Xnke

BRAAP, the lash pads are hardened, but not that hard. I have turned them in a lathe with carbide tooling, they cut beautifully. I'd imagine they were something like 4140 prehardened, or something.

Ok, that oil pump is a stock oil pump, with the bottom half of the housing replaced by a Nissan Motorsports Part Number 15015-GC002. The usage and installation of that part is detailed in Frank Honsowetz's "How To Modify your Nissan and Datsun OHC engine", Nissan Part Number 99996-M8012. (the book has a Nissan part number, too.) The oil pan and pickup look like Nissan Motorsports parts, as well. There are pictures of this setup in the book, as well. You'll note that the oil pump has an open AN-8 line on it...that goes directly to the external oil filter, then to an oil cooler, then gets routed back into the side of the block where the oil filter would thread on...you may want to double check that you have all the pieces there, since you have an oil filter screwed onto the block. This oil pump and pan combination will not work with the stock oil filter, you'll need an external filter, and either a adaptor plate or a thread adaptor to go from the block to the oil line fitting. All this is detailed in the book, too.

Zmanco, I just received the same .160" thickness pads, and they also came rusted up straight from NISMO. I think they just haven't been oiled, ever.

Looks like a Nissan external oil pickup. It's in the How to Modify book, I'll look it up and get you the Nissan PN for that part.

Best way to get it together is to build you MS, copy his program in, and swap units with him, to debug your system. Then build your harnesses modeled after his, and I'd go with EDIS as well, it's a great little system. This way, you know your MS will work, and you can swap out parts with the other guy if he's willing to help you get it all together. (swap out parts to check and make certain that everything works, I mean.) Best torque will be realized with a MS, turbo cam, and a T3/T4 hanging off the exhaust manifold, methinks.

check the throwout bearing sleeve. It seems like it's too short, something that is common with using a different clutch assembly 240Z clutch needs 240Z throwout sleeve, 280Z clutch needs 280Z throwout sleeve, KA24 240SX clutch needs a KA sleeve, ect. they are different lengths.

It is not that one block is particularly stronger than another, I think, but more that the blocks are designed for different applications, and have different design mechanisms in place. NOTE! This is pure speculation, based off the knowledge gleaned from this site and some personal experience. Has anyone weighed a bare N42 block vs a bare F54 block? I'll bet the F54 would be lighter. The N42 has thick, strong cylinder walls, and is designed around that. The additional bracing is not needed, with those thick walls. Pros would be less cylinder distortion, less prone to cracking, and more even distortion characteristics. Consequences would be slightly longer warmup time, different weight distribution in the block, or heavier block. The F54 has thinner, well-braced, stiff cylinder walls, and is designed around this. The thinner wall allows for faster warmup time, at the expense of more cylinder distortion, and less even cylinder distortion. I would venture a guess that due to the uneven thicknesses, cracking would be more common in this casting. Pros are faster warmup, lighter block possible due to more efficient block design, and more overall cooling capacity. Again, this is all conjecture, and I would use either block for any application short of a massive overbore, where I would grab an N42, just because that would be my personal preference.

The P90 is going to be what you want. The E31 will cost you much more to get to the same level of performance. First, you're gonna have to have the seats and guides replaced, that's 400$ at my favorite machine shop here. (250 for the valve job, plus the seats themselves, plus 120$ of new valves, plus guides.) Then, you'll have to spend for a porting, or port it yourself. (expect to spend another 300$ here, if you haven't ever ported a head before.) If you don't, well you might as well just not spend the money, the ports are going to flow even worse due to the big step in the port. Then, look at the P90. Shave 2mm, at my favorite shop is 55$, including hot tanking and straightening. 2mm custom shims were 32$ at the local fab shop, and the valves are still about 120$. As long as you don't need a valve job, that's all she wrote, you're done. check the valve seats, you might get away with a simple lap to seat in the new valves. Again, these prices are local to me, at my favorite shop. I trust these guys, they don't screw around. Look around in your town, check the yellow pages, go talk to the machinists. Find out who knows there stuff, and pay what they want, these guys are not in it to get rich usually. p.s. I'm gay!

Not the headbolts for the LD28, as they are 12mm instead of 10mm. You are probably thinking about the main bearing cap bolts, which do fit, and are stronger. Headbolts from the ZX turbo are a little stronger, but look identical to the original Z and ZX-non turbo headbolts. There are no distinguishing characteristics that could be seen with the eye.

Ever since my IAC motor died in my old ford clunker, I've had to left foot brake just to keep the engine going if it's under about 50F out. Never even though about using it as a driving technique, other than that! Learn something new every 10 minutes, I guess.

