"BJohnson11" (brettjohnson01)
07/30/2014 at 22:54 • Filed to: None
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"BJohnson11" (brettjohnson01)
07/30/2014 at 22:54 • Filed to: None | 7
| 27 |
So HotRod Magazine did a build up of what they thought was a junkyard 5.3L truck motor. The goal was to find the end limit of the LS motor. I'd say they did. The article lists all the details, and is definitely worth a read. I'll point out the highlights.
!!! UNKNOWN CONTENT TYPE !!!
They took the motor, tore it down for inspection, and rebuilt it with pretty much stock internals. Hotter cam (but stock pushrods and rockers), opened up the heads with some porting, threw 75 lb injectors, a fast LSXR intake and a 102mm throttle body. Oh yeah, they also added two 76 mm CXRacing turbos.
Impressive build. The motor made over 60 dyno pulls (a good number over 1000 hp), and it sounds like they beat on it pretty good. It failed at 27 psi of boost, but the failure was related to the ignition, and when they tore the engine back down, found no issues.
My thoughts on the build though are mixed. They ran the whole thing on 118 octane (makes sense though for a drag engine). Also, the turbo lag must be incredible. That said, 1200+ hp out of a 4.8L LS engine is insanity. 4.09hp/ci. Shows how well engineered and robust the LS is. The smaller bore motors (4.8 and 5.3) handle boost especially well because the cylinder walls are thicker than their bigger bore counterparts.
My final thought is this. I've always thought the 5.3 (and potentially 4.8) is a better motor for an LS swap. You can pick up a 5.3 and a 4l60e from a truck from a junkyard for cheap (under a grand most of the time), and with some mods (cam, tuning, injectors, intake, etc, and not necessarily turbos), they return plenty of power for a street car, while still offering great driveability, decent mpg, and cheap maintenance. Considering junkyards LS2s and LS3s are a couple grand for the motor alone, I'd say it'd be significantly cheaper to build a 5.3 up.
HammerheadFistpunch
> BJohnson11
07/30/2014 at 23:00 |
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5.3/4l80e swaps are de rigueur over at ih8mud.com for 80 series cruiser. Solid build and less weight than the 1fz-fe
nFamousCJ - Keeper of Stringbean, Gengars and a Deezul
> BJohnson11
07/30/2014 at 23:01 |
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Put it in here, don't care how, don't ask why, etc, etc, etc.
GhostZ
> BJohnson11
07/30/2014 at 23:03 |
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4.8 might have a small bore, but that short crank and long rod configuration also make it a great revver and able to have a low CR for more boost without shortening piston height or reducing rod ratio. If I were building an LS I'd be sticking its crank inside a wide-bore LS2 for a 332 that could rev to the moon.
FJ80WaitinForaLSV8
> HammerheadFistpunch
07/30/2014 at 23:07 |
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Interesting opinion. Can't say I ever considered the 5.3, when there were 6.0 and 6.2's out there for swapping. I suppose my preference would be to not open the motor up at all, however I might have to reconsider that.
ly2v8-Brian
> BJohnson11
07/30/2014 at 23:08 |
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5.3l and 4.8l are identical. The difference is that the 5.3l has a longer stroke, and the piston type (4.8 had flat pistons and the 5.3 dished).
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BJohnson11
> ly2v8-Brian
07/30/2014 at 23:10 |
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I'm aware. Thats why the 5.3 and 4.8 are both capable of handling plenty of boost. Same bore size, different stroke.
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ly2v8-Brian
> BJohnson11
07/30/2014 at 23:16 |
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I should've prefaced it as for those that don't know.
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HammerheadFistpunch
> FJ80WaitinForaLSV8
07/30/2014 at 23:16 |
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6.0 really is the one people want, but 5.3's seem much easier to get and...frankly...are going to be a huge upgrade from the 1fz anyway.
CPT Speedbump
> BJohnson11
07/30/2014 at 23:27 |
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I mean..I'll just take a LS to build.. any LS can make better N/A power then my VQ35 I'd say, lol
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GhostZ
> BJohnson11
07/30/2014 at 23:32 |
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Oh, and I want to add something to my other comment: They used an off the shelf cam and stock heads . And got to 7000rpm. Imagine what they could do on a solid roller cam, high flow heads, and new valves and a higher peak RPM. I bet with more money they could have done 1300+ by just walking up peak HP from 6600 rpm to 7500, which is totally possible.
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GhostZ
> FJ80WaitinForaLSV8
07/30/2014 at 23:33 |
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DatAssun around here swapped a 5.3l into a 240z. It's beautiful, keep an eye out for his posts.
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GhostZ
> CPT Speedbump
07/30/2014 at 23:34 |
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An LS will never make better specific power than a VQ by nature of their configuration, but it definitely has better upgrade potential and costs a lot less.
