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Do Hartech know something Porsche don't ?

Kryton

Well-known member
Joined
5 Mar 2005
Messages
542
My new GT3 will have a 4.0 engine and given what I've read on here, Hartech are going to offer a 3.9 and I'm sure I read on the forum that they don't recommend going to 4.0?

Just hope this isn't going to be another 996/997.1 example for my 4.0 engine where Hartech new better than Porsche? :?:
 
Kryton said:
My new GT3 will have a 4.0 engine and given what I've read on here, Hartech are going to offer a 3.9 and I'm sure I read on the forum that they don't recommend going to 4.0?

Just hope this isn't going to be another 996/997.1 example for my 4.0 engine where Hartech new better than Porsche? :?:

I would imagine the new GT3 units are more than strong enough for 4.0 and the "don't recommend going to 4.0" was aimed at m96/m97 (996/997.1) units.
 
I take it the original post is just a bit of fun :wink:

Hartech is referring to bore size for a M96/97 engine. The engine was originally designed as a 2.5 to begin with, (Porsche boxster). Stretching the bore out to 101mm (4.0L) could affect reliability. The GT3 engine is completely different design so 4.0 is not an issue.
 
Kryton said:
My new GT3 will have a 4.0 engine and given what I've read on here, Hartech are going to offer a 3.9 and I'm sure I read on the forum that they don't recommend going to 4.0?

Just hope this isn't going to be another 996/997.1 example for my 4.0 engine where Hartech new better than Porsche? :?:

I wouldn't worry, what are the odds you will keep it beyond the warranty?

Collect this one and the same day place the order for the next one.
Repeat until there is no premium
 
Hmmm the IMS will take a pounding! I think Porsche are of the assumption these cars will never actually get used so no one will ever know :D


All joking aside it is a completely different engine to the M96/M97 as others have mentioned above.
 
It's the RMS I worry about, and the D-chunking
 
GT4 said:
Kryton said:
My new GT3 will have a 4.0 engine and given what I've read on here, Hartech are going to offer a 3.9 and I'm sure I read on the forum that they don't recommend going to 4.0?

Just hope this isn't going to be another 996/997.1 example for my 4.0 engine where Hartech new better than Porsche? :?:

I wouldn't worry, what are the odds you will keep it beyond the warranty

18 months from new probably.

I know the new engine has titanium conrods and solid lifters but I thought the engine block would be the same casting (knowing Porsche's tight nature)

I'm a retired builder not an engineer.:)
 
........ and I'm in the wrong job!
 
Kryton said:
GT4 said:
Kryton said:
My new GT3 will have a 4.0 engine and given what I've read on here, Hartech are going to offer a 3.9 and I'm sure I read on the forum that they don't recommend going to 4.0?

Just hope this isn't going to be another 996/997.1 example for my 4.0 engine where Hartech new better than Porsche? :?:

I wouldn't worry, what are the odds you will keep it beyond the warranty

18 months from new probably.

I know the new engine has titanium conrods and solid lifters but I thought the engine block would be the same casting (knowing Porsche's tight nature)

I'm a retired builder not an engineer.:)

To be fair to Porsche, apart from the initial 991.1 GT3 run gremlins, they have all used bullet proof engines, either Mezgers or the 997.2 derived DFI (MA1) blocks.
 
Would a hartech 3.9 rebuild be less reliable than a 3.8 rebuild?
 
I am afraid my answer will have to be Hartech know better than Porsche , Hartech build engines to be the best they can build improving on inherent weaknesses in these engines . Porsche build engines and are led by accountants for profit over anything else and will as we know substitute the prefect item for a cheaper will do the job item. this has been seen on 996, 997.1 cayman boxters etc its a bit early to say on 997.2 and far too early to say on 991 but if history repeats the trend there will be some things it may not be catastrophic like the IMS or even the liners but it will show its face on things like the tandem pump , coolant pipes etc things that despite knowing they have not learnt that guys are going to end up with engine drops to refit £100 worn out parts or just have to replace badly located parts like the tandem pump I would have a bet that despite wide knowledge that the steel pierburg pump cover not being fit for purpose on an engine hung out the back of a car the newer models will not be fitted with a stainless steel cover and still come with the mild steel cover , its those types of things that dont get addressed model after model that tells me Hartech know better than Porsche

re the uprated engines by Hartech

It is my opinion that any engine from Porsche whether a 996 or a 991 could be improved upon by Hartech. mainly because they are automotive engineers and not accountants.

They do have at the R&D stage a 4ltr engine for the 997.2 and currently offer for the earlier cars the 3.9 upgrade.

