JMortensen

EXACTLY. This is why I said that I thought it was such a huge improvement over the type I. HELP! PLEASE! ANYONE ELSE WHO UNDERSTANDS! Drax? Someone! I'm going to try again. Torsen--Look at the yellow picture that Drax provided before while you go through my expalanation: The invex gears slide on their axles. When the helical side gears turn on the invex gears, they slide until they hit the case. There is your "side gear face to differential housing". The side gear continues drive the invex gears, but now there is added friction. This is the "Side gear to element gear Invex gear meshes." Remember the bushing that Drax mentioned that sits between the side gears? That's there because the pressure of the invex gears pushing against the side of the case makes the side gears inside want to move the opposite direction, together. This is the "Side gear face to side gear face." In order to get a 1.5 way action on the diff, they've put needle bearings (which Drax also mentioned) on the outsides of the side gears, so that it won't make as much friction on decel. And that is the "Side gear face to differential housing." The Truetrac is pretty self explanatory but if you don't get that one, read the pdf I linked to again.

Dan--READ the links. They tell you EXACTLY what factors need to be in place to have quench. You DON'T have it. OK Dan, this is all I can do to actively prove my point to you. This is my last shot at delivering you from what I can only describe as beligerent ignorance. My current build: Stock 2.8 bottom end with flat tops no overbore (notched the block, removed the casting, balanced, but that's it) 12 lb flywheel euro damper E31 head, ported and polished by me, 280 valves 490/280 cam 44 mikunis on Cannon manifold MSD running through ZX dizzy The closest I've come to a dyno was a G-Tech test, because I've never had money lying around that I didn't want to use to buy something to make the car faster. The clutch was slipping BAD, as I was still running the stock clutch at the time. I had a buddy in the car, so the weight of the car was 2660 lbs. ET 15.5. Trap speed 108. According to this calculator: http://www.speedworldmotorplex.com/calc.htm I'm putting down 266 hp, 11 MORE horsies than you!!! Now most people say that the Gtech is a little high on its trap speed, couple mph anyway. Lets drop it down to 104. Now I'm putting out 234 at the wheel. Since you have a 10% displacement advantage if you knock your number down it would be 229.5. So I'm STILL putting out more than you per liter. I'm not saying that I totally believe these numbers. If I were to estimate my rwhp I'd say 225. But I've got a total of about $1700 in my motor. How much do you have Dan??? If you want to tell everyone how to build an $8K (guessing) motor that puts out 82hp/liter fine. I'm not telling them not to. I'm just saying that there might be a small advantage in the quenchy head. There might also be a small advantage in the rod ratio. I'm sure I have a small advantage in the way that I notched the block to match the unshrouded head, and the way I blended the seats into the chamber. If I told someone such as yourself about the number of hours I spent doing those things (it was over 40 easy), you'd probably have told me it was a total waste of time. But IMO it is not. Every little bit counts. The only track proof I have is I know that I was within 2 seconds of Mike Eckhaus's best time at Buttonwillow when my motor was in a really bad state of tune and it was 105* on the day I was there, and he's supposed to have crazy hp. More than you. I think you let that one dyno sheet and all the compliments you got from it go to your head. Your motor is impressive. Don't get me wrong. But since you've built it you've become the self appointed authority on rod ratio and quench, NEITHER OF WHICH YOU'VE USED. I didn't want to use my "evidence" because I know it is half-assed. But my 1/2 assed evidence shows that there just might be another way to build an L series engine. EDIT--FORGOT TO MENTION, GTECH AND TRACK RESULTS WERE WITH MY PREVIOUS LOWER COMPRESSION ENGINE. WENT FROM 8.5:1 TO 11:1, I HAVE YET TO GET ANY PROOF OF THE INCREASE IN POWER I CAN FEEL ON THE BUTT DYNO.

I am definitely not an engineer, but I read the info from Tractech and Torsen below and I have good comprehension skills. I just don't think I'm wrong on this one. Especially since the manufacturers themselves seem to agree with me. Or am I missing something? From Trachtech: From Torsen:

Well I'd ditch the flowmaster and get a better flowing muffler like a Super Turbo or even better an UltraFlow. Mandrel bent? I've got a friend with press bent 2 1/4" and I swear it probably flows like mandrel 1 3/4" from the looks of it. I suppose it depends on who does it, but mandrel makes a big difference regardless.

