Choosing an engine for your Porsche

The Porsche 996 engine, the M96, has a variety of ways it can be damaged that will require a full rebuild. Unfortunately, the M96 is a difficult and expensive engine to rebuild, with many undocumented special assembly steps, special tools needed, and expensive parts that need to be replaced every time the engine is taken apart. We would not recommend the home mechanic attempt to rebuild the M96 themselves.

We should mention that Porsche is now offering rebuilt short block M96 engines through their dealers, for around $6,000 to $8,000. If your engine heads are still good, you could swap the short block yourself, or have a shop install it for you. Also, there are a few companies that will rebuild these engines and sell them as a complete drop in, though they are not cheap. The cost of a new engine can easily exceed the value of the car. We would not recommend buying a used M96 engine, since it is hard to verify the condition without disassembly.

It's worth pointing out that if you are not excited to take on a project like an engine swap or rebuild, but just want your Porsche fixed, there are options. A shop will have a much easier time replacing an M96 with a rebuilt one than swapping in a different engine. The Porsche 996 has become a lot cheaper and selling your car with a damaged engine and buying one in good condition may be your best option.

If you want to sell your Porsche with a damaged engine or no engine, contact us. we can help find a buyer for your car.

 

Chevy LS3 Engine Swap

Swapping the engine for a Chevy LS3 is a project that can be done in your own garage with normal tools. It is my goal to assist anyone that wants to take on this project and remove as much guesswork as possible. Mechanically, it is not a difficult project. There is minimal cutting for clearance required, but with the right parts, the engine can just bolt in. The actual process of dropping the engine and transmission, removing the M96 engine and adding the LS3 engine, and lifting it back into the car, could be done in a weekend.

Currently, the cooling hoses, exhaust fabrication, and A/C lines are the majority of the work getting the engine running and ready to drive. These are areas of future development to make bolt in kits available. These are good projects to have a local shop help with, but you can do them yourself. See the relevant web pages for more advice on these areas.

The wiring can easily be the most difficult and time consuming part of an LS3 engine swap. You have a lot of options depending on your budget, goals, and level of skill. See the Choosing a Wiring Harness page for more details.

LS3 E-Rod Crate Motor

Buying a crate motor from Chevy Performance is the easiest option for a great engine, especially if you need emissions documentation where you live.

Junkyard Motors

Buying an engine from a junkyard can be a great way to find an LS engine for cheap. I will often refer to the LS3 on this site, but there are actually a ton of options in the LS family of engines that will work great to swap in a Porsche. There are a wide variety of cars that can with some variant of an LS engine, but some will need more changes than others.

