It's gone pop... £££
Discussion
After 40 minutes of gentle motorway driving, I'm sitting waiting for electronic gates to a car park to open and all hell breaks loose.
A noise akin to a car driving by with the exhaust dragging on the floor eminates from my engine. Immediately switch it off. Because of where I was parked, I had to restart the engine and move it 20ft so it was out of the way. Oil pressure ok, oil and water temp ok but a noise like 1lb of nuts and bots located within the mufflers being tumbled about. No fluids underneath.
The car was recovered to a local Indy on a recovery vehicle with strict instructions not to start.
So far, I've been told 'it's serious' but not much more.
Anyone know what's happened? IMS shaft? Timing chain? Piston failure?
Just know that Christmas has got a lot more expensive... :-(
A noise akin to a car driving by with the exhaust dragging on the floor eminates from my engine. Immediately switch it off. Because of where I was parked, I had to restart the engine and move it 20ft so it was out of the way. Oil pressure ok, oil and water temp ok but a noise like 1lb of nuts and bots located within the mufflers being tumbled about. No fluids underneath.
The car was recovered to a local Indy on a recovery vehicle with strict instructions not to start.
So far, I've been told 'it's serious' but not much more.
Anyone know what's happened? IMS shaft? Timing chain? Piston failure?
Just know that Christmas has got a lot more expensive... :-(
JapanRed said:
Isn't 60k miles a bit late for IMS to go bang? Usually go earlier than this don't they?
They can go anytime, there is no set mileage. Driving style and the type of driving and roads etc.However, the biggest variable is whether the seal splits and lets oil into the bearing. This extends its life.
Here are some words from Baz of Hartech which he posted on 911UK very recently. I hope he doesn't mind me quoting him, as he often comes on here as well.
"To try and answer why there are different solutions.
A ball bearing does not benefit from a pressurised oil feed it just needs a supply of fresh cool oil and to be part of a filter system to remove and small pieces of worn metal that inevitably wears off parts slowly. A linear shell bearing does need a pressurised oil supply to keep the shaft metal apart from the shell bearing material as a result of the pressure in the oil between them - without which it could seize.
The sprocket diameter on the end of the shaft runs in an oil bath at up to around 4,500 rpm and the chain fitting round it also travels at up to 40mph in the same oil bath - these between them splash oil in all directions at enormous force and speed and it gets everywhere and is entirely capable of lubricating an open ball bearing nearby.
In fact when the dust seal that Porsche fit has worn slightly and the grease has leaked out - the pressure and force of oil nearby is sufficient to get in and out of that minute seal lip and in most cases can lubricate the bearing sufficiently to last for up to 150K (if it was not damaged too much during the period the grease mixed with wear particles, eventually escaped and the seal lip was worn enough by then to allow oil to seep in again). You can imagine how much better that would be if the whole seal was removed.
The test set up of a bearing rotating in an oil bath does not describe the actual process as the centre of the IMS bearing remains stationary and it is the outside race that rotates. it is true that a rotating disc will throw oil outwards under centripetal acceleration but the gear is many time larger than the bearing running directly in the sump oil bath and the chain running at high speed in the same oil bath throws oil against the crankcase wall where is splashes in ample quantities with much more force and volume that the small IMS bearing does in the opposite direction and so - it is entirely sufficient to lubricate the bearing.
Furthermore that oil bath is a continually cooled source of fresh filtered oil - nothing more needed.
The small bearing itself is just slightly under a spec that would make it reliable for 100% of all fitted with it in this application - so perhaps 99.5% reliable say but with the seal in place that reduces to perhaps 90% or so.
Lots of IMS products are s old as upgrades but in our opinion the only true "upgrade" is to fit the Porsche shaft with the larger bearing or some other modified original IMS that does so. The larger later bearing is man enough for the job but once again benefits from removal of the seal on assembly - which we do during rebuilds.
Baz"
"To try and answer why there are different solutions.
A ball bearing does not benefit from a pressurised oil feed it just needs a supply of fresh cool oil and to be part of a filter system to remove and small pieces of worn metal that inevitably wears off parts slowly. A linear shell bearing does need a pressurised oil supply to keep the shaft metal apart from the shell bearing material as a result of the pressure in the oil between them - without which it could seize.