I was trying to figure out your compression ratio, and looking at the How to Modify book. Be CAREFUL when you try to figure this out. It looks like your pistons from the Big Bore kit should have a positive deck height of .025 (the book suggests machining the pistons), where most 3.1 builds have the KA pistons -.37 mm below the deck (from Lengine program). That's a big difference. I suppose that Nissan could have eventually changed the pistons in the kit, but I was surprised when I saw that in the book and I've never heard anyone else mention a positive deck height with the pistons. Did Sunbelt give you a build sheet? You'll need to know how big the chambers are post shave too. I would think you should be able to get more out of it too, I'm wondering how much carbs and possibly exhaust are restricting you. You pretty much have everything else covered by the looks of it. EDIT--You've seen this right? http://hybridz.org/nuke/index.php?name=PNphpBB2&file=viewtopic&t=34844

Was looking at How to Modify and I noticed a couple things: The FIA L series heads have a big quench area and a heart shaped chamber. Stupid Nissan. How could they let themselves get sucked into this decades old quench "fad". You'd think they'd know that quench doesn't matter on the L series; everyone knows that's just for V8's. Also, Devendorf's IMSA GTU L28 used, get this, 140mm rods. Looks like he used 133mm rods in his GTO turbo car. Looks like he was going for that bogus rod ratio of 1.8. What a dumbass. Too bad Dan wasn't there to keep him from falling into that whole rod ratio trap. Too bad I can't back up my points with any "proof".

Not really, because for those of us running stock valves we'll still need to get the N heads for the longer valves. We'll just take the valves out and throw the head away...

Dan, that is what I call "pseudo-insulting." You and I have argued before and I have admitted when I was wrong. It wasn't that long ago either. I think we've argued points on this board or the IZCC list several times over the past 5 years or so. I don't know if all of them had an "outcome" or a "winner", but you should know by now that I WILL admit when I'm wrong, even if it takes beating me over the head with logic a couple hundred times to get me there. In this case though, I think it is you who doesn't have a leg to stand on. John's engine has it. Norm's apparently has it (if what Bastaad says is true). Yours does not. If you would bother to read what the experts say about quench before deciding that you can't have an opinion about it you would have known that your engine couldn't possibly have it. If I recall your build correctly with pistons just below deck height and a 2mm gasket, your engine DOES NOT have quench. You'd need a P90 with a gasket short enough to get the piston within about .040 to get the most quench in an L engine with flat tops. The N42 does have a very small bit around the edge of the chamber. You may say that this proves your point that it is not necessary, but I would say that I suspect you're missing out, and only have the hundred experts who may or may not have built an L engine to back me up. The problem here as John said is that once you start modding the heads, then it all becomes a moot point, so I guess further arguing about it is pointless. If you are not an astronaut believing only what you see makes you a good candidate for a Flat Earth Society membership.

You're going to need a rubber line between the engine and the fender. If you put a solid line between these two every time the engine rocks back and forth it is going to bend your steel line until it eventually breaks. You could use ss braided line. Also, maybe I just haven't been exposed to enough brake lines, but the stuff I'm familiar with is way too small for fuel line.

I'm sure the valve guide hole could be machined larger and offset to the side, then a regular centered valve guide with a larger OD and same ID could be installed to get the valves farther apart. Then you'd just need one hell of a port job.

When they had those in Simi Valley and Moorpark CA years back that's what my friend with dual Mikunis on his 510 did. He didn't shut it off, but he would put it in neutral and idle past. He'd just blast up the onramp then roll on by. He never got pulled over and they used to set the trailer up on the onramp he used to go home from work, so it worked for him more than once.

Yep, I sure do. I AM arguing that the P heads are better. I dunno. Swap modded P heads (and pistons on John's) on all those motors and see what happens. I'm not about to try and duplicate all the work in those engines to prove a point to you. Evidence: http://www.federal-mogul.com/cda/content/front/0,2194,2442_897063_6800,00.html http://www.theoldone.com/archive/quench-area.htm http://www.speedomotive.com/Building%20Tips.htm http://www.chevyhiperformance.com/howto/47075/ http://www.beckracing.com/page05.htm http://www.chevyhiperformance.com/techarticles/94138/ http://www.popularhotrodding.com/tech/0311_phr_power_squeeze/ http://www.atvrideronline.com/quads/100_0308_racer/ http://www.westechperformance.com/pages/Tech_Library/Understanding/hpvstq.html http://www.moparmusclemagazine.com/techarticles/5115/ http://www.corollaperformance.com/TechInfo/1ZZFE.html http://www.se-r.net/about/200sx/scc/feb98/february.html I CAN KEEP GOING. I CAN DO PAGES AND PAGES OF THIS. You've got imports, domestics, even ATV's in that list. Everyone seems to think that quench is an extremely beneficial thing, except you Dan. And you won't say that it is NOT beneficial, just that you need proof that it is, and of course the above experts' clear explanations of why quench is important and beneficial don't qualify under your "show me Norm's motor or my motor or John's motor with a P head making more power". You can choose to require a form of proof that will not exist until you 3 put P90's on your engines (so basically it will never exist). I'll choose to side with all the experts, realizing that I'm not an expert myself and also realizing that you specifically state that you aren't an expert either. EDIT--Found a better quote:

Total agreement here too. Wow. Agreement...

