Zed Head

There doesn't seem to be any smoke in your two videos on Page 1. Is the smoke a new thing? Smoke that doesn't smell strongly is usually coolant. Oil and gasoline smoke both smell like either oil or gasoline. Are you a smoker? Maybe get a fresh nose on it, I know smokers can't smell well sometimes. No offense. Check your head bolt torques. Maybe they've loosened or were never properly torqued.

Any videos, or performance numbers? I think that either of those would help sell it. Interior pictures also. Looks like a well-built car.

Stop doubting. It slides. I tried to post a picture from the FSM but there's a problem. Check pages BR-11 and -12.

Thanks Mark. Who knows. If ti's still upper 90's then my Z is not going to be on the road, for sure Got no AC.

The melted plastic might be the seal from a sealed bearing. No need to remove the pressure plate, you can take a measurement with it installed. With the collar sitting on the fingers of the pressure plate, the distance from the surface the fork rides on, the two "ears" on the sleeve, to the flywheel should be ~92 mm. The collar with the melted bearing looks like it might be from a different model of Nissan. Could be that somebody repurposed a part that doesn't really belong. Are the hole diameters the same for the two that you show. Maybe the one that got destroyed got cocked because it's too big.

Others have more experience but it's looking like at least one, maybe, two valve-piston collisions occurred, bending the valve. That would explain the noise and the pressure readings, and the misplaced retainers and lash pads. That's what those parts are, they hold the valve spring to the top of the valve. Without those parts the valve can slip down and the the piston will hit it. You can probably get by with just removing the head and having it repaired. Look closely at the round piece on the top of every valve and you'll find the two that are different. I can't really see it in your pictures, they're dark.

You posted something about this on another forum about five years ago. I had copied the link here in this thread but, apparently, I'm guessing, Mike thought that I was trolling or baiting you and deleted it. Don't really know what to do now since Mike deleted the information but if you search "240Z differential crossmember threaded hole" on Google you might find it. I think those are the words I used. The answer in the other forum was that the threaded holes are for exhaust system hangers. There was no answer on the plate. I'm going to guess it's a shim to bring the diff nose up for diff alignment. Sorry Mike, but my reply that you deleted was an honest post, and the edit was after I saw that the same name, DJACEY, was on the other forum. If you clicked the link that I posted you'd see that the name was hard to see, above the actual post. I did not see it until later. @Mike

So...what's going in on its place? 4 barrel, Webers, SU's?

Not sure what that means. But you want the throwout bearing sleeve to match the pressure plate, not the transmission. They tend to get associated with the transmission because of the spring clips holding the fork and sleeve to the transmission, but they really should stay with the pressure plate. If yours broke, keep the pieces and measure the height of the ears on the sleeve, and find a similar replacement. Or get a new pressure plate and matched collar. Post a picture of the broken sleeve, just for fun. We like scenes of destruction.

We just finished perfecting it. What happened?

The crazy tach sounds like your Pertronix has problems. Try 3800 RPM in the other gears. If it's tied to RPM that's a clue. Same general idea as revving to redline, like Mark M suggested.

That VR unit is the 77 unit right, with the single pickup coil and one tooth causing the voltage? I wonder if that's why Nissan went to the six tooth setup with the ZX distributor, beside giving a more consistent trigger pulse. Sounds like you've already moved on. but maybe a ZX distributor could get you going quicker, in the meantime.

"Should" probably depends on what the manufacturer found would work. If you supplied a brand name somebody might be able to say if theirs is the same or not.

I spent a lot of time cleaning the area at the base of the bolt of rust so that the PB Blaster could sit in a groove and seep in. Also cleaned up the sides of the stub and filed flats in it so that my Vise Grips would get a firm purchase. Then, when trying to turn it, never forced it. Once I got some movement I worked it forward and backward, to work in more lubricant and break up the rust. I waited a lot also which you might not be able to do. The basic message is - don't use brute force. It already broke once. Even if you weld a nut to the stub, you can still break it so be careful.

You might change your title to add "1970 240Z". The mounts alone are boring so nobody's going to click. Your picture is great though, for illustrating the question.

The one on the top with the shift lever would be a 4 speed. You can tell by the plate with the six bolts. The one on the bottom would be an early model 5 speed, assuming that both came from a Z. You can tell by the two forked exhaust hangers on the back, and the dust covers for the drive shaft. They will have the same ratios in 1 through 4 and should bolt in/on exactly the same. Completely swappable. The numbers on the castings don't seem to correlate to much. People have tried to tie them to a year or model but it doesn't work.

Close. So, carnut, I'll leave this thread alone now. Good luck with the rebuild, whichever way it goes.

You got the wrong guy. I did not write "not worthy".

I did apologize, just not directly. It wasn't aimed directly at HS30, although he might have been the catalyst. It was aimed at the guys who try to protect the low 240Z image by denegrating other people's efforts, and lack of knowledge It was an "if the shoe fits" comment. Beside that, in civil discourse, the general apology right afterward I offered is enough. Issue closed. We could all ignore recent discussion and dig up old posts to get indignant about. I don't owe HS30 anything at all. He chose to ignore the correction and grab on to something that he could use to be indignant, as is his tendency. I will apologize to carnut though. But, with a condition - I was trying to stop the denigration I anticipated (the fin in the water) before it got too far. Read posts 20 and 21 and you can see it starting, in typical fashion. What justifies the superior tone? Everything was fine util then, I even asked a question to try to clear up a potential misunderstanding. It was ignored. I know that you guys like him, but you can't justify everything he writes.

Doesn't really matter. Edit - since I apologized for it in Post #33. Posts 31-35 are a good example of getting back on track, like good civil discussions do.

This might be the heart of many of the arguments. Not sure how many people think of this site as a "marque specialist forum". Still, it's possible to correct people without the extra verbiage.

Here, I'll be more constructive, with an example. The replay below would have been very educational, reset the tone, AND (bonus) been "bigger" than my comment. Win, win, win. It's all of the extra stuff that's unnecessary. "The car in question is (according to the engine bay identity tag) an S30-prefixed, early 1970 production dated 'Fairlady Z-L', so calling it a 240Z would be incorrect." Then, maybe, even refer back to your first post in the thread, #4, which is educational. Again without the extra WTF's, and LOL's, and insinuations. It's called being civil.

The bottom ends on these engines are pretty durable. Might not be worth the time and money tearing it apart. Your list is kind of the typical small effect things that people do. You might not even notice a benefit over stock. If your dad wants you to get the car moving again, and you want to drive it. a simple head refurbishing might make more sense, then buy a separate engine to build. The EFI system kind of limits how much benefit you can get, without making certain things worse, like driveability and emissions. You never gave much history on the car and why you even wanted to pull the head.

That's a great picture and you probably know how lucky you were that it's in such a convenient spot. I was thinking more of the big cloud of bees that fly around aimlessly after the queen bee lands, until they finally find her and form that bee ball. I climbed a tree with a pruning saw, tied a rope to a branch with a swarm like yours on it, then cut the branch while my grandfather pulled the rope. He talked me in to it. Only got stung three times when the swarm let loose, but almost fell out of the tree on the way down at warp speed. Good old days...

See that? Another opportunity to pass on some knowledge, a correction of a simple error in nomenclature, turned in to some not-unexpected righteous indignation. Does it do anything at all for anyone but the author? Not really. The knowledge will die with the people that don't share it. For anyone that thinks the information is readily available for anyone that has a computer, do a Google on Photobucket. The people that own the servers that hold the knowledge will let them die with that knowledge.