996 Engine Case Reman - Bullet Proof

I am looking for a group "buy in" to rebuild Porshed 911 Carrera 3.4/3.6 engine case remans. It takes awhile to set up, so we can set up and do a bunch of them at a time for a discounted rate. If we can get about 5-sets of cases per run, we can get them remanufactured for about $1650 per engine. These Rokket Race sleeves have been in my 951TS for 2-Sebring Enduro Track Records. Here are some of the benefits: Cast iron performance in an aluminum block Improved block integral strength Improved cooling Kits can be installed by your local machine shop Custom Displacement & Compression Options "Wet sleeve" replaceability and Repairs Increased horsepower output potential High boost and horsepower potential Superior oil and compression control Superior cylinder sealing and ring wear Street or strip application Bulletproof Darton ductile iron, 130,000-psi tensile strength Precision Machined and Press Fit Aluminum Engines (Nikasil/Alusil) are more Robust and Reliable Unlimited Piston Aftermarket Piston Options (Wiseco, Wossner, JE) Easy to Replace for Future Repairs/Overhauls Custom Piston to Wall Clearances available for performance Porsche Stock Piston Set costs $4100, Rokket Engines Performance 3.6L Piston Set $1199 Save $3K over Stock w better Components! Precision Machined with materials and tolerances for the Ductile Iron conversion in Aluminum Engine IMG_1003.jpg IMG_1027.jpg IMG_1068.jpg IMG_1069.jpg IMG_1143.jpg IMG_1141.jpg IMG_1142.jpg IMG_1029.jpg IMG_1138.jpg IMG_1144.jpg IMG_1139.jpg IMG_1073.jpg

Can you explain what process you do to the blocks? I can't quite tell from the pics, but it looks like you bore/ream out the cylinders and press fit some kind of steel or iron liner with a top retaining lip?

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you must be a sponsor right? You couldn't possibly think of setting up a groupbuy for your products on here without being a sponsor, could you?

if you have proof that its in fact bulletproof and I can put a supercharger /turbo on a 3.4 and use high boost I will be in quickly ... but i am skeptical from everything i have read about these engines

Subscribed for the fireworks.

The cylinders are only one of a dozen issues with this motor. Its hardly the final solution.

Every time I see someone else rebuilding M96's, it makes me happy. Sure, there will be pecker contests, but it's still a good thing for the ecosystem.

This doesn't look like a wet sleeve. Looks like dry sleeve.

+1 on more people giving us more options for the m96/m97 motor. Dunno if anyone else has seen the guy on the 964(?) forum who started a business making brand new upgraded cases for the 3.6 air cooled motor. Very impressive but expensive to do. Be awesome if someone did the same for the m96/m97, perhaps allowing it to use the off the shelf mezger wet liners from the turbo/GT3 After digging around on the interwebs, I found this post by the owner of a UK company that manufacturers liners, they supply for m96/m97, interesting he mentions the technicalities of correct fitment/process to success: "My name is Duncan Andrews and I am the owner of Westwood Cylinder Liners. We supply cylinder liners for a wide range of engines, including the water cooled Porsche engines. We were made aware of the problems that the 6 cylinder water cooled engines were having about 4 years ago, and customers were buying our universal repair liners which had suitable dimensions for 96.00 and 99.00mm bores. Within a year or so we were asked to produce a specific liner for each engine (less cutouts and holes). These second generation liners have sold in their hundreds, and led us to produce a Ductile Iron liner which has all the cutouts and holes machined for each individual cylinder. We have sold these all over the world and have one particular customer in the UK who has at least 6 sets a month. Cast iron liners have been used in Aluminium engines for many years, and continue to do so. Look at all the American V8 engines that are aluminium with cast liners. The fitting of the liner is the most important thing, generally involving liquid nitrogen and a suitable oven! This is the important point with regard to the liners. There is a specific way in which the blocks need to be machined, then the liners need to be fitted in a certain way, and of course final finishing after fitment. I have no issue with what Hartech do with their engines, and it is a solution that works. BUT, cast iron liners in these crankcases work as well, and as pointed out are considerably cheaper. I have a reputation to keep with my business, and would not sell a product that was "not fit for purpose" We have reacted to market requirements, and acted accordingly. In all the time we have been selling these liners for the water cooled Porsche engines, no one has come back and said they do not work. We have over 25 companies in the UK that use the liners, and they keep coming back for more!! Our sales are increasing month on month and we expect this to continue. I do know of companies sourcing liners from other suppliers overseas, so cannot make comment on the quality of their cast iron products. I know our product, and am fully convinced it is suitable for job. It is also fair to say that the sales of these liners within our business make up for less than 2% of our overall turnover, so we are not doing this to make huge profits, its because our customers have asked us to produce them. We will continue to sell our product and keep up with the ever increasing demand from our customers for the cast iron liners. We do not fit the liners, but we can highly recommend a number of Porsche specialists and engine machinists that work on these engines on a regular basis. Some of these are well known companies, that have seen the benefits of the cast iron liners. Please contact us directly for more information. We will not discuss any technical information or fitting requirements on any forum or webpage, because once its on the internet its there forever!! We work by talking to our customers on the phone or face to face. There is no hiding behind a screen and you get to ask all the questions you want. Hartech has mentioned "the legal position". I have spoken with my lawyer this morning, and we are quite prepared to take further action with any company that continues to make comments about my company, that are blatantly not true. If anyone has an issue, including Hartech, then pick up the phone and talk to us. In our world this is how things are done. Might be a bit old school, but you will get a straight honest answer and you can then make your own decision. I hope now that certain people will accept that there is such a thing as competition!! Some may not like that fact, but it is life."

