View Full Version : i always use premium 98octance fuel, and valve/injector cleaner when needed.

05-14-2008, 03:06 PM
hey guys i've recently opened up my engine to rebuild and clean it all. when i took of the head and looked at the pistions there were heaps of chuncky fakes of carbon. is this normal? this is the first time openening up the engine. the thing is i always use premium 98 octane fuel and i also use valve/injector cleaner aditives. so why is my engine this dirty? this worries me becuase i run 20psi of boost and the carbon that foats on top of the carbon can create hot spots of amber, and this can potentialy cause knock(not that i've ever got it before). and i'm running a after market pod filter


05-14-2008, 03:07 PM
Damn dude, that's actually pretty clean. Nothing to worry about there. The one on the left appears to have had a bit action than the others, but still not bad. Better than normal I would say.

05-15-2008, 02:29 AM
are you running 20psi on stock everything?

according to what i've been reading on here, the stock fuel rail doesn't supply an even amount of fuel at higher boost levels which is why ATS supplies bored versions of the oem rail to help with that. if this could be the issue for the extra action on the left most piston, the fuel pressure at the furthest injector is much higher then the rest. from left to right basicly, injectors go from highest pressure to lowest pressure. having a bored fuel rail fixes this or the use of an aftermarket fuel rail.

again, this is what i've read and seems to be the most likely to show that extra beating on the left most piston.

05-15-2008, 04:26 AM
yeah i was running 20psi on pretty much stock eveything, besides frountmount intercooler conversion with 2.5in piping and pod. but yeah your logic seems right. i always thought that the stock fuel rail would be able to be consistant for about 300hp.

05-15-2008, 03:43 PM
if you think about it, you're about double the boost basically so the stock fuel rail probably isn't holding up anymore is my guess.