Zed Head

You should check your diff for sure. If it has an L28 it might also have an R200. I never know for sure what's going on with the 240Z diffs. The FSM seems to show certain things and people find different on their cars. The 1973 FSM shows a 3.364 ratio diff in your car combined with a 3.592 first gear. But that still leaves a 3.364 final ratio in 4th gear, which is "tall" and should not leave you grabbing for 5th on the freeway. A 280Z with a 5 speed would have a .864 x 3.54 final ratio >>> 3.06. But the 280Z's came with 4 speeds for three years, a 3.54 final ratio in top gear. So your stock 73 240Z should have a nice cruising RPM in top gear. Anyway, in short, know what you have before you buy replacement parts. You can determine your diff ratio by turning the wheels and counting propeller shaft revolutions. Take a picture and post it and we'll tell you if its been replaced in the past.

Metal fatigue is a whole different world than metal strength. If the cam towers were off a little bit that small bending motion could fatigue the shaft over a few billion revs. Turning the back half by hand/wrench might show if a valve is bent. Might help with planning the repair, if you want to do it all in a short time. On the other hand, you could just unplug the back three injectors and drive it that way while you pick up parts.

Funny that in this case two wrongs actually made a right. I missed where you told who that guy was that did the final tuning and problem solving. He seemed to know what he was doing for sure. Those washers are called yokes. People have problems with them often, even the header manufacturers don't seem to understand that they need thick flanges on their headers to match the intake manifold flange thickness. Lots of bad header designs out there. Good video, worth a watch.

Camshaft. I saw that. That's what I meant about the front three should have run fine unless cam timing was off. I think I read "front fire" as a problem with the front three cylinders though, so I guess you were running on half power, cam timing is probably fine for the front three. Front firing is typical of a flattened cam shaft lobe. Really common on small block Chevys. So that does make sense since the back six valves were stuck closed or open, or in between. Any thoughts on why it broke? Have the towers ever been moved?

Could be engine oil or transmission fluid. Smell it. Both require transmission removal though. Might as well do them both. Might as well replace your throwout bearing while it's out. And the clutch is probably worn. You'll be down by the slave cylinder too. And its hose. The transmission mount is probably worn out. Pilot bushing. Probably have to remove the exhaust system, check the gasket surface. Might break a stud removing the pipe so that could be an issue. If you have to remove the exhaust manifold you'll have the intake manifold off. Might as well replace the injector seals. Don't forget......

Looks like the o-ring is still around. Not sure what transmission you have but they're probably all the same one. http://www.carpartsmanual.com/datsun/Z-1969-1978/power-train/transmission-control Here's a spendy one. https://www.amazon.com/Nissan-32857-14600-Cap-O-Ring/dp/B01LY9R00E

Is that really your engine in the video, or were you just telling a story to set up the puzzle? Pretty cool. Not sure why it ran like turd on three, seems like three should have been okay, unless this is a case where the timing chain actually did jump a tooth or two.

The thing about the mounts, including the trans and diff, is that they have a lot of rubber. So I didn't feel bad putting a little bit of tension on them. I levered things together and bolted them down. They settle and distort over the years anyway, and move a lot when in use.

I think that that is a Maxima or 300ZX alternator with a pulley swap. Or, Ithink that there is one or two specific years that still use a V pulley on a 60+ amp alternator. It's not a bad option. It would be good to know that actual brand of the alternator. If he is just buying OReilly Auto parts and swapping pulleys, that could cost a lot in return shipping until you get a good one. Lots of bad-from-the-box reman alts out there. Worth asking him via message. Looks like you have to do some wiring. His image shows TYC, which is probably where he got it. OR maybe he just borrows the image. Looks like you might have to buy a plug also, maybe. Not clear. https://www.carid.com/tyc/alternator.html

There was just a few posts about this on the forum somewhere. The striker rod seal hardens up/wears out, and leaks, apparently. One possibility. Hard to fix.

I remember some of those threads. I think that my motor mounts are Anchor brand, from Oreilly auto. There are others. Brand was a question. Mine had screwed up threads on the studs.

Which parts are not aligning? I left all of my nuts and bolts loose and a pointed chisel as a drift pin to align the motor to mount holes to get the bolts through. My problem was the motor to mount alignment. The locating pin to mount stud distance was fine.

