1 fast z

Hey Z-GAD, May I ask, were these F54 blocks? And did you ever consider offset boring?

BTW, I run a 12-1 compression ratio on my 3.1 liter, and my car is driven EVERY day, sees, at least 7 grand EVERY day, and NO detonation. This is on 91 crappy Arizona gas might I add. So you can run that much compression if all varibles are set up correctly.

I know If I sold one of the 5 LD cranks I have lying around, it would be double or more than that price, so I say yea, go for it, as long as its not just a classified zcar.com one! Yes IM bitter about it!

Ill have to measure what my skirts are in my stroker motor, but I belive they are three thirty seconds of an inch. It takes ALOT of time to lighten pistons CORECTLY everywhere, leaving all of the critical dimensions. Im not gonna spill all of my secrets and dimensions on a online forum, but you can "look" if ya like. (2.75 lbs lighter than a stock flat top recipicating mass)

Oh yes, It is WELL worth it to have pistons lightened. Every amount of mass you take out of a piston, it makes the rod and crank that much stronger. F=MA, if the M is less then the force on the rod is less. It makes a motor run so smooth and rev soooo quickly also. Makes for QUICK spool as well. Yes I will never understand why people build motors and spend thousands on it and wont get maximum lightening out of there pistons.

Yea, the Stock 240 rod, has plenty of tensile strengh to withstand. Shipping on heads isnt that bad, you could do it all for like 90 bux, thats shipping both ways. Ok, I dont know how many times I have written about the Blocks but Ill do it again. The TRUE, FULL siameesed blocks are the N42 ones, NOT the F54 blocks. F54 has water passages BETWEEN all of the cylinders, which entitles NOT siameesed. The thickness between the N42 cylinders are the full thickness of the in between bore spacing in all cylinders except for between number three and four. I own a sonic tester and I have sonic tested all L series blocks, P30's, N42's, F54's V07's. So this isnt just some far out "claims" these our FACTS. Search my old post and you will see the actuall cylinder thicknesses I have posted in the past. So to sum it up, if your going for a BIG bore motor, USE a N42 block, and get one from a first two year 280 car, for the high nickel content.

Heres the info on the pistons from the other thread, BTW this was comparing against a stock DISHED pistons, as if I was comparing against a flat top stock piston, (P79) It comes out to 2.75 lbs total out of the recipicating mass! Ok, so I wasnt totally sattisfied by the amount of mass I had scavanged out of the 3.1 forged pistons, so I took them back to the bridgeport, and started some more work on them, there still not as light as they could be, but frankly I am just running out of time, and it takes ALOT of time to do these procedures correctly to 7 pistons. But yea got them all finished and balenced within a half a gram . Should finally be assembling this weekend! Ok, for the numbers, they are 320 grams, the pistons by them selves. Combining the pistons and pins I am right at about 150 grams lighter than a stock dished piston. thats what about 2.0 LBS out of the recipicating mass, WHOOOO HOOOOOO!!!.

180 a piston, WOW. Go get custom forged for a Third the cost of that, AND with ALL your custom dimensions, MUCH better way to go. BTW, ALL State side 240sx pistons are 89mm bore stock. A 3098cc motor is 83mm stroke and 89mm bore. USE a N42 block, as it is the TRUE siameesed block, and NOT the F54. BEST to sonic test and ACCOMIDATE for core shift, as This is the best way and the best insurence for cylinder thickness. REVERSE dome the pistons EXACTLY to that of the P90 chamber for maximum quench, and run a .020-.025" Piston to Head clearence and you can run MUCH more boost.

PUMP 91 octane, ~34 deg Full, P90 shaved .1", DIRECT flatop with .015 Neg Deck Height. NO detonation! Wait, can that be? Well, yes IF and Only if everything is setup correctly. STOCK dia valves BTW, PORT velocity.

The human Eye can see daylight in as little room as .0002", so You need to FEELER guage it, not "if you see light". .003" will work BTW.

All you do is put the ID beveled edge torawards the rear of the car, slip that end on first. THE BIG BEVELED EDGE.

No, not dynoed yet, NO time, like AT ALL, Been working CONSTANTLY 7 days a week

Actually cam right now, is VERY mild, iniatially. Only .480 lift, and 282 duration. I am inserting a .510, 296 cam very soon. Only draw back, is that I will have to go TPS based, instead of MAP based, as the vacume is REALLY low (I know its not vacume, but rather pressure difference so no flaming!)

So I finally got the motor dialed in, and MAN, I am real satisfied. Took it to the autocross event a couple weeks ago, and performed flawlessly. LOTS of torque and power. I have taken it to 7600 is the highest so far, everything is holding up nicley. I am going to peg the tach here one of these days once its REALLY dialed in, nothing like a straight six at 8 GRAND .

What harmonic are they designed for? I would guess either 4th or 5th. 7", well depends on the CFM flow of each port, etc, but that would be like a 4th at 8000 RPM, or somewhere around there? What is the minor or major diameter of the runners? (I could figure each out, as long as you give me one of the diameters.)

Actually No resistance, IE, wires shorted together or ground, will seem like anything above 160 deg F. Which is NORMAL driving mode.

About the same fith as the SX, Wait, I think the EXACT fith. But the Late ZX is .745-1

For everything, IE. Air Cleaners, Velocity stacks, etc. DIRECT MECHANICAL bolt on, is about 1600.00. Price does vary with Runner size, etc.

My system uses a Pot type 240sx TPS. My system also uses STOCK lingkage, so you can use your stock linkage bar, so NO modifying. ALL directy bolt on mechanicly anyways. This system has to be used with a MAP style based ECU, ie. Megasquirt, SDS, etc. TB's are 46mm, which will flow ALOT more than a DCOE 45, as there are no chokes

Or you guys could always buy one of my units

IMHO, 100 PSI is a bit much, ALOT of HP loss there, while driving that oil pump. Bearings may start to wash out, etc. THis is just my oppinion, and not to be taken as a hit upon you John. I ran 75 LBS on a motor once, then tore it back apart, and the bearings were REALLY washed out.

Your right, it doesnt have the brace half way down the cylinder, it has it ALL the way down the cylinder.

Nissan changed the block design for BETTER COOLING, and yes, I guess that goes hand in hand with expansion and contraction. But the main reason is they figured the turbo would add more heat, and the block would then be more endothermic, and therefore, they figured they needed more cooling. Ok, if it were me. If you were boring a block more than 1 mm over, for a turbo app, I would DEFFINITLY use a N42, if not, then yea, use the F54. But for overbore motors, I would use a N42.

" He was a student at UTI at the time" This tells me alot, THANKS for clearing that up. No offence to any UTI guys here if there are any, but I have met MANY of them, and OMG. They dont know much, thats for sure. Yea, I used to think the same when I first started in z's. I was building my turbo stroker motor, and I used the F54 block, cause Like you said, thats ALL I had read. Well, we sonic tested and offset bored, yada yada, and I could only go .050 over, to obtain 1/8" cylinder walls. So then I said, What the hey, and went out and grabbed one of the N42 blocks. So I sonic checked it just for the heck, of it, and I was like, WHAT!!!! Noooo, this cant be true, cause I have read on a dozen sites that the F54 is the SIAMEESED block, but sure enough, it ISNT. So I finished boring the last bore on the F54, just to complete the boring job. I then hot tanked the N42, then started boring that one .125" so I could still obtain .125" cylinder walls in the thinnest points. YES I have sonic tested a V07 block. They have .150" walls already. Which means you could do a 2mm overbore safley, but that would be about it, unless you took extra percations then you could maybe get a .120 overbore out of it.