pparaska

Agreed - the extra FEW lb-ft or HP that a mm or two of overbore will give you is not worth worrying about. When I had my 400 block done, I was looking for .020" oversize pistons, instead of the .030", incase I ever wanted to bore it again. Especially in a turbo app, I'd be looking for maximum bore stiffness with thick walls, and just turn up the boost. I'd just do a stock or one-size over bore and do the deisel crank. JMO.

Thanks, KraZ4spd! I like that color too! Of course, Audi/VW screwed it up in 98 when they changed the formulation of "Europa Blue Mica" to a lighter hue.

I'm 6'2" and have no problem fitting in a non-2+2 Z, FWIW

One thing to consider is that the Z unibody is "flexible" in the front between the strut towers and firewall area. Large torque applied to the engine frame rails, resisting the reaction from the diff through the unibody will tend to flex this area a good bit. I think that the increase in safety and consistency in launch, etc. would be worth considering a full cage for a high torque application. Although the frame rails and subframe connectors help to add stiffness and strength, it'd be more effective to add these attributes with a cage that goes through the firewall. Frames that try to add torsional stiffness in a flat (plane) are inefficient and less effective, compared to adding stiffness with a space frame structure like a cage. I still feel like my car's setup (better engine frame rails tied tightly to subframe connectors, and installation of a meager, inefficient roll bar) is not the best course of action. That roll bar probably isn't doing much except help react SOME of the suspension loads through the towers. A correctly done cage like 'Mark' had a Circle track builder install in his car is a far better way to add stiffness and strength.

SPIIRIT, I'm not going to say that going without a full cage is the way to go, but I'd consider doing a cage like "Mark" from NC did. It hides behind the A and C pillars and is a full cage without door bars that get in the way. I wish I'd done that. I did front frame rail replacements (2.5x2.5" .093 wall steel tubing) in the engine compartment HEAVILY gussseted to 2x3" .085 wall steel tubing subframe connectors. Here's the page documenting it a bit: http://mywebpages.comcast.net/pparaska/structuralmods.htm I also had a modified S&W roll bar installed. It connects to the front/top of the rear strut towers and to the top/side of the driveshaft tunnel. Other than that all I did was replace the structural steel that had rusted, usually with thicker material. Like the inner rocker panel ends, floors. I had an longtime ITS 240Z driver (Wayne Burstein) take a ride with me and I was hammering the car and throwing it through corners. He commented (without me asking) about how stiff the chassis felt. That was enough to tell me I'd made some improvement over a stock chassis. Anyway, I think for a street rod type of machine with all the power you are planning to put in it, I'd look into a good tight-to-the-car full cage. They can be pretty unobtrusive, if done right. And they offer alot of stiffness, especially if they tie into the front frame and strut towers well.

Damn, that does suck. Glad nobody was hurt . Also glad you had the water shut off. So many people forget to do that. My sister went away for a week and they had to remodel 1/2 the house after that due to a burst pipe to the ancient dishwasher.

YES - Tremec TR-3550 (same size as TKO, TKO II) in JTR position

Mike has good points on the cost to do a 400 vs a 350. But if you are buying the engine, it's in good condition, and not planning a rebuild, then the 400 will be a good way to go. With the right intake, headers, carb, and maybe a cam (if it's still stock), you can have a nice performer. Any idea if this is a stock engine, or modified? Any aftermarket stuff in/on it? (intake, cam, etc.) Compression ratio? Even the cranking pressure and cam specs would help you determine the range of compression ratio you have in it.

I have 300 lb/in springs in the rear. The Tokico Illuminas (240Z fronts in the rear strut tube) set to 5 damps that spring well. But it beats the hell out of you on the street. Rt 85 through N.C. about killed me. I turned them down to 4 with that spring and the ride is alot better, but it pogo's. I know that will wear the cartridge out, but I'm mostly just cruising around. I plan on putting 250 lb/in springs in the rear. That's supposedly the most spring you should run with the Illuminas. Anyway, with 300 lb/in in the rear, and the Tokico Illuminas set of 4, the ride is stiff, but not HORRIBLE. I have 225 lb/in in the front and the Illumina's set on 3. Just another data point/ ride opinion. The strut carts need to be selected / adjusted to the springs and the car. The 300s require a 5 setting (max) and it's too rough for street driving. Plus the 300s will wear out the Tokico Illuminas. So I'd think 200s would be fine for the street. Oh, another reason people say to use more spring in the rear is because you want a different (usually higher) natural frequency in the rear suspension than the front, to keep the for/aft pitching away as you hit tar strips, etc. Since the front/rear bias of the Z is so close to 50/50, the same springs front and rear COULD make the natural frequencies the same.

