Austin240Z Posted October 1, 2008 Share Posted October 1, 2008 So I just picked up a virutually rust free '77 280Z shell with all the paper's (including the original Datsun Salesman "Buz Garner's" business card from '77) Everything is there and original, minus the motor and trans. So Sunday morning, I decided I'd build a motor out of my spare parts so that I could drive her around untill I had a chance to build the real, turbo motor. I've named this motor the "Black Bastard" and here's why... It's made from parts off of atleast 7 different L seireis, and the whole setup is contradicting. The block and pan are gloss black, the valve cover is a powder coated flat black. N42 Block N42 Dished Pistons E31 head 1 E88 valve(the E31 was missing one) N47 Cam towers N47 Cam N47 Rockers SU Carbs (made from two sets from different years) L28 electronic dizzy Pallnet Carb Fuel rail (like it matters, I just like it =P ) The pan, vavle cover, intake manifold were ones I have laying around, no idea what year/motor they came from. I spent 13 hours straight, in the heat on the asphault infront of my storage unit building this motor, and I'll be the first to admit.... I did a piss poor job of building it. Here's what I'm looking to figure out. The Key componants are the Dished pistons, E31 Head, The N47 cam and the SU's. I just need it to run halfway decent, and I think it will until I get the good motor built. BUT out of morbid curiousity... I'm wondering HOW WELL it will run. After a little discussion with some local people,we're thinking probably 8:1 compression, but as for projected horsepower numbers we're still kinda scratching our heads a little. It's not in the car yet, as the car is still all apart and in boxes, so I cant give yall a rough "seat of my pants dyno" number. Any thoughts? Questions? Comments? *EDIT* will be running this with an MSD 6AL *END EDIT* P.S. here's the car: No pictures of the motor I'm afraid... I no longer have a working camera Quote Link to comment Share on other sites More sharing options...
jeffer949 Posted October 1, 2008 Share Posted October 1, 2008 If you run a felpro 1mm gasket your CR is 8.67:1 Quote Link to comment Share on other sites More sharing options...
naviathan Posted October 1, 2008 Share Posted October 1, 2008 Compression would be more than that I believe. The E31 head should net some decent power in sheer quench and combustion. I wouldn't give it much over stock horsepower for an L28e though. Quote Link to comment Share on other sites More sharing options...
fhptom Posted October 1, 2008 Share Posted October 1, 2008 That's a great looking shell. With the running 77 280 that I am trying to get rid of you would have a nice car. Too bad you are way over in Texas. We could combine our 2 cars then sell it to make a nice profit. Tom Quote Link to comment Share on other sites More sharing options...
blue72 Posted October 2, 2008 Share Posted October 2, 2008 He loses all the quench benefits by using dished pistons though. 160 hp is my guesstimate. Quote Link to comment Share on other sites More sharing options...
Challenger Posted October 2, 2008 Share Posted October 2, 2008 160 whp, or gross? Quote Link to comment Share on other sites More sharing options...
RayG1988 Posted October 2, 2008 Share Posted October 2, 2008 Gross, a regular l28 makes like 145 gross. 160 whp would be amazing for that little bastard motor, lol. Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted October 2, 2008 Administrators Share Posted October 2, 2008 Can we stop playing the HP guessing game, puhleeeze? Its totally meaningless. So much more goes on in making power than a list of parts that its completely laughable to assign a number. We've all seen motors with nothing but massaged stock parts make really impressive numbers... and ridiculously expensive motors fall totally flat. Any more 'guesses' will be deleted. Quote Link to comment Share on other sites More sharing options...
Challenger Posted October 2, 2008 Share Posted October 2, 2008 I thought most BRAND NEW l28's made around 130ish net, 170 gross. I believe the later zx l28s with the p79 made the 140net. Also these are new, as austin said, he threw the motor together therefore it probably isnt like a new motor. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 2, 2008 Share Posted October 2, 2008 Here's basically the same engine with a cam and triples. Same ~8.5:1 compression, L28/E31 combo with dished pistons but it was bored .020 over. http://videos.streetfire.net/video/2000-autox-indisde-and-outside-I-think-my_8051.htm Quote Link to comment Share on other sites More sharing options...
Challenger Posted October 2, 2008 Share Posted October 2, 2008 WOW!!! That made me dizzy... What was done on the suspension? Quote Link to comment Share on other sites More sharing options...
blue72 Posted October 2, 2008 Share Posted October 2, 2008 True, there is no real way to know unless it was put on a dyno, but even dynos differ from one to another. I'll just stop bench racing now and put away dyno2000. Quote Link to comment Share on other sites More sharing options...
ozconnection Posted October 2, 2008 Share Posted October 2, 2008 True, there is no real way to know unless it was put on a dyno, but even dynos differ from one to another. I'll just stop bench racing now and put away dyno2000. Dyno 2000...I have this too. How 'accurate' do you think this program is or is it good for Chevs Mopars and Ford V8 type engines only? Whats your experience? How close does it come when working with L Series engines? Quote Link to comment Share on other sites More sharing options...
