TheNeedForZ

A bad dampener won't make you feel the engine vibrating, it's something else. The cause could be rough running or one or more cylinders that are not working....fuel starvation? Just my guess.

A new member isn't necessarily equal to a newbie....

Hey who stole all your punctuation?

With a new Skyline coming to America in the near future, will Nissan ever bring out a next-generation Z car? Anything under development?

Yep, if you look closely, it says BMW somewhere.

I think it's just clear coat.....our Zs are so weathered, sometimes we forgot cars are normally shiny and rust free.

In reality that's not the case since the heat is taken away from other product gases which in turn, cool and shrink in size(partial pressure of water increases, but partial pressure of other gases decrease). The only time when water injection increases horsepower is when it replaces fuel as chamber coolant. Like in a nitrous injection situation, instead of using a richer a/f ratio to supress detonation, water is injected to provide cooling and the a/f ratio is kept normal.

Now thats a old-timer straight six with DOHC 4 valve head. Cool

Here is the excerpt taken from the book "How to build & modify Chevrolet small block V-8 Cylinder heads" by David Vizard Here he explains how squish influence detonation resistance : In addition to swirl, the "squish" effect produced by the quench area can have a significant effect on how well and how rapidly the charge burns. In essence the effect of squish form the quench area is rather like that of throwing the mixture into the fire to speed the burning process......The ability to burn the charge quickly close to TDC means that less ignition advance is needed. This means more of the pressure rise can be used on the downward side of stroke rather than the tail end of the compression stroke.....As swirl and turbulence are increased, the rate of flame propagation through the charge is speeded up. This means the last part of the charge to burn spends less time exposed to the radiated heat from the flame front. This, in effect, cuts the tendency of the charge to detonate. .....the closer the piston approaches the quench area, the better the squish action and the faster the charge between the piston and cylinder head deck surface is shot out into the chamber. Second, if the gap is too large it presents a "critical detonation section." It appears that anytime a charge thickness of around a 0.100 in. exists, it's a prime candidate for detonation. This is especially so if it's off from the mainstream area of the combustion chamber.....On a stock Chevy a 0.038in. head gasket and a 0.050 in. deck height constitute the quench area---that is, about 0.090in. This density of charge in the quench area isn't outstandingly conductive to suppressing detonation, and often detonation will occur. .....by the time these gases(air/fuel mixture) are ready to ignite, the critical charge thickness of around 0.100 in. exists; in other words, the piston has just gone past TDC and has started down the bore. These charge thicknesses are too thin to ignite and burn conventionally, but they can be burned after the effects of radiated heat and pressure from the advancing flame front do their thing. The result is detonation. and here he shows a case example, a SC SBC improved by using quench On the dyno a supercharged SBC with an 8.5:1 CR revealed trace detonation with 10psi of boost. The piston-to-deck clearance was about 0.040 in., giving a total piston-to-head clearance of 0.078in. Previous experience with other engines had indicated that the quench clearance could be significant in suppressing detonation, The engine was stripped and the block was decked 0.045in. to bring the piston 0.005 in. out of the bore, which with a Fel-Pro gsket thickness of 0.038in. gave a piston-to-head clearance of some 0.033 in. The resulting CR of the assembled engine was now approx 9.0:1. No detonation was seen on 10psi of boost, and the engine made an additional 12hp under full-throttle conditions and produced better Brake Specific Fuel Consumption(BSFC) figures when delivering 60hp at 2200rpm, my standard highway cruise test. Those results were significant enough in themselves; however, subsequent tests showed that an additional 2 psi of boost could be put into the engine before detonation again reared its head. Those extra 2 psi produced some 28hp more from the engine. So in this respect we see that attention to the quench area allowed the engine to produce some 40hp more, along with a significant improvement in about-town and cruise economy.

hmmm good question, never thought about it.

It's a sticky in the turbo/supercharger forum. http://forums.hybridz.org/showthread.php?t=99620

I am not sure about it being the "major" component as it is really diluted in leaded Gasoline, like 1/1200.

I'd hit that.