 
Year Make Model Engine Reluctor Wheel Camshaft gear
count
Cam gear
bolt pattern
PCM/
ECM type
Block Material
2004 Buick Rainier 5.3L LM4 24x 1x (on camshaft) 3 Warren Iron
2005-2006 Buick Rainier 5.3L LH6 24x 1x 3 E40 Iron
2007 Buick Rainier 5.3L LH6 58x 4x 1 E67 Iron
2004-2005 Cadillac CTS-V 5.7L LS6 24x 1x (on camshaft) 3 Warren Aluminum
2006 Cadillac CTS-V 6.0L LS2 58x 4x 3 E67 Aluminum
2007 Cadillac CTS-V 6.0L LS2 58x 4x 1 E67 Aluminum
2009-2015 Cadillac CTS-V 6.2L LSA 58x 4x 1 E67 Aluminum
2001-2006 Cadillac Escalade 5.3L & 6.0L 24x 1x (on camshaft) 3 Warren Iron
2007-2013 Cadillac Escalade 6.2L L92 58x 4x 1 E38 Aluminum
1998-2002 Chevrolet Camaro 5.7L LS1 24x 1x (on camshaft) 3 Warren Aluminum
2010-2015 Chevrolet Camaro 6.2L LS3 & L99 58x 4x 1 E38 Aluminum
2012-2015 Chevrolet ZL1 Camaro 6.2L LSA 58x 4x 1 E67 Aluminum
2015 Chevrolet Z28 Camaro 7.0L LS7 58x 4x 1 E38 Aluminum
2011-2016 Chevrolet Caprice PPV 6.0L L77 58x 4x 1 E38 Aluminum
1997-2004 Chevrolet Corvette 5.7L LS1 24x 1x (on camshaft) 3 Warren Aluminum
2001-2004 Chevrolet Z06 Corvette 5.7L LS6 24x 1x (on camshaft) 3 Warren Aluminum
2005 Chevrolet Corvette 6.0L LS2 24x 1x 3 E40 Aluminum
2006 Chevrolet Corvette 6.0L LS2 58x 4x 3 E38 Aluminum
2006-2013 Chevrolet Z06 Corvette 7.0L LS7 58x 4x 3 E38 Aluminum
2007 Chevrolet Corvette 6.0L LS2 58x 4x 1 E38 Aluminum
2008-2013 Chevrolet Corvette 6.2L LS3 58x 4x 1 E38 Aluminum
2010-2013 Chevrolet Corvette 6.2L LS3 Dry Sump 58x 4x 3 E38 Aluminum
2009-2013 Chevrolet ZR1 Corvette 6.2L LS9 58x 4x 3 E67 Aluminum
2003-2007 Chevrolet Express 4.8L, 5.3L, 6.0L, 8.1L 24x 1x (on camshaft) 3 Warren Iron
2008-2009 Chevrolet Express 4.8L, 5.3L, 6.0L 58x 4x 1 E38 Iron
1999-2007 Chevrolet Silverado, Avalanche 4.8L, 5.3L & 6.0L 24x 1x (on camshaft) 3 Warren Iron
2007-2013 Chevrolet Silverado, Avalanche 4.8L, 5.3L & 6.0L 58x 4x 1 E38 Iron
2011-2014 Chevrolet Silverado 2500HD 6.0L 58x 4x 1 E78 Iron
2003-2004 Chevrolet SSR 5.3L 24x 1x (on camshaft) 3 Warren Iron
2005-2006 Chevrolet SSR 6.0L LS2 24x 1x 3 E40 Aluminum
2001-2006 Chevrolet Suburban 4.8L, 5.3L, 6.0L, 8.1L 24x 1x (on camshaft) 3 Warren Iron
2001-2006 Chevrolet Tahoe 4.8L, 5.3L, 6.0L 24x 1x (on camshaft) 3 Warren Iron
2007-2013 Chevrolet Tahoe, Suburban 4.8, 5.3, 6.0 58x 4x 1 E38 Iron
2007-2013 Chevrolet Tahoe, Suburban 6.2L L92 58x 4x 1 E38 Aluminum
2003-2004 Chevrolet Trailblazer 5.3L LM4 24x 1x (on camshaft) 3 Warren Aluminum
2005-2006 Chevrolet Trailblazer 5.3L LH6 24x 1x 3 E40 Iron
2007-2009 Chevrolet Trailblazer 5.3L LH6 58x 4x 1 E67 Iron
2006 Chevrolet Trailblazer SS 6.0L LS2 24x 1x 3 E40 Aluminum
2007-2009 Chevrolet Trailblazer SS 6.0L LS2 58x 4x 1 E67 Aluminum
2003-2004 GMC Envoy 5.3L LM4 24x 1x (on camshaft) 3 Warren Aluminum
2005-2006 GMC Envoy 5.3L LH6 24x 1x 3 E40 Iron
2007-2009 GMC Envoy 5.3L LH6 58x 4x 1 E67 Iron
2003-2007 GMC Savana 4.8L, 5.3L, 6.0L 24x 1x (on camshaft) 3 Warren Iron
2008-2009 GMC Savana 4.8L, 5.3L, 6.0L 58x 4x 1 E38 Iron
1999-2007 GMC Sierra 4.8L, 5.3L, 6.0L, 8.1L 24x 1x (on camshaft) 3 Warren Iron
2007-2013 GMC Sierra 4.8L, 5.3L & 6.0L 58x 4x 1 E38 Iron
2011-2014 GMC Sierra 2500HD 6.0L 58x 4x 1 E78 Iron
2001-2006 GMC Yukon, Denali, Yukon XL 4.8L, 5.3L & 6.0L 24x 1x (on camshaft) 3 Warren Iron
2007-2013 GMC Yukon, Denali, Yukon XL 4.8, 5.3, 6.0 58x 4x 1 E38 Iron
2007-2013 GMC Yukon, Denali, Yukon XL 6.2L L92 58x 4x 1 E38 Aluminum
1999-2005 Holden Commodore 5.7L 24x 1x (on camshaft) 3 Warren Aluminum
2007-2008 Holden Commodore 6.0L L98 58x 4x 1 E38 Aluminum
2001-2005 Holden Monaro 5.7L 24x 1x (on camshaft) 3 Warren Aluminum
2005-2006 Holden HSV 6.0L LS2 24x 1x 3 E40 Aluminum
2007-2009 Holden HSV 6.0L 58x 4x 1 E38 Aluminum
2003-2007 Hummer H2 6.0L LQ4 24x 1x (on camshaft) 3 Warren Iron
2008-2009 Hummer H2 6.2L L92 58x 4x 1 E38 Aluminum
2008-2009 Hummer H3 Alpha 5.3L 58x 4x 1 E67 Iron
2003-2004 Isuzu Ascender 5.3L LM4 24x 1x (on camshaft) 3 Warren Aluminum
2005-2006 Isuzu Ascender 5.3L LH6 24x 1x 3 E40 Iron
2003-2004 Oldsmobile Bravada 5.3L LM4 24x 1x (on camshaft) 3 Warren Aluminum
1998-2002 Pontiac Firebird 5.7L LS1 24x 1x (on camshaft) 3 Warren Aluminum
2008-2009 Pontiac G8 6.0L L76 58x 4x 1 E38 Aluminum
2009 Pontiac G8 GXP 6.2L LS3 58x 4x 1 E38 Aluminum
2004 Pontiac GTO 5.7L LS1 24x 1x (on camshaft) 3 Warren Aluminum
2005-2006 Pontiac GTO 6.0L LS2 24x 1x 3 E40 Aluminum
2005-2006 Saab 9-7x 5.3L LH6 24x 1x 3 E40 Iron
2007-2009 Saab 9-7x 5.3L LH6 58x 4x 1 E67 Iron
2008-2009 Saab 9-7x Aero 6.0L LS2 58x 4x 1 E67 Aluminum

