JMortensen

Regardless of whether there is another piston going up, can we all agree that there is pressure in a crankcase? Can we all agree that it gets higher with rpms? I would think so. Anybody else ever seen a Volvo 4 cyl in a 240 or 740 with the PCV plugged? It blows oil out the valve cover, oil cap, and anywhere else there is a gasket or seal. How about a newbie hot rodder that plugs all the PCV ports because he wants to eliminate all that smog stuff. Fire it up and it leaks immediately. With this in mind, when the piston goes down, it is still compressing the air underneath it, and that air is pressurized. It may be less pressurized because of another piston going up, but it is still pressurized. And there is still the issue of wind resistance that putting vacuum to the case would alleviate. Jon

It creates power because there is no air resistance in the crankcase. That's why I brought up the example of mile high stadium. Isn't it Sleeper that lives in Denver? What's the air pressure at 5000 ft Sleeper? Isn't it something like 12lb/in vs 14 at sea level (guessing here). And that 2lb/in means that the ball travels farther with the same effort. Less energy or hp in our case wasted to push the ball or engine internals through the air. Here's a totally different example. They say that open wheel cars use 80% of their hp in just pushing the car through the air. Take that same car and put it in a vaccum, and what's the new top speed? It's gonna be way higher. Because the resistance is not there. Take that same car and put it in a track that's inside a huge hyperbaric (sp?) chamber that's at 3 bar pressure. Top speed is going to be seriously reduced (assuming the engine isn't getting that 2 bar boost!!!). In the engine we're not talking about top speed, but the resistance to movement created by the air pressure inside the crankcase. Someone mentioned routing the PCV to a vacuum source. Only problem there is that you don't have any vacuum at WOT, or a lot less anyway, and that's on an N/A engine. So at the time when you have the most crankcase pressure, you have the least amount of vacuum trying to suck it out. But if you use the exhaust you would have more vacuum at higher RPM's, which is when you need it. But the crankcase is filling with blowby and air pressure is generated just from the crank spinning and pistons going up and down. This I think is the important part. When the piston goes down and there is pressure in the crankcase, it is forced to compress on the DOWNSTROKE as well, even if it is to a much lesser extent. Someone else mentioned hooking up a vacuum pump to the PCV. I suppose that might work, but the expense involved would be a lot more than the kit at Jegs, for sure. I imagine it would have to be a pretty big pump too to move enough volume to evacuate the crankcase. I haven't seen anyone else's setup (I wish I could though). The GN story made me think that hooking all of the PCV ports to the vacuum source may be a bit much. I'm thinking now of putting a filter on the pipe coming out of the PCV on the block, then hooking to the valve cover. If you felt like this was too large a hole, you could always put a restrictor inside the filter to get more vacuum and less fresh air coming through. Jon

I have had a wheel spacer fail, and I have heard of one other failing. That being said, I wouldn't hesitate to use them, and have some on my Z right now. The reason for the failure in my case, and I suspect in both cases, was the failure to check that the wheel spacer fit properly. Both were Mr Gasket cheesy auto parts store spacers, and mine failed because the inside hole was about .005" too small. It looked as if it sat flat against the hub, but in fact it was tweaked between the hub and the wheel. I fought what I thought was a tire balance problem for over a year. I couldn't figure it out, neither could the tire shops and alignment shops I took the car to, neither could any of my racer/mechanic buddies. I finally figured it out when the spacer cracked. It didn't fall out luckily for me, just cracked. I replaced them with a set of billet spacers from Coleman, and machined the front spacers so that they were lug centered, not hub centered. For this reason I recommend a lug centered spacer and not a hub centric spacer, unless the hub centric is made for your car, and I mean FOR YOUR CAR, not for a Z, or a Mustang or whatever. IME as a Porsche wrench, I saw many factory and race modified Porsches running THICK spacers. None were bolt on, all were slip ons, and judging by the looks of the material all were cast aluminum. Never saw one fail. The only warning I would give with spacers is that you should have a GOOD set of wheel studs. Aside from that I've seen 500 hp roadrace 911's with 335/35/18 slicks not break a 1 1/2" spacer. Jon

