JayBee280 Posted July 30, 2009 Share Posted July 30, 2009 IVE SEARCHED BUT IDK MAYBE THE SEARCH FUNCTION SUCKS OR MAYBE IM NOT GOOD AT SEARCHING BUT SWEAR I CAN GOOGLE MY A** OFF! Ok this is pertaining to the 280z stock l28 owners and owners of L28ET. If yall didnt know i just got my 280z stock unmolested a week ago and ive been searching here and there with the time i have. And of course im a little confused at why owners of a perfectly good L28 that is ready for turbo choose to swap for a L28ET...? first i see people saying they do so because of the flat top piston.....let me do some corrections for second. the l28's from 70's have dished top piston pistons. the only l28s to come with flat tops were in the ZX models 81-83 or w/e I believe the L28ET has some major flaws one being the low compression ratio it has. 7.4:1 i just think its to low. i really think you need more boost to make good power with that compression ratio. it seems to have much more potential to make good power idk intake manifold maybe. 8.3:1 comp. ratio for a turbo motor i think is perfect for good power especially since the early L28's came with dished pistons begging for boost. seems you could make some good power off of that right there. and another thing. My 280z came with 170hp (refering to sticker on my car itself) from the factory and it doesnt matter if its at the crank(which it probably is) or at the wheels. the l28et only has 180hp which is 10hp more. Now we all know engines are going to vary on the dyno, but just looking at numbers and numbers only that 10hp is like an intake and exhaust on most cars. and im not involving tq for a number of reasons. THATS JUST NOT BANG FOR YOUR BUCK NO MATTER HOW CHEAP THOSE ENGINES ARE. But honestly it seems like everybody says the L28 has flat top pistons and i havent read once on here someone saying dishtop pistons in the L28. And its like alot of people swap for the L28ET and i can understand if you didnt have the L28 to start with but why swap if you have an L28 for L28ET?? I would (which i am) just start with exhaust manifold and wiring harness. instead of swapping the motor. IDK maybe its the electronics of L28et supressing power. but idk can i have some answers or some keen knowledge to let me know i lil suttin. Sorry for any typos or missed words. Thanks, JayBee Quote Link to comment Share on other sites More sharing options...
Challenger Posted July 30, 2009 Share Posted July 30, 2009 - The 170 GROSS v. 180 NET is not 10 hp difference. - Alot of the L28s have round ports rather than squares that the exhaust manifold had. - You still need to plum for oil lines to the turbo, l28s dont have it. - The p90 was specifically designed for the turbo engine. - Not hugely important but the knock sensor was only on the turbo engines. I ask in return why mix-match parts when a major automotive company has already built one for us?? Also dont apologize for typos and missed words, just fix them. Quote Link to comment Share on other sites More sharing options...
B00STDZ Posted July 30, 2009 Share Posted July 30, 2009 http://datsunzgarage.com/engine/ When I first got into older s30's that site shed alot of light to me... Quote Link to comment Share on other sites More sharing options...
B00STDZ Posted July 30, 2009 Share Posted July 30, 2009 - The 170 GROSS v. 180 NET is not 10 hp difference. Site I posted above says the 280z is 170 SAE but 135 net... it says the 81-83 280zx is 145 net... Quote Link to comment Share on other sites More sharing options...
Challenger Posted July 30, 2009 Share Posted July 30, 2009 Thats the NA. Quote Link to comment Share on other sites More sharing options...
B00STDZ Posted July 30, 2009 Share Posted July 30, 2009 Thats the NA. All the better to make a comparison...2.8 L for 2.8 L, NA for NA the 81-83 engines opened up 10 extra hosepower, probably due to the better head design... Quote Link to comment Share on other sites More sharing options...
wigenOut-S30 Posted July 30, 2009 Share Posted July 30, 2009 Hey Jaybee, Im not far at all from you.. just over in Mobile AL, bout 50 miles west of you. Another thing you might consider when choosing a block is the type of distributor, the turbo motors came with the a much better distributor and I believe a better oil pump. Also the turbo oil pan has the oil drain inlet already there. My setup is a turbo block, F54 with forged JE dished pistons, P90 head and a 1mm nismo HG. My compression should be in the 8.0:1 range. We have quite a few Z nuts over here in mobile hit me up on PM and maybe we could meet up. Quote Link to comment Share on other sites More sharing options...
