Broken piston after 343k kms(rebuild help)

Rub87 said:

800° after turbin says me that you're easily making 900°c before.. if you take a car with DPF you can see in channel 75 temp before turbine, temp after turbine and temp after dpf, under full load there's often around 200°c temp drop over the turbine..

or did you measure 600° in that position?

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In this position the max I measured was 800ºC with smoke and only 1.3bars.
Now the max I get is 750ºC on a long uphill. In a normal flat road it does a max of 650ºC.

I can get it a bit lower by adding 100g of boost but that goes a bit of the best A/F ratio.

Regards

What a/f ratio are you aiming for?

I dont have a lambda sensor but from tests done on other cars that have Im aiming for a 0,9 value that it still smokes but not much.
So if I add more boost smoke will be gone , how it is now its smoke a little.

BTW , what SOI shoud I test at 5000rpm? Im currently using 20º.

Regards

0.9

This verifies my stereotype image about portugese diesel performance tuning

I'm running lambda 1.2 at 4500rpm..

anything under lambda 1.05 is turning smokey..

1.08 is lightgrey I experienced..

I will try to post a video of it smoking...is not that much.
1.2 is what it does stock isnt it?

My aim is more less 0,9 to 1.0 that is more less what Im runing , remember that you can run 1.2 to 0,8 with same tuning at diferent RPMs.... my lambda at 2200rpm now must be some think like 0,8 lol but after full boost comes on its more to the 1.0 side

Here is a old video/gif when I got a "typical" portuguese tune (like you are saying hehe) :



Too much fuel for low maf readings... thats a typical tune over here lol

Now only at 1200mg of maf the fuel comes in so not much smoke

BTW , what should be a safe max intake temp? Im testing some limiters at the ECU and I just "installed" one at 70ºC ...it lowers the IQ from 51mg to 47mg when it reaches that temp (I dont think it will...).

Regards

70° seems a little high, it doesn't hurt but it'll be on the smokey side by then.. unless you enable the maf iat correction map..

Rub87 said:

70° seems a little high, it doesn't hurt but it'll be on the smokey side by then.. unless you enable the maf iat correction map..

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Yes I have enabled that map... I was going for the boost correction but with that I could not limit fuel...
I want the limiter there just in case... so 70ºC seems a good max value... its more less what I read at a maha dyno using 1.8bars of boost (yes I tested 1.8bars with the VB lol)

Regards

Aurthur my no 3 piston had scored the bore, to this day I do not know the exact reason.

Just finished my rebuild, here is a breakdown of the parts I used

Head ported w/3 angle valves
dbilas cam (hopeless, tappetts lasted 45km, put stock cam in for now)
BGW pistons (passat 2.0l 8v) lighter, stronger
rods from rosten
block girdle from eurospec tuning (this also increases oil volume to nearly 5.5L, not a bad thing)
arp studs everywhere
all new bearings, seals etc
Bildon axles (now i think I'm going to regret them)
fmic
full pd 150 intake inc airbox and omi
pd150 intake manifold with torn up and ported egr (kept shutoff valve)
vnt1749vb turbo
pp764 nozzless

probably a bunch of parts I forgot to mention.

having trouble with the dbilas cam I would discourage using them for a cam (have a look at my cam thread)
rosten was a great help, even when asked questions about parts he does not stock, he showed me and explained, in great detail very quickly, + his parts are top notch, it is a pity though that he doe snot carry more TDI items.

Good luck with your build,

Please feel free to mail me with any info / numbers you may need.

James did your No piston have a hole in it as mine did as i've forgotten or the middle / top ring broken/distroyed.

Steve, no, the top was perfect, for some reason it just seemed to defore a little, just enough to scratch the bore.

prob due to high boost and high oil temp (and me racing a tuned wrx)

Hi Piranha ,
thanks for the input.
When me engine went "cabum" I searched all rebuild threads and yours was one of those.
I could not find here the BGW pistons so I ended up buying the normal but better TDI110 ones.
The head was not ported , I was worried that I would lose some strength on any part so it was only polished (more less).
My engine was bored and the CR a bit lowered also.
I also installed all new seals and valves , only the valve springs I left the stock double ones.

I just got over 7000km now and its feeling strong specialy after 4000rpm.
Another thing is that this setup is getting better consumption , just a tap over 6L/100... and nearly 4L in the first 1000km

About your cam , for now I will leave mine there , but I spoke to my mechanic and he sayd he will open the top to see it if I want...if I have time I will let hem see that and I will post pics.

Good luck with your engine and keep us posted with dbilas news... and news about the cam your are going to use now.

