Engine Rebuild - Local Specialist or Hartech?
Discussion
Hi all,
So I'm in a quandary about this, and would appreciate your thoughts.
My car, as you might have seen on other posts, suffered IMS failure a few weeks back and is waiting a strip and rebuild.
There's a very good Porsche specialist just down the road from me, and I trust them implicitly. I have no doubt that they would do a fantastic job of rebuilding the engine and that I would have no problems with it. They are also really great guys and I'd hate them to infer that I'm doubting their abilities by doing so. Nothing could be further from the truth.
However, there's some kudos, clearly from comments on here and elsewhere, that a Hartech engine rebuild is a bonus in terms of resale to a new owner. Where as there's a high chance that people won't have heard of my specialist, being a much smaller, though admirable, organisation.
Aside from not wanting to slight the local guys by suggesting that they remove and send the 'long' engine to Hartech for stripping and rebuilding, I wonder if there's really anything to be gained? For a buyer, would it suffice to show a detailed and professional invoice for the rebuild from a good specialist? Or do you think having a Hartech invoice is worth the extra hassle?
Thanks all,
J.
So I'm in a quandary about this, and would appreciate your thoughts.
My car, as you might have seen on other posts, suffered IMS failure a few weeks back and is waiting a strip and rebuild.
There's a very good Porsche specialist just down the road from me, and I trust them implicitly. I have no doubt that they would do a fantastic job of rebuilding the engine and that I would have no problems with it. They are also really great guys and I'd hate them to infer that I'm doubting their abilities by doing so. Nothing could be further from the truth.
However, there's some kudos, clearly from comments on here and elsewhere, that a Hartech engine rebuild is a bonus in terms of resale to a new owner. Where as there's a high chance that people won't have heard of my specialist, being a much smaller, though admirable, organisation.
Aside from not wanting to slight the local guys by suggesting that they remove and send the 'long' engine to Hartech for stripping and rebuilding, I wonder if there's really anything to be gained? For a buyer, would it suffice to show a detailed and professional invoice for the rebuild from a good specialist? Or do you think having a Hartech invoice is worth the extra hassle?
Thanks all,
J.
There are a lot of variables to be considered here - one mans "full engine rebuild" might be "new IMS, bearings shells and gaskets", whilst to another it would be "new liners and pistons, close the deck, re-do the cooling flow, replace all consumables".
Which means that there's a big range of prices, and a prospective owner might not consider what you have done as being a sufficient rebuild for them, no matter where it was done (if that makes sense?)
Also worth noting that Hartech won't tell a new owner what a previous owner had done, for data privacy reasons, so the whole subject can be quite opaque if the paperwork isn't there.
If you don't intend on selling the car, then this is moot - you just need to keep yourself happy.
If you do want to move it on in the next 2-5 years then I'd say that the Hartech name would be worth more than the Indys when put next to "full engine rebuild", but I don't think it's possible to quantify the value of that in GBP.
Some do search "996 hartech" to filter to only those cars that they would consider on eBay, but that's likely a tiny minority.
Also, to many buyers any mention of "engine rebuild" will have them running for the hills as it potentially betokens future trouble, it's only nerds like us that would seek out a rebuilt car (for a given value of rebuilt).
What do you intend on having done and how long do you want to keep the car?
Which means that there's a big range of prices, and a prospective owner might not consider what you have done as being a sufficient rebuild for them, no matter where it was done (if that makes sense?)
Also worth noting that Hartech won't tell a new owner what a previous owner had done, for data privacy reasons, so the whole subject can be quite opaque if the paperwork isn't there.
If you don't intend on selling the car, then this is moot - you just need to keep yourself happy.
If you do want to move it on in the next 2-5 years then I'd say that the Hartech name would be worth more than the Indys when put next to "full engine rebuild", but I don't think it's possible to quantify the value of that in GBP.
Some do search "996 hartech" to filter to only those cars that they would consider on eBay, but that's likely a tiny minority.
Also, to many buyers any mention of "engine rebuild" will have them running for the hills as it potentially betokens future trouble, it's only nerds like us that would seek out a rebuilt car (for a given value of rebuilt).
