[Doubleup]

Hello, I recently purchased an 18k mile Charger Hellcat and while doing some intake improvements I noticed some residue inside the throttle body. Is this normal from blow by/dirty filter or?? Seems concerning however it runs great...

 

[Trizzle]

Probably from the blow by from the heads. Get yourself a catch can and that will help alleviate that residue.

 

[Reaperhwk]

You want to see residue? This was on my Tahoe with a Direct injection motor with 110k miles. Bought it used has a catch can now. Had to walnut blast all the valves! That amount I see in your pictures isn’t anything that would be a problem.

 

[Doubleup]

Thank you both! This is my first supercharged beast so I'm learning!

 

[Arabex]

Thank you both! This is my first supercharged beast so I'm learning!

While the amount you currently see is nothing relatively to what Reaperhwk shared a catch can still won’t be 100% bulletproof, but certainly will help to mitigate a significant amount of blowby for sure.

 

[Sarna March]

You want to see residue? This was on my Tahoe with a Direct injection motor with 110k miles. Bought it used has a catch can now. Had to walnut blast all the valves! That amount I see in your pictures isn’t anything that would be a problem.

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Did this vehicle have forced induction? If not, I think this is backflow during overlap that is causing this, yes?
I am guessing it is exacerbated by the direct injection, as in, no gasoline mist washing the intake port walls all the time, or the back of the valves.

 

[Arabex]

Did this vehicle have forced induction? If not, I think this is backflow during overlap that is causing this, yes?
I am guessing it is exacerbated by the direct injection, as in, no gasoline mist washing the intake port walls all the time, or the back of the valves.

Backflow? How much flow you think you’ll get? All of that is caused by the fact that there’s a PCV valve/system diverting crankcase to the intake system for emissions purposes, such crankcase fumes are heavily rich in oil mist that’s what ends up building up in your cylinders heads plus the fact that on direct injected with no port injected fuel will produce that gunk build up. Nothing less, nothing more.

And the above applies to both N/A and boosted applications…

 

[Reaperhwk]

My post with those filthy valves was just to illustrate how much gunk they pcv system dumps in the intake. With a DI engine I feel that a catch can is a must. With port injection I personally feel the fuel cleans those valves well so there is no NEED for a can but it definitely can’t hurt.

 

[mschultz443]

My post with those filthy valves was just to illustrate how much gunk they pcv system dumps in the intake. With a DI engine I feel that a catch can is a must. With port injection I personally feel the fuel cleans those valves well so there is no NEED for a can but it definitely can’t hurt.

You just stepped in it......... wait for it............

 

[Reaperhwk]

You just stepped in it......... wait for it............

Stepped in what? Bring the pain!!!!

 

[2ndAmend]

For the young guys:

Back in the day before PVC, the blow-by went wherever it could. Enthusiasts would install Breather Caps. Regardless, the oil mist would leak out and coat the entire engine compartment and dust/dirt would stick, then be re-misted and re-dusted. Normal people who would just drive and not clean their engines would end up with a 1/4" thick coating of a gritty black oily tar like substance with a wrinkle finish over everything. We don’t see this anymore because all that blow by oil goes somewhere else.

 

[Sarna March]

Direct injection DOES lead to dirty intake valves, yes. That cleaning effect of port injection is why no one injects fuel (except the occasional cheapo nitrous kit) before the supercharger rotors. They don't want to have the fuel attacking the special coating on the rotors (and inside the blower case? I dunno.) I am guessing that that is not good for any bearings that would contact the fuel mixture directly, either.