02-28-2020, 09:25 AM | #15 |
Drives: '18 2SS/EU (+Recaros) M6 Red Hot Join Date: Nov 2018
Location: Sweden
Posts: 260
|
|
02-28-2020, 10:32 AM | #16 |
Drives: 18 1SS 1LE HyperBlue Join Date: Aug 2018
Location: Twin Cities, MN
Posts: 612
|
The type of fuel is irrelative in the LT1 engine - the valves never see any fuel at all. Just air from the intake.
The build up is oil vapor and moisture that comes from the crankcase into the intake tract thru the PCV system. From my observation it comes from two major problems - (1) there is excessive amounts of oil vapor in the crankcase and (2) the factory PCV system doesn't have a real good way to caputure the vapor and give it a chance to settle & drain into the crankcase. The biggest contributor to problem #1 is that the vast majority of people over fill the oil system. The system HOLDS 10 quarts, but nobody measures how much oil comes out when they drain it. If there is a quart of oil in the engine still when you fill it, and you put 10 quarts in it, you are now at 11 quarts. This in turn creates a ton of oil vapor as the oil level is so high that the crank and rods are now slinging more oil around which creates a ton of vapor, all getting sucked thru your intake and sticking to your intake valves which are hot, so it turns it into the burnt maple syrup you see here. After rebuilding my engine over the winter to put in forged internals, I can tell you, there is at least a quart of oil in the engine when you drain it. I have worked on several other LT1s and LT4s for friends, and have seen probably 90% of them have some kind of residual oil in the intake when you take it off. i let my engine sit on the stand for two days with the plug out, it was still dripping. There is every bit of a quart trapped in the lifters, pushrods and oil galleys in the block that doesn't drain due to suction. I have a friend who works at GM at the Prooving Grounds, and they actually thought far enough ahead to put a catch can on these cars stock - it is the black box that sits between the passenger cylinder head and water pump, with the three vertical connectors on it. Two go to valve covers, the third goes over to the intake tube between the throttle body and air cleaner. When they discovered this catch can setup wasn't scrubbing the oil, they were really far down the road towards production, so they came up with a revision where they added a small little box that helps catch the last little bit of oil. If you follow the hose that comes from the box catch can box thing, that hose goes to this little box which hangs underneath the main air intake tube. This little box will catch that little bit of oil, but only if the oil level is NOT overfilled. If the crank is overfilled, it can't keep up. When I first got my camaro and started seeing this stuff, I called my buggy at GM and he said "just fill it up until the oil gets to the very tip of the dipstick, like no more up than about 1/8 of an inch and the oil vapor will go away". However - if you preach this logic around this forum and on the groups on FB, you will get told it is crazy to oil put 8.5 or 9 quarts in. The goal is to have 10 quarts in the system - not to pour in 10 quarts every oil change.
__________________
2018 1SS 1LE / HBM - ECS Novi 1500 S/C Tuned by Carl @ CJ Tunes
|
02-28-2020, 10:58 AM | #17 | |
Drives: '18 2SS/EU (+Recaros) M6 Red Hot Join Date: Nov 2018
Location: Sweden
Posts: 260
|
Quote:
|
|
02-28-2020, 01:01 PM | #18 |
Drives: 2018 SS 1LE Join Date: Apr 2016
Location: Oxnard Ca
Posts: 241
|
So with this factory catch can system is there anyway to drain it..???
Whats the point of catching the vapors and oil if can't drain it.. or be instructed to drain during oil changes.. |
02-28-2020, 01:28 PM | #19 |
Drives: 19’ Camaro SS 1LE Join Date: Nov 2016
Location: SoCal
Posts: 309
|
Received my car back today.