What do you intend on having done and how long do you want to keep the car?
If you had an OPC warranty, I would say get a new block, and enjoy 1-2 years more than sell it. I'm sure hartech and autofarm makes kick-ass engines, but when you look at the prices and the final outcome (it's a water-cooled, problematic engine at the end, nothing special imho), difficult call.
I personally would not pay premium for hartech or autofarm car if I was looking for a 996/997. Maybe a few hundreds or grand more but that's it.
My older 986 had an engine rebuild by a local specialist. It was a proper neat job and probably still going, but never thought of spending more as these cars are not that unique. Good for a proper weekend fund though but that's it!
I personally would not pay premium for hartech or autofarm car if I was looking for a 996/997. Maybe a few hundreds or grand more but that's it.
My older 986 had an engine rebuild by a local specialist. It was a proper neat job and probably still going, but never thought of spending more as these cars are not that unique. Good for a proper weekend fund though but that's it!
I would not be worried about offending your Indy - it is your coin and your decision. There is some good advice up thread about how to start deciding which route feels right for you.
`My` Indy has an in house engine building & repair facility. They can put most failure modes back to working order, but they also work closely with Hartech. Customers needing engine work have the option of sending the engine or even whole car to Hartech. A lot of people choose to send the engine for machining only of upgrades and have final re assembly and fitting done locally by said Indy.
This saves a bit of time and money in most cases, and as I understand it results in a good warranty and some nice paperwork to document provenance of the rebuild. If your garage are pushing you to use their offering, they are perhaps not offering you the full range of choices you deserve.
edited to say : OP - just realized, we use the same garage! Chris & Ash will NOT be offended if you send the motor north to have some machine work and upgrades to internals- they can and will happily re assemble it and put it back in the car. This was normal, until very recently - perhaps things have changed? Are they offering to close the deck, improve the oiling, improve the IMS etc? insert Nikasil liners? - do a `full fat` job or just repair it?
`My` Indy has an in house engine building & repair facility. They can put most failure modes back to working order, but they also work closely with Hartech. Customers needing engine work have the option of sending the engine or even whole car to Hartech. A lot of people choose to send the engine for machining only of upgrades and have final re assembly and fitting done locally by said Indy.
This saves a bit of time and money in most cases, and as I understand it results in a good warranty and some nice paperwork to document provenance of the rebuild. If your garage are pushing you to use their offering, they are perhaps not offering you the full range of choices you deserve.
edited to say : OP - just realized, we use the same garage! Chris & Ash will NOT be offended if you send the motor north to have some machine work and upgrades to internals- they can and will happily re assemble it and put it back in the car. This was normal, until very recently - perhaps things have changed? Are they offering to close the deck, improve the oiling, improve the IMS etc? insert Nikasil liners? - do a `full fat` job or just repair it?
Edited by rival38 on Thursday 16th August 20:42
Edited by rival38 on Thursday 16th August 20:47
anonymous said:
[redacted]
Good post. I'd like to add that I recently sold a Hartech rebuilt car. Buyers didn't really know/care about the advantages of having this work done.
On the plus side you're free to give it absolute death without worrying about imminent failure!
If you're going to the expense of getting it done take it up to hartech and get both banks sorted.
I've made my feelings known on this a few times, but I'd get it done by someone you know and trust and not worry about the name There are plenty of great rebuilders out there, it's just an engine after all.
If you could sell a car with a Hartech rebuild for 2k more, then you'd go that route all day long, but from what I've seen that isn't the case and so I'd suggest using the local place and keeping the relationship going.
If you could sell a car with a Hartech rebuild for 2k more, then you'd go that route all day long, but from what I've seen that isn't the case and so I'd suggest using the local place and keeping the relationship going.
[quote=rival38]
edited to say : OP - just realized, we use the same garage! Chris & Ash will NOT be offended if you send the motor north to have some machine work and upgrades to internals- they can and will happily re assemble it and put it back in the car. This was normal, until very recently - perhaps things have changed? Are they offering to close the deck, improve the oiling, improve the IMS etc? insert Nikasil liners? - do a `full fat` job or just repair it?
