cgmeredithjr Posted October 21, 2010 Author Share Posted October 21, 2010 Should post up some pics of the ports while its apart. Told you I did not think it was a bent valve, though it may be now lol. Here are some pics from when I initially took off the head to fix some leaks a while back. Cleve Quote Link to comment Share on other sites More sharing options...
Administrators BRAAP Posted October 21, 2010 Administrators Share Posted October 21, 2010 Maybe the valve bent and then when it returned to the seat it caused the seat to become dislodged due to uneven strike? Cleve Highly unlikely to almost impossible. You can beat on one side of the valve seat all you want, that wont dislodge a properly installed valve seat. 99.9% positive the seat fell out and that is what bent the valve as the piston tried to help reinsert the valve seat using the valve as its drift, so to speak, not the other way around. Quote Link to comment Share on other sites More sharing options...
Tony D Posted October 21, 2010 Share Posted October 21, 2010 Maybe the valve bent and then when it returned to the seat it caused the seat to become dislodged due to uneven strike? Cleve highly unlikely, I have seen severely bent valves just tear up the seats. Bent valves don't drop seats, improper installation (or cracking) does. I have VW's and Corvairs, I know about loose valve seats dropping! Quote Link to comment Share on other sites More sharing options...
cgmeredithjr Posted October 22, 2010 Author Share Posted October 22, 2010 Highly unlikely to almost impossible. You can beat on one side of the valve seat all you want, that wont dislodge a properly installed valve seat. 99.9% positive the seat fell out and that is what bent the valve as the piston tried to help reinsert the valve seat using the valve as its drift, so to speak, not the other way around. You are correct, dropped it off today at the machinist and preliminary diagnosis is that it was not installed properly. Having the entire head gone through...obviously. I'm going to pull the bottom end and go through it also (#5 rod bearing probably took a beating) and then will start playing again. Cleve Quote Link to comment Share on other sites More sharing options...
Tony D Posted October 22, 2010 Share Posted October 22, 2010 Install it like a VW or Corvair and they won't come loose. Chill in LN2, heat head to 275F and have a heavy-press interference fit at THAT temperature differential. If they kept my 140 Seats in place when my CHT said 600F, they will stay put in a water-cooled Datsun! Quote Link to comment Share on other sites More sharing options...
cgmeredithjr Posted October 22, 2010 Author Share Posted October 22, 2010 Install it like a VW or Corvair and they won't come loose. Chill in LN2, heat head to 275F and have a heavy-press interference fit at THAT temperature differential. If they kept my 140 Seats in place when my CHT said 600F, they will stay put in a water-cooled Datsun! Tony, thanks for the guidance. I have decided to go ahead and rape the ZX and most likely install the motor mated to some type of 5-speed in my zero rust 1976 280Z...SLEEPER Cleve Quote Link to comment Share on other sites More sharing options...
ModernS30 Posted October 22, 2010 Share Posted October 22, 2010 Z32 TT trans foh sho. Quote Link to comment Share on other sites More sharing options...
cgmeredithjr Posted October 23, 2010 Author Share Posted October 23, 2010 (edited) Inexpensive Paint Thickness Meter. Had some fun with the chassis after stripping her: http://www.youtube.com/watch?v=p1LfLESthTw Edited October 23, 2010 by cgmeredithjr Quote Link to comment Share on other sites More sharing options...
B00STDZ Posted October 23, 2010 Share Posted October 23, 2010 Hahaha! Glad to see you getting rid of the 280zx in style! Accually moderns30... the th400 auto trans has made alot of cars go really fast in the 1/4. Im looking forward to seeing this buildup... Isnt TimZ the record holder right now for l series power at 650whp? Quote Link to comment Share on other sites More sharing options...
rturbo 930 Posted October 23, 2010 Share Posted October 23, 2010 Hahaha! Glad to see you getting rid of the 280zx in style! Accually moderns30... the th400 auto trans has made alot of cars go really fast in the 1/4. Im looking forward to seeing this buildup... Isnt TimZ the record holder right now for l series power at 650whp? The TH400 is an auto thought and the owner wants a 5speed since he's more into road racing. Don't blame him. And no, based on what Tony D has said, I believe 650whp is not even close to the record for most power out of an L28ET. Quote Link to comment Share on other sites More sharing options...
B00STDZ Posted October 23, 2010 Share Posted October 23, 2010 The TH400 is an auto thought and the owner wants a 5speed since he's more into road racing. Don't blame him. And no, based on what Tony D has said, I believe 650whp is not even close to the record for most power out of an L28ET. Then i guess i should say 650whp is the highest documented l28et. As i havent seen a dyno sheet/buildup/pictures of one over 650whp... Quote Link to comment Share on other sites More sharing options...
ModernS30 Posted October 23, 2010 Share Posted October 23, 2010 Yea, I was saying that because he will be road racing the z. I heard the TH400 is a power robber actually. Cleve, LOVE they was you are removing the bondo. I had a hood that was showing cracks in the bondo and you could see the dimples on the underside of the hood. Rather than hammer, I just jumped on it. Rather effective. Quote Link to comment Share on other sites More sharing options...
