jmortensen

Some of the CP racers would mill their triple manifolds to angle the intake manifold up. Then they'd port the head to match. The idea is that the short side radius in the head is straightened this way, and it's done to improve flow rather than to stick a longer manifold or air horn on. There are pics of some of these manifolds in the How to Modify book.

Just took a look at one of Alan's photos. Judging by the perfectly straight intake runners I'm guessing Nissan designed the S20 head for Mikunis (duh!). Unfortunately this is not the case with our L engines, but I suspect that on the S20 you could put a very large stack on the end of the carb, and that might potentially enable you to get more air through the carb and into the engine.

You could put the cam in a set of V blocks and put a dial indicator on the lobe and measure the lift. Multiply that by 1.5 and then you'll have the lift at the valve. Doesn't tell you everything, but you'll at least know a little bit. I suppose you might be able to do the same with the head on the block by popping off a rocker and measuring it right on the car.

One answer would be to time it at 3000 rpm. Should be in the mid 30's degrees at that engine speed. Then whatever it is at idle, it is. I think you might be able to adjust the mechanical advance on that distributor. If you can then knock it back to about 15 degrees total advance, then you'll have your 20 degrees at idle and you'll be in the mid 30s total. You'll need a timing light with an advance knob to time it at higher rpms, unless you have a fully degreed harmonic balancer.

That's a good one Eric. I don't really know an answer other than to say that the closer the carbs are to the head the sharper the bends and the more severe the taper from carb outlet to the port size has to be. I've heard some really sketchy reasoning behind why having more air/fuel already mixed in the manifold was better, but they sounded so hokey to me at the time that I didn't commit them to memory.

Actually with a Cannon manifold and Mikunis, my main issue was that the air cleaner just barely clears my strut tower bar clevis, which in my case is welded to the strut tower. Even if that weren't there, you still couldn't use a really long stack because there wouldn't be enough room between it and the strut tower to finagle a deeper air filter on there.

If you see the two side by side the short manifold has quite a sharp curve and funelling effect to it compared to a longer manifold. Based on this I chose to use a longer manifold, and so far I have told several race engine builders about my choice and they've all said the longer manifold works better. The problem is that you won't have as much room for an air cleaner, velocity stacks have to be shorter, and the linkage has to be adapted to work. If you're not racing just use the manifold you've got.

The main oil galley on the side of the block feeds oil to the chain tensioner on the L6. It's the one that you either tapped and plugged or put hammered a plug into on the front of the block. Actually you kinda have to be careful that you don't plug it when you screw in a pipe plug if that's what you're using, because the hole that feeds to the tensioner really isn't very far in there.

Not 100%, but it sure sounds like the roll pin on the gear selector fork fell out. This would mean that the rail moves back and forth, but the selector doesn't move. This would only affect 1-2, or 3-4, or rev in your case. If nothing else got damaged it's an easy fix, but you have pull the transmission and split the case to get to the roll pin. A little safety wire through the roll pin will prevent that problem from happening again.

You know, my previous statement wasn't a very good one in truth. There's a lot of variables, disk size is only one of them. Others are piston size, brake pad size and pad coefficient of friction. If you're using dual masters the master size also affects the bias. The stock front brakes are 11". The vented Toy setup is the same diameter, but uses a much larger caliper and brake pads. So that affects bias. I think the Toy front would be a pretty good match for the 240SX rear, but I haven't tried it myself. Here's a spreadsheet that will really confuse the crap out of you, courtesy of Tom Holt. www.sth2.com/Z-car/Brakemath.xls That's really getting anal about it. If this is a street car the Toy front, 240SX rear and an adjustable proportioning valve should be all you really need.

It's Jon, but you're welcome anyway!

Vented Toyota setup is 11" I think. Really if anything fronts should be a little larger. They do more than the rear because of weight transfer, and the increased leverage from the larger disk can be helpful in getting the right amount of bias. Look up some specs on most new cars and you'll see larger disks in front. Look at motorcycles and you'll see that they have 2 larger disks up front and one smaller one in back. But if you really want them to look the same, probably the vented Toy front with the 240SX rear is your best bet. I think Ross sells all of the necessary parts.

www.modern-motorsports.com

He isn't the best at responding to emails, but that's because MM is a side biz for him. He also has a full time job. Sometimes you just have to be patient with him, but on the upside he makes some really good parts that you won't find anywhere else.