Thanks everyone for all the comments. To answer a couple of the questions, I'm intending to keep the car long term. And I'd like to rebuild the engine in all respects ... bottom end and top ... because it will be nice to drive it for the first time without the nagging doubt that most of us on this forum live with! But it does come down to money at the end of the day. I don't have unlimited resources. I do have a warranty, but that has a claim limit of £5000. So if I do the whole show, I'll probably be in for the same again or more. And that's assuming theres no problem with the claim and they honour it, and that the failure did significant damage to other components which they will pay to repair, thereby keeping the cost of what I have to pay for to a minimum. Obviously, they'll only pay for stuff which was broken by the failure of the IMS.
Rival mate - I'm sure you're right...it's because they're such top blokes that I really don't want to ask!! We haven't been through all the options yet because they haven't yet stripped the engine down. But Chris did mention upgraded liners, forged pistons etc. I would deffo improve the IMS. It didn't have a scoring problem before...and since the failure happened at low speed, there is a possibility (slim) that it's only got top end damage, and we could therefore leave the bottom end as it is. But I suspect not. And I think it would be a good investment to have the liners done.
What do you mean by 'Close the Deck'? not heard that one before...
edited to say : OP - just realized, we use the same garage! Chris & Ash will NOT be offended if you send the motor north to have some machine work and upgrades to internals- they can and will happily re assemble it and put it back in the car. This was normal, until very recently - perhaps things have changed? Are they offering to close the deck, improve the oiling, improve the IMS etc? insert Nikasil liners? - do a `full fat` job or just repair it?
Edited by rival38 on Thursday 16th August 20:42
Thanks everyone for all the comments. To answer a couple of the questions, I'm intending to keep the car long term. And I'd like to rebuild the engine in all respects ... bottom end and top ... because it will be nice to drive it for the first time without the nagging doubt that most of us on this forum live with! But it does come down to money at the end of the day. I don't have unlimited resources. I do have a warranty, but that has a claim limit of £5000. So if I do the whole show, I'll probably be in for the same again or more. And that's assuming theres no problem with the claim and they honour it, and that the failure did significant damage to other components which they will pay to repair, thereby keeping the cost of what I have to pay for to a minimum. Obviously, they'll only pay for stuff which was broken by the failure of the IMS.
Rival mate - I'm sure you're right...it's because they're such top blokes that I really don't want to ask!! We haven't been through all the options yet because they haven't yet stripped the engine down. But Chris did mention upgraded liners, forged pistons etc. I would deffo improve the IMS. It didn't have a scoring problem before...and since the failure happened at low speed, there is a possibility (slim) that it's only got top end damage, and we could therefore leave the bottom end as it is. But I suspect not. And I think it would be a good investment to have the liners done.
What do you mean by 'Close the Deck'? not heard that one before...
Edited by jezzaaa on Friday 17th August 21:48
https://www.youtube.com/watch?v=J3cWE1Azwgs
Machined rings added to provide support to the top of the cylinder liners. This removes the risk of several failure modes - D chunking, where a piece of the cylinder liner breaks off & Ovaling, where the cylinder goes out of shape with use.
Machined rings added to provide support to the top of the cylinder liners. This removes the risk of several failure modes - D chunking, where a piece of the cylinder liner breaks off & Ovaling, where the cylinder goes out of shape with use.
rival38 said:
https://www.youtube.com/watch?v=J3cWE1Azwgs
Machined rings added to provide support to the top of the cylinder liners. This removes the risk of several failure modes - D chunking, where a piece of the cylinder liner breaks off & Ovaling, where the cylinder goes out of shape with use.
Ah interesting!! Ok thanks mate. I guess this will all come out when they've stripped it and we know what's what.Machined rings added to provide support to the top of the cylinder liners. This removes the risk of several failure modes - D chunking, where a piece of the cylinder liner breaks off & Ovaling, where the cylinder goes out of shape with use.