Six_Shooter Posted July 30, 2009 Share Posted July 30, 2009 I simply turbocharged my bone stock (AFAIK) N/A L28 that came in my 240Z. (*gasp*) I also don't see the reason to swap to a lower compression engine just to add a turbo, seems counter productive to me. Turbo block was not the only block to have a KS location, mine, which as I said was an N/A block, also had a KS location (which I tapped for a different thread for my GM KS). From the information I've found on my engine it has 8.8:1 SCR, which is even low to me for a boosted application. I've never quite under stood why people would want to run a low SCR, then lots of boost pressure to achieve a HP number that could be had with higher SCR and lower boost pressure, which protentially quicker spool, and definatly better off boost drievability. I laugh when people gasp when I tell them what my SCR is, they seem to be living in the 1960s and listening to the turbo "wisdom" of technology long replaced with newer and better controls, and just better and more efficiant mechanical technology. The only fitting that the N/A engine doesn't have is the oil return, which goes into the pan anyway, and can be added very easily, if not just swap the oil pan. My "N/A" L28 is running just fine with a Nissan turbo exhaust manifold, 6.5L diesel turbo, modified N42 intake (smoothed and machined for 14mm O-ring injectors), non-intercooled (hope to change that soon, just need some time to build the IC), GM ECM and DIS ignition, running about 10 PSIG, above 60 MPH (my boost ramps in by speed). Also most people will end up "upgrading" or swapping parts anyway which will then mean that most of those stock parts that were swapped in will be swapped out, I like to skip that step and just go to the end result or closer to it. Quote Link to comment Share on other sites More sharing options...
jeffer949 Posted July 30, 2009 Share Posted July 30, 2009 Stock NA pistons dished or flat top have a thinner top ring land. Turbos are bigger which is stronger and can handle more boost. Quote Link to comment Share on other sites More sharing options...
wigenOut-S30 Posted July 30, 2009 Share Posted July 30, 2009 Stock NA pistons dished or flat top have a thinner top ring land. Turbos are bigger which is stronger and can handle more boost. Hey Jeff I thought that as well but didnt want to post anything until I knew 100%.. Quote Link to comment Share on other sites More sharing options...
FlatBlack Posted July 30, 2009 Share Posted July 30, 2009 Please read this entire thread http://forums.hybridz.org/showthread.php?t=151302 Most of the time, people don't swap L28ET's into Z's and keep them stock. There is a much higher potential for a Turbo motor that you do not have with a N/A L28E with thinner ringlands as jeffer said. You need to read up on the problems that the L28s have under boost. Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted July 30, 2009 Administrators Share Posted July 30, 2009 7.4:1 i just think its to low. Many VERY successful members of this forum have a different opinion. You'll find their reasons here, if you look. i really think you need more boost to make good power with that compression ratio. That is actually backwards. Again, the reason why is spelled out within this forum. and another thing. My 280z came with 170hp (refering to sticker on my car itself) from the factory and it doesnt matter if its at the crank(which it probably is) or at the wheels. the l28et only has 180hp which is 10hp more. Now we all know engines are going to vary on the dyno, but just looking at numbers and numbers only that 10hp is like an intake and exhaust on most cars. and im not involving tq for a number of reasons. THATS JUST NOT BANG FOR YOUR BUCK NO MATTER HOW CHEAP THOSE ENGINES ARE. L28E is 135 NET. L28ET is 185 NET... 50 HP. But honestly it seems like everybody says the L28 has flat top pistons and i havent read once on here someone saying dishtop pistons in the L28. And its like alot of people swap for the L28ET and i can understand if you didnt have the L28 to start with but why swap if you have an L28 for L28ET?? I would (which i am) just start with exhaust manifold and wiring harness. instead of swapping the motor. IDK maybe its the electronics of L28et supressing power. but idk can i have some answers or some keen knowledge to let me know i lil suttin. The L28E came with both dished and flat throughout the production years. First two years (N42) had round exhaust ports with liners. Some of us have concern with liner integrity in turbocharged applications. In a nut shell, you have a lot more research to do lil suttin. IDK Please write in plain English. Quote Link to comment Share on other sites More sharing options...