Austin240Z Posted October 2, 2008 Author Share Posted October 2, 2008 That's a great looking shell. With the running 77 280 that I am trying to get rid of you would have a nice car. Thanks! I actually have absolutely every thing body and trim wise, minus the actual engine and transmission. It was a Killer deal. If you run a felpro 1mm gasket your CR is 8.67:1 I am running a felpro 1mm, so i definitely appreciate the compression #'s as austin said, he threw the motor together therefore it probably isnt like a new motor. This is definitely true, again, I'll be the first to admit I did a sub-par job of putting it together, the only things I really replaced were all the gaskets and seals and the valve stem seals. The bottom end came out of a strong motor with around 100K, the rings and bearings did have some wear as would be expected, but nothing that seemed to warrant replacing them (I'm sure I'll eat those words later) I checked the cylinder walls, and they were actually very clean, free of any visible scoring or excessive wear. I did a very quick very light honing of each cylinder and rechecked with a light, and again did not see anything of interest. ( I spent the majority of the time on the bottom end) The valves on the other hand, though I did clean them up a little bit, still do have quite a bit of carbon build up. Where I was working on it sunday I did not have access to anything but a dremel with a steel wheel attachment(my tools are in 4 different locations atm). Needless to say, the steel wheel attachment did not last long. I did what i could to clean the area closest to the seat, but had to keep it to a minimum to make the dremel attachment last long enough to get through the whole batch. Here's basically the same engine with a cam and triples. Same ~8.5:1 compression, L28/E31 combo with dished pistons but it was bored .020 over.http://videos.streetfire.net/video/2000-autox-indisde-and-outside-I-think-my_8051.htm Very impressive video, the question is though, were you using dished pistons or flattops? Can we stop playing the HP guessing game, puhleeeze? Its totally meaningless. So much more goes on in making power than a list of parts that its completely laughable to assign a number. We've all seen motors with nothing but massaged stock parts make really impressive numbers... and ridiculously expensive motors fall totally flat. I know that the HP guessing game is kind of a joke because there are so many different things that affect how power is made. I've definitely found that out firsthand in the past (I love my SUs) BUT at the same time, since I only plan to use this motor for a long period of time, and I dont think I will ever dyno it (unless I feel the motor is strong enough to warrant it), I am trying to at least figure out a rough projected number based on the experience and knowledge of people here who may have seen or built a similarly ass backwards L motor. Granted the guesses really dont mean anything compared to actually biting the bullet and putting it on the dyno, but I figure in the spirit Hybrid Z, I'd attempt picking some of yalls brains on a setup that is... well, not exactly something I would call common or ideal. Quote Link to comment Share on other sites More sharing options...
woldson Posted October 2, 2008 Share Posted October 2, 2008 Great shell, won't you need more than that engine in order to drive it;)? Quote Link to comment Share on other sites More sharing options...
blue72 Posted October 2, 2008 Share Posted October 2, 2008 Very impressive video, the question is though, were you using dished pistons or flattops? He states dished pistons. He, however, has a higher lift and duration cam, tripple carb setup, and is probably running a header. Your vehicle, with stock SU carburettors (with unstated needles), an unstated exhaust manifold (stock or header?), and a stock L28e cam profile will, of course, be entirely different. Other variables to take into account are the weight of the 280Z with all the trim, plus transmission and rear end ratios. All of those factors will play into your "butt dyno". Dyno 2000...I have this too. How 'accurate' do you think this program is or is it good for Chevs Mopars and Ford V8 type engines only? Whats your experience? How close does it come when working with L Series engines? I don't personally have any experience testing the veracity of any Dyno simulation program. I have only used Dyno2000 for theorizing. I need to put my own Z on a dyno to see how close the real numbers are to what I think they should be. Still, of all the stock engines I have simulated with the program (Jeep, Chevy SB and BB, Ecotec, Datsun, etc...) they have all come extremely close to the manufacturer's factory HP and Torque figures. Not to do anymore guessing, but plugging all the variables into the program, and assuming a stock exhaust system on "Black Bastard" dropped my "guesstimate" significantly lower than post #5. Of course, that is only a simulation, and assumes a healthy motor in a good state of tune. I agree, there are just too many variables and unknowns for anyone to make an honest to goodness estimate from afar. Quote Link to comment Share on other sites More sharing options...
