doradox

You could put a large return line at the carbs with a low pressure regulator just past the carbs. In other words bypass most of the volume from the pump back to the tank to lower the pressure. Steve

It is generally accepted that CV joints are more efficient than Cardan joints. One might argue that CV joints aren't really all that modern though. Steve

Modern engines have higher compression, lower internal friction, and ignition/fuel systems that are extremely precise. Add aerodynamics and low friction drive trains to that. I think your mid 20's highway goal is achievable though. Steve

Because it's lighter. Not because you have more power. Your car won't be faster in a top speed way because you don't have anymore horsepower. It will get to that top speed quicker because it's lighter. Flywheel weight loss is especially effective because you double dip. You lose rotational mass and overall weight. On an Inertia dyno you will show a HP increase but a brake dyno you won't. The inertia dyno is fooled by the reduction in rotating mass since it calculates HP by how quickly the drum accelerates. Since all the rotating mass in the car is factored in to the HP calculation any changes in the car's rotating mass throw off the calculation. It's the same thing if you put light tires and wheels on. Your car would magically have more power. You wouldn't say my car has more power after putting on a set of light wheels and tires would you? Steve

If I'm in your neck of the woods when it happens then why not.:classic:

I have just one thing to say. EMP attack. You folks with electronic igintion will be sitting on the side of the road while I motor past on the way to my hideout in the hills. Steve

Nothing wrong with a well maintained distributor with points. Well maintained. Most folks have no idea how a set of points and condenser function let alone what is required for them to perform properly and reliably. My first 73, which I bought used with 60,000 miles on it, ran just fine for another 140,000 with the stock point distributor. Yeah, they needed serviced every 10,000 miles or so and I had the distributor rebuilt at 120K but they were far from unreliable. Steve

The first gear on the input shaft and countershaft are a constant multiplier for all gears except 4th. power comes in the input, is transferred through the first set of gears to the countershaft, then from the countershaft to the gear that is selected then out the output shaft. Fourth gear is just the input and output shafts locked together. You need to take into account the ratio of that first pair of gears.

CV joints? I wasn't aware that a 280 Z had those. I thought they were Cardan joints. Steve

If the alignment shop had measured SAI (steering axis inclination) you would have a better idea if you had a bent strut. Good SAI and bad camber means bent strut or spindle. Bad SAI usually means bent frame/control arm/etc but does not indicate a bent strut but does not rule it out either. From your numbers and your observation it sounds like a bent strut. Steve

Maybe this will help you figure out which oil is the best for your Z. http://www.swri.org/4org/d08/GasTests/home.htm Steve

Combustion byproducts leave acids in your oil. Starting a cold engine and then shutting it off leads to water condensing in the engine and exhaust. Acid + water. They do their damage while your car sits waiting for the spring oil change. Rich mixture on start and poorly sealing cold rings and cylinders accelerate the contamination. There's no good reason to start your engine if you are storing your car. The parts car I bought a while back was "stored" outside and hadn't been run in 15 years or so. When I pulled the valve cover everything was coated in a film of .....oil. Steve Steve

There's a lot of debate about what our engines require and it comes down to this. Nissan recommended an oil that met certain performance specifications, not chemical specifications. Here's one they do today on a flat tappet engine. http://www.swri.org/4org/d08/GasTests/IVAtest/default.htm There are some modern oils that perform quite well on this test even with low levels of the additive many will claim is a "requirement". Mostly there is no one "best" oil as none outperform all others on the many tests required to be certified. http://www.swri.org/4org/d08/GasTests/home.htm You may want to research your oil choice and pick one that performs well on the test or tests you believe to be most important to the life of your engine. Steve

Check the pedal free play is about the only thing needed. It might not hurt to check the fluid level just to be sure even though the trans has been rebuilt recently. Too much fluid, or the wrong weight, might make your problem worse than it would normally be. Once the trans fluid is warmed and thinned out the rpm change would be less as it would be easier for the motor to spin the gears and that seems to jive with what you experiencing. Steve

When the clutch is depressed the engine disengages from the transmission and no longer spins the gears in the trans. On a cold morning that could account for what you are experiencing. Does it do it after you've warmed up the engine and driven the car? If you had a dragging TO bearing the opposite would be true. The drag would occur when the clutch was depressed. Steve

This we can agree on. Steve

E10 has about 3 % less energy than "clear" gas by volume. It's unlikely one would see a 20% drop in mileage. Steve

Color tune is for mixture, Unisyn is for air flow. Steve

Assuming you want to stress relieve and not harden (you did leave out the critical cooling phase definition and wire hanger is typically low carbon steel which doesn't harden well) why would you waste the time and money to do that? In other words, what's your point? Steve

Your stuff is comedic gold. 1. Yes you are. (how do you like that for fact filled and compelling argument?) 2. You are right, the air, where once there was steel, between the cut flanges will help maintain their alignment. Everybody knows that. There is no chance that residual stresses in the tube will cause the now free end of the flange to move out of position. That's just crazy talk. 3. "as long as there is proper port alignment" ? You're right. As long as you get lucky and after cutting up this header the ports are still aligned then they are still aligned. Why didn't I think of that? See the part about the air helping to keep them aligned. 4. Oh no! The dreaded "on the contrary" argument. Well, I just have to say that one was well played. I just took an old multi-flange header and bent some of the tubes out of alignment and all the other headers in my shop suddenly became misaligned. I hope I didn't mess up everyone's headers. So I guess you are right. They do matter to this one specific header we are discussing! Who could have imagined such a thing? Steve

Yes, it is easier to line things up during welding and keep them aligned after welding because of the flange structure. Taking this header, designed and manufactured with a solid flange, and cutting it after the fact defeats the purpose of using the solid flange structure to maintain alignment. Cutting a part compromises it's structure. Is it compromised to the point of the entire assembly failing? Possibly not, but that's not the point. Can it still maintain port and bolt hole spacing? Who knows. It wasn't designed to do so after being cut up in the field. No engineer would even for a nano second wonder if his design would still perform if some joker took a hacksaw to it. Are other headers designed with separate flanges? Yes, and they were designed and processes specific to that design were used to maintain proper spacing after manufacture. Steve

If cut the flange would be structurally compromised. That's a fact. As a matter of fact it's pretty much the definition of structurally compromised. Why can't you admit that? If cut it can no longer perform the function of controlling port and bolt hole spacing between cylinders. So not only is it structurally compromised but also functionally compromised. That's a fact. This header was not designed or manufactured with a split flange. Fact. How all the other headers in the world are made is irrelevant to the structural integrity of this header. Steve

I think the obvious conclusion is that if one cuts up an existing structure it's integrity is compromised. Will it still work. Maybe, but that's not the point. 5thhorsemann said.... "the integrity of that structure is compromized" His statement, for all intents and purposes, is true. Steve

Gee, I'd have to say that if one cut something in half that it's structure might be compromised just a little. But maybe that's just crazy talk. Steve

Did you mean clearances and not tolerances? Steve