How an LS Engine Turned a Broken 911 Into a True Budget Supercar

Peter
By Peter Brock
Aug 13, 2022 | Porsche, 911, 996, LS | Posted in Features | From the Dec. 2011 issue | Never miss an article

Photography by Peter Brock

[Editor's Note: This article originally ran in the December 2011 issue of Grassroots Motorsports.]

Scott Mann of Renegade Hybrids is far from a Porsche purist, and the seeds for his latest project were planted nearly a decade and a half ago. In 1998, Porsche introduced the first of its liquid-cooled Type 996 cars in both two-wheel-drive and four-wheel-drive versions. 

The factory wanted to broaden its appeal to a much larger portion of the market. This meant increasing production to reduce costs and meet the expected demand. While their earlier, air-cooled models were hand-built, Porsche expanded and streamlined their manufacturing methods to use robotics and just-in-time component delivery on the production line—much like the Japanese car factories of the era.

Porsche gave the 996-model 911 a softened suspension and a refined, quiet ride quality in hopes of making it appeal to a whole new class of potential buyers. The targeted demographic was more familiar with the cushy ride characteristics of a couple less-sporting luxury coupes, and the 996 would be selling against those cars.

Of course, the 996 was a step away from Porsche’s traditional sporting image—a marketing and design anomaly—so these first cars weren’t exactly embraced by the brand’s longtime fanatics. In those circles, the 996 was often disdainfully referred to as the Camry of Porsches.

On top of that disparaging moniker, some of these early production models also suffered from mechanical problems with their engines, lowering their value even further in the secondary market. Porsche quickly rectified the engine problems and, realizing their marketing error, soon introduced the more “Porsche-like” Type 997, which turned out to be one of the most popular 911s ever.

However, those early 996s, especially those out of warranty with broken engines, were left in a unique price depression. Due to the high cost of some Porsche parts, rebuilding the cars to the latest specs was prohibitively expensive. Buying a used engine from a salvage yard was pretty risky, as there was no way to ensure quality. Worse still, remanufactured engines from respected Porsche specialists were even more costly. 

As a result, many owners just pushed their 996s into storage, hoping the prices on junkyard engines would eventually sink. So far, that hasn’t happened; the cost for a rebuilt engine remains high.

Consequently, prices on 996 Porsches have dropped well below comparative prices for used earlier and later models. This may not be good for those disgruntled early 996 owners, but it is a serendipitous score for those with a more adventurous spirit and the boldness to think out of the box. Since the 996 was essentially a first-class chassis that could be easily updated to later 997 specs by adding more sporting suspension modifications, why not also insert a different engine—one that’s less costly but more powerful? 

GM to the Rescue

The replacement heart for this particular swap hails from a similar era as the 996 itself: The Corvette received GM’s first LS-series V8 engine for the 1997 model year. Soon after, GM Performance offered these alloy-block wonders for sale as complete crate engines. 

At first, GM’s intended market was the solid street-rod segment. Those enthusiasts were in desperate need of an engine that would meet modern emission standards. Several states were demanding clean-burn engines, even for hotrods and customs. 

GM Performance replied with their eco-friendly LS3 E-Rod package, complete with wiring harness, electronic control module, and matching catalytic converters and oxygen sensors for the exhaust system.

The cost of a remanufactured, chassis-correct engine for the 996 remains sky-high, so Scott Mann of Renegade Hybrids started exploring some alternate means of propulsion. It turns out that, despite the extra cylinders, the GM E-Rod crate motor fits in the available space with minimal cutting.

Scott (left) showed author Peter Brock his company's header and oil pan solution for a V8 swap in a Porsche 944. A custom pan is needed to clear the cross-member on that front-engined model.

Renegade Hybrids used their adapter setup to mate the GM V8 to the 911's transaxle on owner Sam Korper's car. The 911's distinctive weight distribution is largely unchanged despite the dramatic engine swap.