This was my experience in bolting an E31 onto an L28 with flat tops too. I am beginning to think that our pinging problems have more to do with CA's crap gas then anything else. I mean my chambers are polished and I still had severe pinging unless I ran drastically retarded timing which is a good way to warp exhaust valves and lose buttloads of hp. I found that I needed to mix gas to get about 95 octane to stop the pinging in my case. If Nissan had it "figured out" then why did they bother with the P79? They could have just left it alone and let the N42 go for another 4 years. How come L4 guys all covet the small chamber heads (similar to P90)? I agree with John when he talks about HIS N42. Like when we were arguing this last time and you said that you had your pistons machined to provide quench on your N42. That makes sense to me. But for the average guy who wants to slap a head on a block with flat tops, run pump gas, and get the best result, I don't think you can beat the P90 shaved .080. Dan's argument turns against him here. You're trying to convince us that the '76 head is better than an '81 head. '76 was right in the heart of the crappiest smog years in history, and that's when the N42 came about. Not that '81 was much better, but the '81 certainly looks a hell of a lot more like the '70. I am going to adopt Dan's approach on the closed chamber heads though because I like the way it puts the onus on someone else to do something: show me an open chamber L engine that makes the SAME power with flat tops and the same compression ratio as a closed chamber, high quench and I'll be convinced. Until that happens I'll keep with the engine builders and promote what is commonly considered the preferable design: the closed chamber high quench area head.

Your header isn't going to cause your car to run like crap after a couple days. It's either going to run strong or run like crap right away. You might want to double check the manifold bolts and nuts just to make sure they are tight though... Could be anything, but not the header. Check the usual driveability stuff, clogged filters, ignition problems, etc. Maybe you knocked a connection loose (coil wire?) while you were installing the header. The Z SU's are easy to tune and easy to maintain. Check out http://www.ztherapy.com if you aren't familiar with them. Buy the video from ZTherapy if nothing else.

Live by the wind tunnel, die by the wind tunnel.

I'm really surprised to see JohnC and tannji holding up FDR as some sort of guide as to how presidents should be. I think if you both look into his presidency you might find some stuff that you don't necessarily agree with. When I think of FDR I think of the Great Depression and the New Deal and "Uncle Joe", and what those things still mean for us today. We're still suffering from the effects of FDR's administration.

The rocker arms have a curved contact surface. Anyplace that grinds cams can properly resurface the rockers. You'll need to change your lash pads in all likelihood if you change either the cam or the rockers or both.

It's getting pretty Orwellian... http://www.msnbc.msn.com/id/5898175/?GT1=5100

If you want better search results, click the "search for all terms" bullet right below your keywords. That way you won't get every post that has "brakes" or "warped" in it. The Powerstops I had on my car put up with AMAZING amounts of abuse. I mean AMAZING. Boiled the fluid probably 10 times, ran the fronts metal to metal twice (just barely), went through probably 6 or 7 different sets of pads, all on the same rotors, never turned them and they never warped or gave me any shudder. Search for Stop Tech if you want to see that article about brake warping. It is interesting, and I believe what it says. Personally I can tell you I have had very bad experiences with Metal Masters and "warping", don't like the braking that I get from your average auto parts store pads, and have liked the Porterfield pads that I've used, although I did find that stock fronts and R4S pads are GROSSLY inadequate for any track use.

I would think you'd just slot them as much as you can... Keep the bolts tight and it should be fine. I've had my front crossmember slotted for ~6 years to adjust bump steer and my front control arms haven't moved at all. I just check the torque on the bolts every once in a while.

Not familiar with the "K-MAC" kit, but have you asked around with any 510 groups? IIRC the MSA kit was basically just a couple of washers that helped adjust a slotted crossmember. I did an alignment on my friend's slotted 510 with no washers and we just adjusted it with a prybar. Wasn't too bad at all. I wonder if Design Products makes a penultimate ZX crossmember (he makes them for 510's, right?). Probably doesn't matter anyway, even if he did it would be $$$...

I recently got a Millermatic 135 from the ebay seller "weldfabulous". Ran $607 for the welder, no cart, no gas, but it did come with a Hobart helmet and a pair of gloves at that price. Immediately upon hooking up the gas and regulator, the regulator blew up. I could have warrantied it, but I talked to a couple of friends who said similar things had happended to them, and that the Lincoln and Miller regulators that you get with the welders are basically crap, so I just replaced it. I think I was in the low $900s with the welder, gas, regulator, helmet, gloves, extra spool of wire and a big ass wire brush and a couple other little miscellaneous things. The weldfabulous guys definitely had the best deal on the welder itself. Nice thing about the 135 is the infinitely adjustable amperage. Go to Sears or Harbor Freight and you'll see that the cheapos have like 5 settings. So if you want to weld sheet metal you have to hope that one of the settings is close, and if not you have to turn it to the next higher setting and lay your beads down really fast.

I don't claim to understand everything I just read, but in Dan's link this is one of the first things stated: Is it just me or does this not make any sense? I was under the impression that a piston on a short rod is going to be faster everywhere, and a long rod is going to be slower everywhere given the same engine rpm.

So was that with or without the diff?