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CPT Speedbump
> GhostZ
07/30/2014 at 23:39 |
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Indeed, also they make good torque. I've been thinking about building the VQ, but odds are building a junk yard LS block would be more bang for the buck I feel
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GhostZ
> CPT Speedbump
07/30/2014 at 23:43 |
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Depends on swap costs if you're putting it in the same car. For a mild build (400-500) you'd be better with a supercharged VQ, as the swap costs out weigh the cheaper power.
Anything over 600 HP though? Yeah, dump the VQ for an LS.
If you're building it from the ground up to put in something that doesn't have an engine (or can fit an LS easily without spending lots on a kit, a la 280z...) then LS all the way.
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CPT Speedbump
> GhostZ
07/30/2014 at 23:47 |
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It'd be the 350Z currently sitting in my garage, which does atm currently have it's stock VQ in place, lol. 400-500 would be what I'd be aiming for anyway, it'll be a track car/weekend warrior/canyon carver when my plans all fall together.
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GhostZ
> CPT Speedbump
07/30/2014 at 23:51 |
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You're looking at 10k to put an LS in that thing including the cost of the motor, and then you have to build it up to that power level. On a stock LS2, that means either a crazy cam and high compression, or a turbo and/or supercharger, both of which will run you about $5000 minimum on top of the swap kit.
Go with a Stillen Supercharger kit and you'll be much better off, I say.
The advantage of the LS is that the jump from 500-600 to 800-900 barely costs anything once you've got boost running through it, as long as your transmission and cooling system can support it.
DoYouEvenShift
> BJohnson11
07/31/2014 at 00:22 |
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One combo that I always thought would be cool. LS7 block= 4.125" bore, 4.8 crankshaft=3.268 stroke. Equals out to 349.39 inches. So a 5.7 liter large bore, short stroke high rpm screamer. Would be a bit soft on the low end, but more than make up in the high rpms.
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DoYouEvenShift
> GhostZ
07/31/2014 at 00:25 |
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Specific power looks good on paper, or internet bragging. But, will it make you feel better about yourself as you watch the tail lights shrink in front you?
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GhostZ
> DoYouEvenShift
07/31/2014 at 00:43 |
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Specific power has many meanings. LS engines have amazing power to weight ratios, despite their bad power-to-displacement ratios. there's also Power-to-fuel economy which has so little to do with the actual engine itself. Then there's power to cost which is the most important statistic of all.
Pushrod designs have a lot more difficulty in producing higher specific power numbers than DOHC designs simply because
But for the same weight, a DOHC ~4.0 liter engine (depending on bore size) is going to weigh the same as a pushrod 6.0 liter engine and take up the same space. And, at least with the LS, the pushrod will cost far less.
Specific power is everything, and you can't have speed without it. No one wants to get 1000HP by sticking an airplane engine in their vehicle. It's just that the LS motor has a very different kind of specific power than the VQ35.
If you're a good drag racer, you're 60% economist and 40% scientist. The rest is just not fucking up the launch and shifts.
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DoYouEvenShift
> GhostZ
07/31/2014 at 09:04 |
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Your right, I agree with just about everything your saying. But on the street, in a car. Its not as big a deal as most make it out to be. Like you said, comparing a 16 cylinder radial engine to the 2 stroke in my weed eater brings out some differences. But, when comparing 2 engines that really arent that far apart in displacement, physical size and weight. Like a 4.8 versus a 3.7, I realy don think its a big deal. Ill give up that superior specific power to be the one ahead. Maybe Im wrong, I love to argue about stuff like this. But you gotta admit, when your pulling ahead of the car next to you, specific output isnt doing him any favors.
Oohhh Dohc vs pushrod. Anothet one of my favs.
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FJ80WaitinForaLSV8
> HammerheadFistpunch
07/31/2014 at 09:06 |
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Yeah, I will start procuring parts in the next month or so. I'll make sure to post the price difference between the two.
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FJ80WaitinForaLSV8
> GhostZ
07/31/2014 at 09:06 |
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I've seen that. Looks like he just got it running.
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HammerheadFistpunch
> FJ80WaitinForaLSV8
07/31/2014 at 11:15 |
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of happenings? I guess a name change is in order to FJ80SBC or something.
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FJ80WaitinForaLSV8
> HammerheadFistpunch
07/31/2014 at 11:29 |
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Yeah you're right, I should do that.
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GhostZ
> DoYouEvenShift
07/31/2014 at 13:20 |
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My point was that in order to pull ahead of the guy ahead of you, you need specific power. But HP/displacement is just one kind of specific power, and not a very good measurement at that. Especially not compared to HP/weight or volume (external) of the motor, which is where LS engines really shine.
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DoYouEvenShift
> GhostZ
07/31/2014 at 13:22 |
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Agreed. HP/weight, thats where its at too.
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CPT Speedbump
> GhostZ
08/31/2014 at 12:24 |
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The Stillen isn't that reliable though, the only good supercharger for the VQ35 is the discontinued HKS, which runs around 8k...only 2 k away from a LS swap, lol