Engines - not so fragile then!

We here so much about engine failures that I thought some good results might cheer owners up. When we started racing the Boxster’s and 996’s 7 years ago everyone (including us) struggled with reliability over a full racing season. Although we had rebuilt hundreds of road engines with 100% reliability – it took a lot of development to get the same engines racing round a circuit reliably. This season in the UK’s top 3 Production based Porsche Championships our engines (built the previous winter) won all three Championships with a 100% reliability record – demonstrating that the small and subtle changes we make (combined with our rebuild skills) are worthwhile. We also ran a podium based rewards scheme that has resulted in all 3 Champions earning labour free winter engine rebuilds – putting over �8000 back into the Sport. Next season the Porsche Club Championship introduces the 3.8 engines and we expect this to follow the same set of challenges and a learning curve as the previous models. Strictly controlled to standard road based internals (with a few minor allowances) this shows that progress has been made and that rebuilds to the right specification can create a very reliable engine. Porsche Club GB class 1 Champion Mark McAleer 8 wins, 2 * 2nd , 1 * 3rd 100% reliability. Porsche Club GB class 2 Champion Jake McAleer 9 wins, 2 * 2nd 100% reliability. Porsche Club GB TEAM AWARD RVR 17 wins, 4 * 2nd 1 * 3nd 100% reliability. BRSCC Boxster class 1 Champion Ed Hayes 15 wins, 4 * 2nd , 3 * 3rd 100% reliability. Baz (Barry Hart, Technical Director, Hartech Automotive www.hartech.org )

Congrats Baz!

Baz Have you guys developed a 3.7/3.8 engine based on the stock 3.4? If not is this something your planning on doing? Would the reliability be as quoted above? And what BHP gain could be expected? Thanks

This is great, and I am a big fan of your approach and the transparency you have. Do you get many US customers? I guess what my real question is whether it is cost effective to ship an engine to you and back, or does turn an otherwise more affordable rebuild into one too costly to be viable?

Yes. Tell us about your VAT free sales to North America...

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Are you talking about M96 engines???

Hartech rebuilds are the gold standard for 986 and 996 engines in the U.K. Legendary.

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Your website is interesting - thanks for posting. I'm curious as to what you find to be the causes of - and solutions to - cylinder scoring and cracking.

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Work your way through the documentation and you will know... http://www.hartech.org/images/downlo...0(interim).pdf

Can only say that I am still quite pleased with my hartech modified block.

In reply to EVIL BUNNY We have been involved in projects for oversized engines for the last 2 years. Initially we started with 3 different cars/models and created them using pistons originally intended for other applications and modified them to get going after re-mapping etc (and di so for a few customers who were happy to proceed themselves by way of increasing feedback � including one form the USA). There followed test miles and strips and rebuilds etc, and then moved on the having special pistons manufactured. These new pistons were developed by a F1 provider and we had different profiles manufactured and fitted different versions to the same engines and continued testing. Engines were then stripped again and the final version of the piston profiles agreed and put into production and some of these are currently under final test while we are awaiting some others that are imminent. Throughout the test we have had no problems with the conversions � all performing well with standard auxiliaries and reliable. It is quite traditional for small business specialists to try out new ideas on customer cars (due to the cost and time scales involved that are beyond many). In contrast we always develop our designs and test ourselves before putting into production. Unfortunately this takes a lot of time (especially trying to put enough miles on the cars between strips and inspections) and often delays our developments from coming to the market before others � but when they do our success rate is excellent as a result. We presently have under test a 996 3.4 now 3.7 (going very well indeed), a 3.6 now 3.9 (again performing well), a 3.8 now 3.9 (performing well but needing an un-connected gearbox rebuild) and a 3.6 still running as a 3.6 but with different profile pistons (for future standard rebuilds). We also are building a Cayman S race car (with a mod to stiffen the crankshaft from flexing) and a Gen 9A1 car awaiting a 4 litre engine that we are building. You can imagine the cost and time involved in owning and developing 6 cars � all requiring miles putting on them while we are flat out internally with customer work anyway. The difficulty in supplying outside the UK is covered in some Countries already through agents in Holland, Germany and Canada and we can always build a whole engine from abroad or just modify crankcases and supply pistons etc � but this still involves lengthy and/or expensive transport. We also have accumulated a lot of crankcases that we can convert for exchange (but so far have simply been too busy to put enough through our own internal machine shop). To help we have a special technical and product exchange arrangement with Alpine Autoworks in Canada who have their own machining facilities. Although machining out cylinder blocks and fitting alloy Nikasil closed deck cylinders sounds easy � it is not if it is going to be reliable and we have refused just supplying cylinders for others to fit for that very reason. We have been doing this for over 15 years and although even our first designs have worked successfully we have gradually improved them over the intervening years and sub-contracted them to a respected F1 supplier 9when the volumes became too high for us to cope with). We use new CNC machines for all the cylinder and block work internally so we can control everything �IN HOUSE�. Alpine have the right credentials for equipment and the right attitude to quality and despite our help - have been taking their time to fully understand the whole process and eradicate any small issues. This means you could send your blocks or engines to us or contact them directly to see if they are ready to proceed on a production basis yet � or deal through them for assembly but for speed they may decide to send the cases on to us. Until now our arrangements with them have been for our standard engine rebuild capacities and they have not yet been involved in our oversized engines but as soon as we are ready to release the product commercially � they will be available through all our agents. There are 2 videos on our webs site that may inform you more about our process. Our cylinders are full wet design with top hat precision locations making the top of the block a full closed deck (not to be confused with some claiming that but who do not fit the top of the liner into a recess). This is important because a tube fitted inside a tube is not as still as a solid tube of the same overall dimensions. With this design you either have a thin inner tube in a thick tube � or a think one in a thin tube and neither is as stiff as one solid tube replacing them all and fixed at the top. This problem is behind difficulties some have with ferrous liners or thin alloy ones although I think we could fit wither better than many (and I am sure some specialists can do it satisfactorily as well) it is just that ours are technically the best way it can be dome and even incorporate external ribs to increase the surface area for cooling (that dry liners cannot replicate). We have over the last 13 years manufactured and supplied thousands without failures because it is the best way to do the job and controlled with high precision and suitable machinery. Currently we are working at full capacity and with new products coming through that is unlikely to change � so engines internally are probably going to take 4 -6 weeks here (we currently process 1/day). Expanding to satisfy increasing demand is not possible because the whole system is in balance between machinery, staff and space and it would be necessary to double in size to expand anymore and we fear doing so would lose the present relationship we enjoy with our customers. Baz