The sprocket diameter on the end of the shaft runs in an oil bath at up to around 4,500 rpm and the chain fitting round it also travels at up to 40mph in the same oil bath - these between them splash oil in all directions at enormous force and speed and it gets everywhere and is entirely capable of lubricating an open ball bearing nearby.
In fact when the dust seal that Porsche fit has worn slightly and the grease has leaked out - the pressure and force of oil nearby is sufficient to get in and out of that minute seal lip and in most cases can lubricate the bearing sufficiently to last for up to 150K (if it was not damaged too much during the period the grease mixed with wear particles, eventually escaped and the seal lip was worn enough by then to allow oil to seep in again). You can imagine how much better that would be if the whole seal was removed.
The test set up of a bearing rotating in an oil bath does not describe the actual process as the centre of the IMS bearing remains stationary and it is the outside race that rotates. it is true that a rotating disc will throw oil outwards under centripetal acceleration but the gear is many time larger than the bearing running directly in the sump oil bath and the chain running at high speed in the same oil bath throws oil against the crankcase wall where is splashes in ample quantities with much more force and volume that the small IMS bearing does in the opposite direction and so - it is entirely sufficient to lubricate the bearing.
Furthermore that oil bath is a continually cooled source of fresh filtered oil - nothing more needed.
The small bearing itself is just slightly under a spec that would make it reliable for 100% of all fitted with it in this application - so perhaps 99.5% reliable say but with the seal in place that reduces to perhaps 90% or so.
Lots of IMS products are s old as upgrades but in our opinion the only true "upgrade" is to fit the Porsche shaft with the larger bearing or some other modified original IMS that does so. The larger later bearing is man enough for the job but once again benefits from removal of the seal on assembly - which we do during rebuilds.
Baz"
Sorry to hear the sad news OP but seems to be an inevitable issue on gen 1 C2s.
Quick question. If a gen 1 C2s is sent to Hartech do their mods guarantee a trouble free engine afterwards? Whats the difference in price between sending a car that has no issues and one thats let go to have the Hartech upgrades. I realise its not an exact science just rough ball park.
Quick question. If a gen 1 C2s is sent to Hartech do their mods guarantee a trouble free engine afterwards? Whats the difference in price between sending a car that has no issues and one thats let go to have the Hartech upgrades. I realise its not an exact science just rough ball park.
9e 28 said:
Sorry to hear the sad news OP but seems to be an inevitable issue on gen 1 C2s.
Quick question. If a gen 1 C2s is sent to Hartech do their mods guarantee a trouble free engine afterwards? Whats the difference in price between sending a car that has no issues and one thats let go to have the Hartech upgrades. I realise its not an exact science just rough ball park.
If I've understood the question correctly I suppose it will depend how much damage has occurred by the bearing failure. It can be pretty catastrophic as i understand it.Quick question. If a gen 1 C2s is sent to Hartech do their mods guarantee a trouble free engine afterwards? Whats the difference in price between sending a car that has no issues and one thats let go to have the Hartech upgrades. I realise its not an exact science just rough ball park.
My car has, amongst many other things, just had the later shaft and bearing fitted by Hartech. Mine was at the point of letting go so i dodged the bullet there.
Yes this wpuld be the news i dread too owning a 997.1 but i would imagine the best course of action would be to get hartech to sort it all out making it a top engine and then simply keep it for ages. For my money the 997.1 engine are absolutely fantastic when running well, its just the odd majorly significant issue that brings them down with a bang.....
The Indy I use have a close working relationship with Hartech. They frequently (how sad is that) liaise and use them them for new liners plus obtain the requisite re-engineered parts for future proofed rebuilds.
I have options to a) send the stripped engine to Hartech, b) get the Indy to rebuild, or c) get Hartech to supply the parts (liners excluded) for the Indy to fit.
Once I know what failed and what else got wrecked, I can hopefully make an informed decision.
I have options to a) send the stripped engine to Hartech, b) get the Indy to rebuild, or c) get Hartech to supply the parts (liners excluded) for the Indy to fit.
Once I know what failed and what else got wrecked, I can hopefully make an informed decision.
Gassing Station | Porsche General | Top of Page | What's New | My Stuff