I like what I am seeing here, many engines running around with steel sleeves in them. Nothing to fear here despite what some of the fear mongers will post. Looks like an excellent alternative to the expensive nikasil cylinders some of the others are peddling. Steel cylinder liners are well proven in the world of engines and there is absolutely nothing to fear with them.

If you google wet liner there are quite a few reputable, remanufacture operations throughout the Southwest.

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Please correct me if I am misinformed, but the only examples of a failed steel/iron sleeve that I have seen are due to improper installation, parent material cracking or sleeves sinking or dropping. Critics of steel/iron sleeves will say it won't transfer heat as well, or it will expand at different rate, but have these issues resulted in a failure? LA Sleeve claims that have sleeved thousands of these engines. If their claim is even close to reality, wouldn't we have heard about failures by now? They must have at least sleeved enough m96/m97 to make them a catalog item.

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how do you figure? The sleeves are nearly fully open to the coolant

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The original aluminum is exposed to coolant, not the cast iron. The cast iron is inside the original cylinder.

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fair point, thats what I get for not looking at the pictures closely

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But if you really understand what a sleeve is and where coolant runs in an engine, you really wouldn't even need to look at the picture...

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please clarify, oh wise one.

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ahh, snarky

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A wet liner has coolant flow all around the outside diameter, its not a thin sleeve pressed inside the AL Wet liner on left, dry liner on right

While it's true that steel is poorer heat conductor (17 BTU/hr ft F vs 118) it is also much stiffer. It will resist deformation at higher temperatures a 3x the rate that aluminum at 200C. I agree with others, having competition and choices works out better for the consumer and keeping these cars on the road.

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yeah, like I said, I looked through the pics quickly and mistakenly believed the entire aluminum portion was remove and replaced with the steel sleeve, not just that the aluminum portion was bored to accept the steel sleeve.

It's a small part of the rebuild though. You will still need -rod bearings -crankshaft bearings -IMS bearing / solution -engine case bolts -head bolts -rod bolts -crankshaft carrier case bolts -timing chains -timing chain guide rails -tensioners (you goin to reuse the old ones??) -new AOS -New or at least cleaned and tested fuel injectors I am missing stuff...that's off the top of my head. all this will add up to about the same price as nickies from LNE

Hey Guys, The first process is to clean the cases thoroughly and inspect them for cracks. The sleeves that we install are "Dry Sleeves" and are precision press fit with ~.001" to .0015 clearance between the aluminum stock bores. 1st Step is to bore the aluminum cylinders ID to 0.001" under size of the OD of the Darton Liners. The bores stop short about 0.50" beyond the bottom of the BDC of the piston skirts. This leaves a ledge that holds the liners firmly in the cases. 2nd Step is to Freeze the Ductile iron liners to ~25'F and the Engine cases are stored at room temp in a climate controlled shop at 75'F. The liners will be pressed in with ~ 0.50" extended above the deck of the blocks. 3rd Step is fly cutting the liners to be about .002" from the surface of the deck 4th Step is to chuck up the cases into the block surfacer (decking) and make very small precise cuts until the liners are exactly flush with the cases 5th Step is the diamond hone the ID's of the Ductile Iron Sleeves and finish the bore to the exact clearance (piston to wall) per piston manufacturers specifications. This usually ranges from 0.002 to .0065" 5th Step is to deck the blocks approximately 0.001" to ensure a flat straight surface. 6th Step clean the blocks and hot tank them 7th Step remeasure everything and install pistons into the bores as test fit 8th Step Gap rings per manufacturer specifications Wet sleeves are VERY expensive and require significant machining of the cases. ALL of the existing OE cylinder walls are removed and the cases are CNC cut / bored to install an entirely new cylinder assembly. The wet sleeves kind of "float" in the bores and use orings/seals to seal the cylinder assembly in the cases. (Similar to GT3's and Turbos) Once the cylinder heads are installed and torqued the wet sleeves will be held firmly in place. The wet sleeves can have several different designs, and one advantage is to have a "block guard" machined in the tops of the cylinder assemblies that prevent movement of the cylinders. Here is a pic of a Turbo Charged Honda block that we sleeved with a block guard installed IMG_1081.jpg A big problem with wet sleeves if when the fail, it is usually catastrophic and the engine blocks or cases need to be scrapped. If there is a failure in a Dry Sleeve, the sleeves is removed and a new one is pressed in.

Subscribed out of sheer curiosity and liking images of M96 engine blocks : :

While I know nothing about engine building, what I really want out of this thread is the manufacture to say, "With our engines, you can reliably run 20lbs of boost." Yeah, that's what I want to hear.

The answer is yes. I'd ask how long can you throw 20psi of boost at it before she blows!

