Xnke

Actually, The earlier heads *in theory* should flow better, as the P79 and P90 heads have a sharper short side radius. Whether it means anything in practice, you'd have to get BRAAP or 1FastZ to answer. Besides that, stock for stock, the Z heads are nearly equivalent in flow performance. Everyone wants a P90 because it has no exhaust liners, and the high quench chambers, AND the large valves. The head swap probably stems from the compression ratio change-the N47 with stock turbo pistons would put you about 8.4:1 compression, and the P90 will put you at 7.4:1 compression. Higher compression off boost means more response off boost, but lower compression means higher overall boost, given that all else is equal.

The high-flow pump is not scarce at all...look at the later ('84+) pickup truck engines. Most Z24 engines have it, and most RWD KA24 engines have it. My local parts stores all carry original Hitachi, for about 100$.

No, it's not the same thing. the dash from a '72 and up will fit, but IS NOT the same as a '71 dash, and can be either a series 1 dash, or a non-series one, '71 dash. THEN you have the non-series one '72+ dash.

Pete, I truly envy that engine bay. Hopefully mine will look similar some day... Anyhow, in getting my cylinder head ready to go back together, I am going to be using a set of New L-6 springs, that came with my last motor buy, and a cam with a .454 measured lift. I know and understand that this is not ideal, but I will be changing the springs later, with a different cam. (That different cam is not in existence yet, or I'd go for it, and skip the two-stage thing) Assuming that the springs are close, but not bound, what would the minimum acceptable clearance be, between coils? This would tell us for dead certain what the max cam lift could theoretically be, before the cam would physically no longer fit in the head.

Ok, the top tank is a 71-72 tank for sure. I have three. All are the same. The bottom tank looks like it could either be a 75-76 tank, or a 76-78 tank. Look inside and see if it is baffled, if it is, AND it fits in a '71, then it is a '75-'76 tank. The other tank WILL NOT fit without modifications, since the spare tire well is cut down in order to fit the larger tank. Other than that, the weird tank is the better bet, the small line on the back of the tank is the vapor line, the large line on the back of the tank is the vent to the filler neck, and the feed and return are as you point out.

Robert, the 4500 rpm thing is when the AFM maxes out and the ecu goes to a pre-programed fuel curve, not really a fixed duty cycle. as RPM goes up, fuel goes up, as RPM rise slows down, the fuel curve changes a little flatter, ect. I don't know how the '87 L24e ECU works, but the '75-'83 units work like that, from what i am able to read and search out on this site and others. The Z31 ecu's from '84 and up are different, and use a different method. Here in the states they stopped using the L-series in 1984, as far as I know, and the last L24E here was in the '84 Maxima. Your Milage May Vary, as you well know. If it still is a Bosch L-Jetronic injection computer, and is NOT similar to the Z31's VG30E computer, then I would bet on it being just like the '75-'83 units and swapping over to preset curve as soon as the AFM maxes out. IF you have a different system, like the Z31's and newer systems, that use a mass air flow sensor or manifold absolute pressure sensor, then all bets are off and I have no clue how the computer will react. By the way, the Early Z31 ecu's often get swapped over to the S130 cars by some simple tricks, such as replacing the CAS with the S130's optical dizzy, and swapping the AFM for the equivilent Z31 part. Probably some major rewiring as well, for what that's worth. If you have an optical dizzy, and something other than the Z-car/Maxima/Cressida/L-Jetronic style AFM, the chances are that I am totally wrong and the car will run great. It's hard to say for certain. But if it's the same as a Z car, and on all the L-series in the USDM to '84, it is, then going too big on the cam will crush any kind of power or performance goals.

Hopefully the cam won't screw up the fuel injection computer, but be warned. It's not the fueling requirements that the injectors can handle so much as the fueling calculations the ECU can handle. The ECU goes into a lookup-table mode above 4500 RPM, basically ignoring any input from the AFM. If your engine is pulling more air, then it will be going into lookup-table mode faster, and not getting enough fuel, since the computer is not even looking at how much air is really coming in. It just goes by a preset, non-changeable fuel curve. So you see, it's not as much an injector problem as it is a brain problem, the stock ECU is pretty dang primitive compared to the newer systems. Let us know how it works, there are some cams out there that can work well with the stock ECU, but the vast majority do not.