This is only my opinion
 
Kev.K there is a simple short answer to the question about the reliability of our oversized engines – which is – that they are more reliable.

If you want more detail - you are absolutely right krispe – the engine was designed originally as a 2.5 with Lokasil bores and ferrous coated pistons – and apart from a mistake over the IMS bearing design (that was much later resolved using a bigger bearing) –was otherwise pretty well bullet proof.

The 2.7 increased the stroke which would normally be followed by making the cylinder block higher by half the stroke increase - but wasn't and neither was it increased when the stroke was increased again for the 3.6 and 3.8. This means that the rod length and the position of the gudgeon pin to piston crown become compromised slightly from the original 'best design" – but any small reduction in performance resulting was more than made up for by the extra capacity.

The 3.2 Boxster s then increased the bore as well as the stroke but the space between the cylinders remained the same and hence the space for coolant was reduced, although the cylinders were made thicker to maintain their strength.

When the 3.4 996 increased the bore again the wall thickness of the 3.2 was not increased but used the same casting – so the cylinder wall thickness became thinner and weaker and they started to migrate oval under the increased power and some eventually cracked.

Increasing the bore once again for the 3.8 reduced coolant volumes even more and with the same cylinder wall thickness but even more power to resist – also went oval but lasted longer due to a change in the Lokasil mixture using larger particles – but then at the same time the original ferrous piston coating was replaced with a plastic coating that resulted in bore scoring when the larger particles became de-bonded from the cylinder wall - and hence the reputation we are all used to.

The original basic design – having been gradually increased by 50% was still OK apart from the piston coating, the cylinder bore material, the cylinder stiffness, the reduced coolant volume and the IMS bearing (in the original versions with the smaller bearings).

Hartech rebuilt engines address all these remaining problems. The cylinder bore material we use is Nikasil (recognised as the current best proven finish for high performance sports car engines with large pistons), the cylinders are stiffer (being aerospace alloy – solid liners – that completely replace the whole of the original cylinders and are supported at the top to prevent distortion converting the engine to a closed deck design), the cooling system is now wet liners providing increased thermal cooling and are ribbed at the top to increase the surface area (and all this is unique to Hartech cylinders) and we alter the proportion of coolant flowing around the cylinders by modifying the inlet to (and outlet from) the cylinder block which combined means the increased thermal cooling efficiency negates any reduction in coolant volume.

Meanwhile we can provide an IMS that houses the new reliable larger bearing for both the original roller chain and newer Hivo chain drives to the camshaft drive. All weaknesses are therefore addressed (and in most cases more than exceed the level of improvement needed).

One good aspect of the gradual increase in capacity of the same basic original design is that (apart from the weaknesses we have overcome) we know it works perfectly well right up to 3.8 and - because our changes more than compensate for the original short comings and result in a much more reliable and stronger engine – it can easily handle another small additional increase in cylinder diameter of 1mm (compared to a 3.8).

The biggest benefit that Porsche achieved while they gradually increased the capacity was in the improved mid-range acceleration and throttle response resulting from better mid-range torque and better top end power - the same benefit applies to our capacity increases.

This is most noticeable in the Cayman S (from 3.4 to 3.9) because it is a 500cc increase and a lighter car than the 911 variants, but the 3.4 to 3.7 and 3.6 to 3.9 produce much better performance and with several years development behind us (including testing different pistons and profiles) result in a inexpensive way to obtain better performance –if you have to have the engine rebuilt anyway. In the case of the Cayman S – the bigger performance increase cost may well be justifiable even if the engine is still OK. Inevitably a 3.8 to 3.9 conversion only shows a relatively small increase in mid range performance (being only a 2.6% increase and 100 ccs).

To follow - the 3.2 to 3.7 Boxster S should be quite some car with 500ccs extra and light weight.

The Gen 2 9A1 engines were never conceived as a 2.5 and gradually stretched bigger- but I would say were designed as a 3,8 and slimmed back to a 3.6 and smaller – so already have the basic design parameters to be stretched further (as we expect our 4.0 litre Gen 2 9A1 will demonstrate in the future).

They have a closed deck block and Alusil bores and seem extremely reliable in most cases. We have experienced some failures of the bores caused mainly by age related cylinder creep distortion that is working in the opposite direction to the M96/7 engines by closing in on the piston over a long period of time and seizing it (rather than increasing the clearances) but this problem is removed when we fit our typical Nikasil cylinders as they are re-machined after the block distortion has stabilised and fitted with a compensating clearance where required.


Baz
 
bazhart said:
Kev.K there is a simple short answer to the question about the reliability of our oversized engines – which is – that they are more reliable.