Scott, who started his business using earlier versions of Chevy’s iron and alloy small blocks for his Porsche conversions, made the shift to the aluminum LS for their 944 kits back in 1999. In the case of the 911, the modern GM engine offered more displacement and more horsepower for a lower price. It was lighter, too. And if the standard 430-horsepower, 6.2-liter LS3 wasn’t enough, GM also offered the dry-sumped, 427-cubic-inch, 505-horsepower LS7.

Scott was eager to try Chevy’s turnkey E-Rod crate motor package in a 911. A quick check with a tape measure ensured that the E-Rod would fit nicely—just a few sheet metal adjustments were needed to accommodate the accessories. An adapter kit with a flywheel and clutch was needed to mate the V8’s block to the Porsche’s transaxle. Scott would also have to apply the knowledge he picked up in his decades of transplanting V8s into Porsches to make various tweaks, like adding a custom chip so the German tach could speak American V8. He also needed a guinea pig.

Willing Participant

Enter Sam Korper, an all-around car guy from Maryland. Sam had heard about Renegade’s V8 Porsche conversions and decided to visit the shop. Having done several engine swaps on his own since high school, Sam was familiar with the numerous potential pitfalls of this kind of surgery. He liked what he saw and offered to participate in Scott’s project.

First, they needed a chassis. Since Sam would be using the car as a daily driver, he opted for the all-wheel-drive version. A quick search on the Web for a 996 with a bad engine turned up a clean C4 in Northern California.

“The best thing about the 996 V8 conversion,” Scott explains, “is the fact that it’s already a liquid-cooled Porsche; this eliminates much of the hassle of routing new cooling lines and reengineering and installing custom radiators.” 

The only hint that this Porsche 911 isn't stock comes when the driver tips the throttle and that torquey LS3 engine comes alive.

Scott modified the cooling system a bit, though, removing the stock water pump from the engine block and installing a Meziere Enterprises electric unit fitted with an integral thermostat. He mounted it just forward of the transaxle, and only two new fittings were required to mate it to the stock Porsche cooling system. 

The shop also replaced the stock power steering pump with an electric unit mounted up front in the luggage compartment. “This left the whole front face of the engine clean so we could use a flat, alloy mounting plate that picked up the stock engine mounts in either side of the engine compartment,” Scott explains. The remaining accessories were positioned tight and low against the block, allowing everything to fit under the stock deck lid behind the rear crossmember.  

Up to Spec

Total weight came out to 3260 pounds, a little heavier than a non-Turbo 911 but dead even with a C5 Corvette. The converted Porsche, however, offers exclusivity, four-corner grip and a driving experience that’s hard to beat.

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Comments
MrFancypants
MrFancypants Reader
9/4/20 8:42 a.m.

Why are these Porsche engines so expensive to rebuild?

pres589 (djronnebaum)
pres589 (djronnebaum) PowerDork
9/4/20 9:35 a.m.
MrFancypants said:

Why are these Porsche engines so expensive to rebuild?

I'm not into these cars at all, so grain of salt, but the parts for basic hard parts for Porsche engines that aren't really VW's or someone else's seem quite expensive.  Pelican wants about $325 for a single Mahle piston for a 996, for instance.  A set of Mahle forged LS1 pistons, all 8, seem to run under $800. 

RossD
RossD MegaDork
9/4/20 9:48 a.m.

People will pay for it. Exclusivity. Isn't there Miata parts that are expensive but then you look for the version of the engine that went in a Kia and its a 1/3 the price? Or a Miata knob in an Aston Martin.

Vigo (Forum Supporter)
Vigo (Forum Supporter) MegaDork
9/4/20 9:48 a.m.

It's interesting to think that 996s cost as little as they do mainly because of what shops charge to work on them. 