Tony D Posted October 24, 2010 Share Posted October 24, 2010 (edited) Depends on what you desire for 'documentation'---in the years before civilian internet what do you do? The Electromotive car could with ease, boil the tires from the entrance of the back stretch at Riverside, to the entrance to the corner at the other end at speeds approaching 160mph... and that was with heavy aero downforce. d If think if they say it made 1100HP (from the mouth of the dyno operator, engine builder, and various other team members from the era) I really have no reason to doubt them. That, and the fact that Nissan Corporate spokesman made a BIG deal about the VG30 being (and I quote) "the first engine of this size to make 1100HP"... And the fact that the same Nissan Corporate spokesman got VERY perturbed when I mentioned the #83 Electramotive car making that kind of HP from 200CC's less and almost 10 years before... His response was 'they were a privateer'... No dispute on the number, just an annoyance that a number not widely known outside corporate circles at the time (non-disclosure arrangements usually do their bidding by having people keep quiet long enough that whatever they were going to blab about no longer matters, or long enough that anybody interested will have stopped asking about it by then!) When the same number comes up from several different people who were at different points on the project, it's 'independent verification'---kind of like finding references to Thai Trade Delegations in Chinese Texts for ventures to the Ryukuan Kingdom which cross check to Okinawian Scrolls to confirm a date in a Thai Stone Inscription which only uses Bhuddist Circular Time References and Anamistic Character reference for the year. Before the internet, there was a way to tell what the truth was... unfortunately that's becoming a lost art, and fabrication of the truth is becoming far too easy for lazy investigators! <EDIT> Seriously, do you think a handwritten list of water brake measurements would be accepted? If they even exist now 28/29 years after the fact? And even if they did, would there be anybody who would look at them (uncorrected) and do the interpolation in their head? I mean I could see some people here looking at the raw data and from familiarity going 'woah!'---but unless it's a nice Mustang Graph people will look at it like just another sheet of handwritten ledger entries and gloss over with a ethereal sales executive's 'So what am I looking at here, guys' kind of exhortation... Edited October 24, 2010 by Tony D Quote Link to comment Share on other sites More sharing options...
B00STDZ Posted October 24, 2010 Share Posted October 24, 2010 Well its alot easier to believe documentation than hear-say... Cleve do you know what size pistons your running? Or the Compression ratio? Quote Link to comment Share on other sites More sharing options...
Tony D Posted October 24, 2010 Share Posted October 24, 2010 Hear-say? I can put up a dyno chart tomorrow for my car showing 900 RWHP and have an impressive list of components. What does that prove? That I'm good with a Mustang dyno and can skew a chart? Seriously, I get a laugh when guys offhandedly refer to people who are automotive icons and proven winners and recordholders serious discussions and brush them off as 'hear-say.' I can tell you what motivation someone has to post a current fraudulent dyno sheet. Can you please tell me what guys who are no longer invovled in racing, have nothing to prove (since they won everything already), and who are simply answering direct questions put to them in a serious discussion about what their accomplishments were 20+ years ago...what exactly would they have to gain by lying? And with that thought in mind, these busy people (some of whom took weeks ahead in planning to talk with) all decided to conspire to fix the numbers at a set given level which did not correspond in ANY way to what was given out to the automotive press while they were STILL in competition? I mean, when the 750hp figure was mentioned, one of the guys actually burst out laughing, and said "Oh yeah, THAT!" And then offhandedly said "I think that may have been the 2 liter number, it sure as hell wasn't the 2.8! We made XXXX out of the 2.8!" I can see where this is going now with this logic... This isn't the government telling us something, dude. We don't need to invoke the Obey Axiom here... The incidences of falsed-up dyno charts I have seen makes me FAR more apt to disbelieve a guy trotting out a scanned dyno chart posted on the internet than some 60+ year old guy reminiscing about the things he did when he was in his 30's and 40's! ESPECIALLY when the record seems to back them up! Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted October 24, 2010 Administrators Share Posted October 24, 2010 Documentation of my 3.2 Z... Quote Link to comment Share on other sites More sharing options...
cgmeredithjr Posted October 24, 2010 Author Share Posted October 24, 2010 Well its alot easier to believe documentation than hear-say... Cleve do you know what size pistons your running? Or the Compression ratio? No, but I will as soon as I finish the tear down. Block is sleeved and I need to mic it and see what we have. Cleve Quote Link to comment Share on other sites More sharing options...
cgmeredithjr Posted October 24, 2010 Author Share Posted October 24, 2010 Documentation of my 3.2 Z... Sweet! What are the details on this build? Thanks, Cleve Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted October 25, 2010 Administrators Share Posted October 25, 2010 What are the details on this build? I have no idea. Google loaned me that sheet. It was simply to make the point that a dyno sheet doesn't constitute documentation. It's the Internet and people do funny things. Without supporting information, claims ought to be taken with the proverbial grain. Quote Link to comment Share on other sites More sharing options...
cgmeredithjr Posted October 25, 2010 Author Share Posted October 25, 2010 :P :P Quote Link to comment Share on other sites More sharing options...
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