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LOL...I thought the same thing. Once again highlighting the fun of mechanical discussions on the internet

I thought the big cheese would have chimed in by now to educate us all a little more.

This is a great idea! Group buy!

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Are you saying that it is possible to get Nickies installed by LNE for $1700? Have you had that work quoted out by LNE? I thought this number was upwards of $4k. Or does that number include all of the parts you mentioned above, since you seem to be lumping all of that into one big lot. I'm not trying to be argumentative, just trying to compare sleeve work to sleeve work pricing for clarity. Hats off to Rokket for stepping up and offering what seems like a viable alternative to the more expensive solution that keeps being touted as the only right way to do things around these parts. By putting this topic up for discussion and offering group discount at the same time tells me he firmly believes in his machine shop and his product, and is sensitive to the costs associated with rebuilding these engines. Strong follow-up post from him outlining the steps in the process as well. Plus, he's apparently got some grande cojones to be doing this in what I have discovered to be one of the snarkiest internet forums around. (But also one of the best) Based on the track record of what usually happens around here when anyone brings up the topic of the Vertex or MBMotorsports rebuilds with sleeves that are on perpetual offer on eBay, I must admit that I'm kind of surprised there have not been more voices screaming from the rooftops admonishing the use of iron dry sleeves in the M96.

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I've learned to welcome others into this arena. They create that much more competition for Martin as possible!!

The ubiquitous LS engines use iron sleeves in an aluminum block, but they e fate aren't pressed into a machines block. That's the aftermarket process, not OEM. The technology does work. Does it work on an M96 and how long does it work? That's what I am eager to see.

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lets revisit this thread in 19 years.

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It doesn't take 19 years to prove durability. Not that I grew up around the automotive testing business or anything like that..... durability tests are usually done in less than a year.

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Yeah, the M96 engine was probably "durability tested" in less than a year. Hence why I have documented 29 modes of failure from the engine. Practical application is is the only test that matters. Time in service is the only way things are truly proven in the real world. It will take any "new" cylinder technology 19 years and 8 months from right now to be as proven as Genuine Nickies are today. That's how long I've been putting them to the test in the real world. That is fact.

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no.

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1). Mad props on your success. 2). You don't know as much as I do about durability testing. Give me as many engines as you dare and the budget and in 12 months I will have over 300k miles in all of them driven as hard as you dare. Literally you pay my price, I quit my job tomorrow and open a new business. It's easy! But you can't afford me. 3) Iron sleeving isn't new tech and GMs sold more LS engines than Porsche has sold all engines combined. We are talking about using old *** tech in a new application. It isn't impossible. It's been done. 4) I'd bet a huge chunk of coin the original m96 durability test was conducted using the old dual row IMSB and we all know those m96 engines last longer. The problems these engines have became apparent long after that phase of testing was complete. 6). I'd also bet your first m96 build wasn't 19 years and 8 months ago. Again congrats and mad respect for what you do.

Oh Jeez...another my d!ck is bigger than yours contest brewing......

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Nope. Takes two to tango. No more arguments from me. Raby out-

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^^Good Call^^

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+1

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HAHA You've already dive-bombed the OP's thread and pissed in everyone's Cheerios but NOW you claim that you are going to take the high road...

It's clear Jake knows what he is doing and his processes are successful. I'm sure he's got plenty of work to do. however sleeving cylinders has been around forever.

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Agree! But there is only one way to do it in his eyes and nothing else is as good as his way. There is no changing that period.

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Like most things in life, there is more than one way to skin this cat. That is the reality.

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I can understand the pride he has in the quality of work and R&D he has done. Yet as an auto guy, I do hope sleeving does become a practical method to make reliable m96 repairs. It's a new application for an old tech. I know I have a ton to learn when it comes to the details of flat 6 engines, but I do have a lot of auto experience. I grew up in the business and spent a stint in it myself. I like what I do now a lot and it lets me afford toys. I'd love to have a high winding / powerful 3.6 or 3.8 in my 996, but right now that looks about double the cost of making my LT5 a 500 hp monster sadly. The LT5 cost include R&R labor too, M96 build is me doing that work and still double the cost.... if this technology can be employed to drive down costs and be reliable, it's a win-win for everyone. There will still be a market for more exotic builds too.

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That's my take as well. Nickies might be the A++ option, but you pay extra for those two plusses... and based on the lack of contrary opinions expressed there's apparently no reason to think that using cast iron sleeves would not result in at least close to the same level of rebuild success when installed using Rokket's described process.

Jake takes a lot of pride in producing what he believes to be some of the best work out there. I appreciate that and understand the amount of ego you have to be willing to put your name to any product. It's a little arrogant to assume that nobody will ever do anything as well as I do, or that doing anything in any way that is not my way is inherently stupid. Yahoo was worth $128 billion in 2000; the annual costs of inflexibility and repeatedly misreading the market, it turns out, can run upwards of 7.235bn...

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Having multiple choices are great however, but that means you have more chances of getting it wrong. I've fixed plenty of blocks that had steel sleeves and also had to throw away many that failed after multiple heat cycles when the crappy parent metal fails from the interference fit of the cast iron/ductile/steel sleeve. There is a reason we don't use an interference fit with Nickies on the M96.