Nick, if the car has 60000 original miles, I'd think even if you wanted to rebuild it and it NEEDED a bore (doubtful) then the cylinder walls will be plenty thick. A larger engine (400 vs 350) allows you to build it mild and have the same horsepower (peak) with more torque across the rpm band - especially the important 1500-5500 range. The only difficulty with the 400 is the external balance (dampner and flywheel/flexplate). But if you're getting the package, all that is there anyway. Look at it this way: for the same package size and weight, you'll have 50 more cubic inches (that's 1/3 the displacement of the L24 that's in the 240Z) than a 350 has. The increase in torque for a similar build will be 1 to 1.2 times that 50 cubic inches, assuming a similar "performance" build level. Or a bit less for a milder build, which would be more streetable than a hot 350 buildup. The 400 is reputed by some to have an overheating problem. That came about when people put different (350 or 327) cylinder heads on the 400 and didn't put the steam holes in the head. That's a very important step. With the steam holes, there is no great increase in cooling needs between a 350 and a 400, especially in a street "performance" build. The increase in displacement does add to cooling needs a bit, but nothing a good Griffin radiator can't handle - same radiator you'd use on a 350. Sure, you can't rev a 383 or 400 as much, due to the stroke making the average piston speed higher than a 350 at a particular rpm, but 6400 rpm is about 4000 fps average piston speed. You won't need to spin it that high even at a 475 peak hp build. If it's a street car, I think a milder 400 is better than a rumpy 350 of the same hp. JMO,

Mark, thanks for posting about the Viper T-56 - good info - especially with the 2.66:1 1st. That .50:1 6th is probably not of much use for highway cruising near legal speeds with any kind of "performance" cam with the typical gearing (3.7:1) and tire diameter a Z has. The TKO II was brought up as an alternative and I was just echoing some more info on it's viability. It's less expensive than the Viper T-56's $2500 price tag, to boot. But Tremecs don't shift as nicely as a T-56 either. Want aZ - thanks for the compliments on my website! BTW, it has a 327 now, but a 406 is being built.

Sounds very much like it would be Arizona Z cars. They've been selling that for a long time. Price sounds like theirs too. Check out: http://www.modern-motorsports.com/catalog/default.php http://www.fonebooth.com/brakes_zcar.html

Broke 5000 posts !

I've found that if I search specific forums for info, nothing comes back. But if I let it search all of them, I get at least some results.

John, Alot of people leave all that info blank - on purpose. You can input your city and state in the location field, but it looks like you'd like to have separate city and state fields. That's cool.

I just spoke with Hanlon motorsports about me having more torque now (450ish?) from my 406 (whenever that happens) and using my Tremec TR-3550. They said no problem, even with the smaller input/output shaft. Especially with only 2700 lbs and at most Drag radials, 10" wide. I'd think the TKO II would be PLENTY. I like it's .82:1 overdrive too - .68:1 in the TR-3550 and TKO is a bit low for 3.7:1 gears, 26" tires and a 2000-6000 rpm power band (which I feel is good for "hot street").

Thanks Grumpy. Now I see why it's called a "quench height". Quench, as in cooling, i.e., like when you temper a metal, etc. Great post! It's in my bookmarks! I actually learned something cool and useful today!

[this is a continuation of a post in the Announcements forum that got off topic. It's about suspension, so I started a new thread here. I'm bad about stealing threads, and trying to reform ]

Is the factory sealant more difficult to clean off than the Black RTV? If it is and the regular Black RTV is good enough, I'd stick with it. Grumpy, thanks for that tip on the dimpling and a bead on both the manifold and block rails. Also, I put non-hardening permatex sealer only around the water passages on the side gaskets. I use a bit of grease elsewhere to keep them from sticking. I hate messy cleanups, especially in this area where you need to keep trash out of the valley. I mask all that off, but less trash is still better. Don't forget sealant of some kind on the intake manifold bolts. the center 2 on each side go into the crankcase area and can weep oil up the threads. The ones just adjacent to those near the center around the water passages go into the water jackets and can weep water/coolant. The most forward 2 and most rearward 2 are blind, no sealant needed, but doesn't hurt. Comments on what I might be doing wrong always appreciated!

Quick discussion of Quench area (actually a volume, I guess): It's the volume above the piston where the cylinder head surface is flat and flush with the top of the surrounding head gasket. As the piston approaches this flat head surface and ALMOST touches it, it causes the mixture to churn and homogenize for better combustion. Probably some more benefits too. If you have too much distance between this flat part of the head and the piston at TDC, the churning is too weak and there are rich and lean areas of mixture in the chamber that burn at different rates or can preignite before other areas. When that happens, two or more flame fronts can be set up and when they collide you get knock. This is probably not a great explanation. Anyway, lowering compression by using a thicker gasket or more deck height means you increase the quench height. Once that gets very far beyond .045 or .050" or so, the reduced quenching action actually can cause more of a tendency to ping than higher compression with better quench (.035 to .045, etc.) Too little quench height and the piston hits the head. After all winging a piston and rod up and down at high speed causes the rod to stretch and compress. It stretches at TDC when it tells the piston to turn around and come back down the bore. If it stretches more than the quench height, bang, the piston kisses the head. Some racers that run really light pistons and light/stiff rods run less than .035". If they don't understand quench height and it's importance, I'd be looking for another shop. Even HOTROD magazine covers that!

Thanks Dan! I looked for a button to click in the edit window and couldn't find one. Oh, now I see. Someone with Admin Rights or Moderator for that forum has to edit the BEGINNING post and at the bottom of the edit screen there's a place to click "sticky".

I'f less than 1/4" gap, RTV works great. Not too much, and make sure the surfaces are VERY clean and oil free. Carb cleaner on a rag!

From what I've heard: To do part throttle tuning, you'd need a dyno that could put a constant load on the wheels. Inertial dynos are not able to do that. You need some sort of power absorption, like a water brake, huge electric generator, etc. to do steady state tuning.

"Sticky" topics? The one about "Another Beginner Question" and the long response by strotter in the Chevy V8 forum: http://www.hybridz.org/phpBB2/viewtopic.php?t=19186 is a great candidate for a "sticky" topic (on that stays at the top of a forum, no matter how old.) Also a great post to link to as a FAQ.