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Gollum, I'm not interested in getting into a contest on this subject, just trying to provide some education based on many years in the world of professional audio. As I mention in my previous posts....I agree that there are many many variables that will alter the root frequency but the basic tone has to do with the size and volume of where the sound comes from and what it propigates through. Another major factor in the tone of an engine is the frequency of the events (RPM).

I've been very happy with my Yokohama ES100s....I'm about to install my third set on my 240Z. They stick very well for a street tire, not as harsch as simliar tires, and are pretty quiet to boot....and of course, reasonably priced!

Mobil #1 synthetic 10w-40W (Location SoCal) I use their filters as well...pricey however!

A possible contributing factor on the dual quads may be in how the throttle linkage is set-up. If under easy driving condition (not much fuel/air required), some of the old set-ups employed only the primaries of the front carb, causeing leaner mixtures to some cylinders. Others linkage set-ups employ both sets of primaries, netting a more even distribution. Of course under full throttle all eight venturis are working. I'm curious....I have no idea how your 400 sbc is built but, I was wondering if two 600 cfm carbs are too much for your engine to handle?

I think I hear an echo Jon!

Maybe the age of the muffler (12 -14 yrs old) had something to do with it's demise!!?

I believe veritech-z has it correct. The coating does reduce radiated heat by about 40% (according to their advertising and testing)....thats one of the reasons it is applied to headers. Another reason is to keep the heat in the exhaust gases. Hot gases flow quicker than cooler gases....hence a slight performance increase. Also, due to the thin nature of the header material they will cool off quicker than say the intake manifold, which is certainly thicker material. Hope this helps explain it!

You might consider the addition of a tube brace from the main hoop forward to the chassis. This would triagulate the weaker door opening area. Getting in and out of the seat will likely be more difficult however!

I believe all that you guys have mentioned certainly contribute to the overall sound of an engine. The point I'm trying to get across may be explained by the following example.......think about why a trumpet sounds different than a tuba! One has more volume and larger diameters (tuba) than the other (trumpet). What do ya think?

Yea, probably electric cars are the future. One good thing is, they have tons of torque (great accelloration). Supplying power will and is the issue of course. Imagine tires with piezo electric technology incorporated to generate supplimental power to batteries...in addition maybe the skin of the car will have solar power generating capability to add to the power generation. Of course my electric car will have an audio system that produces the sound of a V12 Ferrari so it will sound cool! Somehow, I don't think they will be manufacturing tunned headers for electric motors.

I think your theory has merrit.....an undamped spring will certainly cycle unabated and would tend to degrade sooner.

Dumpster diving.......had to laugh because I used to do it! Well it wasn't a dumpster but the rem pile at the base general machine shop. When I was prototyping a new...can't tell ya or I gotta kill ya, do-hicky for a project I would stop by the general machine and scroung what ever was applicable.....and it saved the tax payers a bit of $$$ too. They tossed out some pretty nice pieces of material.

Typically teflon tape is not recommended fpr fuel system fittings. Why, because if allowed to enter into the fuel system it can clog things up.....like pumps, regulators, jets......! If you are using flared AN fittings, they require no sealant. They seal via the flares. The threads on a flared fitting do not create the seal. However, if you are installing a NPT fitting it can be used provide you don't apply the tape to the first three thread (an aircraft requirement IIRC). This practice is some insurance that the teflon tape doesn't get into the working system. A good alternative to the teflon tape is teflon pipe dope but, the same applies about not allowing it to get into the working system. Hope this clears the air a bit! Tom

Heres an observation on why one engine sounds different than another. Think about the diameter and volume of the cylinders, number of cylinders, and intake and exhaust runner lengths and diameters. In the world of acoustics, a smaller diameter and or volume device will provide a higher frequency responce than does a larger diameter and or volume device. Some food for thought!

veritech-z, Thank you....you are so right about stance. Hate to see a nice set of tires/wheels on a car with 4" of radial clearance between the fender lip and tires. Gotta love having coil-overs for adjusting ride height!

I've always admired that engine bay.....very very nice!

My feelings concur with dr_hunt! I'm betting you had an odd feeling when you let them do your engine! As an aircraft mechanic, you are probably telling yourself......man I knew I shouldn't have done that. Personally, I'd start from square one and have everything checked out.....never know what an un-educated high school mechanic student may or may not have done.

So, are you suggesting its basically impossible to make a women happy...long term?

Dayz, Electric fuel pumps are just fine, plus you will free up a little HP that a mechanical pump requires to operate. My only recommendation is to get a gear driven pump as opposed to a diaphram type pump.....the gear type pump design is less noisey!!!

If you are talking about the vaccum advance pot on the distributor, I don't think so. Inside the distributor, a linkage arm is connected between the vacuum pot and the timing advance plate assembly. I cannot see how you could use this as a boost actuator. Or, are you suggesting that you take the vacuum pot off the distributor completely and use it?

Just out of curiousity, were the rockers shown in the pics new or did Zmanco use the old ones?

Isn't it interesting how the right set of wheels/tires can turn a so-so looking car into a bad azz looking car!

Crashing sucks!!!!!!!!!!!!!!

Gotta love those "Jeff Gordon" seats and NASCAR wheels. Just kidding of course! The front facia looks pretty nice....but the rest of the 280Zx......well, like I was once told "If you don't have anything nice to say don't say anything"!

Sounds like its time for some wrenching!!!! Sometimes the only way to know for sure is to open her up and do an inspection. Be safe and use some decent jackstands.