Jump to content
HybridZ

1 fast z

Donating Members
  • Posts

    1159
  • Joined

  • Last visited

  • Days Won

    8

Posts posted by 1 fast z

  1. Then crower rods it is :) Is 175$ shipped a good price for an LD28 crank? and my other debate is pistons... I'll use the N42 block as 1 fast z has suggested...

     

     

     

    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!

  2. 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)

     

     

    pistonpics3.1stroker003.jpg

  3. 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.

  4. 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.

  5. 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!!!.

     

     

     

    pistonpics3.1stroker003.jpg

  6. 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.

  7. 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.)

  8. 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.

  9. 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.

  10. " 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.

  11. Ok, the F54 Block provides BETTER cooling than the N42. Which is stronger? Well the N42 is. SOLID between the bores, 1-2-3, 4-5-6. Whats more rigid, solid form or webbing? No brainer there. I HAVE sonic tested MANY L series blocks, as we own a sonic tester. I use N42 blocks for ALL my builds, that require an overbore. I run a HOT 3.1 liter N42 block with a stock radiator, and see NO overheating problems. The cylinder thickness on F54 blocks is already .150" in ALOT of spots on most cylinders. It doest take a rocket scientist to realize that on a .120" over bore, that is .090 Walls. Which isnt that bad really, as some sleeves are that thickness, but Woule you rather have .150" or .200"+ like is on the N42 blocks? The casting content on the 75-76 blocks are ALSO a high nickel content, which is always stronger, than a regular cast iron low nickel content block. Your buddy probably didnt do something right on his motor build, and did not sonic test for core shift on his motor. I also offset bore my blocks to compensate for the core shift. My last bored 3.504" bore I moved as much as .025" in some bores, some needed no shift with the boring bar. To obtain MAXIMUM thickness, a sonic tester IS needed, and offset boring is optimal.

  12. Ok, so I have been getting into disscussions with other engine builders about this. WIth say a big Block chevy, you want about 10 PSI PER 1000 RPM. Since the MAIN bearing is so large. But with a smaller bearing motor, such as the L28, It is not needed to have such a large Pressure of oil, right? The more oil pressure is not better, ie. Washes out bearings, takes HP to drive the pump, etc. So what is the LOWEST Solid Oil Pressure that can be ran, say at 7,000 RPM? I belive that 45-50 is PLENTY, and 45 would be fine, as I have run my L28's at this and had no problems. Just wanted to see what some of you guys thought about this.

×
×
  • Create New...