1 fast z

Well yea tony. You remember what happend at 7200 at the last hard corner of the MSA autocross event last year in ole silver! Yea, stock pan is no good for hard driving. I now use a baffled oil system.

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.

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.

picture?

Ok, some pics, Ill get some of it in the car soon. Yea so last night we got the stroker dropped in and running, and finished doing the sx tranny swap (VERY NICE BTW) today. Well we got it out on the road tonight, and WOW!!!! Yea, I see a 12 sec pass coming along this weekend, hehe. Yea so we got it on the street, and had to run a bit less timing, (32 total) and fatten it up a bit. It needed ALOT more fuel then with the old motor. Like 30% more!! Yea, 11.8-1 compression is NICE!! I cant wait till friday night when we go to the strip, and put CAM 2 in the car, with 36 total timing, HAHAHHAHA. Yea, so first gear is SICK. I mean from 2 thou to 7 thou in like 2 seconds, no exaduration. It gets to 120 REALLY fast compared to before. The motor is SOOO smooth. ALOT louder than before (hard to hear the girl friend talking, haha.) But yea, the torque is TREMENDOUS. I love how when the tires arent hot, and you punch it in first, it just rips them off all the way through first, then you slam second, and it tears them up about 3/4 of the way through.

What do you wanna know? Bore=86mm. Compression distance= 38.1mm. Pin DIA=21mm, with a press fit in the rod, and floating in the piston. Top ring is 1.5mm and the second is 2mm wide. I cant remember off of the top of my head what the readial thickness is though.

Sure, I get some footage of it. Sorry if I seem like an A$$ its just that everyone always ask that question "how much HP" BLAH. Its Ok though, I know your not an idiot by your post that you make, you know your stuff. Yea, I could probably scavenge another 10 grams if I REALLY REALLY tried. Under the pin boss is sitll about .400 thick but I would need to plunge through the wrist pin hole, with a carbide drill, and If I had more time I would, but I need to get this motor together.

7 for one extra, and that extra was used for mockup, and first artical machining.

Its amazing how everyone reffers to EVERYTHING to "how much HP can this or that take" Its not a matter of HP!!!!! Its a matter of FORCES!!!! Lighter pistons do MANY things, but I will touch on the main points. FIRST and MOST important is that it makes the ENGINE stronger and last longer. The lighter the mass on the end of that rod, the stronger the rod, block, crank, etc. are going to be, for the reason that you do NOT have to stop and accelerate so much mass. Kinda see what Im saying, say you take a rock on the end of a string, that has a mass of 10kg, and you swing it in a circular motion, to create a certain centripital force. Then you take a mass thats 7kg, with keeping all other varibles constant, and swing it in the same motion and direction, and speed, the centripital (NOT centrifigul) force will be reduced ALOT, wich in turn makes the string stronger. Sorta see what Im saying? It also raises the red-line of the engine, makes it rev faster, etc. These pistons are not PAPER thin, like they may look, they still retain all the critical thicknesses.

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!!!.

Well, Time doesnt make a difference. I know LOTS of 30 year experience machinest, and they dont know carbide from high speed. Im just saying, if YOUR machinest breaks 4 TAPS in a block, something isnt right. But what the hay, what do I know, Ive only been a machinest for about 12 years, and Im only 21. Wait, can that be?????

Ok, Ill let out a bit more information. To get the MAXIMUM quench say on a turbo motor using a P90 head this is what you do. Make the Piston to Head clearence about .025". Then, put in one piston at a time, as an assembley on the crank, rod, etc. Then put "prussion blue" on the head, around the CC. Then put the head on with NO head gasket, then bolt it down. Then take and "bump" the piston and let it hit the deck of the head. This will then give an EXACT map of where you want to make your dish. You DONT wanna go outside of your "map" though, although, you can stay inside it, as much as needed. Another trick is to use a solid copper head gasket, with stainless orings in the block, and make the gasket an EXACT continuation of the bore, this will also yeild the HIGHEST quench.

" I had my machinist tap the crank and he broke 4 taps in it. Hard steel..." Your machinest didnt have the slightest clue what he was doing obviosly. The crans are not hard on the counter weights. I just tapped on last week, with zero problems.

Actually, I run about 22 though of piston to head clearence on my motors, but I just didnt wanna say that, so then every jo blow, goes out and does that to their motor, without taking the correct percautions, ya know. Yes, if you have a high quench head, and you have say .060" piston to deck clearence, and then you take that same motor, and make it .025" you will see NOTICABLE HP increase, as well, you will be less prone to detonation. I am not just making up stuff I have "read" somewhere, I have actually tested these therorys. Again, This is just what I have learned, you dont have to use one bit of my advice, im just trying to shed some light.

