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MattyR Hockenheim

Joined: 21 Sep 2015 Posts: 684 Location: Somewhere Nr Tunbridge Wells, Kent
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Posted: Fri Nov 08, 2019 5:17 pm Post subject:
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Wasn’t the B7 RS4 renowned for this? Isn’t a good old Italian tune-up the cure?..  _________________ Atlas Grau on Ocean Blue Gen 2 997 C2 Carrera
Sold: Aventura Grün 993 C2 Carrera
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deMort Dijon

Joined: 21 Mar 2015 Posts: 7573 Location: Brighton
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Posted: Fri Nov 08, 2019 7:26 pm Post subject:
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Some more images of before and after walnut cleaning plus one of what the injector looks like when installed . _________________ .
My Daughter's Crowdfunding has hit the target .
Thank you all so Very much .
She's not going until july 2020 though .
7pm - 9pm
Now At An Indy.
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FZP Estoril
Joined: 18 Jan 2015 Posts: 3850 Location: Cheshire
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Posted: Fri Nov 08, 2019 7:32 pm Post subject:
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That is quite the improvement. _________________ 997.2 Carrera 2S GT Silver/Cocoa.
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deMort Dijon

Joined: 21 Mar 2015 Posts: 7573 Location: Brighton
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Posted: Fri Nov 08, 2019 7:50 pm Post subject:
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For now this is something we are working on at work .. walnut cleaning is not really feasible with the engine in situ .. we just don't have good enough access hence we will be trialing the cleaning machines in a few weeks time .
We also cant clean the cylinder heads / pistons this way ..
walnuts are used as they are soft .. if a single particle ends up in the cylinder then it wont do any damage ... also a bit messy as it tends to go everywhere !
Can't spin the engine over to use compression i'm afraid to remove it .. high pressure fuel system which is removed to get to the injector .. bit dangerous .. Also running the pump dry is not good for it .
This is not an achilles heel so no one wants to worry unduly about this .. a slight lack of power or a higher usage of fuel is what i expect would be the only issue with this problem at this sort of mileage .
Injector spray onto the valve when open is indeed supposed to help .. it doesn't seem to though .
For my way of thinking this is due to the closed crankcase system .. engine gasses and indeed oil being in the intake will cause this ... hence fuel type , how its driven won't really make any difference .. what's in the inlet tract will though .
Normally fuel will help clean the valves but as in this case and on other makes of cars then it seems it's a common fault of this type of design .
red X .. ahh yes .. in theory it would work here as well .. down side is the engines are highly tuned these days so they might not appreciate running on that stuff .. brings back memories though .. 5 pound of 4 star and a shot of red X please !!!
Phil 997 is the only person i know to have actually had it cleaned out .. i remember you first posting about it .. that's pretty much when we first started to look into this fault ..
You are our inspiration young man
For now .. we test things .. and that usually means to the death to come up with a solution .. probably like all garages .. we need to prove something works effectively before we offer it as a service ... in short .. you lot are getting an early look at a work in progress
Anyways .. don't forget i posted above this first with more images .. _________________ .
My Daughter's Crowdfunding has hit the target .
Thank you all so Very much .
She's not going until july 2020 though .
7pm - 9pm
Now At An Indy.
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MattyR Hockenheim

