3.2 -> 3.4 engine swap DYI instructions

[ChrisZang]

So my engine died the famous "intermidiate shaft" death two weeks ago and my mechanic is currently debating with my warranty company...

Be it as it may, I need a new engine, and now I am of course considering a 3.2 -> 3.4 engine swap.

I read in several posts that it is very simple and straightforward but then I found a DYI on this forum which made it sound more like, yes you can do it, but it's not a straight fit: you need to re-program the DME, several parts on the 3.4L 996 engine are on the wrong side, you need to change the wiring harness, etc.

So I was wondering if anyone here

a) actually did a 3.2 -> 3.4 swap and can share experiences (the DYI was for 2.5L -> 3.2L)

B) anyone has another set of DYI instructions

btw: I have a 2002 Boxster S

Thanks

[catmanluge]

So my engine died the famous "intermidiate shaft" death two weeks ago and my mechanic is currently debating with my warranty company...

Be it as it may, I need a new engine, and now I am of course considering a 3.2 -> 3.4 engine swap.

I read in several posts that it is very simple and straightforward but then I found a DYI on this forum which made it sound more like, yes you can do it, but it's not a straight fit: you need to re-program the DME, several parts on the 3.4L 996 engine are on the wrong side, you need to change the wiring harness, etc.

So I was wondering if anyone here

a) actually did a 3.2 -> 3.4 swap and can share experiences (the DYI was for 2.5L -> 3.2L)

B) anyone has another set of DYI instructions

btw: I have a 2002 Boxster S

Thanks

I finished a 3.4 swap on a 2000 standard. Its pretty straight forward except for the engine has to be lowered. The intake on the 3.4 isw higher than on the 2.7 I replaced so I needed 1 3/8 spacers on the front engine mount and 3/4 inch lower transmission mount. I achieved this by cutting the mount and rewelding adding a addition metal plate for support. Thye wiring harness I used was from the Boxster.

Hope this helps but Todd Holyoak is the expert read some of his info on this site...

Catmanluge

[tholyoak]

You can't put a 3.4 in your car. You would do a 3.6 or 3.8 swap. Read this site, it is all laid out. The 996 engine swap into a boxster is very simple as far as engine swaps go.

-Todd

[ChrisZang]

You can't put a 3.4 in your car. You would do a 3.6 or 3.8 swap. Read this site, it is all laid out. The 996 engine swap into a boxster is very simple as far as engine swaps go.

-Todd

Hi Todd,

actually I did, I spent a few hours on this site yesterday searching for "engine swap", "conversion" etc.

btw: during these few hours my admiration for your work and knowledge grew and grew and grew :) too bad you live far far away from here ;)

The parts that worried me in your DYI (2.5 -> 3.2) were that you obviously had to build a few "adapters" yourself.

questions:

a) why 3.6 instead of 3.4 ? I thought the 3.6 has DME 7.8 and won't work with a 2002 Box

B) any better search terms for this site, so I don't have to bug you anymore?

Thanks

too

[tholyoak]

The only adapters are spacers to lower the engine in order for the taller 996 manifold to fit under the engine cover.

Your car has a 7.8 DME, thus you do a 3.6 swap or if you are a bit more adventurous you can do a 3.8. Search under my user name, you will find a ton of info.

-Todd

[koendp]

Maybe a stupid question, when doing a swap, can you preserve the rear trunk?

And is the swap visible when inspected from under the car or do all those engines look the same?

When I all read those stories about swapping engines I am kind of jealous about you're being able to do swaps without any implications of Tax (which is engine displacement dependent here) and Insurance (which is power dependent here)

Just to know if you have to register your new engine to the authorities or if it would pass visual inspection?

[tholyoak]

Again, use the search function.

There is no effect on the rear trunk. Visibly you can't tell the difference.

-Todd

[gandrade1]

B) any better search terms for this site, so I don't have to bug you anymore?

Thanks

too

Click over his name in this thread and select 'Find Member's Topics'

Best,

Gus

[Topless]

Does anyone know if you do an engine transplant with an increase in displacement, and include the cats, O2 sensors etc. will it pass a smog inspection in California?

[Bristol]

Does anyone know if you do an engine transplant with an increase in displacement, and include the cats, O2 sensors etc. will it pass a smog inspection in California?

That's a good question and I believe the answer would be unquestionably YES. First, if you do an engine swap like this in California you technically should take it to a referee after the swap. They'll check everything out and make sure it's acceptable. You are required to swap in an engine from a car from the same year or newer, no older engines than what you already have. HOWEVER, as has been mentioned here, you can't visually tell that it's a 996 engine vs a 986 engine, at least the normal joe can't tell. If you don't take it to a referee, who is going to know or even be able to tell? Technically they're supposed to check the engine at smog, but I've never had anyone ask me to open her up before. It's a PITA to get to the engine any way.

