bthomp Posted October 29, 2012 Share Posted October 29, 2012 Alright guys, need your opinion. Iv got an l28 engine from my 78 280z and a vg30e from a 85 300zx. The l28 I melted a piston and needs bored and a valve job to be reuseable. The vg needs nothing. Right now I'm putting the vg in my 280, but I'm not sure if I want to build that up or redo the l28. What would you guys do, and would you turbo them or build it up na? Quote Link to comment Share on other sites More sharing options...
78zstyle Posted October 30, 2012 Share Posted October 30, 2012 I hope you have access to a welder. Quote Link to comment Share on other sites More sharing options...
bthomp Posted October 30, 2012 Author Share Posted October 30, 2012 Lol I do. Made my own full 3" exhaust system inc downpipe for the l28. And a few other things Quote Link to comment Share on other sites More sharing options...
78zstyle Posted October 30, 2012 Share Posted October 30, 2012 You will need to obviously make mounts. If its NA you might not have an issue with the steering column, but if its turbo you will have to have custom manifolds made. Quote Link to comment Share on other sites More sharing options...
bthomp Posted October 30, 2012 Author Share Posted October 30, 2012 I won't, but I'm looking more for what you guys would do. As in which motor would you build up and would it be a na or turbo build up Quote Link to comment Share on other sites More sharing options...
78zstyle Posted October 30, 2012 Share Posted October 30, 2012 (edited) I would go with the VG30et between those two. But if I wasn't going with the L series, and wanted to stay Japanese and turbo, I would go 1/2jz. Beats the crap out of both of them. Edited October 30, 2012 by 78zstyle Quote Link to comment Share on other sites More sharing options...
Pharaohabq Posted October 30, 2012 Share Posted October 30, 2012 Well between those two engines I'd turbo the Vg30 but you'll need to know that you can't run much boost at all without having some serious issues. The VQ30, like the L28 were designed for NA operation. When you just bolt on a turbo, you're pushing the internal stresses far beyond the original design. Failure is highly likely. That's not saying you can't do it. But really you'd be better off getting an "ET" version of either engine. The Turbo versions are already setup with stronger components and lower compression to allow for the higher turbo pressures without major failure. It's your engines, so you do what you want, but just try to keep in mind what the engines were originally designed for. Now the main reason I recommend the VG30 over the L28: Aside from the .2L size increase, the VG is more modern on the EFI standpoint. You set it up with a MAP for better fuel management. I assume you'll be running stock harnesses/ECU or megasquirt. The VG also moves the center of gravity back slightly, inproving handing. Both I'd setup with electric rad fan. The Steering shaft can be trouble, but it's easy to reroute like we do to get around the VQ exhaust. It is a buttload of fab work to retrofit it into the car though, so that's a downside. McKinney Motorsport sells a mount kit for it so you might consider that, or at lease build something like it. Quote Link to comment Share on other sites More sharing options...
HowlerMonkey Posted October 30, 2012 Share Posted October 30, 2012 I usually swap L28s into VG30 equipped cars. Quote Link to comment Share on other sites More sharing options...
bthomp Posted October 30, 2012 Author Share Posted October 30, 2012 Internals in both engines would be replaced to fit the build, na internals for na and turbo internals for turbo... ill be using megasquirt 2 since I have it. The reason I'm I'm asking about these 2 engines is becuase its what I have to work with. BTW, the l28e can hold a lot more boost stock internals than what people give credit... I turboed mine 15 lb of boost. Was my dd and Made a trip down to FL from MD and back with no problem, wasn't till I went to 20lb did a piston melt. But the reason for that is a whole nother story. Pharaohabq- I'm intrested to see how much difference I feel in the car with a better center of gravity with this VG once its in... Not to worried about custom fab the downpipe and what not. Did it once, can do it again. Also I didn't think about mapping with the VG and how it might be easier. Howler, why is it the you put l28s into those cars? Quote Link to comment Share on other sites More sharing options...
Pharaohabq Posted October 30, 2012 Share Posted October 30, 2012 There's a sticky on the VG install in the V6 section. Take a look and see what you think. Megasquirt will make things a bit easier or harder depending on how much you know. I'm a fan of keeping stock electronics. But to turbo, MS2 is probably easier. The VG is a good engine. Upgrading to MAP based modern EFI makes a huge difference. Not to mention sequential injection. On the L28, if you didn't start with the ET then you were on borrowed time unless you upgraded your own internals. Upgrading things to Turbo spec is the key. A thicker head gasket will help to lower compression. Sure turbo on an NA engine CAN work, but for how long is the unknown. @15Lbs it could have lasted just as long as it did before you melted it, or it might have lasted years. The point is that you're pushing the engine beyond it's design. That it holds up is just because it's well built, and a bit of luck. I'm not certain if you'd had Turbo internals for your old engine. 15 Lbs is a lot for an NA L28 engine. Quote Link to comment Share on other sites More sharing options...