BuT. ..but...some guy you can't afford and has never seen the inside of a flat 6 says differently.

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Thank you, I needed that. Made me laugh.

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How can you not be for more economical solution? I thought I remember several occasions where you mention the cost of your rebuild unfavorably? It has nothing to do with "can't afford". Who wants to spend 15-20K on an engine for a car that is likely worth the same?

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This is one of the biggest problems with these thin pressed in sleeves IMO, the cylinders in these motors crack and D-chunk by themselves with AL on AL 'sleeving', putting a thin steel jacket that is tightly pressfit on the inside of AL with different expansion coefficient seems rather risky. The full replacement wet liners would appear to be a much better solution, at least it is one metal type alone and the walls can be made adequately thick to deal with the cylinder pressures and thrust loads. EDIT: Looks like this guy is buying up a monster turbo motor using Darton sleeves, be very interested to see how it holds up to the crazy HP figures he's aiming for: https://rennlist.com/forums/997-turb...ine-build.html

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A sampling of one guy doesn't make it bulletproof. I know who Darton is and yes, they are well known for what they do, but this isn't a Honda. Jack of all = master of none. No one has the experience I have with the M96 engine and has tried as many crazy things as Jake and I have done. I've re-done wet sleeved and dry sleeved M96 blocks. The wet sleeved ar the ones that we have had to pitch when the blocks fail at the bottom of the water jacket. The dry sleeved blocks typical die from scoring, but haven't been a problem to re-do with the Nickies process because they haven't compromised the block in the process of sleeving it, like when they wet sleeve them.

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Fast, Good, or Cheap. Pick two. Or the Porsche tax. Lastly, do it once and do it right. Pick whichever works for you. All are applicable here.

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I was talking about our friend Anthony and his comments to jake that he couldn't afford his services. This was around (steel sleeves) when I was shopping for my rebuild. After talking with various people, I decided to go with nickies rather than have my local shop out in steel liners. I wanted something proven.

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The value of the car is completely unrelated to the availability and cost of rebuild options. Nobody owes m96 owners a cheap rebuild option that's proven to be reliable. It may be something people want, but if the technology isn't there, it's simply a reality that must be accepted. It's nice of Charles to share some details on why variant options from the Nickies approach can be problematic, and fundamentally I think they charge a very reasonable fee for the services offered. $4-5k for a properly re-sleeved block is understandable. One of the main problems with the m96 is that rebuilding requires new c-rods due to inferior OEM part quality. Same goes for the timing chains. When you break down the costs involved in a $20k rebuild, I see an expensive solution to a range of problems with the OEM design. If the c-rods were good to reuse and/or the timing chains didn't have issues with reliability & stretching, the rebuild costs could be materially lower. The high cost seems a direct result of Porsche's decision making & not that of independent builders. We should be thankful 996s depreciated to the level they're at & that high-quality rebuilds can be done a la carte based on the owner's preference.

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Charles, what is the "NSC Recond." option on your website? I don't remember that being there before. https://lnengineering.com/products/w...-included.html

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Depending in mode of failure the rods don't need to be changed. It wasn't a recommendation from LNE. it's all the other things that add up. The timing chains are cheap compared to everything else that needs to be replaced in a rebuild.

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Looks like the Nickies without the JE pistons and rings to me.

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If that's true, what are we arguing about this? Dry iron sleeves for 1600, wet iron sleeves for 1800-2000 (guessing), and 2265 for Nickies. Comparing sleeving processes alone, it seems like an easy decision to make. Pistons are another story.

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Yeah exactly, even a cheapskate like me would spend the extra $665 for nickies Vs dry iron sleeves etc

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That option looks to me like an "NCS Reconditioning" or "Replating" service. The "nickies" install parts and labor looks like $3365, the whole shebang ,pistons ring and all is $4995, I would think the $2265 would be for a "replating" service if your "nickies" got inadvertently damaged by something not covered by the lifetime warranty ie collateral damage.

What ever happened to this? I have two turbos off of 6.0L diesel engines waiting for my iron sleeved M96. I plan to run 145PSI.

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Rokket engine rebuild thread coming soon... I have info from a reliable source that he's done several 996 blocks in the last few months.

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None of you can actually AFFORD the durability testing you think you need to justify your expenditure. OEMs spend millions on durability testing. Running cars 1,500 miles a day 6 days a week, servicing them, inspecting key parts, reinstalling said parts, issuing reports etc requires lots of facilities, lots of people and big bucks. You provide the cash and as many engines as your heart desires and I will get the mother fin test done. Capice? Have that t shirt. But yah I don�t know what I�m talking about. A lot of auto enthusiasts demand proof no one can provide due to economic constraints but internet blow yards can still insist on it for proof..... doing it is something else entirely.