 

Reluctor Wheel

The biggest and most relevant difference in engines to look for is whether it has a 58X reluctor wheel or 24X reluctor wheel. A reluctor wheel is a toothed wheel on the crankshaft that a sensor detects to measure RPM and crank position. The bottom end of the engine needs to be taken apart to change it. Unless you plan on completely rebuilding your engine, you will have a much easier time getting an engine with the correct reluctor wheel.

You want a 58X reluctor wheel wheel for this engine swap, because it will match the Porsche tachometer signal. This means you can splice into the LS crank position sensor (CPS) and get the tachometer on the dash to read correctly.

A 24X reluctor wheel has proven problematic. There is currently no off the shelf solution to convert the signal. There is a also a difference in CPS voltage, 12V for the 24X and 5V for the 58X. Supposedly, the E40 ECU can be programmed to output the correct signal, but it will be 12V and need to be reduced to work. This currently an area for more research because a lot of people want to use these engines. I hope to find a reliable solution in the future.

Iron Block or Aluminum

Either engine block will work fine in a Porsche swap. An aluminum block LS3 will actually be about 50 lb lighter than the Porsche M96 engine. I would recommend aluminum if can afford it and are going to be naturally aspirated. An iron block LS engine weighs about 100 lb more than the aluminum block and that means it will be about 50 lb heavier than the M96. If you plan on turbocharging or supercharging your LS and making big power, the iron block is stronger and might be worth the weight penalty.

Intake manifolds

Basically, you want a car intake manifold, not a truck one. The stock LS3 intake manifold will only have an 1/8" to 1/4" clearance between it and the top of the engine bay. That is after removing the fuel rail crossover, intake manifold cover, and the sound dampening from the engine bay. If you buy an engine from a truck, you are going to have to swap it because it is too tall.

Some aftermarket intake manifolds will clear, like the FAST 90 and 92, but anything taller than stock will not work. You are better off getting your stock manifold ported and spending your money elsewhere.