bthomp Posted October 30, 2012 Author Share Posted October 30, 2012 I was talking to blozup on his instal. I'll take a look at that sticky next. Not going to lie, Megasquirt and I have a love hate type of relationship... The L28 was a stock NA for everything inside the block and head. Outside was all custom to some degree. The melted piston could of came from a number of reasons, not to say the turbo didnt help push things along faster... Over all my main reason for even thinking about keeping the L28 is simplicity and knowledge. They are fairly easy engines to work on, and I know a lot more about them than the VGs. Quote Link to comment Share on other sites More sharing options...
cgsheen Posted October 30, 2012 Share Posted October 30, 2012 I usually swap L28s into VG30 equipped cars. Quote Link to comment Share on other sites More sharing options...
HowlerMonkey Posted October 31, 2012 Share Posted October 31, 2012 (edited) The L28et is more than two seconds faster in the quarter mile and the VG30 is difficult to turbo in this car without substantially more work than swapping in the L28ET. It might even fool a state emissions inspector if it blows good numbers. Edited October 31, 2012 by HowlerMonkey Quote Link to comment Share on other sites More sharing options...
bthomp Posted October 31, 2012 Author Share Posted October 31, 2012 Being that the externals are already done for the l28, it would make everything a lot easier... Quote Link to comment Share on other sites More sharing options...
Gollum Posted November 1, 2012 Share Posted November 1, 2012 (edited) I love VG equipped S30's, but that's 100% about weight, placement of said weight, and packaging size. YES, it's more difficult to fit a turbo + exhust into the engine bay, especially without steering linkage modification. YES, the L motor is better all around. Revs higher dollar for dollar, has less oiling issues, YES, the L motor has proven to make more NA power time and time again. BUT!!!! Not only is the VG a bit lighter (not by more than 50 pounds by most accounts), but it's HALF the length, AND it's a V motor keeping the center of gravity LOWER. That's what I like about the VG, but same could be said about nearly ANY V6 between 2 - 4 liters. I also like that the VG has commonly available turbo parts and a stock ECU and injectors will take you to 300+whp just fine, and you CAN tune it if you so desire. The VG is also dirt cheap. As the VQ becomes cheaper and more readily available then I'll say the VG should just be left alone, but that day isn't here yet. A quick and dirty VG versus VQ will be less than half the swap costs. That's hard to argue. Now..... All that said... Unless you're setting up your car for hardcore HPDE racing, the S30 will handle JUST FINE with a L motor in there, and then all the benefits of the VG I mentioned just went out the window. The L engine is very capable. So it's really up to you. Edited November 1, 2012 by Gollum Quote Link to comment Share on other sites More sharing options...
Tony D Posted November 1, 2012 Share Posted November 1, 2012 On the L28, if you didn't start with the ET then you were on borrowed time unless you upgraded your own internals. Upgrading things to Turbo spec is the key. A thicker head gasket will help to lower compression. Sure turbo on an NA engine CAN work, but for how long is the unknown. @15Lbs it could have lasted just as long as it did before you melted it, or it might have lasted years. The point is that you're pushing the engine beyond it's design. That it holds up is just because it's well built, and a bit of luck. I'm not certain if you'd had Turbo internals for your old engine. 15 Lbs is a lot for an NA L28 engine. Hmmmm, I've been living on borrowed time since 1985 then! 15#? Try 21#! Boost doesn't kill engines, detonation does. The NA block and components when not DETONATED will last OEM Reliability-wise with a turbo no problem. Most stock turbos will go 300,000 miles + without a whimper. Exactly how much longer do you want them to last, exactly how much time are you borrowing? Hell, by simple numbers if tripling the HP cuts engine life to 1/3rd, that means a 450HP L28NA Conversion will ONLY last 100,000 miles! Now let's see, I'm at 350.... made more than that on occasion, but generally are running at the 350 level.... So I've got 70K on that modification, on top of the 15,000 on it when I started. Oh, yeah, I better get ready, I might need another engine in about 20 more years! N/A internals, JDM "Cherry Brand" head gasket, safe-rich tune and NOT DETONATING IT. I would say I'm not alone, and it's nowhere 'pushed beyond it's design' in the least bit! It's not the ENGINE, it's the FUEL AND SPARK MANAGEMENT. Quote Link to comment Share on other sites More sharing options...
bthomp Posted November 1, 2012 Author Share Posted November 1, 2012 Boost doesn't kill engines, detonation does. or in my case, a melted piston... Like I said though, whole nother story Tony, what transmission are you using on your engine? Quote Link to comment Share on other sites More sharing options...
