2007 Porsche Cayman S with LS3 Engine Swap

This current home garage build-in-progress involves what most would consider to be a sacrilegious engine swap, but before casting any judgement on the project it should be noted that the owner of this 2007 Porsche Cayman S, Joshua Murray, bought the car with a blown engine. A new 6.2 liter GM LS3 crate engine is in the process of being fitted to the standard factory Porsche transmission with use of a Kennedy LS adapter mount and a lot of custom fabrication. Future plans include a Quaife sequential transmission for full throttle clutchless up shifts, as well as the installation of a dry sump oil system. With what started last November is left most currently updated just last week with a post test fitting the rear swaybar and undertray support, while the engine is already in the process of being made to fit. It will be interesting to see this monster hybrid when it is completed, but in the mean time check out the following page for build pictures and a short time lapse video of the impressive project so far.

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“After test fitting the LS3 a dozen times I decided the ‘normal’ install position that most folks use is just not that great.”
The CV’s “were pushed back about 4 (inches) from stock, you have to run an electric water pump and options for dry sumps are limited. Also, the front of the motor sits a couple inches low(er).”

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Below, the seats are all of the way back to show how far forward the Chevy engine now sits in it’s new Porsche housing.

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Hopefully we will be seeing some attention given to suspension modifications next to help compensate for the additional horsepower and torque, which we normally like to see done as the first step of a project. Porsche brakes are notorious for being top notch, so probably not much will be needed to upgrade them other than proper fluid, pad, lines and cooling. Keep an eye on updates in Joshua’s “CaymanRSR” blog HERE.

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20 Comments on 2007 Porsche Cayman S with LS3 Engine Swap

  1. i’d like to see some vid of this thing when done. i normally don’t go for american v8 engine swaps in porsches, but i have no hate for this build. impressive.

  2. interesting project, looking forward to seeing what it can do. wonder what the weight difference is btwn the two engines and gearboxes. if this v8 is sitting lower, should make for even better mid engine handling. if used for the track, a dry sump is necessary in these with stock engines b/c of oil starvation i’ve seen a few track prepped cars experiencing around high g force turns. not sure what this is being made into, street or track, but looks intriguing.

  3. i have a feeling this build is going for more straight line performance than anything else, which would be a shame considering what it was originally designed for. to each their own, i will reserve judgement until the project gets further on.

  4. I like this and if my Cayman’s engine grenaded I would go this path. Yes straight line torque would improve, but the chassis is still all p-car and expect it to be good. Similar to the Boxster that renegade hybrids has done: https://www.youtube.com/watch?feature=player_embedded&v=P67OSN2DqAE

  5. I’ve been looking into doing this to my 08 cayman s. Minus the cost for the car how much do you expect this project to cost.

  6. This is a track day car. I doubt I’ll every 1/4 mile it. The LS3 basically weighs the same as the flat 6. I will be putting a Daily Eng dry sump in there. Just getting phase 1 done now. Feel free to email with questions.

    Josh

  7. TShreibDog, why do you think this build will render the car more of a straight line performer? More HP and torque sure makes the Cayman GT4 go a lot faster through the turns than the Cayman S. The LS3 weighs the same as the factory 6 cyl so it’s not a weight issue. So a perceived center of mass shift? Center of gravity shift?

  8. It looks like LS3 has clearance issue behind the seats 🙁 . Could You please tell me: What is the Length of the engine from BELL-HOUSING to CRANK PULLY? I searched different sites/forums and they all have different measurement numbers. it is an awesome project good luck. You the Man.

  9. This whole setup is cooler than the underside of my pillow.

  10. I see you are placing the engine more forward than others I have seen. These were the Renegade kits. One fella has had problems pulling the CV joints apart at the axle. His solution was to put in spacers that look to be about 5/8″ thick. I effectively lengthens the axle, You may have a similar problem. The spacers are made by Tarret Engineering as a part of a lowering kit.

    I am going to attempt the project as I have a Cayman with a noisy engine. I have done swaps before but non this challenging.

    Good Luck

    • Hey Don,
      Mine does sit further forward than the Renegade kit afaik. I have about 1000 miles on it now with no axle issues. I saw the Boxster you were talking about and was concerned and considered the Tarret spacers you mention. I modeled everything in Solidworks and moving the the transmission back 2″ only moves the CV flange 0.11″ further from the hub. Basically it’s in the noise and doesn’t make a difference IMHO. Where the Tarret spacers help is if you are changing camber angles by lengthening the lower control arms GT3 style. Just roughing a few numbers without taking a strut off to measure it adding 2 degrees of negative camber will stretch the axle nearly ~.69″.

      Thanks for checking the Cayman out and let me know if you have any questions.

      Cheers,
      Josh

      • Josh
        The 2006 thru 2009 Impala, with the V8 option, used the LS4 engine. In order to install this engine transversely they had to shorten the over all engine length. One thing they did was to have a remote water pump. I don’t know if it would solve the water pump length problem. I have seen a picture of the pump in a parts cat. But to find one in the flesh, so to speak, is next to impossible due to the limited production numbers. You cut out the entire firewall in order to move the engine forward. Moving the engine forward compounds the water pump problem as it limits the seat location. I suppose the mechanical tubing you have welded in is the provide the structural strength you removed. You also show the intake manifold in it’s original location. It is likely that you installed the manifold reversed. I will undoutedly go with Renegade “kit”. I don’t what emission problems confront you in Washington but here in New Jersey they only check for emissions using the ALDL. If no codes are present you pass. You can either use a state facility or a private one. My good friend has a repair facility and he gets his much modified Z06 through emissions. I plan on using the ERod LS3 and expect the project will cost about $20,000.

        Keep in touch

        Don S.

  11. Hard Racing Performance of Mooresville NC sells a sequential shifter for the Cayman. Clutch-less up shifts and clutched downshifts. It cost $5000. I am sure that a sequential transaxle with cost many times that. There is a video and good pictures showing the unit. It looks well made.
    Don S.

    • That looks pretty neat Don. My interest in the quaife sequential is primarily it’s power holding capability. The sequential shifting is a bonus. Thanks for the note!
      Josh

  12. Hey muy buen proyecto, pero donde conseguistes ese adaptador del motor a la caja de velocidades

  13. Hey very good project, but where you conseguistes that adapter engine to the gearbox

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