1 fast z Posted July 30, 2009 Share Posted July 30, 2009 Many VERY successful members of this forum have a different opinion. You'll find their reasons here, if you look. That is actually backwards. Again, the reason why is spelled out within this forum. L28E is 135 NET. L28ET is 185 NET... 50 HP. The L28E came with both dished and flat throughout the production years. First two years (N42) had round exhaust ports with liners. Some of us have concern with liner integrity in turbocharged applications. In a nut shell, you have a lot more research to do Please write in plain English. Actually 75-76 has Dished pistons, 1.5mm top ring, 1.2mm second ring. 75-76 Generally has N42 head. Square Port Ex. NO liners. 77-80 has N47 head. Liners on the ex, which dont hurt flow actually. Same pistons, same combustion chamber as N42. Some Early 77's have N42's. 81-83 NA has P79 head, flat top piston, 1.2mm top ring, 1.2mm second ring. 81-83 turbo has Same amount of dished pistons as 75-80, but has 1.2mm top ring, and 1.2mm second ring. Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted July 30, 2009 Administrators Share Posted July 30, 2009 You're right Bryan. That was *supposed* to say first two years were square port (N42), later heads were round port.... Brain got behind my fingers... sorry guy's. Quote Link to comment Share on other sites More sharing options...
jeffer949 Posted July 30, 2009 Share Posted July 30, 2009 If im not mistaken the turbo pistons are 1.5mm, 2.0mm not 1.2mm like you stated. Ok just a quick check on ebay says that they are 1.5mm, and 2mm for the L28et and the 75-80 L28E are 2mm and 2mm. Cant find any for the 81-83 NA pistons though Quote Link to comment Share on other sites More sharing options...
MaTTSuN Posted July 30, 2009 Share Posted July 30, 2009 i was just thinking of putting my 81 l28T top end onto a 80s l28 N/A low miles bottom end im looking to improve low end response and power for milage so i dont have to rev it out to get moving i think i have all the right parts to keep it in the sweet spot for durability 15 psi should be ko for this set up i think.. Quote Link to comment Share on other sites More sharing options...
1 fast z Posted July 30, 2009 Share Posted July 30, 2009 Yes, I did type that wrong, all 75-80 pistons are 2.0, 1.5 rings. 81-83 ALL pistons are 1.5, 1.5. Quote Link to comment Share on other sites More sharing options...
jeffer949 Posted July 30, 2009 Share Posted July 30, 2009 That is not correct 1 fast Z. it is as follows. 75-80 l28e Top ring 2.0mm bottom ring 2.0mm l28et(maybe 81-83 na also but ive never messed with them) Top ring. 1.5mm bottom ring 2.0mm They made the top ring thinner so they could have a .5mm thicker ring land under it so it was stronger. Quote Link to comment Share on other sites More sharing options...
trwebb26 Posted July 30, 2009 Share Posted July 30, 2009 IVE SEARCHED BUT IDK MAYBE THE SEARCH FUNCTION SUCKS OR MAYBE IM NOT GOOD AT SEARCHING BUT SWEAR I CAN GOOGLE MY A** OFF! Your right... you suck at searching. Try again. Quote Link to comment Share on other sites More sharing options...
Challenger Posted July 31, 2009 Share Posted July 31, 2009 HBZ has a google search built in right below the normal search engine. Quote Link to comment Share on other sites More sharing options...
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