Do you need adjustability or is yours broken. The stock one is adjustable.

I think that a good radiator cap and recovery system might tell you something. When I had an external coolant leak through the HG the recovery system didn't work. It wouldn't pull coolant back in so the radiator level was always a bit low. Had to keep refilling. Of course, you'd only know if you ran the engine every day for a week or two. You could pressurize the system, cold, and see if it holds. It's supposed to be a closed system with an ~13-15 psi release pressure.

Sorry, I thought you meant an L28 N47. The Maxima N47 does have the smaller combustion chamber so would give a higher CR, even on a dished piston block. Most people call that head the MN47. I think that one of the valves is smaller than the L28 N47. It's fuel injection head on a later model car with catalytic converters and O2 sensors, I think. So it would run cleaner. The injectors might be worth getting, they're probably the same as the L28 injectors. Even the whole engine control system if you want to set one up with O2 sensor feedback.

N47 on an N42 block with dished pistons is the 1977 to 1980 L28 engine. You might be thinking of the late 1980 and up F54 block with flat top pistons. The N47 head is the same as the N42 head except for the round exhaust ports and liners. So now you have a spare engine and a spare N47 head?

I think that there are two but the FSM only shows one path. I have an old HG in the garage and it has two copper sealed oil passages, one in the middle and one up front by the cover. The actual orifice in the block is tiny.

You don't really have to block flow just make sure that it's not a wide open path back to the water pump inlet. I "blocked" mine by just kinking the "bypass" hose. Your leak is most likely one of the hoses from the heater core to the valves in the firewall. Hard to reach but you can see them from underneath the glove box.

Not sure on the various payment methods. The car does have open questions. No VIN listed. No mention of title, might be a salvage title. Also looks like it might have a lot of iffy body work, I see waviness and mottled paint. An old 71 with a salvage title and bad bodywork might be about a $4000 car.

Actually, more come up if I click on the broken images.

Does seem like a sweet deal. I could only get one picture to come up. Original 1971 Datsun 240 Z Numbers Matching with same owner for over 30 years. Documented with service records, low mileage 102k actual miles Been stored the last 20 years in Original drivetrain 6 Cylinder / 4 Speed transmission All original body - never taken apart - solid rust free body Original slot wheels - suspension - original undercarriage & floor pans Factory Silver, was repainted gray sometime in the 80's, upholstery reupholstered Still remains the original spare tire. Solid floor boards, frame structure & trunk compartment Beautiful dash, no cracks. Running & driving just fine. Starts right up, original carburetors Shifts, brakes & steers just fine. I still have the original California emissions in a box. Overall, an original Early 71' 240Z, running & driving.

I would be interested in seeing it. I have no interest in another Z so I promise not to steal it. I might see a reason for the low price, who knows.

I don't see that they list the stock on their web site. It's supposed to start with Craigslist or some other online marketplace. Where did you find it? On Craigslist or Oodle, the seller lists the item for sale and answer questions from potential buyers. After an agreement is reached, the Buyer must Register on our website. If a new price is negotiated with the seller, it must be specified in the Registration Form as the "Purchase Price". After registration, we will contact the seller and verify if all the information is accurate. An invoice will be sent to the Buyers e-mail address provided in the registration form. This information will be kept private as stated in our Privacy Policy. https://www.eautostock.com/consignment-centralstore/checkstock.html

It's basically like eBay and PayPal. https://www.eautostock.com/consignment-centralstore/forbuyers.html our service is absolutely free for buyers, we don't charge a penny more than the price originally listed. We deduct all fees necessary (shipping, handling, listing fees, etc) from our commission. There are no hidden fees.

There doesn't seem to be any risk to the buyer, in the beginning. Seems like the buyer could opt out of the eAutotrader thing and the seller has to pay their commission. The process is absolutely FREE! for buyers, all fees associated to any transaction is deducted from our commission. On Craigslist or Oodle, the seller lists the item for sale and answer questions from potential buyers. After an agreement is reached, the Buyer must Register on our website. If a new price is negotiated with the seller, it must be specified in the Registration Form as the "Purchase Price". After registration, we will contact the seller and verify if all the information is accurate. An invoice will be sent to the Buyers e-mail address provided in the registration form. This information will be kept private as stated in our Privacy Policy.