Regards

Piranha said:

Steve, no, the top was perfect, for some reason it just seemed to defore a little, just enough to scratch the bore.

prob due to high boost and high oil temp (and me racing a tuned wrx)

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Ha har!! the very same reason why mine blow but of course i was racing a STi

mojogoes said:

Ha har!! the very same reason why mine blow but of course i was racing a STi

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Bahh , I was "racing" alone

But this time i'll go past him............if i can find him again

mojogoes said:

But this time i'll go past him............if i can find him again

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This time he will come moded... like Ken block?

?????

mojogoes said:

?????

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Havent you seen the Ken Block videos?

Where do you live

Small update:

Engine is now with 13k kms , I went to nurburgring with it (more less 5k kms in 4 days) and everything went fine.

The only thing Im not liking is the oil consumption , I must have probably done the break in with a "bad" oil. Its taking ages to run in properly.

In the 5k kms trip I had the oil in the max level before the trip and when I got there (after 2100kms) it was under half level. I added 500ml and on the way back (more 2100kms) when I arrived it was again under half level , now even lower then before.

So in 10k kms after the first oil change it used more less 2L of oil... Im thinking in changing the oil for a 10w40 so it finaly runs in.

What do you think?

Regards,

bad pistons rings or turbo?

Rub87 said:

bad pistons rings or turbo?

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The turbo was changed.. forgot to tell it here.. its now a 1852

About the piston rings , if it was the rings wasn't it worse?
And if the problem are the pistons or assembly then the oil consumption will get worse right?

Something strange my mechanic said was something like this "dont worry about the oil consumption , it will get normal above 20k kms... we changed somethings at the engine so it is stronger... but it will use more oil at the start!"

He also said that the rings one my pistons are the "hard" ones and they take more time to break in then the "softer" that ussualy come on a piston set.

One thing is for shure , I dont mind it using more oil... if that is the only problem the engine has hehe

I havent yet opened the valve cover to see if the dblias cam is ok and not like piranhas one

Regards,

is yours also making some noise? mine did it from the second it was in.. how did you drive in the engine? my engine doesn't use any oil and it now has around 7000km on it..

Rub have you checked your cam lately..........if so i take it that its in good order!

nope will do it as soon as I have time.. but the car is going so well it's just addicting to drive

Rub87 said:

is yours also making some noise? mine did it from the second it was in.. how did you drive in the engine? my engine doesn't use any oil and it now has around 7000km on it..

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Mine has a different noise from stock,it has a louder idle but its fine.
I did the breaking with the first 500km very slow never over 2500rpm,then until 1500km some small WOT runs to 3000rpm and at more less 3000km stared pushing it hard.

First km it had a oil smell at the exhaust but after 1000km it was gone.

What oil do you use? Im using Bp visco 7000sport 5w40.
The old engine would use like 1L per 15k kms more less...abit more with track days.

Regards,

I just drived first few km easy and then used some pressure (boost) but not much rpm to applie some pressure on them so the run in well..

Rub87 said:

I just drived first few km easy and then used some pressure (boost) but not much rpm to applie some pressure on them so the run in well..

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I did 1500km with a remap that max boost was 1.1bars and I also did that type of driving , pushing from 2000 to 3000rpm some times.

What oil do you use?

I will change mine next month and see if the consumption gets down.

Beside that car is fine. In france we did 700km at more less 120 to 140kmh and the fuel consumption was only 5,8L/100... thats with 4 people a lot of things in the back and 17" wheels

I now use regular VP oil, 10w40 half synthetic is that I guess..

prior I was using PD piss oil 5w30 full synth, but I pulled the pistons to make the valve pockets deeper I found exessive wear on rod bearing 3 and 4 while 1 and 2 looked new, so I ditched the imo too thin piss oil

why didnt you get the 1856??

Rub87 said:

I now use regular VP oil, 10w40 half synthetic is that I guess..

prior I was using PD piss oil 5w30 full synth, but I pulled the pistons to make the valve pockets deeper I found exessive wear on rod bearing 3 and 4 while 1 and 2 looked new, so I ditched the imo too thin piss oil

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I have at home 6L of Mobil Super S 10w40... I can put that in if I want.
Now it has the 5w40 , the same oil I used for 343k kms in last engine and everything was fine

Bencarr23: I only wanted and upgrade of the VB , this new turbo is only making 1.6bars at 4000rpm so the VB was enough , I just wanted something stronger the the other turbo.

Actually the turbo is a complicated thing... compressor is from the 2.5TDI 180bhp... turbine is from 220cdi and the rest if from a VB .
I know what you are thinking .. you are now like the thing is , it works and its running nice until now