Until the engine is stripped down then make decisions on costs and rebuild. If the liners are damaged, then there is no reason why bottom end cannot be sent to Hartech to get 1, 2 or whole bank replaced. The remaining work can be completed by any competent engine builders.
Floating deck (as in m.96) allows coolant to flow freely around liners at top - they are fixed deeper in the block. I believe Hartech fix the liners at the top (closed deck) keeping them rigid but using materials used in air-cooled & GT engines. There are pluses & minuses. I would stay away from cast iron liners, although much cheaper than Hartechs solution.
Floating deck (as in m.96) allows coolant to flow freely around liners at top - they are fixed deeper in the block. I believe Hartech fix the liners at the top (closed deck) keeping them rigid but using materials used in air-cooled & GT engines. There are pluses & minuses. I would stay away from cast iron liners, although much cheaper than Hartechs solution.
I do appreciate the contributors that support our solutions – thanks for that guys – but every so often (especially if I haven’t posted for a while) I notice some (particularly new) contributors seem to lose their way a bit about some of the important technical issues – and so here are a few reminders pertinent to this topic.
(1) Modern manufacturing does not run with 100% inspection – but we do – every single liner is measured and fitted with tighter tolerances than most manufacturers could ever achieve commercially (and many customers who have visited us will have seen this in action with record sheets and individually fitted components). Specialists like us generally do a much more thorough job than original manufacturers can justify. Furthermore I will state that compared to brand new Porsche piston and cylinder blocks - ours are more round, accurate and consistent and with much more accurate bore clearance control!
(2) The only reason the Porsche block has a floating top of the liner is because to make the molten aluminium flow through the porous Silicon rich pre-form they had to make all metal casting moulds that could withstand high casting pressures (and not use sand cores).
They actually did a very clever job and if you look carefully at a set of cylinder block castings you can see why and as a result the casting is cheaper to make but needed very clever design to allow all the metal mould parts to be removed/withdrawn in straight lines and hence the top of the block had to be left open.
It was a solution that worked when the bores were small (for the original 2.5 Boxster) and there was room for the cylinders to be quite thick – but while they expanded the capacity within the same cylinder pitch and deck height – right up until the 996 3.4 (when the space left between the cylinder and block for coolant became smaller and coolant flow became a concern) – they made the cylinder wall thinner. The combination of higher piston force on the liner from the bigger engines with a thinner unsupported cylinder wall allowed too much movement making bores go oval and some to eventually crack.
This casting method was also one of the reasons that a separate crank carrier cassette was part of the design (cleverly sealing off the crankshaft oil gallery) but led to difficulties aligning the cassette and the RMS hole requiring a new deformable RMS. Having learned that lesson the Gen 2 went back to a conventional combination of metal moulds and sand cores to create a closed deck top and 2 piece crankcase. So the original open deck design IMHO had nothing to do with coolant flow around the top of the cylinder – just design necessity to deliver the Lokasil initiative that had flaws combined with fake news about the benefits.
(3) Fitting a liner inside a tube results in a reduction in thermal cooling between the two interfaces (even if it is an aluminium liner). Ours is a one piece complete new cylinder, had a ribbed exterior (that increases the surface area in direct contact with the coolant) and has superior heat transfer as a result. The “top hat” flange that secures the top of our liners to a precision machined recess actually has slightly more surface area in contact with the coolant than the circumferential surface area it replaces – so overall much better cooling thermal flow and completely rigid and stable.
(4) I don’t agree that iron liners are “much cheaper”. We supply and fit 6 aerospace aluminium Nikasil coated liners for £2,500 and this includes cleaning, measuring and inspecting the original cases, precision machining to a very high quality with small tolerances on a new CNC machine with expensive diamond tipped tools, machining the top face (in one pass and not 2 as with original cylinders often leaving a small ridge on what should be a flat surface) and improving coolant flow.
