compromise will definitely be felt. The Maxima and 280Z heads both share the same size exhaust valves which matter the most on an L24 vs L28 (for a stock L24 you don't gain much from the larger intake valves vs a stock or modified L28). But it is also important that you realize that if you run these larger (44mm) exhaust valves on any head on a std bore (83mm) L24 you need to grind reliefs at the top of the cyl bore or the valves WILL crash into top of the cyl wall. The E31 and stock 240Z heads have 42mm exh valves that clear (although reliefs at exhaust side of bore helps flow even with smaller valves). Cutting the reliefs is easy even with the block in the car. The Maxima N47, let's call it N47m, has a closed chamber design which seems to ping less than the E31 (about the same size chamber) at the same c.r. All things considered, eliminate the E31 unless you are willing to put new hardened seats in it (and if you do this, you'll want to upgrade the exhaust valve size and maybe the intakes). Between the N47m and the L28/280Z N47, let's call it N47z, both have provision for f.i. should you choose that route later, but the N47m is hands down the better performing head on a stock L24 due to the significantly higher c.r. produced and the closed chamber design. You do need to swap in a 240Z-280Z(X) cam and intake valve springs but that's trivial. DAW

The only good thing about the 260Z carbs is the butterfly plate choke vs the sliding mainjet mechanism (which can stick) of the 240Z round top carbs. Otherwise they are an overly complex, poor performance, vapor-locking carb. DAW

Yasin-The L4 head flows much better than the Z4 head as you're probably aware, but with the displacement of a Z24 shortblock under it the c.r. can easily get out of hand. The open-chamber U67 head is basically the only option as the SSS or W53/58 chambers are too small. Someone who had done this L4 head/Z24 shortblock hybrid told me he had to use a Mercedes Benz timing chain connector link to size the chain correctly. BTW, re drivetrains and the L4, you cannot use the Z22/Z24 trans if you use the block for a hybrid engine due to the different tilt. You must use an L4 or L6 trans. DAW

You could take a Z22S truck block, bore it 0.080" to 89mm, combine with 89mm pistons of your choice on Z22E rods (car, 148.6mm), Z22 crank (92mm stroke), then turbocharge and make up f.i. manifold from L28E manifold segments. The primary limiting factor is the lack of turbo exhaust manifolds. In my little 720 pick-up I have an L20B with L18 pistons (9.6:1), a W58 head, twin 240Z SUs, and a long-tube header and 5-spd, and it will pull a heavy trailer with no problem. So I can see the swap in an early lightweight 240Z but it makes little sense in a 280ZX. DAW

The L4 block mounts are 7" rearward from those of the L6. That seems like a long for some sort of extender plate to span. You might be able to adapt a second crossmember placed 7" behind the Z crossmember. It's not hard to adapt the L4 heads to the Z4 series blocks (Z22, Z24) to get more displacement but these are both taller than the L6 block (and use longer rods btw). DAW

A fairly consistant indicator is the condition of the front frame rails. Crouch down and look at them, viewed from just behind the front tires. Many Zs will be corroded through here. If so, just look for another one unless you're willing to reconstruct (for high performance use). DAW

I've seen oven cleaner do a number on aluminum parts...don't leave it on very long or you'll regret you used it. When you're polishing away with Mother's or another aluminum polish (Simichrome is excellent) and that black aluminum oxide is building up to the point you think you won't ever get rid of it...use some flour while buffing and, like magic, it's gone! DAW

Oh, BTW, if you want to lose a lot of lbs on a post-'74 Z, consider Fiat X19 aluminum bumpers. They are the right shape & size and you can remove a section from the plastic "accordian" bellows trim pieces to compensate for the displaced distance when the stock bumper shocks are deflated & compressed and the Fiat bumpers fitted. DAW

I have a question: If you mill the head on the 360 by .060" to increase the c.r., do you need to mill the intake manifold and/or substitute shorter pushrods? DAW

I used the standard bumper mounting brackets for a '72, removed the bumper shock pistons from my '75 and then made a long "J" bolt from 3/8" threaded rod which hooked into a hole in the early bracket and ran back through the existing hole at the rear of the shock cylinder and pulled it snug with a 3/8" nut. Once everything is in place and lined up, spot weld where the early bracket goes into the shock cylinder. DAW

These look a bit rough but they're rare and probably worth more than the $38 they are at presently. DAW http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=1872796825&category=33550

Check out Flatlander Racing site for some good piston sources. See if they have Nissan pistons in the Silvolite "KB" line of economy-street performance pistons and check the Top-Line brand that's listed (price is good, check around re quality). Also, check out Sterling. I know they have an L28 cast piston that can be used with an L24 rod and L28 crank (improved rod/stroke but correct deck ht.) and it has a very shallow dish to keep street c.r. reasonable with an N42/N47 head. DAW

Don't mill anything off the head, especially since you're increasing displacement a bit. As it is now you may have to go back and replace the headgasket with a thicker one if you have detonation problems with your c.r. which will be something like 10.6:1 (I didn't crunch the numbers but that's close). You might need to run octane booster. Valves: you're on a budget so I wouldn't look to aftermarket valves. Your exhaust valves/springs are fine as is, you need to install L28 (N42/N47) intake valves/seats/springs. You don't want the Maxima cam in there so either use a performance cam or an L28 (from N47 or P79 Z/ZX head). Unless you've got a lot of time on your hands leave the exhaust port liners alone. You'll need to richen up the SUs and install lighter damper springs. A couple of steps colder on the plugs. Conservative on the timing until you've gotten all the lean spots out then try to bump it up a little at a time. DAW