Having just finished the A-Pillar rust repair on my '72, I can say with a little experience that the repairs you will have to make in that area will drive you crazy. Mine was not nearly that serious, and I had to cut a large amount of the metal away to get at it. It's caused by the cowl area rusting through and leaking into the space behind it, combined with badly adhered weatherstripping in the door. If you don't fix the cowl, you won't fix this rust. Also, you'll ruin your interior and floor pans, eventually, since the space that the rust is invading provides a door seal, and the leaking portion of the cowl is also directly connected to the space where the top door hinge bolts up. It'll likely be rusty too, gonna be fun to fix. Lucky for me, my door hinge area was just light surface rust, the wire wheel and POR-15 did it. If you are farming out the rust repair job, make them take pictures of EVERYTHING when they work on that area. Tell them about the cowl rust issue, and make sure they fix it where it won't come back and can prove they did fix the cowl. I'd take an extra careful look at the cowl area along the firewall in both the engine bay and in the cabin to make sure it's not rusting out around there too, just in case.

the difference between the maxima caliper, the ZX caliper, and the SX caliper is the offset distance between the mounting face on the strut, and the mounting points on the caliper to properly position it on the car. The offset needed for an SX caliper on a ZX rotor on an S30 rear strut is 0.900" I don't know for the other calipers.

The stock nissan computer will not handle an aftermarket cam very well...spend the money on a new injection computer first, then cam away. Just a little heads up; otherwise your new larger cam *may* run like crap.

Looks like it has good compression, if just a tad uneven. I'd say get it running and you'd have a good strong motor for premium fuel, if the other numbers come up to the 200 range, if #6 falls to the 160-179 range, then mid-grade should do. Seems to have good rings and slightly sticky valves from not running for a while. I'd go ahead and change the oil, fix the fueling issue, and run it. If the valve sticking goes away, they were just sticky, if not, then you'll need to check the head out closer.

Floors are not the issue here, It's the front frame rails and the door jamb areas that are the problem. Couple that with the really ratty looking rust holes in the front frame area, plus all the other hidden rust that hasn't reared its ugly head yet, and I'd be just about afraid to take it on. But, it can be done, with enough time and effort. My car had WAYYY less rust than that and I'm still working on rust repair two years later.

Yes, not having the alignment dowels is a problem. You will want to fix that, methinks.

I'm with brian on this one wax, I'd take the whole of what you have, and drop it down a bit. It wouldn't be too hard to do, just seperate before the first bend, and angle the first straight section down about 10 degrees, for an inch and a half or so.this will rotate the turbo a smidge, but it should still be ok. it will help ALOT with heat. Even with the ceramic coating, you will still hit a heat problem real fast with this design. Besides, you aren't changing anything major, and a little prep is gonna be worth a lot less headache later. That said, you've got an awesome pile of snakes there. I wish I had the time to do one like that, i probably will after i get my car running. A simple head swap between the two N42 castings i have prepped and i'll be able to go from 9.7:1 to 8.3:1...Future-Proofing, they call it. Can't wait to see it all finished and cerama-chromed up! :mrgreen:

Well, Monzter is running the MN47 at 11:1, I'd PM him and get details, and I'd ship the head to BRAPP, or 1fastZ, either can do a really excellent job with them. Keep in mind that the MN47's are prone to cracking between the valve seats, and the E31 head is prone to serious erosion to the water passages. I'd get an E88 and weld it up, myself, but I have lots of cores to screw up. Do some more reading on the subject here, and you'll find more answers. I seem to recall that when properly set up and run, the oversize markings on the piston will 'ghost' imprint on the quench pad, not actually contacting the head, but so close that the burr from the stamping causes the ghosting. Don't quote me on that one though, it may have been a fluke.

Ok, to answer the 85mm bore thing, yes, it is a Nissan spec according to the Hanyes manuals. It's quoted in a table in the engine rebuild section as being the "Maximum Factory Recommended Overbore". I assume this means that you should be able to cut 2mm oversize bores in any L-series without an issue, as long as they aren't compromised in some other way, like being eaten by corrosion, or cracks. I was curious, so I sliced the three P30 blocks I have, one '72, one '73, and one '74. One cut lengthwise, and then cross cuts across the bores. Measurements of the cylinder walls (83mm bores) were made at four points, per cylinder. The 72 block averaged 4.2mm wall thickness, so a 2mm bore would make the walls approx. 3.2mm thick. The 73 block was the same. The 74 block had 5.3mm thick walls, which I knew already from sonic testing, but the testing also confirmed a suspected crack in cylinder 5. (so much for the 2.8L P30 turbo project...see below.) I didn't feel as bad about cutting it up as I did the functional 72 and 73 blocks... Anyway, If you're gonna do this, an 85mm bore should be just fine, but check for excessive corrosion and cracking or other general unsuitable traits. My recommendation for a 2.7L *P30* block Bang/Buck combo would be as follows: P30 Block at 85mm L28 crank L24 rods Z20S pistons MN47 head, unshrouded and chambers opened up ALOT to 44.5cc's OR P79/P90 cut down to 44.5CC's or so, this will give approx 10:1 compression. Unaltered MN47 would put you at 11:1 or so, possibly workable with EFI and GOOD tuning, I wouldn't try it myself. N42 will give 10:1 compression unaltered, but open chamber head, so detonation problems are likely. The reason for using the L24 rods and Z20S pistons is to get a flat top piston, because the 85mm pistons for the L18 and L20B are both dished, 4cc's and 11 cc's, approximately. A side effect is a better rod/stroke ratio, but really, I think it's neglegable at this level. If you really want to get crazy, try this 2.8L one: P30 Block at 85mm LD28 crank L28 rods Z20S pistons You'll be .59mm down in the bores, so quench is gone. Good enough for most turbo setups, I guess. MN47 produces a 10.5:1 compression ratio, P90 gives 8.3:1 compression. Looks like a good turbo setup, compression ratio wise, if you are stuck with a P30 Block and want L28 displacement.

