Zed Head

Kind of looks like the guy who wrote the eBay copy didn't actually build the car, or oversee the build. It has a blowthrough turbo with a Holley carb, which he doesn't really describe at all, and he says it had a "frame off restoration". It was only driven to break the engine in. The usual exaggerations also. 500 miles on a brand new engine, with a turbo and nitrous, and he's already claiming that it's "just an awesome reliable ride to cruise around in". Cars like these really need quarter mile times, track times, or dynamometer numbers to show performance, or they might as well just have an empty block with the external shiny parts bolted on. Who knows who put that engine together. The first fill of the nitrous bottle might be hilarious.

I am fairly certain that I tried to turn those adjustment screws and they wouldn't budge. I've also tried to turn the adjustment screws in my oil pressure gauge and they wouldn't move either. The only adjustment I've been able to make on any gauge is on my voltmeter. I wonder if Nissan didn't use some kind of threadlocker on them, since they should only need adjusting one time. Maybe a drop of acetone or MEK on the screw would break them free, or some heat from a soldering iron. A future project maybe, for a spare meter.

My 76 tach shows a steady 200 RPM too high, when compared to my meter. It's a Fluke 115, I use DC hertz to measure, then do some math. I've had my tach dash jump around and misbehave with a new ignition module,even though the engine ran fine. An extra condenser on the negative wire brought it back to life. The tachs seem sensitive to noise. They don't need much "signal" to work, there's actually a 2,300 ohm resistor inline with the coil, on the 76. Your 240Z tach uses the positive side though but may still be sensitive. Maybe a new condenser or an extra on the circuit would help damp some noise.

At least you got to drive it for a little while. I get the impression that the guy is kind of a BS'er. This quote just goes against all that I've ever seen about the L series heads - " built hundreds of heads without worrying about matching rockers to the cam and centering the wipe pattern with no problems to date". On the valve seals, if he didn't use the little straws to protect the seals during installation, he could have cut them. Maybe another internet myth. Also noticed that he talked to you like he rebuilds the heads himself, but the eBay site says thet they're rebuilt by a professional machine shop. Same company, but different stories. He even told you hundreds, but says dozens below. The Datsun Parts LLC disclosure is at the bottom of the eBay ad. "*THESE ARE REBUILT AT A PROFESSIONAL MACHINE SHOP THAT HAS SEVERAL YEARS REBUILT DATSUN HEADS. I HAVE SOLD DOZENS OF THESE WITH PERFECT EBAY FEEDBACK. **" http://www.ebay.com/itm/Datsun-Z-240Z-260Z-280Z-ZX-Rebuilt-N47-Cylinder-Engine-Motor-Head-1976-1980-/151491312445?pt=Motors_Car_Truck_Parts_Accessories&hash=item234595fb3d&vxp=mtr Sorry, hope I don't kill your interaction. Send a PM if you want to keep things quiet for a while and I'll edit this down.

Same comments we're making over here. Validation! I guess if you don't need the cash right away, it's an investment of time to wait for the "right" buyer. Like lurking out in the weeds for the right trophy animal to wander by. Bagged him...$80,000!

Details on the L24 "enhancements" would be interesting. You could probably sell the engines and the car separately more easily. There are a few members in your area that might have some ideas for a local sale. Put ATL GA in the title.

I'm not saying that those rocker arms are bad. Just that they appear to be pulled from a collection of odd rockers. I'm pretty sure also, that I can see the typical shiny line in the middle of the contact pad that used rockers get. DPLLC probably just shipped a batch of collected rocker arms off to Delta for refinishing and pulls from the collection when a head is "rebuilt". He just messed up on lash pad selection.

Look at the pictures and you'll see that design isn't the same. Not small differences. Even someone carving their own arms from a chunk of wood to be used for forming the sand mold would get them closer than that.