Austin240Z Posted October 3, 2008 Author Share Posted October 3, 2008 He states dished pistons. He, however, has a higher lift and duration cam, tripple carb setup, and is probably running a header. oops, totally spaced on the second half of his post Your vehicle' date=' with stock SU carburettors (with unstated needles), an unstated exhaust manifold (stock or header?), and a stock L28e cam profile will, of course, be entirely different.[/quote'] That's defiantly an understatement, the tripplets with a cam make a pretty big difference. As for the SU's and the exhaust. The exhaust is the MSA 3-2-1 header, and depending on what looks like it will be easier, either the twice pipes, or a single magna flow(I have a few laying around) out the rear. The SUs on the other hand are the biggest variable for me. The pair I have that are complete... are well... rather damaged. The guy I bought them(and an l24) from years ago had "Rebuilt" them, drove on them for about 1k miles before he finally got fed up and tore the motor down because the care ran so shitty. He told me that he was having "Fuel problems due to worn out rocker arms" Well, when I got the carbs apart....... I dont know how you can even call them anyhting close to "rebuilt" The throttle plate on the front carb is damaged and does not close fully, the neddle in the front carb was a 1/4 to half an inch LOWER than it should have been, and the needle on the rear carb was probably an 1/8th of an inch HIGHER than it should have been.... they set completely different. AND on top of that the screws that are supposed to hold the needles in were so over tightened that they had actually FLARED OUT at the end and made huge impressions on the needle itself..... I re-rebuilt them as best I could but because of the damage that was already done, I couldnt really do much with them. I had a seriously difficult time getting them balanced, as the front carb wanted to do it's own thing at idle. But running it on a completely stock (with the same MSA header) L24, this was my Dyno result: I'm going to take my other, incomplete, but unmolested carbs, and use those, butchering the damaged carbs for what good parts that are left. Other variables to take into account are the weight of the 280Z with all the trim' date=' plus transmission and rear end ratios. All of those factors will play into your "butt dyno".[/quote']That is deffinately the truth when talking WHP Not to do anymore guessing' date=' but plugging all the variables into the program, and assuming a stock exhaust system on "Black Bastard" dropped my "guesstimate" significantly lower than post #5. Of course, that is only a simulation, and assumes a healthy motor in a good state of tune. I agree, there are just too many variables and unknowns for anyone to make an honest to goodness estimate from afar.[/quote'] hahaha, I'm curuois what kind of numbers you got, I suppose I'm used to low numbers =P I've actually been looking into getting a dyno sim program for a while, but havent had much luck finding anything availible for people with no disposible income Quote Link to comment Share on other sites More sharing options...
Forrest Posted October 3, 2008 Share Posted October 3, 2008 Here's basically the same engine with a cam and triples. Same ~8.5:1 compression, L28/E31 combo with dished pistons but it was bored .020 over.http://videos.streetfire.net/video/2000-autox-indisde-and-outside-I-think-my_8051.htm As usual, your car is nothing short of inspiring. I love the outside shot of you sliding at the corner! Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 3, 2008 Share Posted October 3, 2008 The one thing that I would have suggested for your build, even keeping it cheap, would have been rings and bearings. A "loose" bottom end on the wide end of the acceptable range of piston to bore clearance makes better power than a tight one, but you need the rings to work to seal it up. Bearings are just a good insurance policy. But if you don't care because you built the engine for nothing, then no big deal. Thanks for the compliments guys. Specs on the suspension here: http://forums.hybridz.org/showthread.php?t=117235 That engine was really nothing special and I raced it like that for years and did pretty well. I estimate the triples gave 40 whp, but that's just a guess, and I've never had the $$$ or time for dynos. The cam was a big deal too. I ran the bigger cam on the SU's and it was much better than the first cam upgrade I did, which was a high lift low duration cam. When I built the flat top shortblock it picked up a lot more bottom end but now needs about 95 octane. Quote Link to comment Share on other sites More sharing options...
Careless Posted October 8, 2008 Share Posted October 8, 2008 The one thing that I would have suggested for your build, even keeping it cheap, would have been rings and bearings. A "loose" bottom end on the wide end of the acceptable range of piston to bore clearance makes better power than a tight one, but you need the rings to work to seal it up. Bearings are just a good insurance policy. But if you don't care because you built the engine for nothing, then no big deal. May I suggest a Flex-hone before installing those rings to proper gap too. They work considerably well for 30-50 bucks. I find they give a better finish than the stone-holding ones with 3 arms that are spring loaded... Nothing like a fresh new bit of cylinder to bite into to seal it up a little better than new rings alone. Quote Link to comment Share on other sites More sharing options...
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