PM sent, haven't had a cell phone in 4 months.

Somebody hasn't read most of the threads in this particular forum.... First, if you want to go turbo, stop at 3.0L. 3.1, 3.2, etc all have very thin cylinder walls, and will not last as long tubrocharged, if at all. Second, it has been said multiple times, the EARLY N42 block is more than likely going to be best for this application. The 1975-1976 blocks have a higher nickle content (rumored by SBF guys to make a stronger block, makes sense since high nickle makes for a more ductile metal) AND if what has been posted here by others with access to sonic testing equipment is true, has the thickest cylinder walls of the L28 blocks. All in all, Get YOUR Block sonic tested first. KNOW how thick your walls are. This is the only way to pick a block for an uber-build. The recipe for the higher-displacement blocks varies, my 2.9L engine has a 88mm bore, and a standard L28 crank. I use off the shelf pistons from ITM, and 9mm L24 rods with arp main studs and rod bolts. MY COST for this block was as follows: Block: 160$, included price of block, bore and hone, and sonic testing. After the bore, I ended up with 3.9mm-4.2mm thick cylinder walls, which I deemed adequete. Crank: 12$, came as part of the block. Magnafluxed. Pistons: 230$. ITM PN #RY6116, original app nissan LZ22S engine. came with rings and pins. Rods: 120$. 9mm L24, magnafluxed. Fasteners: ARP main studs were 151$. rod bolts were 59$. YOUR COST WILL BE HIGHER, prices on all of this have gone up, and i used cast pistons for my N/A build. Expect to spend double or more. ALL of this information easily could have been found by reading the last 60 or so pages of this forum.

Ok, so the 7000 differential seems to be an R180, the 9000 an R200, and the 10000 is apparently an R230. Search with the terms R200 LSD will pull up what you can get these differentials from. I hope this helps you find what you need to know.

I have saved my car from exactly the same damage, and it was not hard at all, as far as the work. tedious, time consuming, but not at all difficult. Unfortunately, it's been two years and I still haven't gotten around to re-doing the crappy work on the roll pan that the PO's bodyshop did, but I have fixed the front end. Basically, you're looking at a 250$ rear panel from MSA, new front and rear bumpers, and a good bodyman can fix those front fenders and the hood, although I'd go with a new hood too, If you are getting it all paid for... The bent-up front is how my car came, and the best way to fix that is with a BFH. If the bumper mounts are flexed down, bolt a bar to the mounting points and have a buddy lift the bar like a lever while you carefully apply the BFH. Use the weight of the hammer, not superman style swings of it. Also, I'd take this as an excuse to get an air dam for the front, because those lower valance parts are never gonna be the same. Although, if you need them, I have the two corner pieces, not perfect but certainly usable. I don't have the center part, however. That said, i'd still go with the airdam.

Miller makes about 80% of every hobart welder out there, according to my buddy who works for Miller. He actually prefers the hobarts, as they are often cheaper that the equivelent Miller machine!

we need to know if you have dished pistons or flat top pistons. Look at the pistons you have, and see if they have a flat top, or a dish cut in the top. All stock L28 pistons will interchange, but come in three flavors: N42 block: 10cc dish, standard thickness rings F54 block, N/A motor: flat top pistons, standard thickness rings F54 block, turbo motor: 10cc dish, 1mm thickness rings. (as per How To Modify...no turbo pistons here to measure ring thickness ATM...)

Yeah, the head bolt behing #6 has been a problem every single time i've pulled a head on an L6. It's always full of rust and crap, and takes forever to get out. Anyone know why?

Like i said in your paint thread, spot putty (the red stuff) is laquer based and will shrink and crack away when you put anything but laquer paint. You need a lightweight filler. Bondo would be better than spot putty, and if you are filling over metal and get it covered with a good primer, it will be fine.

Seriously, I would get the patch panel from tabco, and do it right. You're about to spend a LOAD of money and time on paint, and if you do it with fiberglass, you are really gonna regret having to do the paint twice. If I hadn't just welded my last passenger side dogleg on, I'd have just given it to you to keep you from ruining your paint in two years. Also, Dynaglass is not going to feather out well. You'll need to use a lightweight filler like Featherfill (I LOVE featherfill...) over it, and feather that out. It will work so much better...