Brapp, i just ordered a bunch of lash pads from NISMO about 10 minutes ago, they said they had them in stock and would ship today. Not sure what the hold up was, they said they had lots of them. I ordered 160thou and 170thou, 12ea, and then 220 thou and 240 thou, 12 ea, for the three heads i'm working on now.

No, it won't tell you that. the piston is moving up and down in the cylinder too. The L series is an interference engine, so the valves, when open, will protrude below the cylinder head surface. The timing between the valves and the piston is what keeps them from hitting, if you increase the duration or lift, then you need to check for clearance, since you have changed the timing of the system.

Usually, valve reliefs will indicate that you have a higher lift camshaft. Measure the cam lobe across the highest part, and then again across the narrowest part, and subtract the two, then multiply by 1.48. This will give the valve lift. Stock valve lift for the A stamp cam is something close to .394".

Sounds like the L24 rods you have have been converted to a full-floating wrist pin. Just get the KA pistons machine for the lockring, and you'll be fine.

All the FS5W71( or © transmissions have a 5th/reverse shared shift fork. It doesn't seem to be an issue; at least I've never heard of one. Did break a R/5th shift fork one time, in my cousins's 240SX. pain in the butt!

I used 1X2" .083 wall tubing, it's twice as thick as the originals, and weighs less. It is still a big rigidity upgrade, but it's not as big, bulky, or heavy as the heavier 1x3 tubing that some use. I'd consider it more of a "stock replacement" weight, than a serious stiffining upgrade.

Not a problem, there is another motor that uses the same piston, they tell me, that is current production. Unfortunately, they won't tell me what motor it is.

No, I think a weaker ring land does make a difference. But in this case, the ring land is .4mm thicker on a turbo piston than a N/A piston. Wow. I am amazed that nissan re-tooled to cut those pistons for thinner rings, unless the move was made to thinner rings across the board, as well. Not trying to be sarcastic, just realistic. If a .4mm heaver ring land is all it takes to keep your pistons intact, maybe it would just be easier to drop 1psi of boost? In the end, still don't think the turbo pistons are any stronger than the N/A pistons. Just different enough to be hard to find. Anyway, if you still want the thicker ring lands, measure a set of Z22 or Z24 pistons, I *think* they have the thicker ring lands as well. Not 100% on that, though. Z22S stock diameter is 87mm, L28 crank and L24 rods put you at the stock deck height, and they have a 9.32CC dish in them. Still plenty of those pistons in stock from ITM last I checked, and they are what i am going to run as soon as I get my head reassembled.

To the OP: You do realize there is no special difference, other than thinner rings, (means thicker ring lands) between the 1975-78 pistons, and the Turbo pistons? Same diameter, same material, same pin height, same dish. The only difference is they were cut with narrower grooves for narrower rings, to allow for a slightly stronger ring land. regular N42-type pistons are not going to make much difference, so why not use them?

ITM. ITM pistons has them, but i don't know if they are hypereutectic or not.

Get gas. ask for C25, and use 0.030 wire. I have a similar welder, and it took me two years to get comfortable with it, and figure this out. I can weld anything from 26g sheet steel to 3/16" plate to full penetration without blowing holes. It took a lot of time, experimentation, and practice, but I finally got this little welder figured out.

Curt, what regrind are you getting? make sure you upgrade your springs if you are going over .450" of lift. (the .480"/280* grind cam is really only .450" lift, but the duration is correct and others have said it's a good street cam.) I have that regrind, but don't have the engine running yet. My head is still in the shop and then it'll be a bit before i have a running car still, as most of the bodywork is still yet to be done. I also have a similar 5 speed, but my OD is .830, and I have a 3.36 ratio R180. We'll see if i need to get a 3.7 or 3.9 ratio diff later on, as my 3.36 is in perfect condition with only 33K miles on it.

Still need a single throttle shaft. I know someone has a throttle shaft out there somewhere.

Not interested in the whole carb, just want the throttle shaft. Still looking.

Yep, ordered them on the phone. I just called them up and asked what the options were for the Nissan L28, 1975-1978. They were out of stock replacement valves, and only had the race-prepped 46mm valves in stock. He split the difference in price for me, and I ordered them over the phone. SI valves is a good company to get stuff from, in my book. Don't go with NISMO for the source, since they mark them up to a crazy number. SI sold them to me for 10$ each, about the same as stock replacements go everywhere else. The race-prepped valve is stock length, but has a larger head diameter and has been swirl polished. I cut the head down to 44.5mm and then since it was so thick, gently radiused the combustion chamber side of the valve, leaving a good margin. (if you go the same route, then you'll see that the valve margin goes from 1mm or so to 3mm or so...limit for replacement on an intake valve is .8mm..)