It's good to see your engine program doing so well !!

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Good Morning Baz. Thanks for your extensive information. May I ask who is your agent in Holland? Are they also able to do a an engine rebuild (3.6/3.8/3.9/4.0) aimed at reliabke track use?

Baz, Thanks for taking the time to reply and providing feedback. I am UK and based and am interested in exploring the uplift from a 3.4 to a 3.7. Ideally I would like to see in excess of the GT3 number of 360 bhp with strong reliability, car will be heavily tracked, based on your current development plan & feedback to you see this as a possibility in the future?

Hi Silk, The only agent that we have authorised to machine cylinder blocks and fit our liners is our agent in Canada. Our other agents are the people that we have done business with for several years and who send cylinder blocks here to be fitted with our Nikasil plated alloy cylinder liners but strip and re-assemble the engines in their own workshops. We also supply them with some other items that make the engines suitable for track use. The most important is our racing sump which unlike many other extensions on the market is a whole new cast sump with valves and flow controls to prevent oil spilling out again in corners (which most other sump extension do not prevent). If you intend to use slick tires on track then we also supply a machined casting to allow the connection from an ACCUSUMP which is essential at racing speeds and cornering G forces approaching similar cars in race trim with fast drivers (but not necessary for just road tire track use). Or you can contact us directly. Baz