I just noticed that the rocker arms appear to be from different sources. One would assume that the rough casting shape would be the same for a common manufacturer but you can see that the portion of the casting on the inside of the wear/rubbing/contact pad is different on several of the arms. Less material. The shape of the "foot" that sits on the lash pad is different also for the ones that have the different contact pad seat. Kind of fits the impression I've had of DPLLC that he collects parts, used and new, from various places, then assembles engines and heads from his collection. Not trying to pile on, just noting. Maybe a little ammo for you to use when talking to Al (the owner, apparently). Interesting also that the cam actually wore some of the casting after it fell off of the pad. The wear pad is supposed to be harder than the casting, apparently, so probably no extra cam damage. Good luck.

Actually, I was almost remembering the wrapped rail. That's what it was. Wrong "not stock" memory. Maybe your FPR got stuck and overpressurized the rail for a moment. Although, having taken an FPR apart, I'm not sure how that could happen. Good luck. I hate the smell of raw gas.

Hey, since the cam and rocker arms took so much abuse but still survived, could you share the names of the companies that made them? ITM and Paraut are typical rocker arm companies. I have a thread on Hybridz collecting info about rocker arms, just because they, or the cams. seem to fail so often. You have dodged the bullet, so far.

Bummer that you have to deal with more problems but lucky that you found it early. I think that you might have some nomenclature/naming a little off. What you're calling the "lash pad" is normally called the rubbing pad. The "bucket shims" are the lash pads. There's a sentence in my Honsowetz How to Modify book that says "The only sure way to determine correct lash-pad thickness is to check the cam-lobe wipe pattern". Page 70. Trial and error. I've seen it described that if the valve stems are all trimmed to the same length out of the head that you only have to do one. But I've also seen that some builders leave random valve lengths in the head so each requires a different lash pad. On the rocker arms, since they're been wearing on half the pad you'll need to carefully check that there's not a discontinuity in the middle of the pad. Worn and unworn. On the oil usage - if DPLLC installed a high lift cam it may be pushing the retainers ( I think that's the part) down in to the valve seals, damaging them. Page 63 of said book says that 0.460" (11.7 mm) valve lift is the maximum. Rocker arm ratio is ~1.5 I believe (although others have measured differently), if you have cam specs. ~7.80 mm (0.307") max Or you could look at a seal. There's a Ford valve seal out there that people use with high lift cams. DP might have used stock seals with a high lift cam. Doesn't really look like he knows a lot. Thanks for sharing though. You should get back to him with what you found and see if he tells you "tough luck" or offers help. At least he should pay for the lash pads and new seals. That would be good to know.

Can't tell whose car is what, but if you have full time vacuum on the advance canister, you could see 32 at idle, which will drop to 32 minus max vacuum advance (the 16 djwarner saw) when you open the throttle. Most people run ported vacuum to the vacuum advance canister. Or disconnect the vacuum hose when checking timing. 16 initial isn't unreasonable. That would give 34 total at open throttle, high RPM, with 18 degree (not uncommon) weights.

More likely that the inner lining would get damaged during installation. They're multilayer. But you already knew that. I was just pointing out the possibility of the leak starting in a not obvious location. Another thought is one of the fittings on your fuel rail. Brass fittings in aluminum might loosen a little over many heat cycles. Just brainstorming...

When my old injector hoses failed they cracked lengthwise internally. I smelled gas, stopped and opened the hood, and a very thin stream of fuel squirted out on to the sidewalk. A tightening with a screwdriver got me home, but that fuel traveled quite a way from its origin.

Wow, that's a big change in pressure. Pretty good example of why valve lash is the very first thing in the Engine Tuneup chapter. You can get low compression also, if the intake valve doesn't open soon enough. It's the air that pulled in on the intake stroke being pressurized that causes the cylinder pressure. Less air to compress = lower pressure. So your adjustment caused the front three to pull more air through the front carb. I know very little about carb tuning. Very little. It's like more vacuum.

You could take a screenshot, save the file, then attach the file. Windows 7 has a tool in Accessories called the Snipping Tool. Open it, circle the stuff you want, then save it as a very small file. I've only been able to paste a few types of files in to any forum's software. Most don't allow pasting images.

