Engine Short Block choices

I have a 1999 C2 and the engine lasted 185k miles. I am shopping for a short block and I have not been able to exactly to determine what exactly this option is: 996-100-996-TU. It seems to be a variation of a possible X51 block, but very little documentation exists. It is offered as a significantly discounted block online from a couple of Porsche dealerships. My car is an early throttle cable car and I would like to just rebuild it. ​​​​ @lnengineering @Porschetech3 Any chance you can enlighten me about this block? Or any other Porsche expert? Thank you in advance!

I picked up one from the dealer. check out my threads for that story. I chose it because of price and value. All the work is being done by myself. Best,

The TU is the core. The short block is the TX. I had called about the same thing. It looks like it is a short block too but it is the core charge part number. Joey

Yes Joey is correct, 996-100-996-TX is the 3.4 short block, it is an X51 but doesn't really matter as the only difference is the x51 has very small notches in the piston tops to clear x51 high lift cams, and it can be used in non-x51 engines with no issue.. Part # 996-100-996-TU is the core charge that will be charged when buying the short block unless/untill the old one is returned..

Sorry that I keep chiming in and am somewhat off topic, but related. I don't know the part numbers, but when I bought my short block from the local dealer they said they had to get the crate/box back with the core. My core charge was $3750.00. Needless to say I kept the crate. I'm ready to take mine back and I called to see what I needed to return. They said just bring it back, and I pushed saying that it was a lot of money and what exactly needs to be returned. The answer was whatever came in the box must be back inside. Can do. I have pilfered hardware off the old block, but otherwise its a direct swap. Best,

Does anyone know who has a replacement on hand I want to buy one and have a pieced out spare engine I can substitute

When I worked for VW, cores needed to be fully assembled. I used to bang them together with an impact gun.

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That's an interesting idea. The local dealer said, just bring it back. I asked about how long it would take to get my refund back. They said they would do the transfer immediately. I wondered if it would get back to Germany and then I'd get docked if it wasn't all there. I hope not.

I had the same question (and hope) when shopping short blocks for my engine rebuild. The TU part number looks like a steal, but it�s not what you need. The TX part is the actual stock short block.

What my receipt shows. I''ve got a 2003 C2.

Good part is that X51 block is cheaper.... as noted not too many differences.... Short Block 3.4L - Porsche (996-100-951-TX) https://www.gaudinporscheparts.com/o...4l-996100951tx

This time last year, I was under the impression that short blocks from Porsche were rare as hens teeth and were basically only available from dealers who had old stock lying around. Is that no longer the case, does anyone know? Is Porsche producing these in numbers again?

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I think the consensus is that they are eliminating the short block program. When stock is depleted it will be over. Get em while you can.

Ok I found gaudin and sunset have TX blocks for sale at around $8300 plus add the core exchange of $3500 at about $13000 does anyone know where I can get it cheaper???

What major short block item am I missing that makes these Porsche short blocks so much cheaper than Nickies? The LN 3.4-3.8 Nickies kit with pistons, rings, pins, clips is only $5,500 or about $3k less than the short block. You will eat some in shipping, but main/rod bearings ($300-$1200 depending on brand it seems) and a balance can't possibly make up that difference, even in a Porsche, plus if you do Nickies you can bump displacement and pick up some free horsepower, sure .4L may require a little extra work/cost, but .2L seems to be plug and play free horsepower. Edit: I forgot IMSB which varies in price depending on what you pick also my understanding is all the reman Porsche blocks have the 05+ IMSB that is robust, but also requires the case to be split to replace... pros/cons

I think the main difference is that with Porsche, you're essentially getting brand new everything, including the cases. The entire short block is assembled and ready to go I believe. Eurocarguy911 can confirm since he actually purchased it. With LN, you're sending in your original cases, fully disassembled in order to be converted to nickasil sleeves. It's cool that the kit includes the pistons and rings to match the new bores. I think by the time you factor in the additional assembly needed with the LN you're pretty much even or maybe a bit more. It's a good option if you want to go that route.

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I went with the dealer short block so I didn't have to crack the case and deal with the crank. Watching all the videos and reading books makes me glad I chose not to deal with the crank and pistons. I explored having LN do the rebuild, getting the halves redone there, FSI was not an option because of personalities. Lots of upgrades on the dealer block such as 997 IMS. More but i haven't woken up yet. New parts like the water pump, chains, chain guides, sensors, etc. And all at a reasonable price. I'll have a brand new engine when I'm done.

Type65 where are you getting your pricing the cheapest complete engine for 99 3.4 is $22k from LNE as for a short block from the dealers and heads sent to Hoffman plus extra parts when out I get $19k without labor for either

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Fair enough on the assembly costs and for sure if you have crank or IMS shaft damage and they aren't going to kill you on the core this will likely be a cheaper option. That's interesting to know, thanks for sharing. I assumed it came as a bare short block (there isn't exactly tons of great available info on these) if it includes a new WP, chainguides, sensors, etc. Then that is a significant value added to the Porsche option. Do you have a build thread where you outlined what all the short block came with? I haven't priced an actual rebuild in years all I looked at was the short block, so I compared LN Nickies to the Porsche short block. And that difference is about $3k without bearings, IMSB, balance, or assembly. Now that I know the Porsche short block doesn't come bare (just case and rotating assembly) I'd have to add all the extras and the Porsche block will become a clear winner in price, since it was about a wash before the extras. I got no problems with the Porsche short block and am glad it is an option I was just trying to substantiate the claims I had heard about it being cheaper, because the math wasn't working out for me, but it's those extras that I was missing.