Joined: 21 Sep 2015 Posts: 684 Location: Somewhere Nr Tunbridge Wells, Kent
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Posted: Fri Nov 08, 2019 8:55 pm Post subject:
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deMort wrote: | For now this is something we are working on at work .. walnut cleaning is not really feasible with the engine in situ .. we just don't have good enough access hence we will be trialing the cleaning machines in a few weeks time .
We also cant clean the cylinder heads / pistons this way ..
walnuts are used as they are soft .. if a single particle ends up in the cylinder then it wont do any damage ... also a bit messy as it tends to go everywhere !
Can't spin the engine over to use compression i'm afraid to remove it .. high pressure fuel system which is removed to get to the injector .. bit dangerous .. Also running the pump dry is not good for it .
This is not an achilles heel so no one wants to worry unduly about this .. a slight lack of power or a higher usage of fuel is what i expect would be the only issue with this problem at this sort of mileage .
Injector spray onto the valve when open is indeed supposed to help .. it doesn't seem to though .
For my way of thinking this is due to the closed crankcase system .. engine gasses and indeed oil being in the intake will cause this ... hence fuel type , how its driven won't really make any difference .. what's in the inlet tract will though .
Normally fuel will help clean the valves but as in this case and on other makes of cars then it seems it's a common fault of this type of design .
red X .. ahh yes .. in theory it would work here as well .. down side is the engines are highly tuned these days so they might not appreciate running on that stuff .. brings back memories though .. 5 pound of 4 star and a shot of red X please !!!
Phil 997 is the only person i know to have actually had it cleaned out .. i remember you first posting about it .. that's pretty much when we first started to look into this fault ..
You are our inspiration young man
For now .. we test things .. and that usually means to the death to come up with a solution .. probably like all garages .. we need to prove something works effectively before we offer it as a service ... in short .. you lot are getting an early look at a work in progress
Anyways .. don't forget i posted above this first with more images .. |
Thanks for the insight Iain. Good to know that you chaps are doing this R&D. It’ll keep our cars on the road a bit longer and in fine fettle  _________________ Atlas Grau on Ocean Blue Gen 2 997 C2 Carrera
Sold: Aventura Grün 993 C2 Carrera
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Luddite Nürburgring

Joined: 18 Dec 2018 Posts: 494 Location: Scotland
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Posted: Sat Nov 09, 2019 8:57 am Post subject:
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Thanks so much for providing the insight to this aspect of modern engine design Iain..one I had not contemplated till I read your post. Also thanks for the up dated series of pics..
It seems as if the internal combustion engine is going full circle, back to a time when engines had to be DE-COKED on a regular basis... though if circa 70k miles in the interim period then that beats the vintage era..(-:
Closed crankcase breathing as has been the norm for years equating to engines having to ingest their own crankcase generated fumes, seems to have been exacerbated by direct injection to the cylinder as opposed to the inlet valves being washed by the fuel as it was with indirect injection or carburation.. DI thus causing build up of crud in the inlet tract and exposed valve surfaces, perhaps being baked on given the temperatures involved...hmm..?
Seems like a new generation and more refined AOS design may be preferable as opposed to inventing a simpler cleaning process..?
I have not a clue if the old idea of an Italian tune up might still work as it once did, though seldom used engines that may spend a fair percentage of their life sitting in slow moving traffic may be even more susceptible to this crud than those that may be fortunate enough to see more regular use...?
Yup I suspect the old chemical additive methods where the crud ended up being blown out the exhaust system would kill a cat, thus if cleaning is required or desired it would seem best to extract the crud directly from the exhaust tract.... But for me the benefits would have to be VERY real before getting involved in that process, and all the possibilities of risk and cost relative to gaining access.
Sorry if my lack of ability to express myself in print caused you to think I suggested using fuel pressure to extract a stuck injector, instead of CAREFULLY using cylinder compression to assist the process... thus no fuel pump or starter motor involvement, more turning the engine by other means to create pressure in the offending cylinder.. Though I did point out that there were RISKS involved, which in these times of elf`n safety are BEST avoided by those who do not understand the risks involved..The flying injector I mentioned weighed in at circa 1/2 a pound and stopped when it hit a concrete roof of a bomb proof bunker, creating a mushroom effect on the threads of the fuel connection point...So yes, without understanding of the forces involved, it is possible if not probable to do a bit of damage... or worse..
Tourist, thanks for posting the cutaway diagram, though given it seems it can be difficult to remove spark plugs, I wonder if in reality any of the threads project beyond the head into the combustion chamber on some engines... though I would hope not..!
Just thinking in type...
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alpinaman Montreal

Joined: 21 Feb 2012 Posts: 580
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Posted: Sat Nov 09, 2019 3:50 pm Post subject:
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Back in the 90's i was a tech at a Mitsubishi main dealer,i believe they were the first in the UK to introduce high pressure petrol engines into production cars.(GDI)
We had issues with them coking up the valve stems after 60k miles approx.
Walnut blasting was in its infancy and worked well.
But so did a gradual introduction of brake fluid into the inlet manifold whilst the engine was running..
Worked a treat
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Luddite Nürburgring

Joined: 18 Dec 2018 Posts: 494 Location: Scotland
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Posted: Sat Nov 09, 2019 6:15 pm Post subject:
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deMort Dijon

Joined: 21 Mar 2015 Posts: 7573 Location: Brighton
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Posted: Sat Nov 09, 2019 7:02 pm Post subject:
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Luddite wrote: |
Closed crankcase breathing as has been the norm for years equating to engines having to ingest their own crankcase generated fumes, seems to have been exacerbated by direct injection to the cylinder as opposed to the inlet valves being washed by the fuel as it was with indirect injection or carburation.. DI thus causing build up of crud in the inlet tract and exposed valve surfaces, perhaps being baked on given the temperatures involved...hmm..?
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Yup .. that's what's happening basically .
Luddite wrote: |
Seems like a new generation and more refined AOS design may be preferable as opposed to inventing a simpler cleaning process..? |
It's hard to separate air from oil without an oil mist being included .. hence the AOS does what it can .. a better system might be made but cost , weight and even if it's feasible are questions that needs to be considered .
Luddite wrote: |
I have not a clue if the old idea of an Italian tune up might still work as it once did, though seldom used engines that may spend a fair percentage of their life sitting in slow moving traffic may be even more susceptible to this crud than those that may be fortunate enough to see more regular use...?
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There is no fuel injection into the inlet manifold so nothing to clean the valves .. running it high RPM will make no difference as nothing changes other than the amount of air flowing through the inlet manifold .
Luddite wrote: |
Yup I suspect the old chemical additive methods where the crud ended up being blown out the exhaust system would kill a cat, thus if cleaning is required or desired it would seem best to extract the crud directly from the exhaust tract.... But for me the benefits would have to be VERY real before getting involved in that process, and all the possibilities of risk and cost relative to gaining access.
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The new machines break down the carbon build up so no large chunks go anywhere .. it burns the deposits off as i understand it .. but we have yet to have the company come in to demoe them and explain the operation so atm .. that's my assumption .. it had better be correct or this system could well damage items !!
Luddite wrote: |
Sorry if my lack of ability to express myself in print caused you to think I suggested using fuel pressure to extract a stuck injector, instead of CAREFULLY using cylinder compression to assist the process... thus no fuel pump or starter motor involvement, more turning the engine by other means to create pressure in the offending cylinder.. Though I did point out that there were RISKS involved, which in these times of elf`n safety are BEST avoided by those who do not understand the risks involved..The flying injector I mentioned weighed in at circa 1/2 a pound and stopped when it hit a concrete roof of a bomb proof bunker, creating a mushroom effect on the threads of the fuel connection point...So yes, without understanding of the forces involved, it is possible if not probable to do a bit of damage... or worse..
: |
It was considered to use compression to get the injector out at the beginning .. these engines though are a little hard to turn over .. there is little access to the crank pulley with the engine in situ and at best we would get a slow turn of the engine to increase compression on that cyl ...
Basically it was never going to work .. it was jammed in there to the point we made up a slide hammer and fixing tool to remove it once the engine was out... it didn't work in situ.
Spark plugs do indeed enter the cyl by a couple of threads .. it's this part that carbons up and makes the plugs on these problematic to remove .
I don't often do a full response to your posts as it takes quite a while to answer every part of what you mention .. always interesting to read though .
So i thought i would on this one  _________________ .
My Daughter's Crowdfunding has hit the target .
Thank you all so Very much .
She's not going until july 2020 though .
7pm - 9pm
Now At An Indy.
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Phil 997 Le Mans


