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About zeeboost

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  1. Thank you all for the replies, I'll follow up with this thread once I get time to tear into the engine.
  2. So you're thinking that the sticking is more from the guide, but not the seal itself? At this point I figured at a minimum I would be removing the changing out the stem seals, since I'm suspicious they're the culprit for the oil burning. With the seals off I can do a rough visual on the movement of the valve inside the guide to see if there's any obvious excess slop. If I have to pull the head off then it's going back to the machine shop, and I don't know how long that will take again...frankly I'm really just hoping the stem seals will do the trick. Though it was kind of odd that literally all cylinders had no compression on startup towards the end of this issue. Thank you all for the replies, sounds like it's pretty narrowed to either valve stem seal or guide.
  3. Yes you are correct, that's what I was referring to. I was curious if the valve guide seal / valve stem seal could be so tight that it can actually cause a valve to hang open. I have not experienced any misfires or running rough within the last few hundred miles, so a leakdown test should pass through all 6 cylinders at this point. It can still pass with bad valve guide seals though.
  4. Guess I should've clarified, the intermittent compression I'm referring to would be from excessive cylinder pressure leakage, thus causing the "skip" or lack of resistance inside the engine while cranking. If the lifters were not pumping up, that would result in low compression numbers if I had a gauge connected, but I should still hear resistance while cranking. Hope that helps.
  5. That's a good question, I had assumed since the head is over 35 years old that they would've been replaced, but I'll see if I can get my friend to dig up the receipt and see what's on there. This head still has the hydraulic lifters, which the machinist thought I was just misinformed when I told him that, until he saw them for himself. Considering all the other Z heads were solid lifters, it's understandable. But if they were a problem then I would still have compression when cranking it over, it'd just be running rough.
  6. So this one is an odd one to me as I've never experienced symptoms like this, and I'm curious what some of the more experienced L28 gurus think. I recently rebuilt an L28et for a friend of mine, which started from an external head gasket leak. Took the head (p90a) to a reputable machine shop, partly because they were the only ones around here that would actually straighten the head before resurfacing. He had the head for a few months (I believe he worked on it in his free time), but once I received it back, took roughly 3 months before it was running in the car. First startup everything was great, drove it easily for a couple miles, brought it back and parked it. Next day while cranking, I could hear one cylinder skipping (no compression), and once the engine fired up it had a dead misfire for roughly 10 seconds, but then it cleared up and drove great. This happened a couple more times, only after the engine sat. During the misfire, I did hear a slapping sound every once in a while that I've heard in the past from sticking valves when trying to resurrect an old engine. I never confirmed that's what it was, but the sound is very distinct. Finally the condition got to the point where I had no compression on startup (sounded like a blender), took at least 30 seconds of cranking on it before it would start to pop, then finally catch and fire up...which again after a few seconds of running rough, would smooth out and run great. That weekend we ended up taking his car on a 200 mile trip, mostly highway cruising, but also some mid rpm pulls under boost as I was tuning it while he drove it. The next morning I noticed it fired right up, didn't skip a beat, and it hasn't acted up ever since (this was a month ago and there have been a few hundred more miles added to the car). But a new symptom appeared, lots of smoke, especially on startup and high vacuum conditions. It's burning oil, and I'm suspicious it's the valve guides as it has the classic symptoms of it. The engine never smoked before I tore it apart, so I don't see it being the rings. Those were the only parts on the bottom end I didn't touch during the rebuild because compression numbers were good and the engine had no oil consumption. I did replace the turbo with a low mileage used unit, but they usually have different smoking conditions than high vacuum. So I'm wondering if the valve guides were initially too tight, causing the valves to intermittently stick open, and now that they're worn, they're allowing oil to enter the cylinder. I've never really seen that happen before though. I plan on popping the spark plugs out and going in with a borescope to see if I can find evidence of oil running down from the cylinder head. Has anyone here had experience with similar symptoms? I'm assuming the p90a valves are identical to the p90? Curious if maybe he installed the wrong guides by catalog error or something. Anything else aside from the guides that could be responsible for the smoke? If you made it this far, thanks for reading.
  7. I’ve gone through 3 datsun 5spd transmissions in my 240z l28et, but it’s modified. The next trans will be one from a z32, but I’m not sure if those adapter kits are still available. Pretty sure the thing now is to mate a 350z 6spd to it, but I havent done any research on that swap. Last I checked, parts are still readily available for the T5 trans, but im not sure if the 280zx T5 uses the same internals as say a foxbody mustang T5. A rebuild kit is more than likely just seals, synchros and bearings, but you may still be able to find replacement gears for yours. If you’re running a stock L28et then a stock T5 should be fine, as thats what they were rated for. But to answer your question, I’ve seen those 4speeds take quite a bit of abuse and keep ticking, so if you’re in a pinch and you can get one cheap, it should work fine.
  8. Curious, was this one Andy’s 240z from Maysel?
  9. Someone stole that one...
  10. A new hope https://portland.craigslist.org/clk/pts/d/battle-ground-complete-z-with-280z-fuel/6882738489.html (would’ve been more appropriate on Saturday)
  11. I wonder if Z enthusiasts had a similar opinion back in 1978. Maybe not since there were some differences from the early models, but it was all still the s30 chassis with the same body for the most part.
  12. If you’re unfamiliar with engines then you should probably just keep the l24 (or l28, whatever engine it comes with) to get your foot in the door with how they work and what it takes to keep them running well. The L engines aren’t boring, especially if you push the car the way it was designed.
  13. In the past I’ve been able to drill / tap a couple m8x1.25 holes 180* from each other, then use the bolts to push against the hub while forcing the drum back. Just alternate slowly between the two bolts, and some hammering in between to help break it free. It may not work in all cases but I would definitely try that before cutting.
  14. Yeah I'm not really understanding the hype. It's a decent foundation, but there are signs of rust all over the car, just not many closeups of it. Though some parts of the body have been buffed to be shiny, it will still need a repaint...especially once the trim moldings are removed and the body damage is sorted out. It will likely still need a minimum of floors, more than likely frame rails too. Not sure how bad the rust goes on the passenger inner fender. I have a hunch the passenger side has more rust damage that's hiding. It's been sitting for a long time, will need brakes gone through, clutch system, all rubbers and bushings. The carbs sound like they were cleaned enough to start, but will still need to be completely gone through to be a driver. Front valance looks damaged, turn signal busted, seats need to be completely rebuilt, dash has a few cracks, rear bumper tweaked, etc. I can go on and I know I'm sounding like I'm being really picky for a 50 year old Datsun, but for $10k I would want something that isn't going to require as much of a restoration as a "rust bucket" that still needs roughly the same amount of repair as the ones listed in these ads: I'm not criticizing his price, everyone is entitled to ask what they want for what they're selling. It's the responses that this should be a $20k+ car that have me confused. Maybe if he sells it internationally...? The car in this post has been for sale for at least a couple weeks now locally, if it was that good of a deal it would've been gone quickly. I don't see a lot of difference between the one being offered for sale on this thread and the ones posted above that just sold recently (green earlier this month, yellow one this morning).
  15. I wouldn’t mind a cylinder head and intake thrown in with it, but generally yes just the crankshaft is what everyone goes for. How much were you asking for it?