With re-coated pistons and new rings the total is £3220 where by comparison the similar new Porsche GT3 liners and pistons cost about £5000 and are not fitted for that – just parts. We have invested a small fortune in making it possible to provide this quality at such a competitive price. It should be no surprise that there has been no more reliable or longer lasting cylinder solution on the market for any price and in comparison to the cost of the whole job from stripping, remanufacturing and fitting the whole engine – what proportion of the whole cost is the extra for such superb quality in comparison to open deck, iron liners? Slightly cheaper they may be but by how much and surely not “much cheaper”?
(5) You would be surprised how many cylinder blocks we (and our agents in other Countries) receive that have had alternative solutions that have failed and that we have to re-manufacture.
You don’t want to have the engine done twice – what small price does it cost to have the only solution (that I am aware of) that combines all these superior Hartech design features with the greatest number of totally successful long term rebuilds and superb customer satisfaction?
We supply individual customers, the trade and have carefully vetted agents in a number of Countries all performing excellent work for their areas and the oversized engine alternatives (available imminently) may encourage owners to remanufacture their engines sooner (or receive an additional benefit for similar costs) making long term ownership more attractive and enjoyable.
Baz
(1) Modern manufacturing does not run with 100% inspection – but we do – every single liner is measured and fitted with tighter tolerances than most manufacturers could ever achieve commercially (and many customers who have visited us will have seen this in action with record sheets and individually fitted components). Specialists like us generally do a much more thorough job than original manufacturers can justify. Furthermore I will state that compared to brand new Porsche piston and cylinder blocks - ours are more round, accurate and consistent and with much more accurate bore clearance control!
(2) The only reason the Porsche block has a floating top of the liner is because to make the molten aluminium flow through the porous Silicon rich pre-form they had to make all metal casting moulds that could withstand high casting pressures (and not use sand cores).
They actually did a very clever job and if you look carefully at a set of cylinder block castings you can see why and as a result the casting is cheaper to make but needed very clever design to allow all the metal mould parts to be removed/withdrawn in straight lines and hence the top of the block had to be left open.
It was a solution that worked when the bores were small (for the original 2.5 Boxster) and there was room for the cylinders to be quite thick – but while they expanded the capacity within the same cylinder pitch and deck height – right up until the 996 3.4 (when the space left between the cylinder and block for coolant became smaller and coolant flow became a concern) – they made the cylinder wall thinner. The combination of higher piston force on the liner from the bigger engines with a thinner unsupported cylinder wall allowed too much movement making bores go oval and some to eventually crack.
This casting method was also one of the reasons that a separate crank carrier cassette was part of the design (cleverly sealing off the crankshaft oil gallery) but led to difficulties aligning the cassette and the RMS hole requiring a new deformable RMS. Having learned that lesson the Gen 2 went back to a conventional combination of metal moulds and sand cores to create a closed deck top and 2 piece crankcase. So the original open deck design IMHO had nothing to do with coolant flow around the top of the cylinder – just design necessity to deliver the Lokasil initiative that had flaws combined with fake news about the benefits.
(3) Fitting a liner inside a tube results in a reduction in thermal cooling between the two interfaces (even if it is an aluminium liner). Ours is a one piece complete new cylinder, had a ribbed exterior (that increases the surface area in direct contact with the coolant) and has superior heat transfer as a result. The “top hat” flange that secures the top of our liners to a precision machined recess actually has slightly more surface area in contact with the coolant than the circumferential surface area it replaces – so overall much better cooling thermal flow and completely rigid and stable.
(4) I don’t agree that iron liners are “much cheaper”. We supply and fit 6 aerospace aluminium Nikasil coated liners for £2,500 and this includes cleaning, measuring and inspecting the original cases, precision machining to a very high quality with small tolerances on a new CNC machine with expensive diamond tipped tools, machining the top face (in one pass and not 2 as with original cylinders often leaving a small ridge on what should be a flat surface) and improving coolant flow.
With re-coated pistons and new rings the total is £3220 where by comparison the similar new Porsche GT3 liners and pistons cost about £5000 and are not fitted for that – just parts. We have invested a small fortune in making it possible to provide this quality at such a competitive price. It should be no surprise that there has been no more reliable or longer lasting cylinder solution on the market for any price and in comparison to the cost of the whole job from stripping, remanufacturing and fitting the whole engine – what proportion of the whole cost is the extra for such superb quality in comparison to open deck, iron liners? Slightly cheaper they may be but by how much and surely not “much cheaper”?