Joined: 05 Dec 2015 Posts: 15551 Location: Bournemouth,Dorset
2009 Porsche 997 Carrera 4S
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Posted: Sat Nov 09, 2019 7:20 pm Post subject:
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[quote="deMort"]
Phil 997 is the only person i know to have actually had it cleaned out .. i remember you first posting about it .. that's pretty much when we first started to look into this fault ..
You are our inspiration young man
For now .. we test things .. and that usually means to the death to come up with a solution .. probably like all garages .. we need to prove something works effectively before we offer it as a service ... in short .. you lot are getting an early look at a work in progress
Thank you Ian , I am watching how you and the team progress closely as I know whatever you end up offering will be a perfect solution to what is going to be potentially something the gen2 will need doing as they start to get to 60/70k miles .
It great for us owners to know that there are Porsche specialists out their being proactive in finding solutions to potentially inherent issues before they become a real problem  _________________ 911 Owners,Some Invest In The Future,
Others Enjoy The Moment Today.
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deMort Dijon

Joined: 21 Mar 2015 Posts: 7573 Location: Brighton
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Posted: Sat Nov 09, 2019 7:31 pm Post subject:
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Cheers Phil .
I'm sure every Indy does the same thing when they perceive a problem that will need addressing in the future .
For us we are at the beginning really .. we have already bought a far more expensive walnut cleaning tool to try out as this obviously needs to be done in situ ... ill post some images next week of it .
We might need some guinea pigs in our area though .. need to chat to the Boss about that lol .
It has possibilities on Diesels as well .. not that i'm a fan of them .. sorry but im not .
Our basic thought atm .. pre demoing the machines is a walnut clean then followed by a machine clean as we just don't feel a machine clean will be as effective .. but we will see after the demo and we strip the car apart to inspect the results
Work in progress and i will post the results as i get them ! _________________ .
My Daughter's Crowdfunding has hit the target .
Thank you all so Very much .
She's not going until july 2020 though .
7pm - 9pm
Now At An Indy.
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Phil 997 Le Mans


Joined: 05 Dec 2015 Posts: 15551 Location: Bournemouth,Dorset
2009 Porsche 997 Carrera 4S
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Posted: Sat Nov 09, 2019 7:39 pm Post subject:
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deMort wrote: | Cheers Phil .
I'm sure every Indy does the same thing when they perceive a problem that will need addressing in the future .
For us we are at the beginning really .. we have already bought a far more expensive walnut cleaning tool to try out as this obviously needs to be done in situ ... ill post some images next week of it .
We might need some guinea pigs in our area though .. need to chat to the Boss about that lol .
It has possibilities on Diesels as well .. not that i'm a fan of them .. sorry but im not .
Our basic thought atm .. pre demoing the machines is a walnut clean then followed by a machine clean as we just don't feel a machine clean will be as effective .. but we will see after the demo and we strip the car apart to inspect the results
Work in progress and i will post the results as i get them ! |
Ah I can see a 911uk bacon butty opportunity looming  _________________ 911 Owners,Some Invest In The Future,
Others Enjoy The Moment Today.
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deMort Dijon

Joined: 21 Mar 2015 Posts: 7573 Location: Brighton
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Posted: Sat Nov 09, 2019 7:52 pm Post subject:
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I very much doubt there's anything to clean on your car !
We will need a 60 - 70 K car i expect that hasn't been touched .. but that's for the Boss to sort out .. i'm just a Grunt
Got to admit .. you leaving our place at the open day still makes me smile .. as does the sound of your car .. awesome is all i can say .. and again ..  _________________ .
My Daughter's Crowdfunding has hit the target .
Thank you all so Very much .
She's not going until july 2020 though .
7pm - 9pm
Now At An Indy.
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MR997 Trainee
Joined: 05 Mar 2018 Posts: 55
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Posted: Sun Nov 10, 2019 6:49 pm Post subject:
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What about dry ice blasting would that work?
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Phil 997 Le Mans


