bimic92 Posted January 25, 2012 Share Posted January 25, 2012 I've recently just acquired a 260z and I'm pretty new to them. I've tried doing my research on this, but frankly I'm a little confused, so any help would be appreciated. My goal for this build isn't too outrageous, I'm wanting L28 turbo, EFI, 5speed, and numbers around 300hp. With all the different types of blocks and heads out there ex.(N47 E31 E88 P79 P90) I'm not exactly sure what I want to be looking at.. I'm pretty much asking what the best head/block combination is going to be to achieve these goals? and I should be able to take it from there Thanks again, any input is appreciated. Quote Link to comment Share on other sites More sharing options...
ttodhunter Posted January 25, 2012 Share Posted January 25, 2012 It looks like you've done some research, but you may be making things more complicated than they need to be. Your best bet is to get a L28et (complete) from a donor car with the ecu and harness. This will be a fairly direct swap and won't require any "frankensteining" of blocks and heads as they are made for each other. You will, of course, need a FI fuel pump (and maybe tank) but the rest should be plug and play. Once the L28et is in, 300hp isn't all that hard with some tuning and basic bolt ons... Quote Link to comment Share on other sites More sharing options...
NewZed Posted January 25, 2012 Share Posted January 25, 2012 http://forums.hybridz.org/index.php/topic/50208-the-ultimate-l28et-guidewhat-you-need-for-350whp/ Quote Link to comment Share on other sites More sharing options...
luseboy Posted January 25, 2012 Share Posted January 25, 2012 (edited) I always refer back to this: http://datsunzgarage.com/engine/. For an L28et, your best combo is going to be an F54 block w/ dished pistons, and a P90 head (stay away from the p90a). 280zx turbos came from the factory with this combo. Make sure you don't get a P79 head or a block with flat top pistons if your doing a turbo. The exhaust liners in the P79 have been known to break off with the higher heat and pressures of a turbo, which means little chunks of metal would try to run through your turbine... not exactly a good thing. Also flat tops have been known to cause too high of a CR for turbo, resulting in detonation. There may be a way to fix that and still run the higher CR, but I haven't seen it. Seems like most of the guys who are running high psi's are running dished pistons. Edited January 25, 2012 by luseboy Quote Link to comment Share on other sites More sharing options...
Gollum Posted January 25, 2012 Share Posted January 25, 2012 I always refer back to this: http://datsunzgarage.com/engine/. For an L28et, your best combo is going to be an F54 block w/ dished pistons, and a P90 head (stay away from the p90a). 280zx turbos came from the factory with this combo. Make sure you don't get a P79 head or a block with flat top pistons if your doing a turbo. The exhaust liners in the P79 have been known to break off with the higher heat and pressures of a turbo, which means little chunks of metal would try to run through your turbine... not exactly a good thing. Also flat tops have been known to cause too high of a CR for turbo, resulting in detonation. There may be a way to fix that and still run the higher CR, but I haven't seen it. Seems like most of the guys who are running high psi's are running dished pistons. I agree, stock L28ET combo is your best bet to get this done. Don't worry about X head or X block. Stock turbo longblock will take 350hp all day long as long as the EFI is working right. All that said though, there haven't been THAT many cases of P79 liners breaking, several people on this board have run them just fine. Taking them out isn't that big of a deal though. There haven't actually been many people at all reporting detonation issues on flat top motors who are actually running a good EFI setup. The guys running high PSI are usually running dish pistons because it IS the most logical way to get to 400hp as beyond. To 300hp, either is a fine option and has been done. I honestly don't know where so many people are getting all this blown out of proportion information. Most of the actual blown motors I've encountered involved some VERY bad ingredients into the pot. Examples would be people trying to use a NA ECU, or a NA dizzy, or the crappy '81 system, or using NA injectors, or never even doing some basic tuning via fuel pressure regulation. People trying to increase boost and/or other mods without doing supporting EFI mods will ALWAYS be at risk to blow something up, no matter WHAT the compression is. If my '82 L28ET with 7.4:1 compression can run on CA 87 octane, I'm pretty darn convinced that it'd run 8.3:1 on CA 91 just fine. Now, I WOULD have to back the timing out a little, as the flame travel distance and time just got reduced dramatically with the increased quench. But what this says it that my required timing is less, but many people assume this means that the detonation threshold is lower. Also don't forget that at higher than stock boost levels more timing needs to be pulled as required timing is reduced yet again. Running any more than 10psi is asking for trouble on a stock turbo ECU, and running more than 1 psi is asking for trouble on a NA ECU. In all this though, to run non-stock setups a programmable ECU is a must in my opinion, and as such it IS NOT a budget option. I just wish people would quit throwing out blanket statements without showing proof that I have yet to actually see. One of these days I'm going to build a 10+:1 motor and make 400hp on it just to show it can be done. Might be a while but I WILL do it. And I'll have scientific results, such as dyno plots and logs to show power differences at various timing levels. Quote Link to comment Share on other sites More sharing options...
bimic92 Posted January 25, 2012 Author Share Posted January 25, 2012 This is why I love this forum. Thanks for all the information, very useful. Now the hunt begins Quote Link to comment Share on other sites More sharing options...
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