I agree with Mat. No one complains when Aux posts pictures of women on mopeds with their helmets on backwards, or a Donald Duck ride. This is the non tech board. If you don't want to look at it, don't look at it. Jon

It's kinda funny Bastaad, but I've been rolling that one around in the back of my head for about 10 years or so, and I just found the kit on Jeg's website like 2 weeks ago. But the idea is sound, so don't let anyone talk you out of it for that reason. There may be other complications like the rear main thing, but the idea is a good one. Jon

I had an idea. Maybe leave the PCV vent open, with a filter on the tube, then route the vacuum off the valve cover. It might prevent the system from drawing too much vacuum, and still use the exhaust to at least reduce the pressure inside the crankcase. Still want to try this... Jon

You might want to consider the weight of a good wire wheel. Seems kinda backwards to put a really heavy wheel on then spend big $$$ for racy tires. All that rotating and unsprung weight isn't going to help your handling or performance. Jon

I suppose that depends on how you combine the two. Jon

The Z mechanic guy I talked to mounted it just after the collector. The higher the exhaust velocity the more suction, so the GN guy may have had too much vacuum. You would think that it would only suck oil if the PCV was really low on the block. Maybe it would be possible to get around that by plugging the block PCV and connecting to the top of the valve cover, which has that baffle built in. I can only assume that you'd still be able to pull the pressure out of the block, but I suppose it would have to be tried to see if it really worked. I know it works, drag racers have been doing it for many years. I just don't know how well it works, and I've always wanted to try it. Jon

The crankshaft is pushing around through pressurized air, which is harder to do than in a vacuum. Think of how many home runs you get at Mile High Stadium, and that's only a few in/lbs less pressure, not a vacuum. So if you run a vacuum in the crankcase, the internals can spin easier. In the How to Hotrod book they say not to put too much vacuum to the crankcase, because the rear main seal will start to suck in and create a huge oil leak. I know one Z mechanic who was claiming 20 hp on a really crazy NA buildup (don't know if I believe him), and I was considering trying this myself, and he said he never had a prob with the rear main. In fact, here's a kit: http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=1783&prmenbr=361 If you're serious about trying it, I'll go halvsies with you on it since theres 2 in the kit. I'll buy it and sell you the other half and we can split shipping. Only thing I would be concerned about in your case is the turbo. I don't know what effect that has on this. Jon

I've always loved that green... Jon

http://auto.howstuffworks.com/differential.htm They've got 'em all. Jon

Nitrogen and oxygen and a few other things are what we commonly refer to as "air". Jon

Camber plates eliminate the rubber entirely, at least the Ground Control units I have do. So they drop the body by the difference in thickness from the original isolator to the new all aluminum pieces, which in my case was I think 1 1/2" or so. I believe that the 240 has a much shorter rubber insulator at the top. You may want to verify that and hunt around for a set of 240 insulators, I don't think there is a difference in coil diameter front to back, so either would work, just find the height you need. Or you could cut the rear springs, which will also raise the spring rate slightly. I have to wonder why there is such a huge difference in ride height front to back. That seems really wrong. Are the front springs cut and not the back or something? Jon

One more thing, I've driven my Z for something like 35K with the noise before it started popping out of gear. This is with monthly autox and a few track days a year for 3 years. Jon

The throwout bearing engages when you push in the clutch, so that is not your problem. I think you have worn countershaft bearings, as do I. This is very common on the Nissan trannys. If it hasn't already, what should happen next IME is that the tranny should start popping out of 2nd on decel. I have a rebuild kit, and was told that it is not really that hard to rebuild it, so that is my plan. I need to get my @$$ in the garage already!!! Good luck with yours! Jon

