2eighTZ4me

I guess I didn't put my reply exactly how I wanted it to come across. I meant to state if BOTH the block and valve cover breathers are blocked off - THEN you have a problem. He does have the valve cover breather. But why wouldn't Nissan just have used the VC breather and plugged off the block completely? Both are plumbed back into the intake system. One pre and one post throttle plate. I dunno - they put two holes there for a reason - one would think. Also - I would like to pose this. I have never had my timing cover off and filled the engine with oil. The gap between the front cover and the pan is the "main" way for pressure to equalize (largest opening). Does 5 quarts of oil fill the pan up completely to the bottom of the block such that if you were to pull the front cover, oil would come out of the front of the pan? If so - there's nowhere for pressure to equalize (rear drain included, as it's draining down - not up) - unless you've got enough pressure in the crankcase to push the oil out of the way to equalize. My guess is if you're at that kind of pressure - your front main is the first thing to go. If the oil level DOES stay below the front main cap when full- then you're ok - but like I said - I've never filled the pan mounted to the block with the front cover off, so I honestly don't know. Anyone done this to test? Further adding to this theory - if the oil drainback hole in the back of the head/block is full of oil draining back to the pan, it's also difficult for air pressure to equalize when the hole is full of oil..unless air gets in with the oil. I dunno - I'm not anywhere close to schooled on fluid dynamics - I'm posing questions (probably in the wrong thread) to learn. Should we take this to another thread? Paul?

On a triple setup - there IS no place to vent back into the intake. Unless you want to poke a hole in the intake somewhere and fit a PCV valve in there. Hence - the problem as it exists today.

"Bust a Josh" - now that's funny right there! Size does matter don't it!!??

If you'll be running NA (read no turbo) cast pistons will be just fine. They can handle just about anything you throw at them sans boost. From a cost perspective, you might just do well to keep the stock L28 rods, buy a set of flat tops 1mm overbore, sell your 240 rods and that'll pay for a bit of your pistons. Unless you're going to be running more than 13:1 compression, cast pistons are just fine.

If it's blocked off and can't vent from both there AND the top of the valve cover, you will build pressure in the crankcase as it heats up and start blowing seals. At least a breather vent - or better yet still - vent to a catch can. That motor looks pretty new, so you might not have experienced it.....YET. Who is everyone? There's a lot of folks on this site that would cringe (as you saw) at that piece being blocked off...it's been discussed ad nauseum in many threads.

HAHAHA!! Ain't that the truth man!! You mean you still HAVE a 401K???

Matt and Daeron - he hasn't "driven" the car yet. He's bopped up and down the street a few times, but wanted to do the dyno tune before hitting the track. The car is far from street legal. I too had suspicions about his float levels. He has a front strut bar that prevents removing the top of the front carb. Told him he's gonna have to pull that and check. He had the carbs professionally redone with new floats. I don't know HOW - but the new bronze floats that were put in the carbs were getting hung on the float bowl walls and not allowing ANY fuel into the bowl. They were just too big. We replaced them with the original floats (which were a black rubber/plastic looking composite instead of bronze) and we had fuel. Checked float levels at THAT time - but nothing further. He ended up putting on the strut bar and therefore no access to the front carb. I'm with you - he's starving for fuel somewhere. He's running 112 race gas, so I doubt there's any alcohol in that formulation. If so - probably negligable to the very furthest extent. Oxygen doesn't burn at all?? Tell that to the folks that drive the medical trucks carrying oxygen - they'll tell you to the contrary. It is extremely flammable in its' molecular form. He's running DIS - Electramotive HPV-1 crank trigger ignition. No dizzy to speak of. I finally got a hold of his dyno run. Red and Blue are with 220 main and 200 air. The blue is where he backed off the 3000rpm timing by 2 degrees.

I can vouch for Randy's cars. He is THE Z collector. Words cannot describe the 73. Unbelievable comes to mind. It looks like it rolled off the showroom floor. He is the ultimate Z connoisseur. His basement is a shrine to all things Z (with some 20+ cars) , and he believes in keeping them factory correct. John Williams does all his work. Every part right down to the hose clamps are factory correct. The hose clamps are even positioned exactly the way they were facing from the factory. He makes sure John puts everything back exactly as original. You will NOT find another specimen like this. I have seen the car on numerous occasions. It makes your jaw drop. If Randy says the 70 is the second one sold in public - I believe him. He has a wealth of knowledge on these cars posessed by scant few. No details escape him. I have a friend who has #17 of a 77 200SX that was given to the owner of Kontrolle shocks back in the day and turned into a GT-3 car. Even his at #17 was not available to the public, so Nissan must have had a few of each model that go to specific destinations other than the general public. Seriously though - the 73 - you'll never see one like it. The 70 - well - if John is doing the work, then it's going to be done properly, and with attention to detail that very few would follow. I think the price was set that way because of its' rarity, and to also keep Z car hacks from getting a hold of it and butchering it up. Ya gotta respect that.

