juddtaylor

My motor bottomed out on what is known around here as a "city titty", and it broke off part of the oil pan and crank case.

So, it's new motor time. However, I really don't want to just replace it with another stock 3.4L, even if it does have some updated internals.

What I really want is the 3.4L X51.

At first my Porsche dealer said such a thing didn't exist. I knew better, and found a part number:
996-100-951-01

My dealer punched the number in, and it did come up as an X51 motor. (What I also know was that this is for '99 C2s not in USA).

He said the parts manager was out, and that a quick glance showed that part as "not available", but also not a lot more $$ than the stock 3.4L. Hopefully the parts manager will be able to hunt one down for me.

So, I'm very worried at this point about the availability of these things. Anyone else come across this situation? Are any available anywhere?

Is there any more advice I can give on this to the dealer?

Thanks,
Judd

himself

Check with Loren over at Renntech. He is a parts guru.

-td

Patrick

I added the X51 kit to my '01 3.4L after the fact. My advice is, don't. There is more bang for the buck available. The engine won't just plug in. You will have to have serious DME work done, or find a euro DME and do a lot of rewiring.

juddtaylor

That's really interesting. The workshop manuals, etc don't mention a different DME being used for the 3.4 X51. Was this required just to get the engine running, or to get it to pass emissions?

Emissions is probably a huge concern here. Once you had a proper DME on, did you have any trouble with CEL or OBDII?

Thanks,
Judd

juddtaylor

Here's what Loren said:

My understanding is that the 3.4 X51 was never submitted for US emissions approval. So the only 3.4 X51's (that I know of) in the US - are in race cars.

You likely could import one from Europe - but I have no idea of the cost. Gert Carnewal could likely tell you (www.carnewal.com).
I don't know what state you live in but if they do not require a smog test requirement you might get away with it.

or option 2
would be to put in a 3.6 X51. You would have to upgrade the DME also but a couple Boxster guys have done that already.

Hope that helps some...


--------------------
Loren
RennTech.org
PCA member since 1978

Rassel

Judd, is there any specific reason for you wanting a 3.4L?
You probably know that with some work you can put almost any modern flat-6 in there.

NJcroc

what year is your car? If it is an e-gas car that swap is differant than if it is an earlier car without it

Patrick

The "workshop manuals" don't mention much about the X51 at all, and some of what is there is wrong. Remember, mine was a kit, but the end result is the same. The 3.4L X51 only has one cam position sensor, US cars have two. The X51 heads do not have ports for SAI. There is not a map available for the US DME to run the X51, so you will have to have the car tuned. At the same time you can delete the SAI test, eliminating the CEL. I have no idea what the ramifications of running just the one cam position sensor would be, as I had the head with the missing boss modified to take the sensor. If you are subject to emissions testing, forget it.

Serious waste of money. If you are going to try something like this, I'm guessing the cost and hassle wouldn't be much more to put a 3.8 in your car.

juddtaylor

More interesting stuff here. The workshop manuals that I have are at least as recent as 2005, and they have very detailed information about teh 3.4L X51 engine. However, it doesn't mention anything about the DME mapping, SAI or the cam position sensor.

I'm looking at this along side my dealership, which is only quoting me a (approx) $2.8k difference between that and the regular replacement 3.4 motor.

The dealer says that they should be able to load the right DME software into my DME with their porsche DME flash tool. Supposedly, they'd just flash my DME with the euro X51 DME software (unless that's impossible).

Did you get your swap/upgrade done at a dealership, or at a 3rd party shop? It sounds like much of your troubles would have just gone away by getting the euro X51 DME code on your DME (or if not possible, getting a euro DME).

Note, however, that my dealership is admitting that they haven't done this before, but they feel confident that they can get it working, and will work with me on any unforseen costs that may come up.

My state does just OBDII emissions testing (no tail pipe stuff). As long as no CEL code is thrown, then I'll pass. Plus, I hear a lot of inspection shops around here on the take, anyways...

From what I've heard, getting X51 as a kit is like a $17k option, while I'm not looking at anything like that layout, as my current 3.4 is a paperweight (not core-able). I can understand the frustration having laid out that much, but do you still think it's a huge waste, given the numbers I'm looking at?

I've looked at the 3.6 and 3.8 options, and they're looking to be much more costly. My car isn't e-gas, can-bus, returnless-fuel. That means to go up in engine the proper way means: re-wiring the car, upgrading the DME (to 7.8), the instrument panel, the exhaust, and the fuel system. Plus, a larger difference on the replacement cost of the engine...

Thanks, however. I'm calling my dealer right now...

-Judd

juddtaylor

I would love to have a chance to contact whoever did your upgrade. If you feel inclined, please PM with some contact info.

Thanks,
Judd

Patrick

Unless your manual is different from mine, any detail it has about the X51 applies to the 3.6. It would be interesting to see if the dealer could get that flash, and if the DME would take it. Does the X51 crate motor come with intake and exhaust? Fuel rails (different plumbing)?

Dealer. Probably be as much hassle to switch DME's as the route I went. Six of one, half dozen of another.

That is bretty bold of them. My dealer did the work for ticket time.
The cost as an option really doesn't have much to do with my cost, it should have come in around $13K, but between rework and the cost of tuning, is was around $20.
e-gas and CAN will be resolved with the new DME, which you will likely need anyway. With everything else, people have been down that road and it's doable, and the result will be better than the 3.4 X51, which essentially makes your car as good as a stock 3.6. I really think you'd be happier putting in a stock 3.4 and tweaking it from there. A blower isn't that expensive, and will make your car a lot livelier than the X51 will.
If you are convinced this is the way to go, PM me and I will help you any way I can.


Good luck.

sbelles

How bad did you break it? The 3.4 that I have in my Boxster had the same problem when I acquired it. Fixed it up with some JB Weld and it's held for 6 years, 50k miles and about 140 track days. It's my understanding that x51s are no longer available from Porsche. You may be able to find a used one but they are scarce.

AudiOn19s

The 3.6 swap into the non e-gas cars is becoming more and more common and many of the bugs now have viable solutions.

Search for posts by Paul996. He did a 3.6 into his non e-gas 3.4L car and covered most of the complications in detail. Sounds like it required much of the same stuff that the 3.4 X51 kit will require BUT if you could source a 3.6 X51 for approx. the same money then that's probably the BEST bet if it requires roughly the same work as getting the 3.4l X51 swap done.

Andy

juddtaylor

The create motor comes with all that. We're pretty sure it will also come with the exhaust headers as well.

The euro and US part numbers for the DME unit are the same (dealer looked this up), so they should have no problem programming my DME with the euro DME code for the X51.

A blower is like $10k, right? I'm looking at just $2.8k here... I also don't want reliability issues with the engine. The compression ratio is already 11.3:1, and supercharging that will put a ton of stress on the motor, and likely require higher grade fuel than 93.

-Judd

juddtaylor

I just checked out Paul 996's posts. He got his work done at a shop that already had 3.4->3.6 swap experience (not my case), and he _did_ have a ton of trouble getting his 5.2.2 DME working withe the 3.6. All things I want to avoid.

It looks like the X51 crate won't require anything that it doesn't come with, except an DME reprogramming. The 3.4 X51 always used the 5.2.2 DME.

All signs point to this not requiring a lot of extra work (knock on wood).

-Judd