(5) You would be surprised how many cylinder blocks we (and our agents in other Countries) receive that have had alternative solutions that have failed and that we have to re-manufacture.
You don’t want to have the engine done twice – what small price does it cost to have the only solution (that I am aware of) that combines all these superior Hartech design features with the greatest number of totally successful long term rebuilds and superb customer satisfaction?
We supply individual customers, the trade and have carefully vetted agents in a number of Countries all performing excellent work for their areas and the oversized engine alternatives (available imminently) may encourage owners to remanufacture their engines sooner (or receive an additional benefit for similar costs) making long term ownership more attractive and enjoyable.
Baz
We are ready with the 3.4 to 3.7, 3.6 and 3.8 to 3.9. We have built several now and put a lot of miles on them but have 3 things to do next. (1) order in and manufacture all the parts and then set production to do them in batches. (2) Prepare our own sales information, publicise the outcome and arrange magazine road tests. (3) Decide on a policy about their sale (i.e. is it only going to be for cars we do the whole job on our through specialists we already deal with etc) and prices.
Having already sent some information to a magazine and seen their response it is going to be a big ask to correct the misunderstanding most enthusiasts and engineers have accepted about this issue over the years.
The big problem is that the general public think more bhp at higher revs equals faster performance - and it often doesn't. Because you have to drive through a rev band when you change up a gear - and use the gear ratios and final drive ratio you inherited with the car - faster performance comes from having more power throughout that rev band (not just at the top end).
Interestingly - while the above is absolutely true when you rev the engine to the rev limit before changing gear - it is even more relevant during normal driving when many drivers are using between 3,000 and 5,500 to 6000 revs yet still want good performance in that power band - and that is what you get when you make an engine oversized. It therefore requires quite a lot of explaining and proving.
Actually it is the torque at the rear wheel that determines performance and we have already produced examples proving that theory and that it is the reduction in rear wheel torque as you change up through the gears that results in slower acceleration when you increase speeds and not the wind resistance (as many assume).
The 3.8 to 3.9 is obviously only a small increase in performance while the 3.6 to 3.9 is very noticeable.
While the above examples only increase capacity by 300cc's (apart from the 3.8 to 3.9) we were not sure if the 3.4 to 3.9 Cayman S (with a 500cc increase) would be a step too far for the inlet, camshaft performance and exhausts - and cost more than the increase is worth - but it has surprised us all - performing very quickly at all revs in the power band and in my opinion very well worth any extra cost.
Encouraged by that we have not yet finished the Boxster S 3.2 to 3.7 - but it is next on the list.
All the promotional and technical information will be available soon including graphs of power and torque and more important than that showing rear wheel torque through the gears.
We just need to finalise the numbers we are prepared to do in each batch and prices and await orders.
It is going to be well worth the wait!
Meanwhile we have agreed to build 2 special engines for owners organising more extreme ad-ons with head, camshaft, inlet, exhaust, gear and final drive ratio changes - that will provide alternatives for even more performance as time goes by.
Baz
Sounds great. I’d have definitely gone for the 3.9 conversion had it been available in late 2015 when you did my full rebuild.
Excuse my ignorance here, but why can’t a 986 3.2 Boxster S be taken out to 3.9? That with some cams, head work etc would be an interesting car. Albeit with an engine costing twice what the original car cost!
Excuse my ignorance here, but why can’t a 986 3.2 Boxster S be taken out to 3.9? That with some cams, head work etc would be an interesting car. Albeit with an engine costing twice what the original car cost!
jezzaaa]ival38 said:
What do you mean by 'Close the Deck'? not heard that one before...
Here is a basic 996 engine (open-deck) - See no cylinder support on the sides? imagine revving that engine on 5-6k rpm...Edited by jezzaaa on Friday 17th August 21:48
And Gt3 block (closed-deck)
also more explanation here;
https://www.cplracing.co.uk/closed-deck-blocks-cyl...
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