You are correct - as stated earlier - I don't have the graph and was going on what he said. Regardless, on a dyno pull or any straight line acceleration, your idle jets are gone by 2000rpm at WOT, so that really doesn't come into play. The problem we're facing is truly focused on the main circuit. Why would it be fine from 2500-4k - take a dump in the "lean" pot, and then start evening back out? I've got my 240 dialed in such that (after tip-in leanness) it starts at about 12.2 at around 2k and works it's way up to about 13.6 at about 7k. Perhaps still a bit lean - but linear nonetheless across the rpm range. Something's amiss with these carbs - starving for fuel? I have got to get him to check the float level on the second carb. That is the ONLY thing I can think of that would cause that type of lean condition. Jets just wouldn't "clog then release" - on a consistent basis of 6 dyno pulls. Even with the larger jets in there - it did the same thing. It' CAN'T be jets if you follow the logic there...dont you think? DO appreciate the input - keep it coming - I'm a Mikuni guy - these Webers are screwing with me! Thanks Lazeum!

With the 200 mains and 180 airs, it shot up to about 19:1, so yeah - even given the "rule of thumb" the car is still out of wack. The 220's brought it down to about 16:1 at that rpm range. Going leaner is not an option. There's something causing a spike at 4k-5.5k that has us baffled. 180s would burn a piston, so I can't take your advice there. The car is like nothing you've ever seen on a street setup before, the car is a full GT-3 car and has parts in it that even I scratch my head at. Idle jets have absolutely nothing to do with the scenario at the RPM range I'm working with. We're talking WOT at 4000rpm. Idle jets are LONG out of the picture at that point. Not even worth addressing. Car idles fine at 12:1 and drops to about 8:1 to 10:1 at about 2k and slightly increases to about 13:1 until it hits 4k - then it shoots through the ceiling. Then strangely enough, starts coming back down about 5500rpm. We're dealing with an anomaly here, not the norm, and I'm trying to find something in the main circuit that could cause it to do this. I have 44 Mikuni's on my 240 and have it dialed in right on the money across the rpm range. Something is wrong here with his car and I can't quite figure out what. I DO appreciate the input though - keep thinking and throwing ideas our way - every little bit of knowledge helps!

My friend took his 77 200SX GT3 car to the dyno today. At base and up to about 3500RPM, the car is so rich it won't register on the dyno's O2 sensor. Right when it hits 4000rpm's it spikes super lean - 16:1, then at about 5500-6500, it starts working it's way slowly back down to about 13:1. Weber 50's, (not sure of choke size) 220 main jet and 200 air jet. They swapped in these larger jets from the smaller 200 main 180 airs, and while the problem got a "little" better, there is still this phenomena of the lean spike starting at 4000rpm. Checked float levels. All OK. The car has a radical cam, and due to the way it was built, the cam was advanced 6 degrees. Trying to get a hold of the graph depicting the spike - he's still got it and I will have to get a hold of it and post. Seems awful strange that it spikes lean when the main jets are full on under WOT. Carbs were freshly rebuilt. One would think that if there's cloggage, it would get worse as it gets higher in the rpm range, but strangely enough - it corrects itself. ANY ideas?

I'm sure that technique is probably good for overall longevity, but as thick as I put it on , it's probably going to stay on there until someone hits me or I put it into the wall! Strongly debating picking up a quart of red and trying to emulate the BRE 46 car...but still up in the air. I guess for now (and for simplicity's sake) I'll just leave it alone and run the pi$$ out of it!

Unfortunately, that is one set of two that I know to be in existence. They are Boyd's Wheels (Boyd Coddington) made in 1996. Ron Zappendorf of Discovery Parts has the other set on his car. I've not been able to find any history whatsoever on them. The race rubber that came with the car when I bought it is going on those wheels. and I'm putting the street rubber on the Rota's that I just bought. If I could find another set, I'd for sure turn them your way, but I'm clueless about them, and the car was apparently setup for them, based on the way they fit. I'll keep researching.....

I'm trying to prolong his "time". Ever been in the middle of rush hour traffic, and you push on the clutch pedal and there's nothing there? I have. Not fun. It's a ticking time bomb at that point. You never know when it's gonna go. $20 is a decent bottle of Cuervo Gold. I've got several of the boots lying around in the bin. Always save removable parts and keep them on hand - especially rubber. You never know when you'll need them.

I'd get that slave boot replaced ASAP. You don't want ANY moisture to get in the slave. Brake fluid attracts moisture, and the moisture will rust pits in the slave cyl. itself, leading to one day when you push in the clutch - it' ain't gonna be there.