We plan to purchase a factory short block for measurement purposes. We are performing a study of how these engines measure up to those that were offered several years that were also measured new out of the box. If someone is interested perhaps we could get better pricing, allow Mr. Raby to measure it and reassemble it. We have no need for a factory block outside of this. The bore scoring studies have greatly advanced and now we have the attention of 3rd party resources that previously were not interested in the studies. Since the factory has supposedly not changed the cylinder processes or surface finishes, we want to confirm this to see how they size up to a new factory engine that was measured, then failed 27K miles later due to bore scoring, back in 2009. Jake also wants to see how these most recent engines measure up in regard to bearing clearances when compared to his previous measurements of new engines that were also never ran.

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That would be an interesting comparison for sure! The only difference I know of is the upgrade to the larger 997 IMS bearing. Would be an interesting study to see if anything else changed. Are you getting the factory block directly from Porsche? I recall Jake being very vocal about the fact that factory short blocks cannot be purchased any longer and are no longer available. I believe he said he bought up whatever stock was there and looked though his sources overseas. It certainly looks like at this point, this is not the case as a few folks have been able to successfully order a new short block from the factory. How long they will be available remains to be seen but it certainly is a viable option for some.

Brs I would be interested in this deal lmk how we can make it happen

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If you could please open a support ticket on the LN website, we'll keep you in the loop on this.

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Not all of the engine designations are available. The block manufacturer offloaded all their remaining new blocks about 18 months ago, and tried to sell them to us. We politely declined. It seems that the availability goes up and down constantly with the short blocks. This is likely because of when the factory does production runs of certain engine designations. The biggest issue that we see in support tickets here with the factory short blocks is finding a reputable experienced source to rebuild and update the cylinder heads, as well as complete the short block. Today most camshafts are seeing wear that requires them to be reground, and that alone is a near impossible feat for a typical shop without buying a new camshaft. The same goes with lifter carrier wear, and the other items that complete the remainder of the engine. Just swapping used heads, cams and etc onto the factory short block has proven to be challenging at best.

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Did you end up buying a factory short block in the end? If so, what were your findings?

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We didn't, but have since seen new ones sent to us for sleeving and there is no discernable difference. Same technology, just newer. They are still finished the same way. Many still go the factory shortblock route since it's the fastest option. I do want to warn that I have seen several fail because the injectors are reused and a bad injector is what led to bore scoring in the first place. End result was a relapse of scoring in the same cylinders within 3,000 miles.

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That�s insane. Although I would imagine that in those cases, the engines were covered under warranty (and the injectors were replaced for brand new parts)? On the flip side, are you aware of any folk with remanufactured short blocks which have covered considerable mileage (i.e. 100,000 miles plus) without any issues?

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Porsche says they are reman, but they are all 100% new. I'm sorry, but I don't have any information one way or another with regards to the factory shortblocks as to their long term durability.

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Fairs. Although I must ask, what makes you say the short blocks are new when Porsche indicate they are remanufactured?

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When complete engines and even longblocks were sold a reman, they were always new. Not a single component was reused. You can see date codes on parts, etc., which also validate this.

If you're interested in someone else's journey and decision making on this topic, 9werks is having to rebuilt his 3.4 and he discusses his situation and decision factors here: You Tube

Great video very informative

Nickies are Nickasil the Porsche short blocks are still Alusill (The reason the original engines bore score) The Nickies are significantly stronger than the stock engine cases are as well. )

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Are still Lokasil not Alusil... Good, short read: https://en.wikipedia.org/wiki/Alusil

OOPS my bad,, I just had some Alusil plating done on a non motor related project,, had it stuck in the buffer.. The nickle base coating is much more resistant to corrosion supposedly, I wish I could find the article, A retired Bosche engineer did a story with one of the network car shows a few years back talking about why many vendors moved away from Nickasil, (Mostly the EPA problems with waste from the process) and what parts of the engine suffer from problems reacting with Ethanol blended fuels, He noted primarily the issues with Ethanol vs bore plating, spark plug electrodes, pintles in injectors, valve seals and head gaskets. Was quite a lot of info ain a short program.

I apologise in advance for not being able to suppress the urge to correct what you wrote (Cunningham's Law strikes again). Your plating would not have been Alusil as it isn't a plating. It is an aluminium casting alloy used to cast the whole part, I.e same material throughout the part. The desired properties as a cilinder surface are subsequently achieved through further processing. Not ethanol was problematic with nikasil but (high) sulphur in the fuel. Now read the Wikipedia article ! I will now.

Since we've gone full pedant in this thread bore scoring isn't so much a function of the cylinder bore material as it is the piston skirt coating. Engines with forged pistons have the issue far more frequently than those with cast pistons because the skirt coating is not as durable. A.k.a. "with great power comes great... errr.... repair bills." https://lnengineering.com/products/w...-bore-scoring/

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Just to add to this, bore scoring also occurs when you have more than 30-40% of the silicon particles fractured in a given area. This results in an inability to form the required tribofilm on the cylinder bore. The coating has steel particles in it that separate the piston from a possible situation of having aluminum on aluminum contact. And to clarify, when the piston skirt coating fails, then you have aluminum on aluminum sliding contact, which leads to galling and metal transfer, also known as bore scoring.