Whilst poking around in the Octy's engine the other day - it was discovered that one of the exhaust valves has a hairline crack in it. Now luckily this was picked up before it got too bad - but obviously it shouldn't have happened in the first place.

Car has done 39k miles, 25k of which with Jabba remap, decat exhaust and induction kit. Remap is quite and old one (one of the first Octys to be done) which according to AMD at the recent RR day had a really bad boost map (up + down all over the place).

Car has always been driven with mechanical sympathy... well OK it's always warmed up and cooled down properly

Any idea what might have caused it? Could it be a dodgy map??

Jeez Dave, when I'm 'poking around in the Octy's engine' I usually just top up the screenwash and check the oil :eek:

That certainly doesn't look too great. :eek: I hope that it wasn't a dodgy map. Possibly just one of those things and you've been unlucky. :(

not sure... i would recommend replacing all the valves with sodium filled ones and possibly a thicker head gasket to reduce the compression ratio when running higher boost...

Hi Paul,

I thought the valves were sodium filled as standard on the 1.8t??

Seeing as the head was off - thought It was just as well to put new pistons + rods in as well. Didn't go for the low comp ones - was under the impression they needed more boost to make similar sort of power?

Dave, I note what AMD said but has the car driven for the last 25K feeling as if it had a dodgy remap? And what other mods have you had done to your engine?

I've seen that a couple of times in the past on both modified and standard cars. I had it on an S3 that had a faulty MAF on it for a long period of time which meant it had been running lean and caused the valve/combustioin area to get too hot (the car was standard). When that valve eventaully breaks of it usually damages the piston and cylinder bore.

Valve that colour (sort of sandy shade and texture) usually indicate a weak mixture. I have also come across it when octane booster is used regularly.

Never feel like a dodgy map - no other engine mods apart from a forge dv.

It was spotted by Mike at Impossible who is doing a bit of work on the car at the moment.

I've always been a little concerned about my MAF. Never had any indication of it failing but it does get extremely dirty + I clean it with Isopropynol every so often. Could it point to a dodgy MAF then?

Tuning engines will shorten the life of many components, as they are running to beyond their normal design limitations.

This is the most likely cause.

JT

what cams etc have you fitted and at what cost?, wouldn't mind doind this sort of thing if it makes a difference, out of warrenty and getting fmic/chip/controller and stuf anyway so i could be interested in this sorta thing, what about the rods and things too?

Think i'll just get the valves + maf changed to be safe! Remap wont be an issue as it's having a nice new map put on next week. I'd still like to know what caused it though.

Bengie - not changed the cams. Pistons/rods being ditched in favour of new forged ones as a precaution really so the engine doesn't go pop.

there is no benefit in changing the cams... maf / running lean is possible but i always found my octy ran rich.... you can see the black overfueling smoke if you look carefully on the drift day vids....

as for sodium valves.. im not sure if they do have them? i know they take the heat better...

Tuning engines will shorten the life of many components' date=' as they are running to beyond their normal design limitations.

This is the most likely cause.

JT[/quote']

Having worked at a reputable tuner and in the VAG dealer network for a number of years i can say that statement is absolute tosh.

As I stated the S3 that had the same problem was a standard car. And most tuning is done within the limits of the car/engine, or the components are upgraded, this is why tuners do research (hence my hybrid turbo).

have to agree with Ross....

It was spotted by Mike at Impossible who is doing a bit of work on the car at the moment.

Care to elaborate as to what work you're having done besides the map e.g. letters 28 or 40...?

Chris

Whilst poking around in the Octy's engine the other day

And every other part of the car AIR.

How do you get 700bhp out of a Skoda?

Easy, park a black one and a red one behind each other at IP's.

How do you get 700bhp out of a Skoda?

Easy' date=' park a black one and a red one behind each other at IP's. [/quote']

Chris - it's the GT28-71RS (the new big one!) I was looking at one that they fitting to an S3 the other week and i have to say the quality of the install looked superb. Can't wait

the calculator on my phone reckons...

"700 / 2 = 350"

:eek:

watching with interest

Chris - it's the GT28-71RS (the new big one!) I was looking at one that they fitting to an S3 the other week and i have to say the quality of the install looked superb. Can't wait

Strange I was talking to Mike last week about this -you have a PM

Overheating valves can lead to this type of thing.. and can happen on stock engines. As said faulty reading MAF can cause lean running and EGT's get a little higher than they should..

have a read here>> http://www.gsvalves.co.uk/head_fractures.htm

There is going to be some decent valves for upgrade available shortly.. from your friends @ Jabba and myself..

One piece valves, forged, in high grade stainless steel inlets and inconel exhausts, specially heat treated for durability and wear.

Std valves (and Schrick) are 2 piece valves, and failures are common on valve heads detaching. (at the join/grinding blend on the stem)

coming soon... these 'special' valves.

Watch this space from Jabba & Badger5.

regards

bill

Lean running does sound very plausible.

hmmm my MAF does get extremely dirty - new one will be installed before car is remapped again (just incase...)

might be worth reviewing the induction to if the MAF is getting really dirty.

why is the MAF getting dirty?

I've seen that a couple of times in the past on both modified and standard cars. I had it on an S3 that had a faulty MAF on it for a long period of time which meant it had been running lean and caused the valve/combustioin area to get too hot (the car was standard). When that valve eventaully breaks of it usually damages the piston and cylinder bore.

Valve that colour (sort of sandy shade and texture) usually indicate a weak mixture. I have also come across it when octane booster is used regularly.

How can an Octane Booster do this as I run Millers Octane Booster in my Revo'd Octy :eek: