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Narrow escape - possible bore scoring.

Pazuzu, after all these posts of, is it/isn't it borescored, the chances of a quick sale I would suspect is fairly low. Throwing in my 2 pence worth, I would take it to Hartech for a borescore check & get their results in writing with the photographs. If it turns out fine, you basically have an unofficial guarantee from a well respected engine builder to show anyone looking at the car with no ifs, buts, maybes. Should the results show it is scored at least you can then decide what you want to do.
Its amazing how perhaps a good cars condition can be shredded by a few keyboard taps. A little knowledge is a dangerous thing comes to mind. Best luck anyway.
 
chicb said:
Pazuzu, after all these posts of, is it/isn't it borescored, the chances of a quick sale I would suspect is fairly low. Throwing in my 2 pence worth, I would take it to Hartech for a borescore check & get their results in writing with the photographs. If it turns out fine, you basically have an unofficial guarantee from a well respected engine builder to show anyone looking at the car with no ifs, buts, maybes. Should the results show it is scored at least you can then decide what you want to do.
Its amazing how perhaps a good cars condition can be shredded by a few keyboard taps. A little knowledge is a dangerous thing comes to mind. Best luck anyway.

It isnt anything to do with the keyboard taps, it was the advice from a well known and I gather quite well respected Porsche specialist.
 
Going by the forty odd replies, no one seems to know if its scored or not. What I was saying for the owners piece of mind was to have it checked by probably the best engine builder in the country.
 
bazhart said:
Impressed with the knowledge many of you have picked up over the recent years.

Pictures are indeed hard to interpret but none of them look like scoring to me.

Although our web site contains a lot of historical information about t he subject it is several years out of date and so I have recently written updates on the bore scoring issue that will soon replace the old text and will answer all of the questions raised.

There is too much involved to reproduce here but just to correct one thing - there are 4 repair modes, new crankcases with the same potential failure Lokasil bores, iron liners (of which we have many that subsequently failed and the new report explains why), plating onto the scored cylinder and replacement with alloy Nikasil liners (of which there are 2 versions on the market and ours is different than the other because it also d=secures the liner at the top and results in it becoming a closed deck method which is generally recognised as superior). Several thousand have been replaced and over a thousand engines rebuilt by us this way without issue.

However when a customer order is accepted for a bore score we cannot insist on all 6 being replaced although (as this post demonstrates) for those unable or unwilling to pay for all 6 use our less expensive alternative - it still has worked well for tens of thousands of miles.

It is always easy for miss-information to discredit or harm suppliers unfairly and as in this case I do wish those responsible would have the courtesy to contact us to find out the full story before deciding to post their opinions.

I hope the new report on bore scoring will help clear u p a lot of the always present confusion - due in probably 3 - 4 weeks time.

Baz

If this reply doesn't offer enough comfort the only logical step is for the seller to ask Hartech to inspect the bores in the flesh.
 
Not Quite "no one knows?" I have stated my opinion - thank you!

The nearest I can get to an analogy is a windscreen with marks where the rubber blades have put minutely small dulling to the otherwise shiny surface that can be seen sometimes like a smear over the surface.

If you measure an original Lokasil bore after say 80K you may find it is around 6 or 8 thou oval and if you measure it at 10 degree intervals round the bore there will be lots of peaks and troughs but because the bore is more dull it is not obvious to the naked eye or a boroscope.

Similarly iron liners will have little ovality but be worn in patches slightly but not show.

Nikasil in contrast is harder and will retain a superb roundness for years. On the odd occasion when a racing version has blown a big end or dropped a valve - we have almost always been able to recover the engine with the original Nikasil cylinders - the surface is that good.

However it is difficult to match ring material to it. The 911 SC 3 litre and 3.2 Carrera models had Nikasil bores and less "polish marks" but the rings were worn down to a point at the ends after around 70K while the compression dropped at low revs making the engines . run at low power until the camshafts kicked in with better timing where they designed the power band.

The M96/7 engines have rings that will last for at least double that mileage but will polish mark cylinders with absolutely no detriment to the running of the car.

It is really unfortunate that the public - aware of the problems - and rightly wanting boroscope reports on their cars (or before buying) and mechanics and engineers do not understand the differences between polish marks and scoring (not really their fault though).

Nikasil is applied a few thousandths of an inch thick and if it ever scored there would be deep obvious grooves in the surface. Lokasil scored would bee even deeper grooves and usually o ver a wider width.

The reports from the owner demonstrate that the engine was working perfectly - low oil consumption and good power after many years and tens of thousands of miles and could have been presented as confirmation of the good work we do for our customers rather than initially appearing to do the opposite. It could have said "this engine has done 30K and lasted 5 years after a partial Hartech spec rebuild (due to the warranty company) and is still going strong" instead of casting doubt on the well proven and supported solution.

THat is why I appeal for anyone suspecting . problems with our products or workmanship to please at least contact us before making up their own minds first, posting on that basis and finding out a more accurate understanding afterwards.

The Internet can be a tough place anyway at the best of times and I feel the good work we do for our customers deserves a little more respect than we sometimes read about.

Baz
 
:yeah: :agree:
 
:agree: :agree:
 
:yeah: :agree:
 
bazhart said:
Not Quite "no one knows?" I have stated my opinion - thank you!

The nearest I can get to an analogy is a windscreen with marks where the rubber blades have put minutely small dulling to the otherwise shiny surface that can be seen sometimes like a smear over the surface.

If you measure an original Lokasil bore after say 80K you may find it is around 6 or 8 thou oval and if you measure it at 10 degree intervals round the bore there will be lots of peaks and troughs but because the bore is more dull it is not obvious to the naked eye or a boroscope.

Similarly iron liners will have little ovality but be worn in patches slightly but not show.

Nikasil in contrast is harder and will retain a superb roundness for years. On the odd occasion when a racing version has blown a big end or dropped a valve - we have almost always been able to recover the engine with the original Nikasil cylinders - the surface is that good.

However it is difficult to match ring material to it. The 911 SC 3 litre and 3.2 Carrera models had Nikasil bores and less "polish marks" but the rings were worn down to a point at the ends after around 70K while the compression dropped at low revs making the engines . run at low power until the camshafts kicked in with better timing where they designed the power band.

The M96/7 engines have rings that will last for at least double that mileage but will polish mark cylinders with absolutely no detriment to the running of the car.

It is really unfortunate that the public - aware of the problems - and rightly wanting boroscope reports on their cars (or before buying) and mechanics and engineers do not understand the differences between polish marks and scoring (not really their fault though).

Nikasil is applied a few thousandths of an inch thick and if it ever scored there would be deep obvious grooves in the surface. Lokasil scored would bee even deeper grooves and usually o ver a wider width.

The reports from the owner demonstrate that the engine was working perfectly - low oil consumption and good power after many years and tens of thousands of miles and could have been presented as confirmation of the good work we do for our customers rather than initially appearing to do the opposite. It could have said "this engine has done 30K and lasted 5 years after a partial Hartech spec rebuild (due to the warranty company) and is still going strong" instead of casting doubt on the well proven and supported solution.

That is why I appeal for anyone suspecting . problems with our products or workmanship to please at least contact us before making up their own minds first, posting on that basis and finding out a more accurate understanding afterwards.

The Internet can be a tough place anyway at the best of times and I feel the good work we do for our customers deserves a little more respect than we sometimes read about.

Baz

Hi Baz,

I think you may have misread the thread or the intended meaning of the thread, and as the original poster I feel I should clarify for you.

Firstly, there is nothing in my original post that you should feel the need to be concerned on. I did not at any time pour scorn on the name of your company, or your standards. The actual phrase I used was:

"So i guess this is just a word of warning to anyone else out there who sees a car advertised as having a Hartech rebuild and thinks that will be a replacement of a proper PPI with a borescope then think again and make sure you insist on the check. And check the invoice to see exactly what has been done in the process of the engine rebuild."

I have been looking at 996 and 997's for a while and i have spoken to more than one owner who insisted that as their car has 'had a rebuild from Hartech' there was no need for a borescope.. This is why I felt a thread detailing my experience would be a good thing for all.

I paid out for a PPI inspection including borecope for a car I was interested in buying. I had this work carried out at a well respected Porsche specialist (LaRose Porsche in Kent) and was advised that there was scoring to all 6 cylinders. I posted up the pictures with the clarification that they are images taken by a phone camera of the snap on scope screen, ie a picture of a picture of a picture compressed to a JPEG and shown on a computer screen.
If you are stating categorically that in your opinion based on those images that this car does not suffer from borescoring then I am sure that the original owner will be very happy, as he can print off this thread and use it as proof of your expert opinion that this car is not a worry. Of course it contradicts the opinion of the people that carried out the PPI (and there was more than just the engine to consider in that report...), and they have the benefit of seeing the actual images directly from the scope, rather than what you have which is a picture of a picture of a picture compressed to a JPEG and displayed on a computer screen.
I will leave it for you to decide if you think it is reasonable and ethical to use a thread on a forum to call another specialists professional opinion into question, you could of course contact them directly to discuss this yourself if you feel that you need to as their name is mentioned in the first post of this thread.

The car has done over 100k. The engine was rebuilt by yourselves in 2015 (at approx 70k from memory) and had one bank repaired, this bank therefore has only done 30-35k in 5 years. The other bank however has done the full 100k. As I had already stated earlier in the thread, the car has a rather large puff of bluey coloured smoke (with the smell of oil) on start up. This was why I specifically wanted a borescope done, and why I personally did not question the opinion of the company I paid to carry it out when they advised to walk away from the car.

Hope that helps
 
Narrow escape - bore scored Hartech rebuilt 'S' engine

:?:
 
Hertsdriver said:
infrasilver said:
Alex said:
Narrow escape - bore scored Hartech rebuilt 'S' engine

:?:

Fairly damning

Or completely factual.
But regardless there is no insinuation of any wrong doing on the part of Hartech in that sentence that I can see?

Then we see differently, to me there is huge insinuation of blame.
 

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