I think I must have missed this original post and am a bit shocked by some of the content. There seems to be a debate about different liner suppliers, costs and technical solutions that I would like to contribute to. The problem is the more you know about the subject the longer the answer can be. Too short and you are open to all sorts of unhelpful responses – too long and no one reads it or you are accused of confusing readers. Here is the short answer. Manufacturers use Nikasil alloy bores for a lot of good technical reasons and because they are a better technical solution than ferrous liners. However in many applications ferrous replacement liners provide a good moderate cost solution to bore problems. This particular cylinder block design and dimensions (being open deck with thin alloy cylinder tubes) is not best suited to a ferrous dry liner solution and makes the quality of the machining and fitting of the liners crucial – and can still cause problems later. A Nikasil alloy dry replacement liner is a better solution (but more expensive) and a wet Nikasil alloy replacement cylinder that converts the design to a closed deck is even better (but also more expensive). Compared to the cost of the whole repair the extra cost of a better solution is minimal but for some can still too much when ferrous liners may well provide a cheaper way out with a slightly higher risk. At Hartech we cannot handle any more cylinder work and will not compromise on our solution but if owners prefer to use alternatives - that is their choice. Here is the long answer. (1) Unlike manufacturers of ferrous liners - we are an Independent Porsche specialist and so have no liner product type or material to promote or champion. We weighed up all the technical issues and costs and decided that because we wanted to provide the best solution for our customers – we would only use Nikasil plated alloy cylinders. (2) The M96/7 996/7 blocks required high pressure casting to force the molten aluminium into the porous Lokasil preform and the way the metal moulds were made allowed for this resulting in a very accurate castings but the downside was a central cylinder tube being free and unrestrained at the top and bottom and only held in the centre to the exterior block part of the casting (like a thin tube being held between fingers in the middle – say). (3) From 2.5, 2.7 and 3.2 engines this cylinder tube was thicker, the bores reasonably stable and good space for coolant - but increasing the bore size to make the 3.4 & 3.6 and 3.8 engines in the same cylinder spacing and overall block size inevitably reduced the space for coolant and later on the cylinders were made thinner to compensate. This meant that they were less stable with earlier examples going oval over time under the forces of the bigger pistons and eventually cracked (“D” chunked). (4) Probable changes to the Lokasil silicon particle size and mix increased cylinder strength in later engines but changes to piston coatings then resulting in scoring. (5) Both the above usually required cylinder replacement to repair but if the original block was just re-plated it retained the original weak cylinder walls. (6) With any liner material the quality of the result requires precise machining and fitting. (7) Dry liners work best on closed deck blocks because the material outside the liner is more stable. (8) Fitting dry liners inside a different material block inevitably can result in different bore sizes during thermal expansion and contraction and with a thin flat steel head gasket can result in some problems with head sealing which is not present if the liner and block are the same material with the same expansion coefficient. (9) These different expansion rates working in combination with the resulting interference fit - influence the running size of the bores from cold to hot. (10) The expansion from cold to hot is a function of the bore size as well and so smaller cylinders (in multi-cylinder engines of the same capacity) suit differential expansion cylinder liners better than larger bores when using the same material becomes more beneficial especially if it is similar to the piston material which provides the best piston clearances for all engine temperatures and conditions. (11) It is a fact of mechanical science that fitting a dry liner inside an open deck tube results in both being weaker than one wet solid cylinder of the same overall inside and outside diameter and we have found that many ferrous liners fitted inside thin alloy tubes while being stable in their own right still gradually press against the thinner outer alloy tube and work the original interference fit loose allowing it to rock and potentially sink leading eventually to head sealing problems or coolant ingression and failure. (12) Most of the failures we have seen of ferrous liners relate to poor design, machining inaccuracy or incorrect fitting (especially regarding the slip in vertical fit on cooling down the heated block). (13) These cylinder blocks cannot be bored out at the top to enable the top of all the liners/new cylinders to fit in a machined recess by a tool that generates a full circle cut and can only be done by some form of circular interpolation that most liner fitting machine shops do not have the equipment to achieve – so very few can create an accurately fitting a top hat to stabilise the cylinder in use. If it did the diameter of the top hat is quite large and would require a very thick original ferrous liner and a lot of machining – adding to liner cost. (14) It is no coincidence that manufacturers of performance engines using large cylinder bore diameters try to use a form of aluminium throughout the design to maintain tight cylinder clearances in all running conditions. Typically relevant examples are the GT3 and turbo versions of these engines that use aluminium cylinders with Nikasil plated bores fitted to precision machined bores throughout their height - despite their extra cost - creating a superior closed deck outcome. (15) Because racing is at one predictable flat out coolant temperature, properly fitted ferrous liners in cylinder blocks with adequate coolant volumes and stability can be perfectly acceptable. (16) In application in which ferrous liners would be the best solution we would be perfectly happy to use them and obtain them from the various suppliers mentioned - including Westwood who have a very good reputation. For supplying iron liners (17) It is clear that some suppliers are managing to fit ferrous liners that work acceptably in the short term and as yet it is impossible (as rightly pointed out by AnthonyGS) to establish the long term reliability until more time passes and mileages increase. (18) Our liners are more properly called “new cylinders” (because they do not fit inside another bore at the business end) and are manufactured under licence by a reputable F1 supplier and machined by us “IN-HOUSE” using brand new multi axis CNC machinery with diamond tooling that creates incredible accuracy with each individually fitted. We do not use interference fits (so no distortion or thermal expansion issues), are ribbed (for additional cooling surface area in the restricted coolant volumes present), and have a precision machined top hat fit in the cylinder block (converting the block to a closed deck). (19) We are not saying there are not other solutions that might work perfectly well but we would claim that by any investigation our solution is the best technically and it is no surprise then that we enjoy a superb reputation for quality and long life. (20) Really our way of doing things should be prohibitively expensive (and only for perfectionists) but because we do it all in house with specially manufactured and fixed tooling in new state of the art machinery and within a production process that is a small scale production line right from car (or engine or crankcase set) in to out again – we have managed to provide this solution at very similar prices (often even less) than competitors with different technical offerings. For example fitting 6 aerospace alloy Nikasil plated cylinders is �2,500 (plus any applicable taxes). (21) We also make other coolant flow adjustments at the same time (after extensive testing and development) and other products included (for example re-coated original pistons where available). (22) From car in to car out with a full rebuild with 6 Hartech cylinders, re-coated pistons upgraded IMS bearing (where required), new chains and runners, new crankshaft bearings, gaskets and seals etc usually runs out around �8,500 to �9,500. Just engines or crankcases obviously less. Video’s on our web site demonstrate this process www.hartech.org . (23) Owners struggling to afford a comprehensive rebuild may find some suppliers using ferrous liners can offer a solution that they can afford and that works acceptably, but it does require exceptional machining and fitting quality which is often undertaken by a variety of specialists with varying capabilities and therefore different success rates. (24) Owners wanting the best technical solution from a supplier with a superb reliability record for many years covering thousands of cylinders and who carries out the whole process in-house - may decide any small additional cost is well worth paying (and it does impact on eventual re-sale values). (25) I have numbered these points and am happy to respond to any arguments that anyone wants to raise and to defend the points I have made on this medium or any other. Baz

