Oil catch can

[MarkV8]

Has anyone on here tryde using an oil catch can to reduce the recirculating oli gases causing the dreaded carbon build up in an Itempt to slow the proses down if so was u successfull ?

[weekenny]

I think on these engines it's caused by valve overlap more than oil vapour being drawn in.

[MikeFish]

It's been tried and made no difference.

[MikeFish]

viewtopic.php?f=35&t=82435

Then he tried it anyway:
viewtopic.php?f=35&t=84617&p=386760

And the results:
viewtopic.php?f=35&t=87910&p=417301

[MarkV8]

Cheers guys I think that awnsers my question it's a shame that somethings not out thair for us guys to alumni ate thiss 20,000 mile issue .

[audi_do_dat_den]

The carbon or sludge build-up in the intake ports is due to the injectors being in the combustion chamber (direct injection) and not in the manifold port like most fuel injected petrol motors.
Also, as mentioned, these engines have a large valve overlap between induction and exhaust strokes, which isnt a problem while the engine is being thrashed (where it likes to be) as the airflow keeps the exhaust gasses from contaminating the inlet valves and ports.

The problem arises when youre driving the car normally, like around town and spending time idling..... then the build-up will begin.....

On an engine with the injectors in the ports, the mist of atomised petrol will tend to 'wash' the port during induction.... and no build-up will occur.
In turbocharged engines, the boost air briefly flushes the chamber during the overlap of exhaust and induction.

[MarkV8]

I can see waire ur coming from a good read to tbh, as I'm quite new to the rs4 scene and I have heard these engines like to be revved, how hard can u rev these v8ts and will they stand the test of time with a good old blow out.

[Surrey Sam]

Engines are strong and can rev all day long with good maintenance.

Water methanol injection is going to be the only method that can help keep carbon build-up down.

[MarkV8]

Has anyone on here actually used a water meth injection kit, after reading I believe that it has to be set up with the stock mapping alterd, I can see the logick in thiss method I wounder wot the results. Would be like on an rs4.

[Surrey Sam]

Have a read through Tony's thread linked below, it's the best detailed thread on here for WM injection. From memory he didn't need to remap the car to run it?

viewtopic.php?f=35&t=103679&hilit=methanol

[MarkV8]

Wow Surrey Sam that's one hell of a good read mate, he didn't get around to saying if it actually cleaned the carbon or kept it at bay I really hope tony picks back up with the thread and gives more pick of valves and manifold, if thiss is proven to work efficiently then I'm in bud.