I never thought an LS swap would make my 996 better as a street car. It was already near-perfect at it. I get the whole 'engine blows up, replacement engines are expensive' thing but again you're mostly paying for someone elses PITA factor. When my 996 got totalled from flood damage, the engine (which never got water in it) was fine and the whole car sold on Copart for $3500. I had my reasons for not buying it back at auction (i couldnt buy it back from insurance because of a stupid state law in Texas) but if someone needed a motor you could pay someone $100/hr to deal with the auction process and have the whole car shipped across the country and have a mechanic pull that motor and you'd still have a good used engine for less than the numbers some people mention, plus you'd have a whole 911 worth of extra parts. Or a better idea.. replace a computer module and have an entire good 911 that just smells funny. 

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
9/4/20 10:06 a.m.
pres589 (djronnebaum) said:
MrFancypants said:

Why are these Porsche engines so expensive to rebuild?

I'm not into these cars at all, so grain of salt, but the parts for basic hard parts for Porsche engines that aren't really VW's or someone else's seem quite expensive.  Pelican wants about $325 for a single Mahle piston for a 996, for instance.  A set of Mahle forged LS1 pistons, all 8, seem to run under $800. 

Some of that has to be volume. How many flat six Porsches are made every year compared to the LSx? 

I looked at the 996 and early 997 a few years ago when moving up from a Miata (I know, I know...). The IMS bearing, D-chipped cylinder liners, and different issues with porosity in the block castings made them feel like you were playing russian roulette. Yeah, it was probably going to be just fine, but there was a 10-15% chance of catastrophic failure. Almost bought a 996 version of the 911S with a blown engine, but even sourcing a new one from Jake Raby meant a 6 month wait. Online community seemed not-great as well-that was probably the final straw and I went another direction.

pres589 (djronnebaum)
pres589 (djronnebaum) PowerDork
9/4/20 1:46 p.m.
Keith Tanner said:
pres589 (djronnebaum) said:
MrFancypants said:

Why are these Porsche engines so expensive to rebuild?

I'm not into these cars at all, so grain of salt, but the parts for basic hard parts for Porsche engines that aren't really VW's or someone else's seem quite expensive.  Pelican wants about $325 for a single Mahle piston for a 996, for instance.  A set of Mahle forged LS1 pistons, all 8, seem to run under $800. 

Some of that has to be volume. How many flat six Porsches are made every year compared to the LSx? 

Oh, no disagreement from me.  My point was that some of the cost difference comes straight from the parts costing a lot more.  Your point about volume is definitely an aspect of why the parts cost more; they don't make as many parts vs. a GM product.  Volume is probably also part of why it costs more to have work done; you get to call yourself a 'specalist' if you're not working on garden variety equpiment.

dwcisme
dwcisme
9/5/20 6:23 p.m.

Way back in the dark ages (early 70's), Car Craft or Hot Rod magazine ran an article about a 60's era Porsche 912 (I believe) with a Toronado drive train. Same issue. Porsche engine too expensive. So why not stuff 455 cubes plus the transaxle (automatic unfortunately) in there? Probably a tad quicker off the line.

Vigo (Forum Supporter)
Vigo (Forum Supporter) MegaDork
9/6/20 12:11 a.m.

I wonder how many of the people dissuaded by the engine replacement cost of a 996 have spent that much in interest payments on a completely mundane car and eventually sold it for an 80% loss. I have to narrow it down to 'prospective 996 buyers' so that im not, you know, talking about nearly everyone who ever financed a brand new car over 40k. Current 2% interest auto loan bubble excepted, of course. 

docwyte
docwyte UberDork
9/6/20 8:46 a.m.

After having done an LS swap into a 944 Turbo, I'll never do a swap like that again.  While the LS itself is far cheaper than a Porsche motor, by the time you've actually gotten the LS installed and everything working, it's FAR more expensive than just swapping in another 996 motor.

Plus the added headaches of custom fab work, trying to get the AC to work, anytime something breaks it's a huge PITA to fix, lack of proper room to work in the bay, issues with heat/cooling on track, most shops won't touch it with a 10 foot pole, etc, etc, etc.

No thanks!  Been there, done that, got the t shirt...

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