OK - well it's been a while, and rather than poking at keys and posting pics on the web page, I've been busy at work... Just did the first oil change after about 200 miles of break in. Cam looks great, and the Oberg oil filter does a spectacular job of cleaning the oil. The 10 micron screen had all kinds of gunk in it, while the 60 micron had only a few pieces on it. They work well in tandem. I've finally got oil temperature. Drove it to work last week and after about an hour in traffic - I got it up to 160 degrees. I have installed a Spal puller fan and removed the stock unit. Installed the new harnesses and put a shorter slave cylineder arm on. Clutch was slipping a little and thought it might be due to the slave cyl. arm. Haven't tested yet. But - the biggest feat - we've got paint! Yes - I broke down and did the $40 RustOleum job. Home Depot is my friend. Thinned it down about 2:1 paint to thinner and put it in a nice DeVilbiss gun. Tack coat went down OK with a few fisheyes from not prepping it as good as it should have been. Laid the second and third coats on nice and thick and it covered up the fisheyes completely. Yes - I prepped the car minimally. Yes - I shot it in my backyard Yes - it was above 60 degrees Yes - I pissed my neighbors off Yes - taping it off was the biggest bear And Yes - I still have about a half gallon of it left over. Looks like the truck is getting paint this Spring. I was going to hold off posting pics until I got my Rota RB's back from the powdercoater. I guess I decided against that huh? I'm having the centers of the Rotas redone in a gloss white to match the car. Got the wheels yesterday and they fit like a champ! Got the 17x9.5 -23 offset rears and the 17x8.5 +4 offset for the fronts and that my friends was the perfect choice. The lips on the rims all match in depth and they fill out the flares perfectly. Street tires will be going on the Rota's, the race rubber is going back on these wheels. Without further adieu....pictures please!! Before...white stripes were sanded down and blended with the level of the blue paint. Everything scuffed with 180grit. My paint booth - HVLP guns ROCK!! 90% of the paint went on the car and not in the air or on the grass. About 30 min. after the last coat. Untaped and in the garage. All in all - I'm pretty happy with it. No sense wet sanding or going further than this. It's a race car. It's gonna get dinged up. And when it does - I just go to Home Depot and buy a rattle can of RustOleum Gloss White and touch up as necessary. Will get more pics when the Rota's come back and I get them on the car. Mission accomplished!! Ready for Road Atlanta Mar. 14-15!!!

Throw out arm (fork) dust boot if it's the one that mounts on the tranny itself.

Dished is what I'm going for since it will be a turbo build. Problem is - I'm going forged pistons, so I'll be custom ordering them. Thanks for the heads up though!

I will be using 240 9mm rods in a L28 block. This will be a turbo build. I will need to have custom pistons made. Tell me if my math is off. Also - tell me if these measurements are off. I got them out of the "How to Modify" book and I've heard some grumblings that all their measurements aren't exactly correct. My machinist measured the two rods and they were close (within .09") to what the book said. 240 rod = 133mm length 280 rod = 130.2mm length 280 pin height = 38.1mm so subtract the difference 133 - 130.2 = 2.8mm Being that the 240 rod is longer - I'd want a shorter pin height. So 38.1 - 2.8 = 35.3. I'd need to get a custom piston - 87mm bore (I'm going .040" oversize bore) with a 35.3mm pin height. Is this correct? I know folks have done this before, but searching through all the "crap" on this site is sometimes like finding a needle in a haystack.

ZMan has them on his website, but last I checked, he didn't have a price on them and they weren't in stock. When I spoke to Oliver, he said they were "coming soon" - and he must be anticipating them soon if he posted them on his website. I'd just give him a call - he can either give you a price or an ETA on their arrival.

That is some VERY sweet bracketry Paul. Mine did come with mounting tabs, although I did mount it to the core support, I put pieces of fuel hose on the bolts between the core support and the radiator that act as a bit of a cushion. Many ways to skin the proverbial cat.

That is an unbelievable price for a Ron Davis unit. I paid nearly $600 for mine. Snag it while the snagging is good!

If you have a machine shop at your disposal... Otherwise, you'll pay more (probably) to have them cut down than it would cost to just buy new at $3.70 a pop. But then again - there's that 'wait' factor......

Well Paul - those Rebello worked Mikuni 44's are feeding YOUR work to the MN47 head. Car runs like a bat out of hell! Can't wait for racing season!

It's all good - the guy is deriving great pleasure from this thread and displaying his jubilance! OK - I'll jump in - why not ....BUT I WON'T YELL AT EVERYBODY........I get enough of that from the wife after she found out how much $$$ I have into this car....... I'm with Dave - paint it black. I used the DupliColor truck bed liner. If it chips off - no big, give 'er a quick spritz from the can and it all blends right back in and dries like it's one coat....