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I have no doubt your work is excellent quality etc, but your facility isn't in the USA. Can you comment on the costs and hassle of shipping partial or full engines to and from hartech stateside? Thanks

The difficulty with all cylinder liner replacements is that the quality of the result depends mainly on the skill, experience and equipment available to the people carrying out the work. This engine type demands more accuracy, different design parameters, tighter tolerances and different equipment than the type used perfectly well for most cylinder liner replacements and liner types. It is in our opinion less suitable for ferrous dry liners than aluminium Nikasil plated ones and better still alloy Nikasil plated ones fitted in a wet liner design with closed deck top fitting applied. Because of this we prefer to limit the supply to that which we can do ourselves or under licence strictly applying our technology with people of similar mentality and this we are doing with Alpine Autowerks in Canada. We have had numerous requests to sell our cylinders in the USA but although it would recover some valuable investment – we have yet to find a suitable outlet that understands the need to adopt our systems, quality limits, machinery and processes or are willing to enter into a technology agreement because they assume it is easy to fit them and that they don’t need any of our support or advice. We know that this attitude could damage the outcome and our reputation and prefer not to do so until and unless we find a suitable technology partner in the USA. Meanwhile we do have some crankcase sets that we might be able to use on an exchange basis but there is little option or alternative otherwise than to send them to the UK and back (or contact Alpine in Canada) which I appreciate is less than ideal. Can I just make it clear however that we are not claiming that our method and technology is the only one that works nor that there are not other specialists in the USA who can do a good job – it is just that this particular engine crankcase design presents additional problems that most other types do not and that as a result the success of various previously good suppliers getting involved in solutions can be variable and leads to problems and arguments over the Internet that are unfortunate. That is why I have tried to explain in more detail exactly why we think our solution is the best and that doing all the work ourselves, “IN HOUSE” and under our total control – is the best way to liberate that superior technology (or anywhere else that strictly adopts the same process – as Alpine are doing). We (like many USA specialists with many years of experience successfully repairing these engines) have experienced unfortunate owners who tried other solutions only to have them fail (and have the evidence to prove it but prefer not to expose other suppliers trying their best and in so doing incurring all the adverse feedback that such a mistakenly perceived attack would unravel). We have all had to do the job again properly after other solutions and suppliers have been tried to save some money - while the unfortunate owner then incurs the cost all over again – and it is this fact that leads good suppliers to appear critical when Internet posts suggest newcomers already have it all sorted out. This engine type is not as straightforward as most other types and reliable solutions require a lot of knowledge, experience and special equipment – which is why – rather than getting immersed in direct arguments with others I have preferred to just try and list facts and allow owners in need of rebuilds to make their own decisions about where to go and what solution to adopt. We are flat out supplying the European demand for our top quality rebuilds employing several specialists in a flow production process that is so efficient it allows us to supply superior quality at competitive prices (in Europe) and the only way we could expand would be to double the whole process which the lifespan of this type of engine repair would not justify. So our advice is not because we are trying to drum up more business nor to discredit what anyone else is doing and our reluctance in supplying our cylinders is purely because we value our reputation more than we seek expansion at a cost. Some USA specialists seem to be coping well and I do not want to get involved in arguments with anyone over there about what they do and who is better or not. I just hope that by providing the facts I have – that it stops some of the inaccurate responses I have read on the subject that simply confuse owners and can result in them making a poor choice that they might regret. Baz

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No affiliation with Hartech or with Alpine Autowerks (but I am Canadian, so I enjoy rubbing Americans' noses in it, but will apologize for doing so.) http://alpineautowerks.com/about.html "Alpine Autowerks wants to announce a new partnership with Hartech Auto as an agent for their M96/M97 cylinder replacement."