Here’s what was done:
__________________
2019 Camaro SS 1LE
|
02-28-2020, 01:29 PM | #20 |
Drives: 2016 Camaro 1LT Join Date: Jan 2016
Location: California
Posts: 3,491
|
The point of the factory system is not to filter out fuel / water (that's intended to remain in gaseous form and sucked into the intake to be burnt and expelled) ... The point is just to keep oil from entering the intake (as much as possible).
if you have an oily intake around the PCV tubes connections then it's not doing it's job. If you dont, then it is doing it's job (though catch can manufacturers will say that job is incomplete at best because it's not separating those elements from the oil that doesn't stay in gaseous form). the PCV system though is not soley responsible for carbon buildup on valves. Running rich can be factor - and just being a DI motor without regular intake cleaning additives (like seafoam..etc) will be a factor. A catch can wont be a total solution. |
02-28-2020, 05:23 PM | #21 |
Drives: Hyper Blue 2016 2SS 6M Join Date: Sep 2017
Location: North Ga
Posts: 1,787
|
I am now. The pic was taken when i had the motor apart, swapping the cam and various other stuff. I added a catch can when i put it back together.
__________________
Baby Blue
2016 Hyper Blue 2SS/6m/MRC/NPP/Silver Rally stripes/ZL1 wheels & brakes/GForce DS and axles/ZLE Cradle Bushings/FE4 ARB front & rear/SEMA Grill/Rotofab dry/95mm TB/Magnuson 2300/Full LT4 fuel system/JMS boost-a-pump/E85 Sensor/Ported CID heads from LME/Cammotion PD cam/Thompson Motorsports forged shortblock/catted Kooks 1 7/8 headers /JRE remote tuned |
02-29-2020, 04:55 AM | #22 |
Drives: 2021 Sierra Denali 6.2L/10sp CC 4WD Join Date: Mar 2009
Location: Houghton, Michigan
Posts: 234
|
These newer engines use technology that is hard on oil. Active Fuel Management, Dynamic Fuel Management, start stop, variable vavle timings, turbo charging etc. All these new technologies put a lot of stress on the oil. Not all oils are up to the task and that's why GM and other oem's have been pushing for better oil specifications to be developed. Yet there are a lot of oil companies who continue to market "good enough" products and customers who refuse to spend the money continue to buy these "good enough" products for their expensive vehicles/engines. They think frequent oil changes are cheap insurance but in reality, cheap oil is the problem.
Why do you think some oils are cheaper? Where do you think they cut the corners? Did they use cheaper oil base stocks and additive packages? Less highly trained chemical engineers? Did they cut back on quality control? How can they afford to spends millions of $$ on advertising sell to Walmart at extreme low prices and still make money if they claim their oil is best?
__________________
Last edited by CTS; 02-29-2020 at 05:33 AM. |
02-29-2020, 06:19 AM | #23 |
Drives: 18 Camaro LS M6 Join Date: Apr 2019
Location: NH
Posts: 698
|
great discussions. I looked at the parts list and they said the exhaust valve was also affected in his case. possibly some other type of defect was going on? one reason I'm considering deploying water injection on my 2T LTG. go fast and go clean.
here is a nod to the legitimacy on WI - https://jalopnik.com/how-the-absurdl...n-w-1760175847
__________________
.
. . NFG M6 2T Mishimoto Hot side pie | ZZP Catted DP | KN Drop in | Borla - Sport Tour | Apex Arc 8 - square | Wookster Tuning+ | Flex Fuel Last PB 4.8, 13.2@106 |
02-29-2020, 07:32 AM | #24 |
Drives: 6th gen Join Date: Aug 2013
Location: US
Posts: 3,675
|
The buildup is mostly from egr reversion from the combustion chamber back into the intake. - per GM genv combustion team
__________________
‘22 2SS 1LE M6 Summit White - RF, Flexfuel, LT2 intake, 95mm tb, ATI udp, VT ramair, full 28” dragpack - 11.68@122
‘16 1SS M6 LT2 intake + boltons on DR 11.0@126+ (Sold) |
02-29-2020, 08:49 AM | #25 |
Drives: 18 Camaro LS M6 Join Date: Apr 2019
Location: NH
Posts: 698
|
valve open timing overlap. high back pressures.. Clogged cats maybe?
__________________
.
. . NFG M6 2T Mishimoto Hot side pie | ZZP Catted DP | KN Drop in | Borla - Sport Tour | Apex Arc 8 - square | Wookster Tuning+ | Flex Fuel Last PB 4.8, 13.2@106 |
|
|
Post Reply
|
|
|