As for emissions - think of it this way - you swap in a 996 engine, reflash the DME to the OEM tune for a 996, keep cats and O2 sensors.... basically what you've got is a 996 engine, complete, in a 986 body. If the 996 passes smog in California, then a 996 setup with OEM tune in a 986 body should also pass smog.

[ChrisZang]

The only adapters are spacers to lower the engine in order for the taller 996 manifold to fit under the engine cover.

Your car has a 7.8 DME, thus you do a 3.6 swap or if you are a bit more adventurous you can do a 3.8. Search under my user name, you will find a ton of info.

-Todd

Todd,

so I did quite some read some reading and research, I would appreciate if you had the time and could confirm my findings:

Again this is for a 2002 Box S with a 3.2L engine

1) a 3.6L (that's a 997 - right?) engine will just drop in

2) I'll have to re-program the DME so that it thinks it's a 997

3) I'll have to lower the engine mounts in order for the taller 996 manifold to fit under the engine cover

4) I'll have to use the headers from my old engine

5) no other changes needed

Bonus question:

so, since I currently have a 3.2L, Porsche will charge me for the engine AND the core.

Does anyone know how much the charge for the core is?

Thanks again

Edited May 20, 2008 by ChrisZang

[tholyoak]

The 3.6 was in 2002-on 996, you reprogram the DME to the 996 maps, yes you need to space down the front motor mount and ideally the rear trans mounts., you can use your old exhaust but it is too small for the larger motor. Sunset porsche is the best place to source a new motor, they can give you the price with core, the total for the motor and core will be in the neighbourhood of $12-15k

Todd

[ChrisZang]

many thanks :)

The 3.6 was in 2002-on 996, you reprogram the DME to the 996 maps, yes you need to space down the front motor mount and ideally the rear trans mounts., you can use your old exhaust but it is too small for the larger motor. Sunset porsche is the best place to source a new motor, they can give you the price with core, the total for the motor and core will be in the neighbourhood of $12-15k

Todd

[ChrisZang]

in case anyone's interested:

quotes from Suncoast:

3.2L 2002 Boxster engine: $8.6k + $2.2k core charge

3.6L 2002 Carrera engine: $11.1k (including core)

[mee]

I thought all 3.6L were VarioCamPlus, so why not 3.8L? VarioCamPlus requires ME 7.8, no? I thought only the '03+ 986 were 7.8. The earlier ones were 7.2 (except 2.5L). I have a 2000 Boxster and am also following threads on this topic.

[ChrisZang]

Your car has a 7.8 DME, thus you do a 3.6 swap or if you are a bit more adventurous you can do a 3.8. Search under my user name, you will find a ton of info.

Are you 100% sure?

I would have sworn that a 2002 Boxster S has DME 7.2 and that DME 7.8 was introduced with model year 2003 with Variocam Plus.

In case I am right I'd guess that limits me to 3.4L engines - right?

[tholyoak]

Sorry, yes the 7.8 DME wasn't introduced until 2003 on the Boxster. I forget it was a year later than the 996. That said, it is just as easy to put a 3.6 in a 2002 Boxster as a 2003, with the exception of buying a new DME, so I personally wouldn't waste my time and money on doing a 3.4 swap on a 2002 (or a 2001 for that matter).

The boxster never received variocam plus until the 3.4 in the 987. The update to the 7.8 only brought along the vane type variocam adjustment of the variocam plus, not the valve lift.

-Todd

[gimmemebit]

Sorry, yes the 7.8 DME wasn't introduced until 2003 on the Boxster. I forget it was a year later than the 996. That said, it is just as easy to put a 3.6 in a 2002 Boxster as a 2003, with the exception of buying a new DME, so I personally wouldn't waste my time and money on doing a 3.4 swap on a 2002 (or a 2001 for that matter).

The boxster never received variocam plus until the 3.4 in the 987. The update to the 7.8 only brought along the vane type variocam adjustment of the variocam plus, not the valve lift.

-Todd

Todd:

So now, I am confused, I have a 2001 S, which 996 3.6L motor works with the least amount of changes to electronics?

I know about lowering the engine & new headers etc.

Thanks.

[tholyoak]

Sorry for the confusion but please to a search here this has been discussed over and over.

A 3.4 is a straight swap. A 3.6 will require a bit of work.

-Todd