I've used the two part epoxy fuel leak repair material on a pin hole leak in a tank. It worked well. Another option.

Just curious, but how did they dyno-tune the engine and end up with the distributor fully retarded? Wouldn't they give you timing specs. as part of the "tuning"? What's the point of the tune if they don't give you the numbers? And shouldn't the engine still have good break-in oil in it? Or did they drain it before shipping? And you would think that if there was odd noise that they would have heard it while dyno-tuning and breaking in. Lots of "doesn't make sense" here.

Doesn't Rebello run their engines for a break-in period? Or is that only if you ask for a dyno sheet? Many of the performance cams run a tighter lash than stock. I agree with madkaw, just do exactly what the builder says to do. He's built hundreds or thousands of these. If it were mine, I would make a video or sound file and send it to him. You might have a problem that can be fixed before it does extra damage. Or even call him first and tell him it's very noisy. He might have a procedure he wants you to follow. On the lash - you can't stick a .010" in there but what can you? What is the actual measurement? Lash grows as the engine warms up, but if you're starting with a valve open when cold, you could "burn" or warp it. Best to get a real number. Bummer that it's not an easy break-in. Extra noise on a new engine is not normal.

I found one that actually worked better than stock for my 76 280Z. But I'm not positive where it came from, I picked it up with a shifter for a 71C transmission. It was either a later model 240SX or a later 300ZX. Had to poke new holes through the rubber, but I was able to use the same holes in the tunnel. The stock one rubbed in 5th gear, the new one was lower and doesn't. Might be this one. $6.78 US, might be worth a try. Probably get it from a local dealer. http://www.courtesyparts.com/34122mb-boot-dusthand-lever-300zx-z32-1990-1996-p-40239.html http://www.courtesyparts.com/300zx-parts-z32-1990-1996/genuine-nissan-parts/power-train/341-transmission-control-linkage/-c-882_883_953_971.html

The eBay guy "harmony01" has been discussed before. He seems like just a sales-type who pushes hard to sell his cars. He does have good comments in his feedback, but the problems with the paper-work make you wonder if he's not very honest or maybe incompetent. http://www.classiczcars.com/topic/50163-1969-hls30-00182-on-ebay/ http://www.ebay.com/sch/harmony01/m.html?item=161438375051&forcerrptr=true&hash=item25967a1c8b&pt=US_Cars_Trucks&rt=nc&_trksid=p2047675.l2562

Sometimes I use a dry shop towel, the blue ones, to find small leaks. The light blue turns dark when it gets wet. Just touch it to all of the interfaces and see what turns color. Also wouldn't hurt to put a screwdriver to the clamps. I've found that the Gates brand EFI hose, although of apparently high quality, tends to creep over many heat cycles. I've read that today's clamps are all spring tension clamps, designed to keep constant tension on the hose. The hose is probably designed for the newer systems. The screw types are constant diameter and the hose can creep and loosen up. My Gates hose took several tightenings until things stopped moving. I'll bet your hose creeped and all of your clamps are looser than when you installed them.

For emphasis - we really need to know who this person is. At least the eBay name. That's what these forums are for, to share information like this.

eBay is notorious for fake ratings. People who sell there will give other users bad ratings if they get one, so everybody gives everybody else a good rating. The ratings are essentially useless. Post the guy's name. If he has sold 100's of cars and owned 100's of Z's then he should be known to this community. Nothing wrong with vetting a person who's asking you for thousands of dollars. And, here in the States anyway, expressing an opinion about how someone does business is not a crime. The old high bidder bailed out routine is a common scam technique. And, on the same point, the high bidder, if there actually was one, is in the same position as you. He agreed to buy the car then changed his mind. He would get sued first, if that was an option. But it's not an option, nobody is getting sued. The seller/scammer is pressuring you because he senses that you are unsure. An easy victim. Everything about this says scam or big problems. He might have a car but once he gets your money, it might take forever to actually get the car, plus I would bet that there will be many extra expenses for shipping, and insurance, and miscellaneous. Please post this person's name. It's probably a fake one anyway. At least post the eBay name.