By on April 14, 2010

Long time readers of this series know I’m a big fan of modifications to achieve a vehicle’s maximum potential. And there’s no better example than a switch to GM’s now legendary LSX small block V8.  To prove the point, I saw an LS6 powered, 1980s vintage, Porsche 911 partnered with a LS1 powered 914 at the 2005 Houston Autorama.  Lo and behold, that 911-LS6 arrived at a recent Sunday morning cruise-in. So I got to touch it.  And then it started up for me. It was Epic.

The LS6 sounds surprisingly similar to a Porsche boxer at idle, proving how important an exhaust design is to a vehicle’s overall demeanor.  I spoke with the owner/creator/fabricator and got the download: the LS-swap saves 56 pounds off the rear end, but the difference is actually 21 pounds after the conversion to a water cooling system with a radiator in the rear wing.

Oh, and this 911 has a supercharger too. Which does nothing for weight savings or handling, but should make for some good times at the drag strip. No matter, the website with more details is here (LINK: and while it’s not the easiest read, check out the 914 with an LS swap too.

So ask yourself, could I beat that car in my ride?  And then remember why the LSX swap is made of WIN.

(Send your queries to [email protected])

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39 Comments on “Piston Slap: LSX + Porker = WIN...”

  • avatar
    The Guvna

    At the risk of sounding like a killjoy, there is something about SBC swaps that just bores the piss out of me…and it usually winds up seemingly like heresy, besides.

    Make no mistake: I think it’s a wonderful engine, as indeed it has been (in one form or another) for more than fifty years. But I’ve just seen one too many rare and interesting cars completely robbed of their original character by some hillbilly shade tree mechanic whose solution to every automotive question is, “Small block Chevy!”. About the only cars I’ve ever seen improved (or failing that, at least brought back to the break-even point) by a SBC transplant are British Leyland-era Jags, particularly the XJ saloons. The displacement is comparable to the Jag V12, and what it loses in quiet refinement it gains in brute force and simplicity (and it isn’t even really *that* raucous).

    Putting one in a 911, though, offends me in a way that I can’t even adequately articulate. And yes, putting an air-cooled flat six in a Corvette or Bel Air would offend me just as much. That 914, on the other hand…

    • 0 avatar

      Just so we are clear: I’m not a fan of SBC swaps, historically speaking. The new all aluminum LS-based motors are all I care about.

      And most importantly: I really, really, want to drive that 914.

    • 0 avatar

      SBC in a 914?

      How about something a bit more appropriate, say a WRX powerplant?

      Sounds right, hauls ass, conversion stuff is readily available, and in keeping with the spirit of the car.

    • 0 avatar

      That sounds expensive, slow and prone to turbo lag and heat soak! I’d rather have 350 N/A horsepower for way less money.

    • 0 avatar

      Easy, reliable 300+ hp. You can have more if you want.

      Turbo lag? Turbo lag is something from the 70s, 80s, and 90s. Now that everybody has ready access to compressor maps, ball bearing turbos, VNTs, and all the airflow tools in the world, if it lags the builder sucks. Or, the customer wanted something stupid.
      The days of spraying raw gas into the hot side to spool it faster are long over. (Ahh, remember those old Audis?)

      If by heat soak, you mean the f’n stoopid location of a WRX intercooler on top of the engine, that’s always the first thing to go anytime you hop a Scooby. Water-to-air solves that problem.

      As to the cost, calculate the *complete* cost of doing a SBC conversion. It’s always entertaining to hear the Renegade customers tell you what their total bill ended up being. And now they have a car that’ll be fun to try to sell.

      But, if you want some 1200 RPM torque, then go with the LSX. I just don’t understand the point in a 914.

    • 0 avatar

      That sounds like a lot of work, little of which is necessary with an LSX. Plus, if you can put a taller final drive in the stock transaxle, I wouldn’t surprised if these porkers can get close to 30 MPG on the highway, just like other LSX/T-56 transplant recipients.

      As far as having that kind of power (and efficiency?) in a 914? Shelby Cobras are light with insane grunt. And people really like them, so why not extend that goodness to a much more affordable application? This isn’t rocket science.

      LSX swaps work for many reasons. Upsetting the purists is only the icing on the cake.

    • 0 avatar

      If you want a Cobra, why not just go build a Cobra? Brand new everything around $20K. Yes, you’ll see yourself 10 times on any sunny Saturday, but that’s more my hang-up than other’s.