We have posted a lot on the subject of bore scoring before and on our web site but briefly - hypereutectic alloy cylinders contain hard silicon particles that resist wear providing a cylinder that expands like the piston - keeping close clearances throughout but not wearing out as it would just in aluminium. With the original Alusil (944, 968) the silicon was cast into the mix in a higher proportion than aluminium can absorb and allowed well distributed growth of silicon to come out of solution and created the hard particles. The problem was it was all over the cylinder block and cost a small fortune to machine because it was so hard. However it also increased the stiffness of the block and hence allowed open deck cylinders to last quite well. It was found during the original development (mainly the Vega engine) that the pistons needed a thin iron electroplated coating to prevent the silicon interfering with the piston surface on the thrust face. To overcome the high machining costs of Alusil, Lokasil was a different way to trap silicon particles just where needed - by creating a pre-formed tube that held silicon particles in space with organic binders and this was cast into the main crankcase casting under high pressure that allowed the molten alloy to flow into the preform, burn off much of the binder and end up with a silicon rich distribution near the cylinder surface only. Unfortunately the remaining alloy was not as stiff as Alusil but the 2.5 to 3.2 Boxster had thick cylinders and not very high piston loads but the increase to the 996 bored out the same block and resulted in thinner cylinders so with the first 3.4 examples the open deck arrangement was prone to go oval under the piston thrust loads and eventually crack. Other than that is was OK and we fitted support rings to the top of the cylinders to prevent ovality and that worked just fine. Then some European Health &Safety legislation handicapped the process to coat the pistons with hard iron and a softer plastic coating was used instead and at the same time because the pistons were getting larger (with the 3.8) the ratio of silicon and the particle sizes in the Lokasil was increased to stiffen the cylinders which they couldn't make thicker in the same block dimensions of the earlier engines without reducing the coolant volume too much. The larger silicon particles resisted ovality and cracking better and for much longer but the particles were not as securely bonded into the matrix as with the Alusil method and when a particle became free from the bore it rubbed against the plastic coated piston and damaged the surface and due to its increased size and the higher thrust loads of the bigger capacity engine - could breach the oil film thickness under high torque and score the bore on the side of the thrust (not a seizure on both sides caused by too much piston expansion) just hard particles rubbing between the piston and the bore and damaging it. Nikasil plates silicon particles in the most secure way possible (so good that even when damaged metal particles enter the combustion area through say valve problems - it often survives. The lokasil could be replaced by an alloy Nikasil plated thin tube creating a dry liner but a tube inside a tube is not as stiff as a solid tube of the same overall dimensions and so we prefer to completely machine out the original cylinder and fit a whole new alloy one with a Nikasil finish and machine a precision fit at the top the secure the position and prevent movement creating a top closed deck. The resulting bore finish is similar the air cooled 911 cylinders that last so well and almost identical to the GT3 and turbo versions of the same models (that are so reliable) and have proven extremely reliable in our production over thousands of liners and over a decade of fitting them. Baz

Thanks for your feedback. In fact my engine-block was modified by Hartech back in 2015 by the previous owner of the car. I tried to trace back what exactly was done to the block but I do not know if it was fitted with Nikasil or steel liners, bank 2 only or both cilinder banks. Were you still doing steel liners at that time? In case I encounter another engine failure I will look for the bigger bore upgrade for a track oriented street car. I hit the track ocasionally for fun driving. I run Yoko AD08r and do not intend to use slicks now or in the future. I have a X51 style pan (FVD) installed and the spin-on adapter with the washable racing filter. Running Millers CFS 10w50 NT I know about the Bilt Race deep sump kit with the windage tray sold by LN. which is merely an extended reservoir with the tray creating a sort of closed chamber which holds the oil and prevents excessive foaming. Does the Hartech solution is more compact? Would you advise such an upgrade compared a X51 style pan for my 'recreational' use? How doesit compare pricewise? Maybe I better drop you a mail with my enquiries.

Hi Silk, please E-mail me direct on [email removed] for more about the racing sump - I do believe it is the only one that physically prevents oil escaping and directs it into the pick up area. We have never ever supplied steel or iron liners for these models (although it would have been cheaper to do so). There has to be specific design suitability in the original block to make a ferrous liner work reliably and not drop or become loose because of the differential expansion rates, the thermal conductivity is not so good (so engines run hotter internally) and they wear faster than Nikasil. Furthermore the expansion rate is about 0.001" (0.025mm) less so you have to run with greater cold clearances (which is OK for racing where the engine is always flat out but not suitable for road use when it hardly ever is) That is IMHO. Iron or steel liners were discarded by most manufacturers years ago (unless they were cast in and ribbed internally and the cooling took account of the expansion rate difference and usually where bores were smaller than 96-100mm and pistons were designed accordingly). The amount a piston expands is proportional to its diameter so the bigger the bore the more unsuitable a ferrous liner becomes. Our first cylinders were basically similar to our present ones - they all were wet liners, all closed deck and all ribbed externally to increase heat transfer even more. However some customers could only afford a damaged cylinder to be replaced - some only bank 2 and some all 6 (now the reliability of the system is proven almost all customers now have all 6). Baz

Reviving an old thread. Hi Baz, January this year I purchased a Porsche 996.2 c2 manual coupe with your 3.9L engine conversion. I currently have Topgear sports headers, Topgear quiet muffler with bypass mod (To make it louder) and FVD X-Pipe with 200cell RedBack High Flow cats, I believe its running stock oem tune. Do you recommend remapping? Is there a remapping option that you do or could you recommend anyone that could do it? . I'm located in Melbourne Australia. Thanks in advance Kind regards Jim

If anyone is interested l have been communicating with Baz from Hartec here; http://911uk.com/viewtopic.php?t=125...r=asc&start=40