BAZ, are you still doing the cylinder support ring and re-rounding procedures? Or do you replace the cylinders on all your rebuilds now with the Alloy/Nickasil cylinders. I think this is a very frugal and an upgrade/preventative mod to extend the life of the factory blocks that have an otherwise perfect bore ( with no scoring). I think any m96/7 bore of 96mm or 99mm factory case if disassembled should get the support rings/re-round procedure as part of a refresh or rebuild. No telling how long the Lokasil surface will last if no scoring occures, they sure don't ever show any signs of ring wear.

The difference in why the same bore surface lasts longer on bank 1 than bank 2 is a combination of various factors like the hotter thrust surface of the bore on bank 2 reducing the oil viscosity and making the oil film thinner and hence allowing loose silicon particles to impact on the piston plastic coating more, the oil draining from the thrust face after stopping on bank 2 but dripping onto the thrust face on bank 1 ready for an oil rich start up etc. Rather like a pot hole in a road – once a few pieces of silicon become free and rub up and down the bore and over the small hole they leave the impact of them on the original bore grows the score until there is too much loose silicon stuck on the piston and the bore gets severely scored. Furthermore the porous surface of Lokasil is (in our opinion) subject to fatigue and releases more silicon particles with age. The bonding is variable and we have seen some engines in which whole areas of Lokasil have been washed away by the oil – over time The piston coating also becomes less bonded to the piston surface with age and is more likely to peel off. Taking all this into account and bearing in mind that new buyers will usually pay a premium if all 6 cylinders were changed – the public have generally come to terms with the benefits of changing all 6 cylinders and fitting support rings has become relatively rare. However we still reluctantly try to help those unfortunate owners that experienced a failure that they simply struggle to afford to fix properly - for whom the support rings can make a difference. Baz

Soooooo.... A year plus later, I can finally report back that Rocket built me a fantastic short block! It took so long because of many reasons. Some of the time-killer highlights included a patient search for a low-miles crank shaft & basket (which took a good month or so); once decision was made to go to 3.6L we had to wait almost three months for Woessner to ship us the new pistons & rings; my mechanic's shop moved three times in the last 9 months due to life dynamics; and I ended up having back issues and resulting surgery for most of 2018. None of the delays are Rokket's fault. Instead, they were more contributed by forced patience as I looked for the parts he told me we needed (the crank & basket came from same car, a wrecked low-miles 2000 Boxster S that uses same crank part number). One other delay came when we spun my engine's IMS shaft on a lathe, and found it to have 0.004" of rollout. I bought two more IMS shafts for us to test and cherry pick, and ended up with one that had only 0.001" rollout, which is now in my engine. The short-block was sleeved using Rokket's described process at the beginning of this thread, and his shop also fully re-built my heads. Rocket offered to port and polish my exhaust ports, as that's a proven internal enhancement that can make a noticeable difference, but my budget simply didn't allow for that. Instead, I opted for simpler gasket-matching the exhaust ports (the next best thing) and dynamic balancing of the entire rotating assembly. I also bought a lightweight flywheel to be spun and balanced with the rest of the engine bits. Rokket buys a lot of P-car parts and also helped me shave about $700 off the eye-opening list of accessories and new bits that we needed in order to really do this properly (chains, tensioners, guide rails, water pump, AOS, oil cooler, etc, etc, etc, etc). So, once everything finally got put back together and installed in the car, the engine started on my mechanic's first key turn. He told me he just stayed on the ignition and watched the oil pressure build, then the compression build and when he let go of the key it chugged to life and settled into a steady idle. Even he was floored by how smooth this engine runs. It has been running smooth for about 600 miles now, running Royal Purple break-in oil. So, I now have a balanced and blueprinted 3.6L instead of a stock 3.4, with gasket-matched port work done to the heads, and a lightweight flywheel. I also added the 200 cell cross-pipes from TopGear UK to my Agency Power headers and cans and the car runs like a raped ape. No check-engine lights. Rokket has been sending these blocks out of town when he does them, so with me being local I have promised to bring him the car after it's broken in so we can put it on his dyno. The car feels a fair bit stronger than it did before, and stronger than my brother's '99 (w/ Fabspeed x-pipe Cat setup) and on par with my neighbors '06 997 C2 cabriolet (w/Fabspeed muffler-bypass). My butt-dyno tells me that my C4 is definitely C2 fast now.., but we are going to get proof. Rokket, thanks a ton for building me a fantastic engine. I'm happy to be the first of your customers to report to this thread and I apologize it has taken so long. I'm also grateful for letting us use that engine-stand bracket for longer than any of us thought it would take. I'll see you either at your shop, or when you're flogging one of your cars around Sebring later this year.