      As the 914 was badged as VW-Porsche in Europe when sold new, the “purist” crowd already looks down their nose.

      I don’t know about relative ease – the Sube plant is small and easy, the LSX is a skosh bigger. Most of the stuff is off-the-shelf for either app though. I just don’t see where the extra work is involved with the Sube.

      I’m sure you could get decent mileage with the LSX in a 914, gear it like a C6.

      I prefer the Sube in the 914 because I think it would be more in keeping with what the car is supposed to be. That, and once again, there’s plenty of Porschevs on the planet already.

  • avatar

    Wow, you’re a dead man the instant you turn the wheel in that thing. Must be fun in a straight line though. I do agree with Guvna though. It’s interesting to a point but boring after a while.

  • avatar

    Scary, but fantastic.
    And not boring at all IMHO

  • avatar

    Other than the ridiculous cowl induction “hood scoop” on the 914, very cool! This looks like a pretty well thought out and engineered conversion. With the small weight savings (albeit a higher CG vs. the original flat 6) and much higher horsepower, this is like having your cake and eating it too.

    Back in the seventies there were several SB Chevy conversion kits for 911s and 914s, and I also remember several magazine tests of a 454 rat motor-powered 911. The 911 purists had their ascots up in a wad over such sacrilege, and it’ll be fun to watch the indignant rants in response to this post, too.

  • avatar
    Paul Niedermeyer

    I vividly remember reading about what was perhaps the first SBC/911 swap: in 1966 or 1967 a police officer in LA bought a stolen 911 at the police auction that had its engine stripped. A replacement was too expensive, so he had Crown make an adapter. But he also had to destroke the 327, substantially, to reduce its torque which would have overpowered the Porsche transmission. It seemed pretty weird at the time; not something I would have thought of.

    • 0 avatar

      Good point, and you’re absolutely correct Paul. Up thru 1977 911s used the fairly fragile 4-speed 901 gearbox. Then, starting in ’78 they went to the more robust 915 5-speed box for the 911SC and ’84-’86 3.2 Carrera models. For the ’87 model year Porsche shifted (pun intended) to the G50 5-speed transaxle, and this is one to have. G50s are very stout and totally V8 torque-worthy.

    • 0 avatar

      The hardcore guys from the 70s ditched the Porsche transaxle.
      They used the Eldo/Toro THM425. It can handle pretty much anything.

    • 0 avatar

      That’s hilarious. I wonder if manual transaxles like the one in the Ford GT might fit, staggering cost aside.

    • 0 avatar

      I just report what I’ve seen…

      Could the GT transaxle fit? Sure. Doubt it would be much of a challenge, save for the purchase price. Haven’t really played with a GT, so honestly don’t know how bespoke that box is. Might be available from a different car, much cheaper.

      If you wanted to really do it up cost-effectively, use a ‘Vette transaxle. Delete the torque tube and Bob’s your uncle. With 375s and massive flares. Merry Christmas!

  • avatar

    Perhaps the LSX angle is slightly interesting, but people have been building 911 V-8s since the mid-70s. If he likes it, that’s great, but it’s as novel as a 5-liter Miata. Or a V8 RX-7. Or a V8 Beetle. There’s dozens and dozens out there.

    Beyond that, running the rad into the rear wing tells me he wasn’t serious about shifting the weight, or he doesn’t even know that it would be useful. Any kind of intercooler, or is he just blowing it straight in?

    Unless it drives far better than the rest of the info would indicate, meh.

  • avatar

    There’s a group of guys who put 5.0 V8 Ford Small Blocks into Miatas. They claim the weight distribution is 53/47 with a half tank of gas. If they figure out how to do the swap with a 4.6 modular motor from a Mustang I might be interested. Or of course an LSX swap. Then when it’s all said and done I’d probably rather have just a plain old Miata cause my manhood isn’t threatened by driving one and Mazda worked hard to make it a great car.

    • 0 avatar

      If you get the opportunity, do drrive one. They really do balance out nicely.

      It’s kind of like a Cobra replica. Except much lower profile, and the top goes right up when it rains.

    • 0 avatar

      Glad to hear someone has experience with one. I’ve seen them online, on TV, but never in real life.

