Broken piston after 343k kms(rebuild help)

Small update.

Engine has now 15k kms and everything seems fine, only the oil consumption is still high but going down a little... maybe I will go to 10w40 next oil change.

Edit: Forgot to mention that I went from 16 to 17" wheels and Im getting more power with this engine and same fuel consumption as the last engine with 16"

Here is a log of the boost control and IAT



Outside temp was more less 20-22ºC... EGTs on this run hit a max of 700ºC.

BTW, 4000rpm = 200kmh

Arthur!! try 15/40 semi

mojogoes said:

Arthur!! try 15/40 semi

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I have at home 8L 10w40 that I use on another car...first I will try that.
The consumption is getting better but not much.

What do you think about my intake temps?

ArturCosta said:

I have at home 8L 10w40 that I use on another car...first I will try that.
The consumption is getting better but not much.
What do you think about my intake temps?

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What oil spec were you using before fully synthetic!!? iat looks a little high are you using a fmic.......i take it that your turbo gives good pressure low down in the revs.

mojogoes said:

What oil spec were you using before fully synthetic!!? iat looks a little high are you using a fmic.......i take it that your turbo gives good pressure low down in the revs.

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I always used the 5w40 100% synthectic.

Engine is now over 17k kms and I found that the consumption is directly proportional to how you drive it.( I know it always is ,but this engine is more noticeble)
Been driving a little slower now and not much consumption but last month I drove most of the time over 3500rpm and a lot of WOT and the consumptions was aiming to the 1L per 2000km line

Since the consumption is getting down will keep using the 5w40 for now.

About the intake temps , my IC is not that big , 55x14x6,5cm core running 1.6bars is not bad that temp.

I have managed to tune a bit more the remap and ussing more 50g of boost and another SOI EGTs went down again so even better now

Thats always good news!!

Engine is now over 25k kms and running fine.

Oil consumption is now really low , under 0,5L each 5k kms.

Small video Wot from 3rd gear 2000rpm.

http://www.youtube.com/watch?v=n9Nzf5qwLxg

After 200kmh its slightly uphill.

Regards,

To have an idea, I have a seat exeo 120hp CR.. as it's the same chassis as your A4, what is the topspeed of your car on a flat road? or are you maybe limited by gearing?

Wow, REALLY good thread!

Sorry I do not have any good thoughts on this project as I am jealous that your engine is mounted in the proper position...

Rub87 said:

To have an idea, I have a seat exeo 120hp CR.. as it's the same chassis as your A4, what is the topspeed of your car on a flat road? or are you maybe limited by gearing?

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Isnt Exeo the Audi A4 B6 chassis? Mine is a B5.

My car is really fast to 225kmh (GPS speed... remember my tacho speed is at 200kmh only 4 kmh more then GPS) after that it goes to 235 and wont do more for a really long time... going downhill it goes over 245kmh and I limited it to 5000rpm so never done more.

BTW , in that video I did 710ºC EGT max... probe after turbo , what do you think?

Regads,

really hard to predict the egt pre turbo that way.. the bigger the expansion over the turbine, the bigger the temperature drop..

my exeo does 250kph on the speedo, which will be around 247gps (speedo is dead on wit 18" gear) altough it's a six speed.. I found in a bargain on ebay some Q7 18" 6pot calipers, is almost pnp with 360mm B7 rs4 discs

Well , the engine has now nearly 37k kms and I have done lately some long trips into high temperature places.

I have done 200kms in 1h with AC on at 23ºC and water temp was from 90 to 95 in the climatronic and oil temp 95 to 105ºC witch seemed high to me until I readed 38ºC outside
This was done in a total of 900km done in 7h only stopping for refuel.

On this trip I also found out that this tune+nozzles+engine..etc is a lot more efficient driving at fast speeds then last one... I did the 900km in one tank of 64L of diesel always running at more then 160kph.

I have done a log with 37ºC outside temp at 800mts altitude ... going WOT at this conditions felt hard to me lol
Still at cruising speeds intake is only 8 to 12ºC over ambient temp ..going WOT from 3000 to 3500rpm in 4th gear climbed to 55ºC fast.

BTW , since the water temp sensor is after the head and reads high values , what is the safe sustained temp I could have run for the entire 900km trip?

Regards,

Here is the "hottest" part of the log. Going uphill .. going a bit WOT then back to 1bar more less. Did not have space for a longer WOT run but you can see the atmospheric pressure that shows it was climbing the hill fast.