If you want more detail - you are absolutely right krispe – the engine was designed originally as a 2.5 with Lokasil bores and ferrous coated pistons – and apart from a mistake over the IMS bearing design (that was much later resolved using a bigger bearing) –was otherwise pretty well bullet proof.

The 2.7 increased the stroke which would normally be followed by making the cylinder block higher by half the stroke increase - but wasn't and neither was it increased when the stroke was increased again for the 3.6 and 3.8. This means that the rod length and the position of the gudgeon pin to piston crown become compromised slightly from the original 'best design" – but any small reduction in performance resulting was more than made up for by the extra capacity.

The 3.2 Boxster s then increased the bore as well as the stroke but the space between the cylinders remained the same and hence the space for coolant was reduced, although the cylinders were made thicker to maintain their strength.

When the 3.4 996 increased the bore again the wall thickness of the 3.2 was not increased but used the same casting – so the cylinder wall thickness became thinner and weaker and they started to migrate oval under the increased power and some eventually cracked.

Increasing the bore once again for the 3.8 reduced coolant volumes even more and with the same cylinder wall thickness but even more power to resist – also went oval but lasted longer due to a change in the Lokasil mixture using larger particles – but then at the same time the original ferrous piston coating was replaced with a plastic coating that resulted in bore scoring when the larger particles became de-bonded from the cylinder wall - and hence the reputation we are all used to.

The original basic design – having been gradually increased by 50% was still OK apart from the piston coating, the cylinder bore material, the cylinder stiffness, the reduced coolant volume and the IMS bearing (in the original versions with the smaller bearings).

Hartech rebuilt engines address all these remaining problems. The cylinder bore material we use is Nikasil (recognised as the current best proven finish for high performance sports car engines with large pistons), the cylinders are stiffer (being aerospace alloy – solid liners – that completely replace the whole of the original cylinders and are supported at the top to prevent distortion converting the engine to a closed deck design), the cooling system is now wet liners providing increased thermal cooling and are ribbed at the top to increase the surface area (and all this is unique to Hartech cylinders) and we alter the proportion of coolant flowing around the cylinders by modifying the inlet to (and outlet from) the cylinder block which combined means the increased thermal cooling efficiency negates any reduction in coolant volume.

Meanwhile we can provide an IMS that houses the new reliable larger bearing for both the original roller chain and newer Hivo chain drives to the camshaft drive. All weaknesses are therefore addressed (and in most cases more than exceed the level of improvement needed).

One good aspect of the gradual increase in capacity of the same basic original design is that (apart from the weaknesses we have overcome) we know it works perfectly well right up to 3.8 and - because our changes more than compensate for the original short comings and result in a much more reliable and stronger engine – it can easily handle another small additional increase in cylinder diameter of 1mm (compared to a 3.8).

The biggest benefit that Porsche achieved while they gradually increased the capacity was in the improved mid-range acceleration and throttle response resulting from better mid-range torque and better top end power - the same benefit applies to our capacity increases.

This is most noticeable in the Cayman S (from 3.4 to 3.9) because it is a 500cc increase and a lighter car than the 911 variants, but the 3.4 to 3.7 and 3.6 to 3.9 produce much better performance and with several years development behind us (including testing different pistons and profiles) result in a inexpensive way to obtain better performance –if you have to have the engine rebuilt anyway. In the case of the Cayman S – the bigger performance increase cost may well be justifiable even if the engine is still OK. Inevitably a 3.8 to 3.9 conversion only shows a relatively small increase in mid range performance (being only a 2.6% increase and 100 ccs).

To follow - the 3.2 to 3.7 Boxster S should be quite some car with 500ccs extra and light weight.

The Gen 2 9A1 engines were never conceived as a 2.5 and gradually stretched bigger- but I would say were designed as a 3,8 and slimmed back to a 3.6 and smaller – so already have the basic design parameters to be stretched further (as we expect our 4.0 litre Gen 2 9A1 will demonstrate in the future).

They have a closed deck block and Alusil bores and seem extremely reliable in most cases. We have experienced some failures of the bores caused mainly by age related cylinder creep distortion that is working in the opposite direction to the M96/7 engines by closing in on the piston over a long period of time and seizing it (rather than increasing the clearances) but this problem is removed when we fit our typical Nikasil cylinders as they are re-machined after the block distortion has stabilised and fitted with a compensating clearance where required.


Baz


:worship: I couldnt have put it better myself Baz :floor: every post you write gives me a little more insight into these engines and your huge understanding of them :thumb:
 

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