    • 0 avatar

      Guy I knew used to build them about 15 years ago. He started out as just a Miata dude, but he blew one up at the track one day, and well, you know how it goes…

      Alcohol+IbetIcanfita+surewtf!+severallatenights = Voila!

      Personally, I’d just build the 4 banger a bit and turbo it. They drive nicely. Throw on CF doors, hood, trunk lid, and fenders, the Miata gets even lighter and centralizes the mass a bit more.

      Mazda did really sweat the details on the Miata. The 5L does detract from that balance.

    • 0 avatar

      Forget the Ford 5.0L or the modular 4.6L. What you want is an LSX swap in a Miata.

      There are several companies that are selling Miata-LSX swap kits now.

      You just need a Miata, an LSX engine, a T56, a diff and this:

      The Miata’s iron block 1.8L wasn’t the lightest engine in the world so doubling the cylinder count and more than tripling the displacement with an LSX V8 doesn’t add a massive amount of weight.

    • 0 avatar

      @educatordan: In the 90’s I worked next door to Kudzu Racing in Atlanta. They had a number of interesting cars there, but they started to specialize in 5.0 L Miatas, the Monster Miata. I got to go on a test drive a couple of times, they were exhilarating.

      @pnnyj: Isn’t there anything that the LSx can’t make better?

    • 0 avatar

      These guys in Australia specialise in road legal Lexus 4.0L V8 swaps into Miatas.

  • avatar

    If it’s well integrated and doesn’t make the driving experience worse then that’s fine and I’m impressed.

    I’m just not really amazed or intrigued at seeing every vehicle with a SBC stuffed in it “just because”. A great deal of my interest in cars is seeing the different engines/transmissions etc. If they’re all homogenized into SBC recipients I lose a lot of interest. That said, the one Paul mentions above was begging for the transplant…

  • avatar
    thats one fast cat

    holy BEJESUS! That 914 looks like it got attacked by a feller’ who believes Grave Digger is the ultimate SUV. While I get the LSx engine in just about anything, do you really have to cornball it up all of the time? Wouldn’t a sleeper (albeit a loud one) be just as good?

    Having said that, I sure would like to drop the hammer in the 1320….

  • avatar

    There used to be conversion kits to put small and large block Chevy V8s into Corvairs. One of them swapped the engine and transmission which made it mid-engine. At least the Porsches came with decent brakes. For a Corvair, you had to get front discs from a Camaro or Firebird.

    • 0 avatar

      I saw one Corvair where they did a reverse rotation grind on the cam and ran it backwards to work with the Corvair transaxle

    • 0 avatar


      If you ever get the urge, you can still put a new one together.

      Google V8 Corvair, I’m sure you’ll find a dozen purveyors and more clubs. Pretty sure there’s adapters for current V8s.

  • avatar

    This is just wrong. But I kinda like it! (Well, except for that ridiculous hood scoop on the 914.)

  • avatar

    I was a pump jockey at a California gas station in the mid-late 1970s. We had a customer who had a 911. He sourced a 454 from a Corvette and hung it out back. I don’t know what transmission set-up he had. The thing idled quietly and had quiet exhaust, so it never sounded “fast” though the owner claimed he could dust any other 911 on a straight piece of highway. He admitted that the setup was heavier than the original engine and that cornering suffered.

  • avatar

    I’ve never liked crossbreeds, like putting a SBC in a ’32 Ford. If you’re going to do an engine swap, at least try to be clever. If you want a V8 in your Lotus, use a Buick/Rover V8, not a SBC.

    I’m toying with the idea of building a Locost/Se7en, using a Jaguar XJS as the donor car, including the V12.

    • 0 avatar

      Exactly. “I’ve got a Duece Coupe with a 350 in it.” Why, oh, why? A Ford small block is too expensive or something?

      Exactly, a Lotus with a 215 evo in it would be fun. Sort of like building the snot out of an old TR8. Make Bob Tullis’ old car jealous.

      Good luck on the Se7en, the XJS12 should make for an interesting build. 5/6 speed or a slushbox?

    • 0 avatar

      @porschespeed: I think the ‘default’ SBC into 32 Ford is leftover from the days when the cheapest fastest swap WAS the SBC. My childhood next door neighbor was representative of the kind of motorhead from the late 50’s early 60’s who migrated his ’32 5-window from flathead power to small block Chevy power because it was cheap, powerful and easy. Just as it was 50 years ago, it is just as easy today.

