Zed Head

I don't claim to be non-ignorant. Feel free to pick out the specific points if I'm one of the purveyors of bad information, on the welding, the acid bath, or the need to re-coat the body. Or the difficulty in getting things clean enough. I'm seeing two messages (or one big one) in your post. Basically, that it's only worth doing for a race car, a waste of time for a street car. Shed some more light please. Thanks. p.s. The OP is just trying to make the car feel firmer and less noisy. Any thoughts on the first things you would do to stiffen the chassis? My car creaks in the headliner area, in the back, if I get diagonal wheels unloaded, like when coming off a ramped, humped, driveway at an angle. I assume it's the body torquing a little but I don't know what to do to stiffen it up diagonally.

That's not a factory blend of parts. You have an L24/240Z head on an L28/280Z block. You'll have to pop the valve cover off and look for identifying marks on the cam. If I had to guess, I would say that it's the cam that came with the E31 head, which would have an A stamped on the back, according the link I posted. The simplest option, just a different block with the old head and carbs (although I'm no expert on what head or carbs came on a 71 240Z so could be way off).

See if there is a letter stamped on to the back of the cam - http://atlanticz.ca/zclub/techtips/cam/index.htm Find the letter/numbers stamped/engraved on the cylinder head, above the 1 and 2 spark plugs (E88, P79, P90, N42, N47...). See if you can find the letter/numbers molded in to the bottom of the block, almost behind the driver's side motor mount, right above the oil pan lip (N42 or F54). Post all of this information and people will tell you what you're working with.

I think that the acid bath will make the whole car a spot for rust to start. You would have to do the acid bath, do the welding, do another acid batch to re-clean everything, then do a dip in E-coat or rust-proof coating of some kind. Could get very expensive. I've seen a thread or two on another site about stitch-welding the seams after extensive media blasting and even then there is lots of smoke and contaminated welds. Sounded like a real pain. Might be more effective to add some of the typical body/frame bracing first and maybe some selective welding. Hybridz has a lot more to look at, since they have a racing tilt over there.

Weird, I never realized that those were in there, I guess they're kind of buried. They're shown in the RA section of the FSM as a spacer. Might explain the quarter inch mismatch on the rear of my car. Edit - Found a diagram and part number. http://www.carpartsmanual.com/datsunS30/DatsunZIndex/Axle/RearSuspension/tabid/1731/Default.aspx

I think that the comments about the bump stops were made because you asked specifically about the strut mounts. You're right, you won't know that they're there unless you hit a large bump. When you said that you had the drive shaft aligned, what did you mean and how did you do it? The SBC swap usually leads to having the nose of the differential too high. Many people use an "RT mount" (design by Ron Tyler), a redesigned differential nose mount for higher strength and less nose movement, which also lowers the nose to get proper alignment. If the front and rear u-joints aren't on parallel planes, you'll get a buzz.

I've stopped by there and they do seem like good guys. What kind of work did you have done? And what kind of work did you ask the other shops to do? Without details, it's just aimless venting. Better to be nice, no one is going to volunteer their services if they think you're hard to please.

Headlights do get old and die. If you have power at the fuse (measure voltage from the fuse to ground), there's probably power to the headlight. I bought a bunch of new fuses and just replaced all of mine. Cheap insurance. I found one that looked original, probably been in use since 1976. Maybe 35 years old. Most of the others looked pretty crusty on the inside. Your ammeter won't bounce between high and low until the headlights work again. No current (amps) is flowing. The connector probably had a poor connection causing resistance that caused heat. When you opened it up and put it back together you created a better connection so the heat went away. When cars sit without moving, the heating and cooling cycles are enough to open up the connections and allow light corrosion to fill in. Use 'em or lose 'em.

A couple of classics for sale in the area, at least one looks pretty nice - http://portland.craigslist.org/clk/cto/3245214464.html http://portland.craigslist.org/clk/cto/3245040229.html

Volt/ohm meter. And don't forget that red is not always the positive cable.

Funny, I have one good one that I bought from someone local when I thought I would need it soon, and figured that I would never find one in the wrecking yards, and another that I found in a wrecking yard about two weeks later. But it has a groove in the splined input piece, from a worn seal, that may or may not be in a critical spot for my use, which would be a 300Zx transmission with a swapped bell housing in a 76 280Z. But the groove would definitely be in a bad spot for an early 240Z. In short, I have a good one and a bad one but want to keep the good one. What do you need it for?

You say that you have the pump powered through a toggle switch. Where does the power to the toggle switch come from? What "connector under the dash" are you testing for voltage? If it worked before, the most likely problem is a loose connection or blown fuse.

I measured the old one from my 1976 Z, off the car, and the rod measures 3 3/4" to the end of the rod from the firewall mounting surface. Fully extended out of the bore by the internal spring. 2 5/8" fully compressed. Stroke length of 1 1/8". The auto store cross-reference shows that they should be the same cylinder. Hope that helps. If you disconnect the rod from the pedal at the clevis the rod should extend out to its maximum, from the internal spring, which would be the desired starting point to get maximum travel, and slave cylinder movement. Might give you a clue on how far off the pedal is from what the master cylinder needs.

You mean the short ones, used with the diffs that were mounted forward. I have a couple of those. I got 21 1/8" from the center of each yoke.

What year car?

To confirm, either the 72 FSM is wrong or the zhome numbers are wrong for 1972. The FSM says the 4 speed is 3.9, zhome says the 4 speed is 3.36. I've always heard that 3.36 is the stock 240Z R180 ratio, but the FSM says otherwise.

The 1972 240Z FSM, PD chapter, has the ratios the other way around from the Zhome site. Kind of confusing.

Might as well get the coil to go with the ignition module on the distributor. Make sure that you get the mounting plate with the distributor also, it's different. Then you'll have a drop-in electronic ignition. With different advance curves, centrifugal and vacuum, than your 240 but they can be modified.

Probably from your writing. Above you said that you're working on the fan clutch, then said that your early 260Z doesn't have a fan clutch. You're either talking about two different cars or just not explaining things clearly. I thought that you had two cars also. Now you said that you've added more weight to the fan clutch which also doesn't make much sense either. Overall, it's hard to tell what caused the over-heating and why it would be better now. But, if it works for you, good luck with it.

beerman made a good point - you might just have a bad battery. How many batteries have you replaced along with the six alternators, over the eight years?

"stumble wen it gets hot" isn't really enough to even make a guess, is it? And who are "they"?

Details of the car and engine, and how far the needle gets toward red would help. The gauges aren't known for accuracy.

This site is handy and informative - http://www.ngksparkplugs.com/tech_support/spark_plugs/faqs/faqcode.asp?mode=nml If you're on a phone (I'm hoping that's the reason for the effortless grammar) - R means Resistor.

www.xenons130.com/reference The factory manuals don't suck.

You're not measuring the correlation of spark and distributor, you're measuring the correlation of spark and piston position. If the mark is at zero when the piston is at TDC, then the flash of the timing light will be accurate. That's why a timing light is used, instead of setting things at the distributor.