When I looked at using VG pistons, the closest I can bring them to block deck(L28) was by using a set of L24rods and LD28 crank. But that ended up with the piston 1.6mm below the deck at TDC. The headgasket is 1~1.25mm thick that means when the engine is on compression stroke there will be a 1.6+1~1.25 = 2.6~2.85mm thick of a flat region of air/fuel trapped between the combustion chamber's quench pad and piston top. Whenever there is a region of air/fuel trapped in a thin space surrounded by metal, it becomes a region that can start to knock easily. The reason for that is because flame travels to that region last and the metal surroundings act as heat sink that prevents the thin sheet of charge to burn normally. As a result, a part of air/fuel charge is preserved while temperature and pressure in the chamber elsewhere keeps on building. When condition is right the thin sheet of charge can detonate. Even when it is not knocking, the metal-charge-metal sandwich reduces power and fuel economy because flame have a hard time reaching there until burning condition improves. On the other hand, if there is enough squish, the air/fuel charge becomes more turbulent to improve flame propagation and it will help surpressing detonation and allows more power to be created(more boost) before detonation emerges again. The theory above was mentioned in a David Vizard book. In the book there is a comparison between a supercharged SBC with no quench and the same engine with quench after the block is decked. If you are interested I can take out excerpts and PM it to you.

good for you.

For surpressing detonation? no it will make it worse. But for ultimate power nitromethane is what they use(top fuel dragster, top fuel = 95%nitromethane) It is not safe neither, it is an explosive than can be detonated. it can combust in oxygen-free environment and produce carbon monoxide in the exhaust which cause fatigue/sleepiness and then kills. http://en.wikipedia.org/wiki/Nitromethane

You know that's is really weird because I don't even have the link to Lengine. I already have the Lengine program. since it's a Windows program there is no need to keep the web address after the download. TheHelix's engine utility however, needs to be run on the browser so I kept the web address. Anyway, now that I have your attention, here is the link, the author is a member here as well. http://www.ozdat.com/ozdatonline/enginedesign/ It has a lot of parts specs including LD but no VG30E or ET specs. To get VG30E piston spec, change the spec of a VG30DE piston into 21mm pin and the rest are the same. I don't know about VG30ET specs but I don't think you need the extra dish. I thought about using VG pistons but gave up on it because it will not give good quench but rather create a condition that might be prone to detonation. Dr.Hunt, The utility is mainly for L series and other Japanese engines so I am sure you won't be interested;) But to answer your question, it is not a dcr calculator. Probably not scr either because you can change the cam specs and the calculated cr won't be effected. The link is written above.

I think he was talking about TEL. Pure TEL is highly toxic. It exists in leaded gasoline only in diluted form.

Like "The five people you meet in heaven", but car related. What are they and why. Here's mine: 1. My current beater and first car, 1996 VW Jetta GLS(deep metallic blue). Dorky, uninteresting, but accompanied me for years. Sentimental value. 2. My 260Z(will be pearl white) with L28et. Of course a Z for me because I never liked cars all my life until I saw a Z. Will prolly still be building it in the afterlife, some panels just won't line up. 3. Jaguar XJ13(black or dark green). The sexiest looking Le Mans race car IMHO. Very low and probably very hard to drive so mainly an eye candy. 4. A fully prepped R34 Skyline(Silver). Must have a 4WD car to enjoy the unique quick launch. If it can't be imported in heaven then a Porsche 959 will take its place. Skyline and the Z will give me something to modify. 5. Placeholder for a "supercar", but which one which one If the Skyline is fast enough for me then maybe I'll get a M1 tank instead.

Respect Yeah! now I am want one too. How does he run boost with 10:1 CR? Must have done something. You think the 1.8T 20V Audi engine is more capable than the SR20det engine people are talking about?

Nice instrument panel Tim.

That maserati is a total babe. The other day I saw an Aqua blue pearlscent Maserati grand sport, sexy. I like your project especially, because sometimes people talk about their ambitious project first and then they don't do it. You do it first, then you talk about it after you begin. This is definitely a project I will closely follow updates of.

This is no juvenile forum, this is a member's car you are talking about. please be polite and save those tactless comments on something that truely deserves them.

humidity or water vapor is a flame front retardant too. It slows down the speed of combustion. The other scenario I can think of is on carbureted engines or engines with electronic management system that is not equipped with oxygen sensor. In those systems, fuel is metered according to vacuum and airflow only. When there is water content in the air, the fuel setting becomes rich because the metering isn't adjusted according to the oxygen content in the intake charge.

nice video Phil. Got the people factor in it.