Pharaohabq Posted November 1, 2012 Share Posted November 1, 2012 Well maybe You're just really lucky Tony-D. Yes Detonation is particularly bad for the engines. For most people just bolting a turbo onto an NA engine and trying to run it on pump gas at 15#+ are asking for damage due to the high comprettion ratio. I don't know the thickness of your head gasket, but adding the thicker gasket can lower compression making detonation less likely. Yes a good tune can limit that too, but the stock NA was not designed for that much pressure and compression. So yes, borrowed time on a stock NA. Not all blocks are equal either, HP aside, if you put 15# in a L24 block it would be more dangerous to the engine than if you put 15# into an F54 L28 block. Can it be turbo'd? sure. Is it risky? sure. Do people do it? sure. Too much pressure causes detonation. An NA engine is not designed to handle excess pressure. To manage it you have to lean the A:F since you can't change the compression ratio. At some point you'll either blow it up or run out of power. The Turbo ET engines have lower compression which allow more air pressure at intake with the same A:F before detonating. So yes, Detonation kills engines, but Pressure and A:F are big contributing factors. Stock NA can't handle what a stock ET can. Quote Link to comment Share on other sites More sharing options...
Bernardd Posted November 2, 2012 Share Posted November 2, 2012 I turn the boost down to 15psi when the wife takes the z out for a ride. Quote Link to comment Share on other sites More sharing options...
Tony D Posted November 2, 2012 Share Posted November 2, 2012 (edited) Seriously? You really believe that? I did what just about every other turbo car did in the 80's in Japan. You didn't even bother to show without at least 350PS... Less than that and it wasn't considered worthy. 300HP L28's in turbo trim were running as daily grocery getters. I don't know how many miles JeffP has now on his L28, but I know he rues the money spent on the expensive forged bottom end he wasted two times whilst learning to tune... Now that he has it down that stock bottom end has run 475hp to the rear wheels (more than the stroked did at 21psi I might add) and he's dialled it back to around 450 for longevity. Luck has nothing to do with it, it's not getting greedy and doing something stooped that keeps your engine in one piece. The compressive strength of the rods and pistons aren't ANYWHERE NEAR their limits at these pressures and engine speeds. In fact, for daily driver usage I was running 87 octane California Arco EC1 for as long as they had it, and my boost was turned down to 12 accordingly... Detonation occurs in NA engines just as commonly as Turbos, and the head gaskets that routinely blow out are evidence of that. My Cherry Gasket isn't some gimmick-gasket to lower compression, it was an OEM Equivalent. You don't need MLS, In fact, if you put MLS in the engine, chances are good you WILL break something when you detonate. Jeff figured that out, after the third Fel-Pro blew out, he understood he was detonating. So he tuned accordingly... I don't have a clue where you're getting your information, but explain to me why "15# is more dangerous on an L24 than an F54"--I mean really? You have and are spreading some pretty egregious misconceptions here, one is the myth of boost and pressure. I can show you dyno pulls of an 8.5:1 engine at 8.5psi making 300+ HP, the bottom end BONE STOCK! With the sock head and cam that power was way down, and with a stock turbo, stock cam, and un ported head yeah, you would have to tune far more carefully because the heat that comes with a stock T3 pumping 16# is on the ragged edge. But a different turbo, pumping 8.5 psi...no inter cooler necessary baby! With the stock crap, and 16 psi, absolutely. The bottom end can handle it. NA or Turbo. The difference they will make is negligible, the skill to tune may be different... But the premise that the NA bottom end somehow can't handle it is ludicrous. And that the L24 is somehow inferior and like some ticking time bomb at the same boost levels is similarly ludicrous! Frankly, if you go with the guys in the know, for maximum longevity and power production, rigidity in the bores is key, and for that the older blocks, and the N42 in particular excel,especially when bored oversized like so many want to do. F54 is nice in stock bore size, and that's about it. The 1100HP L28 was an N42... NO engine is designed to handle detonation, save the knock engine the sae uses to test fuels... NA or Turbo, you detonate, you will go boom. Not if, when. As I said before, the key is not getting greedy, and doing something stupid. Know your limits as a tuner, and have realistic expectations from what you're building, and the engine will be as trouble free as a stocker, and blindingly fast. ***this has moved away from L28/VG30, if there is a debate about L-Engines ability to hold up and what it's design limits are, I'd suggest this move to a different thread*** Edited November 2, 2012 by Tony D Quote Link to comment Share on other sites More sharing options...
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