Joined: 05 Dec 2015 Posts: 15551 Location: Bournemouth,Dorset
2009 Porsche 997 Carrera 4S
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Posted: Sun Nov 10, 2019 7:25 pm Post subject:
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deMort wrote: |
I very much doubt there's anything to clean on your car !
We will need a 60 - 70 K car i expect that hasn't been touched .. but that's for the Boss to sort out .. i'm just a Grunt
Got to admit .. you leaving our place at the open day still makes me smile .. as does the sound of your car .. awesome is all i can say .. and again ..  |
That was a great get together mate. I agree my rebuild still only has 5k miles on it so maybe a while before it needs a clean .  _________________ 911 Owners,Some Invest In The Future,
Others Enjoy The Moment Today.
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Luddite Nürburgring

Joined: 18 Dec 2018 Posts: 494 Location: Scotland
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Posted: Sun Nov 10, 2019 8:33 pm Post subject:
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My goodness Ian, what a gent you are sir. Please feel no pressure to respond to any of my rambles, I am just trying to keep the old grey matter ticking over by remembering past experiences and trying to understand better the realities of owning and running a modern Porsche, the insight you provide is priceless, thank you so much.
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deMort Dijon

Joined: 21 Mar 2015 Posts: 7573 Location: Brighton
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Posted: Sun Nov 10, 2019 9:08 pm Post subject:
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Luddite wrote: | My goodness Ian, what a gent you are sir. Please feel no pressure to respond to any of my rambles, I am just trying to keep the old grey matter ticking over by remembering past experiences and trying to understand better the realities of owning and running a modern Porsche, the insight you provide is priceless, thank you so much.  |
You do tend to go in depth when posting .. i wish i had more time to answer and debate things with you ... unfortunately that's not the case but i do always read what you post and pick what i can to answer .
Trust me .. i Do read what you post !
Keep it up !
Just a humble mechanic here doing his best . _________________ .
My Daughter's Crowdfunding has hit the target .
Thank you all so Very much .
She's not going until july 2020 though .
7pm - 9pm
Now At An Indy.
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deMort Dijon

Joined: 21 Mar 2015 Posts: 7573 Location: Brighton
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Posted: Sun Nov 10, 2019 9:12 pm Post subject:
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MR997 wrote: | What about dry ice blasting would that work? |
Yup .. but it would be the same as walnut ... the trouble we have is the amount of work needed to strip down the parts to be able to do this .. we are looking for a more cost effective solution atm .. hence seeing what the machines can do . _________________ .
My Daughter's Crowdfunding has hit the target .
Thank you all so Very much .
She's not going until july 2020 though .
7pm - 9pm
Now At An Indy.
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GlenB Silverstone
Joined: 20 Jul 2018 Posts: 126
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Posted: Sun Nov 10, 2019 10:37 pm Post subject:
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MattyR wrote: | Wasn’t the B7 RS4 renowned for this? |
It was. I stripped my B7 down and walnut shell blasted it as demort has with this 911. The difference was phenomenal! Though access to a B7 is considerably easier than a 911. I look in my 911 and just close it again
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NLW73 Albert Park
Joined: 27 May 2014 Posts: 1553 Location: Yateley
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Posted: Mon Nov 11, 2019 10:23 am Post subject:
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WOW the difference in those pics is just huge. amazing work. the coked up inlets and valves look in a right state and no wonder it was running badly. looks like a great job done
they did change the 997.2 engine to a different design and to DFI...sounds like it comes with its own challenges as age and mileage is starting to show.
am guessing that doing this walnut cleaning is a lot cheaper than having to do a 997.1 engine that has been scored and needs new liners?
am thinking about going 997.2 and this is an eye opener and thanks _________________ 997 C2s Schwarz
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