Tim, you've got it right. JohnC, I think that was probably YOU. Most of the time when customers get pissed, it's because of the guy on the phone. And being friendly is VITAL to selling and making customers happy. I picked up the habit of having a mirror in front of my desk while I was at my last sales job. When I first got there I was thinking--DAMN! This is a room full of VAIN people!!! Now, when I talk to customers I look in that mirror. If I see a person in the mirror that I wouldn't want to have a conversation with, because I looked pissed off or frustrated or whatever, then I take a break. Being knowledgeable and friendly are two different things, and quite a few people have one or the other!!! It was pointed out to me at one point that I sounded pissed off. I didn't realize it, I wasn't pissed at all, but I would take a big breath before I picked up the phone, then sigh as I picked it up, and there was a shortness of breath and a tendency to stop my sentences suddenly, just the way I talk I guess. One of my managers told me that were he in the room with me, he would know by my facial expressions and body language that I was not upset, but over the phone the difference was amazing. People were being adversarial with me for seemingly no reason. I corrected this problem and my sales went through the roof, and my customers became happier! Another good lesson I was taught, some people just shouldn't talk to each other. I don't know if it's some sort of auditory thing or what, but some people will rub each other the wrong way IMMEDIATELY. Those people should talk to someone else in your company. Anyone else. It's not personal, it just happens. All of this may seem like nitpicking. It is not. I went from the bottom third of the sales staff at that job to the top 3 in ONE MONTH, just by changing my speaking voice a little tiny bit. Jon

You gonna hang some tassles from that curtain in the windshield? No, it looks GREAT! I love black Z's! Congrats. Panels look FLAT. Those hood vents are looking good too! This was your 1st paint job??? Nice work! Jon

Nitrogen isn't flammable (thank god because it's what 70% of the atmosphere). The only reason they do that is because it is more stable at temperature, so your pressures don't vary as much when the tire gets hot. If there is a 2 oz weight savings per tire I submit that you could run regular air and take a crap before you got in the car and get the same effect, and not have to buy a tank of nitrogen. If you're racing there are other reasons to use nitrogen, but that's not what we're talking about here. Jon

Since I mentioned this on another thread, the new GM I6 in the Baja trucks. It doesn't sound like a Baja truck... Jon

I am familiar with Spicer joints, although not the ones used on Z's in particular. The newer "Snap Tite" units (not a reference to the models for 6 year olds) have a forged cross, and you can get them with no zerk fittings. That would be the best, although like I said I'm not sure if you can get them for a Z. Jon

You might want to check out some 510 forums for a good answer to this question. They seem to know how to make the recirculating ball setup work, and work well. Have you tried adjusting the steering gearbox? Is it loose? Jon

If your car isn't running yet I would suggest checking all hoses and rubber and just start replacing what is needed, you'll probably end up replacing it all, and you can do them one at a time. If you want a nice ride try KYB GR2's or better yet Tokico "Blues" and cutting the stock springs with a cutoff wheel, 1/2 coil at a time until you find a ride height you like. Cutting the springs makes them stiffer, and I had my first Z setup that way. Worked out great, that car handled really nicely. Don't bother with the tranny until you do the turbo swap, because you can get both at the same time from a donor car, and the Z 5 speed should work fine until then unless it is already in need of a rebuild. Brake upgrades can wait as well. I got my LSD from a junkyard for $325, but it needed to be rebuilt. Spent another $300 on that. Should have bought one out of a runner from someone on a forum like this. Any idea why it isn't running now, or did you buy it already dead? What happened that you ended up having it parked? HTH, Jon

You might want to take a look at the How to and Tech articles at http://www.zhome.com/. They have some good stuff in there. Are you going to do your own wrenching, or pay a shop to do it? A lot of the parts are reasonably inexpensive, but the shop's $$$ will be more substantial, especially on something like installing poly bushings or strut cartridges and springs. You can usually find info on doing those things by searching here (I see you've already been searching), but if not you can always ask. You may also want to join the IZCC mailing list, as it is more directed towards those just fixing up or slightly modding a Z, and this forum is more for advanced engine swaps and racing style suspension systems. Don't abandon this forum though. There are some seriously talented people here, and when you get advice from people as knowledgeable as some here are, it may just save you time effort and $$$ on a huge scale. Welcome! Jon

Over 60% of degree holders don't work in the field of their degree (can't quote the source of that stat, sorry). Start looking elsewhere for a job. My materials engineer degreed brother-in-law is swinging hammers on a construction site today, and making more $$$ than he was working for NEC doing manufacturing control on DRAM chips. Maybe have a pro look at your resume. Send it to corporate headhunters. Just some suggestions, take them for what they're worth. Jon