      I think it’s almost a foregone conclusion today, but mostly because the folks back then did it that way. The younger people are learning by example.

      Me? I’d like to put a LSx in a Datsun 240Z. That would be slick.

    • 0 avatar

      I’m old school, I figure a deuce coupe should have a flathead V8 with Ardun heads, and while I have nothing against fiberglass Corvettes and Loti, plastic hot rods are an abomination, no matter how nicely finished they are.

      There are apparently a few Loti running Buick/Rover V8s, mostly Elite/Eclats, though apparently it’s been done with an early Esprit, and I have a vague memory of reading about an Europa that someone converted.

      Early on, working with Lotus GKN made a one-off Europa with a 215 and a 5 speed.

      As for the Se7en, I’d start with a slushbox, maybe replace the THM400 with a 4 speed THM700, a fairly common Jaguar modification. It’s easier to install, don’t have to work up a clutch pedal, etc, and it’s not like a 300HP 2000lb car is going to bog down because the gearing’s too high. Also, a 5 speed conversion wouldn’t be cheap since it’d need a custom bellhousing and some kind of clutch setup.

      I like the idea of using a big Jag as the donor car because in addition to the V12, it’s got the classic Jaguar IRS setup complete with brakes that’s been used as a bolt in by hot rodders since the early 1960s, plus the front suspension and steering also are intact on a bolt on crossmember. Getting the right spring rates might be a challenge, since the finished car will weigh half or less than half of what an XJ or XJS weighs.

      I’m surprised that more customizers don’t use the Jaguar V12. It’s probably the most common V12 ever made – Jaguar built about 100,000 of them over the years.

      It weighs about 680 lbs fully dressed, which is a bit heavier than the Coventry Climax in the original Seven, but there are plenty of Se7ens built with SBCs. There’s even one with a LT1, which weighs close to what the V12 weighs.

    • 0 avatar


      Perhaps there was a case prior to the 70’s. I guess I just don’t understand why anyone would do it now.

      HP that 99% will never marginally exploit, is now within cheap, easy reach from anyone’s crate – GM, Ford, Mopar. To me, it just seems more adventurous to keep it in the family. Or at least, close.

      But, we all build for different reasons. There’s no challenge to me in throwing a 350 Chevy in anything.

      I imagine you know there’s probably 20 sources for the 240Z conversion. It’s rather straightforward. They do haul ass.

    • 0 avatar


      I always thought a JPS Europa with a 215 would just be right. I almost did a 215 into my GT6 when I was a kid, but other priorities intruded.

      I see your logic on the XJS as a donor, good choice in many ways. Also, cheap to get. Should be a fun project.

      You certainly don’t need manual, the 12 has plenty of torque. I just ask as long-ago I had the opportunity to drive a 5-speed 6cyl a few times (greymarket) and it transformed the XJS.

      I doubt you’ll have issues finding the springs, but I’m sure you know that there’s many ways to skin that cat.

  • avatar

    FWIW, supposedly the engine bay of the Lotus Elise was designed to accommodate all FWD drivetrains in production at the time (mid 90s), including the Modular V8 Ford put in the Continental and the Northstar V8 in the FWD Caddys. I don’t know if the supercharged LC3 version of the Northstar will bolt up to the FWD 4T80 transmission, but ~450HP in an Elise could be fun.

    • 0 avatar

      Hennessey is supposed to be doing a 700+ HP V8 Elise.

      We all know Hennessey’s, umm, colorful history, so take that for what it’s worth.

      But I have heard from some who toy that it would fit. Superchargers can always be relocated anyway. It’s not a tall unit, and it can be replaced with a less tall unit if it really has to be done..

  • avatar
    johnny ro

    I was a gas jocky in the 60s and 70s at family station.

    Guy pulls up in VW van, around 1970? Fat tires. Up a bit too high in the air.

    -Gimme the hi-test pump. I will get it. I got it. Let go.
    – its special.
    -listen to this. 230 effen horsepower pal. Ya heard uh Porsche? Thats a Porsche engine in there.

    Revs up the flat six he grafted in there, watching me out side window, me a skinny pimply kid with greasy long hair. Whole thing rocks and makes lot of noise. He does a burnout leaving the station.

    Next car in was mid 20s babe in a dark green GTO convertible, top down. Wearing a bikini. I gaped and gawed while I washed her windshield. I liked the GTO better.

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