BTW, at what atmospheric pressure /height do you start to feel more lag in your turbo to spool up?

Engine now at 45k kms everything running smooth...

http://www.youtube.com/watch?v=jPURGO9Acug

Runs cooler then a stock car in the winter

70k kms now since rebuild .. still going strong:




Development on the car stopped as a trackcar is now the main money spender .
Aside from a clutch that went worn and a engine mount that couldnt handle the abuse everything is great on this near 20 year old daily

so my AFN is running 190bhp and has done 330,000km - is it worth me borescoping through the glow plug holes every 10k miles?
Are the higher compression pistons (like mine at 19.5:1) more prone to issues, over say the ARLs?

ArturCosta said:

70k kms now since rebuild .. still going strong:

Development on the car stopped as a trackcar is now the main money spender .
Aside from a clutch that went worn and a engine mount that couldnt handle the abuse everything is great on this near 20 year old daily

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Holy **** That would be instant headgasket failure if I tried that

bhodgkiss said:

so my AFN is running 190bhp and has done 330,000km - is it worth me borescoping through the glow plug holes every 10k miles?
Are the higher compression pistons (like mine at 19.5:1) more prone to issues, over say the ARLs?

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In my case the engine ran 250k kms stock... I had 180hp for more less 50k kms. There is not much you can do to avoid this. Pray is probably the only thing
The AFN pitons dont have cooling gallery so they tend to have more heat in them and crack. The new ones have the gallery and cool the pistons better.

Mikkijayne : Im more afraid of the con rods that are stock and may feel like the pistons are weighting too much and let them go lol
This is a TDI115 gearbox so that was nearly 250kph... 243 more less from the gear calc.

Hmm I'll get my ARL/BHW pistons fitted asap then! Many thanks

Mikkijayne said:

Holy **** That would be instant headgasket failure if I tried that

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MJ,

My A4 did that twice on the return from Devon last week.... and ran so smoothly!!




And the letters GLF on the left... Goes Like Fu........ry!!

I need less boost or stronger bolts

'course thats in an A6q which weighs half a ton more, so less weight might help too. Now I'm running round in an A4 it seems a lot more feasible.

Mikkijayne said:

I need less boost or stronger bolts

'course thats in an A6q which weighs half a ton more, so less weight might help too. Now I'm running round in an A4 it seems a lot more feasible.

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Well my A4 is a Ben tuned beastie and goes like the clappers....


Since the head change and the install of the 150 bolts the water leak has subsided completely. Not sure if the bolts were a contribution to the loss but seemed prudent whilst swapping the head to install them.


Seems like the problem has been deleted...


I have found someone who will do a pressure test on the head for £40 or so, so should have an expert opinion of the condition of the head in a few weeks.

Is this forum still alive?

Engine has now a tad over 100k kms and it is still running ok. The usage now is a bit different or Im just getting old!

Aside from killing 3 clutchs in the past 30k kms and some small oil leaks everything is in order. Did a dyno last month of 184hp but had a problem with a vacum leak so not the correct boost at low RPM. Still it has 180hp at 3800rpm and 184 at 4800rpm so a nice flat power curve probably helped by the 260º cams.
Funny that I work on thisfor quiet a while and never get a chance to dyno my own car...

Small video , the only recent I found , of a pull in 5th gear.

https://youtu.be/RAcibXjW3EA

Thought of selling the car 2 year ago..but for the value it is worth I still have a amazing daily car very cheap and reliable to run.

Who still runs his old VP TDI here from the "old" guys?

Regards,
Artur

Yep, the beast is still alive...

Having some R520's installed this afternoon and see if that reduces the smoke a little on lower boost...


Otherwise its going like a ........

FlyingFin said:

Yep, the beast is still alive...
Having some R520's installed this afternoon and see if that reduces the smoke a little on lower boost...
Otherwise its going like a ........

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Nice to know. I also have some R520 here but my engine is running so well with the PP764 I dont think I will every change it. Most probabply would change to a 11mm pump then the nozzles.

FlyingFin said:

Yep, the beast is still alive...

Having some R520's installed this afternoon and see if that reduces the smoke a little on lower boost...


Otherwise its going like a ........

Click to expand...

You'll need the map tweaking for r520s if you really want smoke fully controlled.

Yep my AFN is still running strong at around 190bhp/400Nm at 225,000miles, with the mods having done 50,000 miles now, driven fairly hard and plenty of nurburgring laps

It will give up at some point