Warning for GTB owners...

[stevobeavo]

mine cracked no4 and that was with a mdx 376 turbo no problem with gtb turbo with tubular mani

What boost was you running? Any pictures? Did cracked along the gudgeon pin.

[coskev]

At the end of the day they are running loads more power/boost etc than was ever taken into consideration when the pistons were designed it's hardly surprising to see failures.

Ref the head gasket,the thickness (amount of holes) relates to the piston protrusion out of the block,so unless your fitting new pistons or decking the block you should stick to the original size gasket.

The head is flat with no bowl in it,so skimming the head does not alter the compression.

Has any been able to measure peak combustion temperatures? EGT temperature don't give the whole picture..

If you fancy buying the equipment your more than welcome to use my car as a test!

Or do you know anyone with the equipment?

[stevobeavo]

If you fancy buying the equipment your more than welcome to use my car as a test!

Or do you know anyone with the equipment?

I can ask a few people but I doubt they will lol.

I think (just a theory) it could be heat and pressure weakening the piston and the gudgeon pin is the fulcrum point splitting the piston down its centre.

Could be a load of rubbish as we don't know how the other pistons have cracked yet lol.

[hutchysrs50]

Surly pushing the injectors is a factor here also. Just seems like the limit on them is getting higher all the time and now things like this start happening.

I dont think we will ever know without someone spending big money, its just going to be a case of back it off a little bit and be happy with the figres.

 

It happens because a piston designed for 130bhp doesnt like 260bhp, simple.

[alex_e3]

Should have time tomorrow to take the head off. So I'll report back then!

[hutchysrs50]

Please do, im waiting to see yours! :P

[alex_e3]

Steady on...

[silky16v]

hummmmmmmmmmmmm

 

As i said it last year and have said to everyone thousand times over!!!!!

 

there is a maximum safe limit for stock injectors for a reason, some car have lasted some haven't anyone running more than 35deg of duration is running a risk of engine failure

 

thats why the older tuners out there say 230-240bhp stock injectors as absolutely max (they know this info for a reason)

 

i'll hold my hands up and ran my 2260 on the Fabia on stock nozzles at silly silly durations because i asked Faboka to push it as i wanted to see what the limits where

 

After a very short period of time i refitted my race nozzles and had the car remapped elsewhere (This was no disrespect to Faboka i wanted to try http://www.dieselpowered.co.uk/ as this is who my mate Steven had his mapped by (the lad with the Red Golf at the RR day)) and i've done 14,000miles running 2.45bar and the car is 100% reliable, doesn't use any oil and has no running or cold start issues

The stock engine can take the power no issues its all about the mapping and setup and in essence every tuner out there has there own method of tuning

 

if you want good power and drivability you need fuel to spool the 2260 on a 1.9 so will get smoke its just something you have to live with

 

all these claims of 280bhp+ on 2260 and race nozzles on stock engine is another story that makes for good reading  

 

Anyhow i'm getting out of the game now and selling up i've done the modified 1.9PD thing for 3yrs now and tbh i hate the Image that the Fabia VRS now has and the idiots that now drive them (they have become the cheap mans corsa spinning round MacDonalds)

Edited 17 February, 2016 by silky16v

[faboka vrs]

You following the fabia Facebook pages too much silky. Been tempted to leave the groups.

[silky16v]

You following the fabia Facebook pages too much silky. Been tempted to leave the groups.

Just look at the posts 85% are muppets that own them now cause they are cheapest they have even been

The idiots I've dealt with selling parts and they want everything for nowt and most can't scrape together 2p

That's when you know it's time to ship out and sell up

In couple of yrs only the good spec cars will be left but fuk waiting that long to sell up!

[sepulchrave]

Is there an oil jet to cool the underside of the piston crown and splash lubricate the gudgeon pin bushes? If so it may have blocked on the cylinder that failed, I've seen this in the past on 16v KR engines which had jets at the the base of the bore squirting up under the piston crown.

[Southy]

Is there an oil jet to cool the underside of the piston crown and splash lubricate the gudgeon pin bushes? If so it may have blocked on the cylinder that failed, I've seen this in the past on 16v KR engines which had jets at the the base of the bore squirting up under the piston crown.

They do indeed have under crown cooling jets. I'm yet to check whether one was blocked or not but it was on my mind to check them when I remove them to borr the block out.

[FromTheDarkness]

hummmmmmmmmmmmm

 

As i said it last year and have said to everyone thousand times over!!!!!

 

there is a maximum safe limit for stock injectors for a reason, some car have lasted some haven't anyone running more than 35deg of duration is running a risk of engine failure

 

thats why the older tuners out there say 230-240bhp stock injectors as absolutely max (they know this info for a reason)

 

i'll hold my hands up and ran my 2260 on the Fabia on stock nozzles at silly silly durations because i asked Faboka to push it as i wanted to see what the limits where

 

After a very short period of time i refitted my race nozzles and had the car remapped elsewhere (This was no disrespect to Faboka i wanted to try http://www.dieselpowered.co.uk/ as this is who my mate Steven had his mapped by (the lad with the Red Golf at the RR day)) and i've done 14,000miles running 2.45bar and the car is 100% reliable, doesn't use any oil and has no running or cold start issues

The stock engine can take the power no issues its all about the mapping and setup and in essence every tuner out there has there own method of tuning

 

if you want good power and drivability you need fuel to spool the 2260 on a 1.9 so will get smoke its just something you have to live with

 

all these claims of 280bhp+ on 2260 and race nozzles on stock engine is another story that makes for good reading  

 

Anyhow i'm getting out of the game now and selling up i've done the modified 1.9PD thing for 3yrs now and tbh i hate the Image that the Fabia VRS now has and the idiots that now drive them (they have become the cheap mans corsa spinning round MacDonalds)

Hmm i only ever see standard vrs's, but i guess i dont go to MacDonald's :p There doesn't seem to be that stigma with the VRS on these forums. 

[JimboVRS]

I've been on the said Facebook groups recently and imo they are terrible. The bad language and text type speech just makes for a bad read. I litteraly just go on there to check whats for sale

[SKYHAWK]

What boost was you running? Any pictures? Did cracked along the gudgeon pin.

cracked exactly the same 2 bar of boost

[alex_e3]

So....

 

 

 

 

EXACTLY the same as Adam's. The only difference being that the crack on mine has not propagated all the way across the piston. Same chunk out of the middle of the piston too!

 

Anyone who's running big durations on those standard nozzles needs to back them off quickly methinks!!

[alex_e3]

Oh and it's also the same piston as Adam's!

[sepulchrave]

I generally expect to see the middle cylinders run hotter than the outer pair on any given inline engine, on a petrol engine you'd run the middle two slightly richer to increase quench, on a diesel you need to run them leaner.

[hutchysrs50]

Exactly the same. Same mods virtually, very similar mileage since the conversion, both went in the same fashion (with oil everywhere!), same piston, same crack...

Not good!

Not good at all...

So... are we saying its stock injectors being pushed to hard as Fabooka earlier suggested?

[alex_e3]

It's looking that way. For some reason it seems that running very large durations is causing combustion temperatures to be higher than if you were to run the same power with larger nozzles in a shorter duration. Quite what the physics behind this is I don't profess to know or understand however...

 

I know there are a fair few cars out there running the sort of boost that we are. I was one of the very first ones who ran 2.5bar on this turbo with standard injectors. Adam wasn't far behind. As such, we've been the ones to do the mileage before most. Hence there are probably a LOT of cars out there that have this potential to go bang unless they knock the power down in my opinion. I'm far from an expert granted, but it does look this way. This is not a coincidence!

Edited 18 February, 2016 by alex_e3

[devonutopia]

It seems to be something discovered a little late, but perhaps for others there is the reassurance of proven failures with identical symptoms from fairly similar setups.

 

I would be interested to know the mechanics of the problem, but if I am to be honest, even if someone told me in no more than 200 words, I would probably still fail to really understand.

[sepulchrave]

It's caused by having to start the injection too early in order to achieve the necessary fuel delivery quantity through a longer duration, so it's a bit like detonation, the piston hasn't travelled far enough before combustion starts and the excessive pressure cracks the piston or the head or blows the gasket if it can.

[alex_e3]

Ha ha, at least you're honest Jason!

 

To be honest, the main reason I started the thread was to try and get to the bottom of it so that others could benefit from the knowledge. The damage is done to mine and Adam's - if someone else can prevent the same thing to theirs, then it's worth it.

 

 

It's caused by having to start the injection too early in order to achieve the necessary fuel delivery quantity through a longer duration, so it's a bit like detonation, the piston hasn't travelled far enough before combustion starts and the excessive pressure cracks the piston or the head or blows the gasket if it can.

 

So you think this is down to combustion pressure and not temperature then? I had the head off it approximately 4-5k miles ago, and pistons looked fine to the naked eye (obviously NDT may have shown something I couldn't see). Why would it go now? I had been commuting in it for ages getting the economy out of it. Then a little WOT moment and it went pop. Can the cyclic pressure loading cause it to wear down over time just like it would with excessive heat?

[coskev]

Needs to be noted though it's not just GTB powered cars running standard injectors at long durations that crack the pistons in the PD eng.

 

Do a Google search and there are plenty of pics and info of cracked PD pistons

[sepulchrave]

So you think this is down to combustion pressure and not temperature then? I had the head off it approximately 4-5k miles ago, and pistons looked fine to the naked eye (obviously NDT may have shown something I couldn't see). Why would it go now? I had been commuting in it for ages getting the economy out of it. Then a little WOT moment and it went pop. Can the cyclic pressure loading cause it to wear down over time just like it would with excessive heat?

 

No, you can't have one without the other remember your gas laws from school?