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Yes, I am glad the intercooler bricks were oil free.

Ya, catch can is for sure needed but it is a pretty good system for an OEM.
For sure the air/oil separator in these engines are much better than the LSA. I haven't had an LT4 apart, so I can't comment on how effective their system is.

Any "snail trails" in your lower intake originating from the PCV port?
 

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For sure the air/oil separator in these engines are much better than the LSA. I haven't had an LT4 apart, so I can't comment on how effective their system is.

Any "snail trails" in your lower intake originating from the PCV port?
It all dumps into the cylinder #2 intake port which had the worst valve build up.
Not evenly distributed at all, the EVAP purge port though is dumped in the center of the intake.

LT4s are better than the LSA but on the Vs, lack of a true dry sump makes it worse.

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It all dumps into the cylinder #2 intake port which had the worst valve build up.
Not evenly distributed at all, the EVAP purge port though is dumped in the center of the intake.

LT4s are better than the LSA but on the Vs, lack of a true dry sump makes it worse.
Makes sense cylinder #2 would ingest most of the "number 2" coming from the PCV given the proximity of the PCV barb and intake port.

Unfortunately that doesn't bode well for even distribution of TOP engine cleaner to the engine if you draw it in via the PCV line, it probably won't be distributed very evenly at all. But, if you introduce enough into the engine before you shut it down some should make it to all 6 intake ports.

Might be better to introduce TOP engine cleaner into the engine via the evap port for more even distribution.
 

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2016 ATS-V sedan 6 speed manual
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Discussion Starter #24
It dawned on me that I never asked why the fuel and/or occasional use of methanol would make a difference if it's not being sprayed on the intake valves. How would this make any difference if the fuel never touches the intake side of the valve?
 

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It dawned on me that I never asked why the fuel and/or occasional use of methanol would make a difference if it's not being sprayed on the intake valves. How would this make any difference if the fuel never touches the intake side of the valve?
Most people running water/methanol on these cars are injecting it into the upper intake, often into the pipes that connect the upper intake to the turbos since that's the most convenient spot.

This means the water/methanol travels through the intake and hits the back side of the valves. Between the methanol acting as a solvent and the water "steam cleaning" the intake valves as it vaporizes, it works very well as a de-carboninzer for both the valves and combustion chamber.

I run water/methanol injection on one of my other cars, and last time I had the engine apart the intake valves and piston crowns were amazingly clean.
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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FWIW, many WW-II and later aircraft gasoline reciprocating engines used water injection to slow down the fuel burn (sort of an octane increase) and thus prevent detonation at high supercharger/power demands. The piston crowns stayed squeaky clean.


Yes, higher octane fuels "burn slower" in order to allow a bit of additional ignition advance to keep maximum cylinder pressure in the best arc of the power downstroke for slightly longer time periods.

 

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Discussion Starter #27
Ok, so use of meth or water injection would be useful but what about those of us who don't? Why does the use of tier 1 fuel make a difference?

And I'm aware of both the water injection and high octane issues.
 

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Ok, so use of meth or water injection would be useful but what about those of us who don't? Why does the use of tier 1 fuel make a difference?

And I'm aware of both the water injection and high octane issues.
Top Tier fuels contain the correct amount of detergent in them to keep intake valves, injectors and combustiom chambers clean.
Valve overlap is the issue here with a direct injected car as thats the only way you get fuel or fuel components into the intake port and onto the back of the valve.



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Meth or meth/water may not do as good a job at cleaning the valves as we had hoped. Even after running top tier gas and putting a healthy does of meth (750ml/min) through the charge pipes, a friend of mine found his valves pretty gunked up when his heads came off. I'm coming up on roughly 2 years of 51/49, then 100% meth, and now 87.5/12.5 meth/water and I've got what I think is a noisy/sticking exhaust valve on the driver side, so my heads are coming off soon also. I'm interested to see how clean my valves are. I recently had a top end clean done by the dealership to try and get rid of the ticking, but it wasn't effective.

I'm going to ask the shop to send me pics of that they find when it happens, I'll post them here. I'm interested to see how much the meth really cleans off.

As others have noted, one caveat of GDI is that it injects fuel below the valve, so all those detergents in the top tier gas don't wash over the top of the valves to clean them.
 
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