Congrats and sorry to hear of the back surgery (worst experience of my life)! I followed this from the start but it's been to long and I'm not going back to read it all. What was the final cost if you don't mind?

just read through this whole thread (my eyes hurt) and this stinking motor in our cars is such a roller coaster of emotions. one minute I want rebuild my motor and do as many mods as I can to it and keep my bragging rights and the next I want to pull it and swap in an American motor. I'm going to drive it hard one last summer and come next winter... the axe drops... not sure for what lolol but I'm doing something to it lol Truly a love hate relationship with my Porsche. Brian

Nothing to hate on until something catastrophic happens...If it ain't broke don't fix/replace it!

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That's my point !! lol right now I love it and don't want to hate it. I read someone say in one of these threads a few months ago about the cloud hanging over our cars for this motor. I cant hate on it and I cant love it cuz it seems like being in limbo for one or the other. but worrying about it I guess wont change anything

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See, this is something we warn people about.. Doing something “for bragging rights” sends a red flag up the pole here during our initial interviews.In my experience this reasoning makes for a project that is done for a reason that usually isn’t true, or everlasting. In the past people that did this would often get tired of the engine really quick, and once the new was worn off of it they would start considering what it cost, and second guess the purchase. For us to be able to keep someone fully satisfied they truly have to love the car first hand. When someone says “all my friends are really interested in what this will turn out like” l wish l hadn’t accepted the job. Its your car, and you are paying the bill. Do what you want for the long term. Just wanted to throw that out there as a bit of a reality check for those who may read this and consider things based on this. l have gotten more and more specific with my questions at the beginning of a project these days, and l often will ask someone for some exact reasons why they want to go this route. l would rather divert them to another idea, rather than having a potential less than perfect scenario unfold due to an expectation that wasn’t clearly set up front. At the end of the day we have to be honest, and understand that probably 1% of 996 owners truly want, and need, our engine at the present. It would be akin to a fellow marrying a girl just because she had some really nice ***** (usually fake) only to find out later (when it mattered) that she can’t cook, and complains al the time. Those usually aren’t everlasting either...

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To each there own I guess. I don't look at my Porsche with religious devotion... its a car. when its not fun to drive and I want something else... I will get rid of it. As a man who is very religious I don't put that devotion mindset on anything other than family or God Sorry I just don't see it like that. Yes I want bragging rights when I'm enjoying my car... its a car and just a car. I've owned 42 toy cars in the last 13 years, corvettes, supras, stangs, Camaros etc. this is my second Porsche and I will gladly toss it to the side when I'm bored with it... its a car. Not ripping on you Jake or trying to start a debate just not sure I came across the way you might have taken it. FOR ME a car is a car, if that ticks some off... its a car!!!! lol for the record ... my wife's are still great, real and she can cook... see you can get the best of both .. sometimes lololol

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Totally see your point of view. As a vendor this just cocerns me, as l wonder if someone will have some sort of buyer’s remorse when we are done, and the new wears off.. We can do our part perfecly, and the car can be a reliable screamer, but unless they want to keep it for the long haul, they’ll never get the value that they paid for. i currenly own about 37 vehicles.. l have them all because **I**love them for what they are, and don’t care about what anyone else thinks. Thats why 3 of them have turrets, and two of them has tracks, and 4 are amphibious. l don’t take them to events, l use them, and drive them, and have my own car show every day.

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Not to come across as evasive, but the original topic of this thread was the group-buy offer made by Rocket to the members of this forum. The sleeve work performed in the first post shows up on my invoice at that $1650 price and I am very happy to have paid that amount and not ship it anywhere. I'm also glad that what I picked up was a nice short block with chains loaded and ready for heads, and I did pay extra for that... I think that everything else done to build "my" specific short block falls into the realm of custom engine work and would require individual discussion with Rokket directly. I was surely much more hands-on than most of Rokket's machine-work customers, who seem to be major dealers and shops in the area. He and I had many calls back and forth as my parts were being mic'd and different issues came at me. He was patient and understanding when I sourced some of the key parts that either had to be, or which I wanted replaced... That local hands-on approach, spaced out purchases and ongoing communications made this whole experience possible (and reluctantly affordable for me - LOL). Shipping my parts somewhere and simply writing one bigger check at the end of it all was not an option. So, with all of that said I would encourage anyone who needs a Porsche engine partially or fully rebuilt to consider Engine Lab in Tampa. Give Rokket a call, it will be a good phone call and he will do good things to your engine at a fair price. He has a good reputation around here, which I can now substantiate. I can't wait to get this car on his dyno....

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Jake your reputation speaks for itself. I researched you and your work couple years ago ... really researched lol and I think its safe to say, your the man with these motors and how you conduct your buisness. I spoke with you about doing a motor and at the end of the day, I couldn't justify that kind of money for a car that just wont bring the value. I don't doubt its worth it but for someone like me who likes to do his own work for pennies it this motor saddens me as it is a lot of fun. Its all good

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do you have a build thread? I'd love to see what all you did.

Until I got this... And I get to drive it everyday!

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I intended to do one, and still plan to... but life got in the way in many aspects. I need to compile pics from different cameras and sources and put it all together. I'll likely do all of that after I dyno and tune the DME. The car runs fantastic, but I can tell there's horsepower and fuel efficiency being left on the table...

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Looking forward to hearing about this too.