Nice article on intake valve coking
02-17-2016, 06:03 PM
#21
The way to know for sure is to simply either remove the IM (takes 5 minutes and all gaskets are resealable) and inspect in person and share pictures. Or, a boroscope snaked down a runner with the TB removed will show you. The engineers that designed these engine also spent a ton of R&D to determine that best shape and texture of the valves and ports for maximum efficiency, so even a small amount will create a degradation in power, but how much vs how severe the deposits are needs before and after dyno runs to document.
I always go back to a LS engine's valves with 140k on them and zero deposits :
and then look at any of these C7's or the trucks (and now Camaro's) at 5-10k miles to see there is no way the engine can operate as efficiently as with a clean deposit free valve. Seat of the pants is not a way to determine gradual degradation of power over time, but do a manual cleaning and the owner thinks they have a new car again as the restoration of power is instant.
Just always go back to this video and the pictures of others showing at low miles the build-up:
https://www.youtube.com/watch?v=7Pz0zTQ1bz0
I will guarantee though if you take your dads truck, do a base dyno as it is, perform a manual intake valve cleaning and do a after dyno on the same day, same dyno, the power restored will shock you.
Even if this was a port injection engine, the "gunk" that these systems separate and trap keeping it out of the intake air charge, and ultimately the combustion chamber makes document able difference just from the more complete burn releasing more energy each combustion event and the reduction in knock retard due to the detonation this mix causes is reason for those wanting the best to install one of these effective systems.
In all the vehicles we have done before and after testing on the owner was doubtful in the beginning that the engine had lost power and response. EVERY single case, yet the after amazed them.
Try it and see, then no assumptions either way. Just undeniable proof. Arguing either way without proof is pointless.
I always go back to a LS engine's valves with 140k on them and zero deposits :
and then look at any of these C7's or the trucks (and now Camaro's) at 5-10k miles to see there is no way the engine can operate as efficiently as with a clean deposit free valve. Seat of the pants is not a way to determine gradual degradation of power over time, but do a manual cleaning and the owner thinks they have a new car again as the restoration of power is instant.
Just always go back to this video and the pictures of others showing at low miles the build-up:
https://www.youtube.com/watch?v=7Pz0zTQ1bz0
I will guarantee though if you take your dads truck, do a base dyno as it is, perform a manual intake valve cleaning and do a after dyno on the same day, same dyno, the power restored will shock you.
Even if this was a port injection engine, the "gunk" that these systems separate and trap keeping it out of the intake air charge, and ultimately the combustion chamber makes document able difference just from the more complete burn releasing more energy each combustion event and the reduction in knock retard due to the detonation this mix causes is reason for those wanting the best to install one of these effective systems.
In all the vehicles we have done before and after testing on the owner was doubtful in the beginning that the engine had lost power and response. EVERY single case, yet the after amazed them.
Try it and see, then no assumptions either way. Just undeniable proof. Arguing either way without proof is pointless.
this goes back to the comment that tadge made about the FACT carbon build will happen, but the customer won't really notice it. like my dad.
Last edited by MikeLsx; 02-17-2016 at 06:04 PM.
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COSPEED2 (02-18-2016)
02-17-2016, 11:05 PM
#22
Pro
http://www.gm-trucks.com/forums/uplo...9339_thumb.jpg
I have a 2015 Denali CC with the 6.2 and on the gm-trucks forum there are pictures of a 2014 5.3 intake deposits with about 30k miles, it had a Catch Can installed at about 20k miles.
I have a 2015 Denali CC with the 6.2 and on the gm-trucks forum there are pictures of a 2014 5.3 intake deposits with about 30k miles, it had a Catch Can installed at about 20k miles.
02-18-2016, 10:49 AM
#23
Melting Slicks
Thread Starter
Agreed. Most will never notice until it becomes a drivability issue.
Just had another BMW Mini cleaning before and after and the owner could not believe the difference.
Just had another BMW Mini cleaning before and after and the owner could not believe the difference.
02-18-2016, 12:34 PM
#24
Pro
02-19-2016, 05:11 PM
#26
Melting Slicks
Thread Starter
Still looking for someone w/20k plus miles on their C7 that wants to see before and after dyno...will do cleaning service free, $800-$1200 value plus free dyno sessions.
Would also like an unbiased group present to witness and document all as well to reduce the nay-sayers. (Will always be some no matter what proof is presented, but should help the group that think somehow GDI in the V8 engine is different than any other late model GDI engine no matter the make/size/configuration.
04-30-2016, 03:37 PM
#27
Melting Slicks
Thread Starter
Here are the results at 20K miles on a 2015 wetsump car that was broken in hard (properly) and factory oil drained at less than 500 miles and only full synthetic run (the DEXOS blend results in worse coking than full syn) and no mods on the car period.
Performed before and after dyno results to show the degradation in power from the intake valve coking:
Owner is now going to run another 20k miles with CoSPeed system installed and repeat all at 40k miles.
The more actual examples like this we can show, the better we can all see the real World actual effects and not just blindly believe what were told.
Performed before and after dyno results to show the degradation in power from the intake valve coking:
Owner is now going to run another 20k miles with CoSPeed system installed and repeat all at 40k miles.
The more actual examples like this we can show, the better we can all see the real World actual effects and not just blindly believe what were told.
04-30-2016, 05:00 PM
#28
Pro
04-30-2016, 05:35 PM
#30
Racer
And this is one of the after cleaning pic.
Also the dyno green is after and black is before.
No funny buisness.I was there the whole time watching the whole thing and taking pics.Dyno was done in sixth gear both runs
Also the dyno green is after and black is before.
No funny buisness.I was there the whole time watching the whole thing and taking pics.Dyno was done in sixth gear both runs
05-01-2016, 02:58 AM
#32
Le Mans Master
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I'm familar with that article and many others that point out the problem with GDI engines and carbon collecting on the backside of the intake exhausts. That's why both my GDI engines (C7 & Optima) have catch can installed. It's cheap insurance especially if you plan to keep the car more than five years.
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COSPEED2 (05-01-2016),
Tron1 (05-09-2016)
05-01-2016, 10:11 AM
#33
Melting Slicks
Thread Starter
Correct. Before and after a manual intake valve cleaning.
We also want to point out the large disparity in catchcan effectiveness. You want to stop all that oil and other compounds that cause this.....and most trap as little as 15-30% tops. The ColoradoSpeed and Elite E2-X stop 95% plus of this.
Want to see more examples like this one so we can have a better idea on say a car that was broken in per owners manual instead of the hard break-in that assures proper ring seating. And has run the dealer syn-blend oil VS full syn like this example (oil type makes a difference).
We also want to point out the large disparity in catchcan effectiveness. You want to stop all that oil and other compounds that cause this.....and most trap as little as 15-30% tops. The ColoradoSpeed and Elite E2-X stop 95% plus of this.
Want to see more examples like this one so we can have a better idea on say a car that was broken in per owners manual instead of the hard break-in that assures proper ring seating. And has run the dealer syn-blend oil VS full syn like this example (oil type makes a difference).
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Tron1 (05-09-2016)