Xnke

You can swap the points breaker and dizzy cap to make a four into a six, although you may have to swap out the whole shaft. I Have done this once to make a four cylinder dizzy for a buddy of mine out of a spare L6 distributor that I had; his had the casing broken, but the shaft intact, so we swapped everything over to make it an L4 distributor. I'm not sure of any other reason to do that, other than maybe the one you have is rebuilt and they just grabbed the wrong casing?

Where are these Open R200 4-pinion diffs coming from?

Can we get some photos of these pistons? Also, if you can measure the diameter and depth of the dish, you can compute the volume, roughly, or you can measure it by packing it with clay and scraping the top flat, then measuring the volume of the clay. I've heard of these pistons; but I've never seen them.

Try again; stock N42 head chamber size is 44.6cc, as is the open chamber E88. On a stock L26 flat-top block, that would put you at 9.4:1 compression, so it's not surprising that you're pinging. I'm running a 42cc chamber, 10cc dish pistons, and 88mm bores in an L28 and am sitting about 9:1 CR. Due to the cam I'm running, my cranking pressures for a compression check are only 100PSI. Exactly 100PSI on every cylinder, but still, much lower than you'd think for a 9:1 compression motor. Compression tests will give you an idea of pressure, and will tell you if you've got an inconsistant cylinder; but they won't tell you your compression ratio. What grade of fuel are you running?

You are going to end up spending the money anyway, to unshroud a head. (BTW, you're UNshrouding a cylinder head...) If you are going to put in the money and time to do headwork, do it correctly or spend more money to fix it later. It took me three cylinder heads before I was able to make few enough imperfections to call it good. I have one other that is "usable" and one that is "garbage/practice/let's chop it up and take a peek inside" Headwork, even repair work, takes time and practice to get it correct, and if you take shortcuts you can end up with WORSE performance than if you had left it alone! If you take some time to search the forums and read the stickies that BRAAP has posted here, you'll find he's given out some AWESOME information on head porting for the L6, with photos and everything. He's a professional, and it's rare that you'll get that kind of information for free. But If it was me... I'd take the N42 head, weld it up, and port/unshroud it to be exactly what I wanted it to be. Failing that, I'd go get a P90 and work it over to be what I wanted. If you can't weld it up, then be very careful how much you increase the chamber size, and be even carefuller how much damage you do to the gasket sealing surface, you don't want to mill too much off, with the flat-top pistons in that block. Compression ratio is getting to be a problem, with a 1mm headgasket, you'll get about 10-10.5:1 on a flattop block with an N42 head, with a 2mm you'll see about 9:1 compression....pretty high for an L28ET. If you are running a P90 and a 2mm headgasket, you might as well not bother running a P90, you're giving up a lot of the advantage there. You've got a flat top engine, so I'd run the stock thickness headgasket, flattop pistons, and a ported P90 head to go turbo. ESPECIALLY if it's a megasquirted street car, and you are planning on moderate (15lbs or so) boost. Now, there are other schools of thought out there, and you'll probably hear from them as well, but that's how I'd do it. (currently have a N42/N42 engine, dished pistons and a ported/unshrouded/chamber resized N42 head in my car, at 9.5:1 compression N/A, going turbo in the future. I'll have to get a 2mm headgasket, which on my engine will drop CR to 8.5:1, highish, but turbo-friendly, for the L28ET.)

Yes, it is mounted on the back of the lock cylinder with two screws. look at where the wiring harness plugs into the ignition, and you'll find two screws. Unscrew them, DON'T LOSE THEM, because they're tiny. you will now be holding the ignition switch, sans lock cylinder, and you will only need a screwdriver to start the car. This is the portion that you'd replace, if it was bad. As far as testing, I just kept swapping it with other switches that I had on hand; I had about a dozen that came in my Z. When i found one that worked the best, i put that one in and was done. Not much help on how to test it, but it's pretty easy to get in and out.

Check the ignition switch. I have two that the stops in them are worn or bent, and you can turn the key far enough to engage, and then disengage the starting position. Same symptoms, click-on as the solenoid almost has enough time to close, then click-off because you never let it hit the starting switch contacts long enough. It's a long shot, but it's not a hard fix.

Wow, you've got a LOT of learning to do before you even start this. Spend some time and money getting the How To Modify Your Datsun/Nissan OHC engine book, Nissan Part Number 99996-M8012, and the How to Rebuild Your Datsun/Nissan OHC engine book, the part number which escapes me. Read both of these books through three or four times, take notes, and study before you start spending any more money on parts. It'll save you time, money, and junked parts in the end. First, the L-series connecting rods and cranks (ALL OF THEM) are factory forged. Second, you can buy an 85mm stroke crank from Kameari for about five grand. This is the biggest commercially available crank for the L series six-cylinder. Another manufacturer that makes/had made custom cranks for the L-gata is Moldex. The L31 and L32 stroker motors are popular because they are simple to assemble, parts wise. You use the LD28 crank, L24 rods, and KA24 pistons, in various combinations, to get the compression ratios and bore sizes where you want them to be. Third, if it fits in the block, it fits in the block. If it doesn't fit, then clearance the block. If you can't/won't clearance the block, it doesn't fit. Fourth. A .495" lift cam is not nearly as hot as you seem to think from your post; there are cams out there with .600" and higher lift, and valvetrain components to match. The important number is the duration. Valve lift is all fine and dandy, but the duration is just as important, if not more. There are people on this board that run cams in the .495"-.530" lift in daily drivers, if i'm not mistaken, or cars that are driven daily.

Apex is exactly right; on the residual pressure valve being incorperated into the master cylinder on the 70-78 z's. You need a ZX master.

The "pressure regulating valve" is the brake proportioning valve, and you should either upgrade it to an adjustable unit, or leave it alone. What brakes are you running on the rear now? What brakes are you running on the front now? What brakes are you upgrading to on the front? Have you driven the car with the new rear brakes on, stock front brakes on, and stock proportioning valve? If you are running the 240SX rear calipers, 300ZX rear rotors, and the stock S30 front calipers, and stock S30 front rotors, then you should be about the same front/back ratio and should not need to change the proportioning valve. BUT you should be using the ZX 15/16" master cylinder, not just because it pushes more volume, but because the stock master is valved for front disk/rear drum brakes, and the ZX master is valved for front and rear disks. The different brake systems need different valve characteristics! IF these are the 240SX rear calipers, I would run the stock S30 calipers for a street car, and not go any bigger than the S12+8 calipers. I still haven't gotten to drive my car, though, so take my caliper reccomendations with a grain of salt. I've just been absorbing this from reading the brake FAQ, the brake Stickies, and reading posts from those who are running these brake setups both on the track, and on the street.

If the L26 has a good head, swap heads! Easy solution right there. But if you're satisfied with the L26, then no worries. As long as it drives good, right?

hahaha, I came home one time and walked out to the shop to find a girl I know sitting in the passenger seat of my Z, wearing my welding helmet/chaps/vest/gloves and holding one of my short handled forging hammers. It's amazing how fast that pile of gear turns into a great halloween costume when you're not expecting it. Got a great laugh out of that one, she did. I didn't even notice her sitting there till i sat down in the driver's seat and started working on the wiring...looked up and saw her turn her head to look at me and jumped like i'd been bit by a sparkplug wire!

as far as i know, they are not graded. He probably means what oversize do you want: i.e. stock, 20 thousanths over, or 40 thousanths over.

Looks like an aftermarket regrind, because of the writing/engraving on the back of the cam; although that stamp might possibly be some kanjii? Cool anyway; can you measure the base circle and lobe lift?

Not so; it could have a neutral safety switch. he'll need to get up under it and look, it will be a switch near the shifter on the passenger side of the transmission. Or, check under the passenger seat for the relay that resides there; sometimes it can cause a problem too.

Basically, it's a 555 timer driving a TIP31C, with a current limiting resistor, running from an old PC power supply's 12V rail. I'll get a schematic up this evening, when I get a chance to draw it up.

I use a pulser I built, and hit them at 10Hz pulses to flush them. After doing the first 16 of them by hand by slamming them with 12V, I got tired of hitting the button, so built the pulser. These are high-impedance injectors I'm working with, so the 12V is fine on them. From the photo above, I'm pretty sure no one cares what kind of gas they run in there '94 galant...all four sets of injectors I pulled from the galants were from '94 models, and all four sets were just as gross. Nasty stuff.

No, these are going into a somewhat built L29, and no, i'm going to be using megasquirt. They are 10cc's bigger than stock injectors, and have faster opening times, so you'll be running rich with these on a stock L28ET with the stock ECU. But they are High impedance injectors, so make sure you've got the correct ECU setup; these injectors do not use dropping resistors.

Ok, so those of you (like myself) who pull fuel injectors from the junkyard to do your barbed-to-O-ring conversions, get them cleaned! This is the junk that came out of 6 Mitsu 4G64 injectors, type INP-065 275cc/min. Really easy to pull from Mitsubishi Galants, two bolts and they're 11mm o-ring types. 5-6$ each at Pull-a-Part type places, usually. That's lacquer thinner, BTW, and was crystal clear when i started cleaning. The injectors were scrubbed down on the exterior PRIOR to being flushed and backflushed into this bucket. That's two passes forward and backward, from 6 injectors! That's a LOT OF CRUD! After flushing, I replaced all the o-rings and the filter screens, and now they're ready to use. Sure, not as good as if i sent them out to be cleaned, but certainly good enough to run, they all seem to flow within a few percent, as timed by my stopwatch and a graduated cylinder.

Jacob80, My compression on a newly built, but not run-in motor was 90PSI. After letting it run for 20min at 2000RPM to break in the new cam, as directed by my cam grinder, compression jumped to 149PSI. I'm still not fully broken in, but it is an impressive difference between freshly built and 20 minutes of run-in.

Hehe, I have, I've worked on many a british leyland and jaguar... godawful wiring...

I found a retailer who carries this. It is for british cars, but they have wiring harness problems like the early Z cars, so I figure it ought to work just fine. I truly do think that the same company manufactured the Z harnesses...

Nick, they all have double valve springs stock; and there are quite a few spring compressors for OHC engines out there. Do you have the How To Rebuilt Your Datsun/Nissan OHC Engine, by Tom Monroe? It's a great reference and has all the part numbers, diagrams, and information that the other books leave out.

620 pickup trailing arms are the same, just heavier and stronger. Try over at Ratsun, they have a lot more 510 and 620 owners.

Might think about the design of this intake as well, it's much more compact and probably has about the same performace, at the power levels in question.