That's right. There's the one on the transmission, then the inner, then the faux leather one on the console.

There is a boot and it does hold onto the rim of the hole like a grommet. Should be available thru a dealer, I think there's a guy who sells them on ebay pretty much constantly, or you could try Courtesy Nissan.

Search on the internet. There are a lot of people who say 2 way is only good for drifting, and suggest a 1.5 way for autox or road racing. I'm running the Nissan 2 way and I love it for autox and road racing, but I thought I'd point out that other viewpoint. The KAAZ unit has more and thicker clutches than the Nissan one. It really is a better design.

Never did make it to a meeting. Not much of a club guy. I just like to show up and race. I guess I'm not the show and shine type, which seems to be the focus of the clubs I've seen. I'm still trying to figure out where to go, but I really can't stand Seattle. Too cold, too much rain, too much traffic, too expensive. Looking at CO and NM currently, but keeping options open. I think I'm going to go white on mine too BTW. So much nicer to drive a white car when it's hot outside, hopefully that will happen a bit more wherever I end up. Sounds like you're doing all the hard work on yours then turning around and selling. Sorry to hear that your situation requires it. Hopefully there's another Z in the future for you. I'd definitely like to meet and pick your brain a bit. GT2 is a pretty big step up from where I'm at.

How about just grinding a bit off the intake manifold?

Seattle here, and looking to get the hell out... one more year.

Quaifes do not have gears with viscous plates. That have helical gears which get driven into the case itself when the side gears try to move at different speeds. The friction of the gear interfering with the carrier is what limits the slip. Torsen makes a unit that looks almost identical to a Quaife, then they have another one which uses the helical gears on their own little axles. The second type looks superior to me. Nissan makes a clutch type LSD, you can also get the exact same unit through www.differentials.com sold under the name Power Brute. Runs about $500. They also make a viscous version, but I wouldn't recommend it. KAAZ and Cusco make R200 diffs for 240SX's. They fit, but you have to make sure you get the one that replaces a 240SX open diff, and not the 240SX viscous LSD, which has a different spline count on the inner CV shaft. These are more expensive than the Power Brute, but you can get them in 1.5 way or 2 way, where the Nissan is just 2 way. I think either of these should be $800 or less. There are some others that I'm not as familiar with. 260DET has a gear driven unit that is from Oz that runs $800AU if I remember correctly. Here's an explanation of the Torsen I consider to be the better design. http://www.sonic.net/garyg/zonc/TechnicalInformation/TorsenDifferential.html Another good page that explains how several of the different types work: http://www.billzilla.org/diffs.htm The billzilla link above has a picture both types of Torsen, and I used to have a link to a good article that laid out the frictional forces involved in a gear driven diff, but I can't find it anymore. Sorry.

240ZMan's 4th gear suggestion works. If the bolt is too tight you could probably rent an electric impact gun from a tool rental place. If that didn't work you could always put a breaker bar on it and set it up against the frame rail then use the starter to crack the bolt loose. Last one is potentially dangerous, but its doable if you're careful. Once the bolt is out you can usually wiggle and pull (a lot) and the balancer will slide off. I never had to use a pulley puller on one. You should definitely be able to hit the torque spec when tightening with the 4th gear trick. I think the spec is only like 110 ft/lbs, but double check that when you're putting it on. Some red loctite might be a good idea too. Sucks when the bolt comes loose. I know from experience.

I bet if you tighten the bolts at the bottom of the window it won't be nearly as sloppy. Easiest to pull the window out to get at the bolts. Carl once very smartly recommended loctite on them to prevent them from backing out later on. The roller helps too, but most of the rattle when you close the door comes from the bolts loosening IME.

I don't know about dave, but I cut the shifter right above the pivot then welded it back on so that it faced straight back, then bent it 90 degrees so that it came straight through the middle of the shifter hole. If you want to run the stock inner shift boot don't cut the metal.

Well I guess we have to agree to disagree. I like to have the brake and clutch pedal heights basically the same, and then be able to adjust the engagement of the clutch independently of the pedal height. It's just one more degree of tunability, and it's definitely not the "wrong" way to do it as you stated above.