"So if .5 will loose "nearly ALL quench" how do low compression motors not detonate themselves to death? I'm not knocking you down, I just want to understand your philosophies on the subject." IT's called REVERSE DOME. You map out exactly what the combustion chamber looks like, and you dish ONLY in that area, this way you can still acheive MAXIMUM quench. Ask and TOP engine builder, and they will verrify my statement.

"Now, has anyone considered a high profile head gasket to bring the compression down .5 or so? That seems like a great idea for people running a MN47 on lower octanes." Ok, you are loosing nearly ALL quench by doing this, if you read what I stated above, I say that you need about .030" to get MAXIMUM quench effect. Doing what you say will decrease compression, but will also decrease quench, and more than likely you will have the SAME amount of detonation, for the reason that you lost all of your quench.

"As an aside, where the heck did this “P-47†crap come from? The last time I checked, the head was cast with an “N47â€, no “P†anywhere. Though I can see where someone who hasn’t really studied the head from a design standpoint might call the MN47 a “P†series due to the fact that the chamber does resemble the P-79 and P-90 chambers in generic outline shape only. If you look closely, the P series heads and the Maxima N-47 chambers are not shaped the same. Plug bosses are different, chamber wall shape, etc. I personally feel that the “P†designation on the P-79 and P-90 heads references the entire design as a whole, not only with the newly designed chamber, but also the shorter valves and revised ports with their sharper short side radius etc. The Maxima N-47 has the standard valve length and port shapes, etc. of the Z car N-47. From several aspects in the heads design, the Maxima N-47 resembles the early heads “way more†than it does the newer P-series. Sorry guys, but it is cast “N47†and being as it does resemble the “N†series MUCH more than the “P†series, it only makes since to call it what it is, the Maxima N-47 or MN47 for short. Or you could just keep on calling it a P47 and the rest of us will just chuckle at you every time we see the “P47â€, LOL" I am soooo cracking up right now over all of this, hahahahaaha. YOU LOST MACK. (mack and I have argued over this for a year, lol.)

YES COMPRESSION IS A DIRECT REALTIONSHIP UPON POWER IN TORQUE!!!! Dang what has this come to. NO you cannot compare two DIFFERENT motors, and say, "well, his motor is the same as mine, except for the compression, there are MANY different factors to be played. The compression basicly just shifts up both curves. How are we missleading people???? I am saying that my setup with MS, just like MACKS would be if he were running it works GREAT. I never dynoed my car, but I ran 13.9, at 101, with a weight of 2950lbs, not bad if you ask me.

Your car ran 15.5 at 108? HMMMMMMMM, those numbers dont jive at ALL. For the reason that 108 is easily in the 12's, and 15.5, is around 85 MPH or so, give or take. You have some problems there. And let me say this again, I run 11.3 ON my Megasquirted DAILY driver, and I dont mean pussy footing around, anyone who knows me (lots of people on the board) KNOWS that I drive VERY hard, 7k, DAILY, and NO detonation. You can take a N42 head, or any other open chamber head, and you take a closed chamber head such as the MN47, you can run about .5-.6-1 more compression, with the same amount of timing. Once again, QUENCH!!!

I know that my customers use DCOE's with the MN47 setup, and run on pump gas, with NO ping. LIke I said, it doesnt make one bit of difference to me which head you guys use, I am just shedding some light.

What the hell is a P47??? No one knows what the heck that is, so stop, freakin saying it!!! LOL. Everyone knows, its MN47!

Yea, you cant tell ANYTHING from a narrow band, so you could be at 14-1, or 10-1, who knows. WIDE band, is the only way to make sure what the ratio is. A E31 does NOT have as high of quench as a MN47 head though, so your loosing some there. I went from a 9.8-1 Flat top, and ZN47 head, and had ping, then kept everything else constant, then went to a 11-1 HIGH quench setup, and got rid of the ping. QUENCH, ill say it again, QUENCH is the key here. Again, this is just my opinion, no one has to follow, doesnt matter to me, Im just tying to shed some of my experience and light on the issue.

On my setup, I run Megasquirt, so yes, I do have some more tuning advatages over others. I run 36 Full at 2000 RPM with my setup as well. NO ping, and I have pulled apart the motor, before, to verify this, no broken rings, ring lands, bearings perfect, etc. If you just tune the car to run a little "fat" then it will work perfectly. Now if you run 11+to one on a open chamber head, such as the N42, N47, NON-early E88, etc. You WILL see ping with that much compression. QUENCH is the key here. The next key is that you need to run no more than .030" piston to head clearence, to obtain this quench therory. When that piston comes up there, and smashes all that charge and pushes it torawads that spark plug, and attomizes that charge well, you will DEFFINITLY reduce detonation. With an ALLUMINUM head, such as L series, the heat gets dissapated alot quicker than with that of an IRON head, and you can generally run a point more compression with an alluminum head for that reason, and people run 10.5-1 ALL day on Iron heads. Another easy way, is to just run more duration on your cam, that will help BIG time on detonation. I run a 270-280 adv cam on my setup.