Flex Fuel use follow-up
 

I just want to bring to attention of long term use and how important to have a catch can setup property to collect ethanol vapors from the crank case. If not for the catch can these vapors can dilute my engine oil and cause engine failure.

Below is a picture of my catch can when I just put 600 miles on my car running nothing but Flex fuel back to back. These miles were not idle nor drive like an old man when on the the local interstate "i75". RPM range was 3-4k making my runs from south Florida to Clearwater Tampa.

In the past using 93 tunes I had some but very very little sludge. But with flex fuel the catch can filled up quickly. The fumes smell like vodka. A/F and tune has been perfect but oh boy I can see some people having problems. A proper setup to catch these fumes is REQUIRED if not the engine oil would degrade to 0w.

Catch can setup has 1/2 hoses running from both crankcase vents to a vent to atmosphere catch-can with a magnetic drain plug. The vent side of the catch-can has a hose that travels under the car and dumps next to the transmission because I don't want to smell that shit.

I like to share as much as I can so no one has to learn the hard way. Communication is key.

http://i45.photobucket.com/albums/f8...ps3bzijzy9.jpg

Which catch can do you have? Some units catch more than others.

Custom. Didn't like the options on the market. I wanted the absolute best breathing, very little restricted flow from the crack case vents. The market everyone else sees is far tomuch markup and glammer.

Let me put it this way. Ethanol blow by is very high. Makes sense to because the car does spray 33% more fuel when running it. I guess the chance on making it past the piston rings so so much higher. Imagation if you had a catchcan not allowing flow correctly, either restrictive or recirculating back into your intake. Your oil would be screwed.

Im done doing highway runs for awhile so ill followup on this again with city driving.

Ethanol boiling temperature is 173.1°F after that point and turns into vapor if it's in your crankcase or oil caused by piston blow by. After that point travels to my catch can, cools down and turns back into a liquid.

Really makes me wonder if I just distilled the ethanol lol.

I'm having similar results and my PCV side catch can fills up with ethanol rather quickly these days. Definitely good info here, and also a reason to NOT use the type of catch can/AOS that drains back into the engine. You'd be draining all of this ethanol back into your oil and thereby accomplishing nothing.

Do you have any pictures and details of your catch can setup? I'd like to put a custom setup together some day as well.

I just purchased a generic 2 inlet catch-can from ebay. Installed a 1/2 barbs on the catch-can. Installed a 1/2 barb on the backside PCV crankcase and deleted the subaru valve altogether. Ran a 1/2 hoses from back crankcase vent and from vent to the catch-can. Took the filter off the catch-can and installed a 1/2 house instead and routed it under the car next to the transmission for dump.

I did have to go to HomeDepot and purchase an aluminum 1/4 sheet metal to make the battery bracket to hold on to the catch-can. I painted the bracket black to match. All said and done I was under $100

http://i45.photobucket.com/albums/f8...psewu0nfqy.jpg

You deleted the PCV valve?

It's actually a necessary component to the engine especially the long life of the engine. running an open PCV may have worked a long time ago, but it has to be sealed and working properly. http://www.agcoauto.com/content/news/p2_articleid/197 read this.

Gone, entirely, its just a barb now. No point to having a check valve as my setup dumps to atmosphere and not recirculated.

Pressure in the crankcase causes issues. Lets not use a check valve thats intended for the intake to pull fumes from the crankcase during idle.

I have a very similar setup to yours:
-PCV Delete
-Two -8 fittings going to a vented can
-Baffler/Filter screen thingie that rests between where both fittings sit
How much did you catch when you were running pump gas? I've been running 11 PSI now since the summer and haven't caught a single drop of oil. I am absolutely positive that it is set up identically to yours outside of a breather filter in place of your 'dump' hose...any thoughts?

https://s17.postimg.org/f7zqq6dej/catchcan.jpg

lol. I have 110,000 miles on a boosted set up with no catch can. So far I ran 70k miles on e85. Took my engine apart and everything was clean. I could basically lick the spark plugs and not get sick.

I can say, for everyday driving, no catch can is need.
The only thing you need to do is change the oil at least every 7000 miles. The blow by does find it's way into the oil I think. I don't know if it is normal for the oil, but the viscosity gets reduced by a lot.

Thanks Cal, that is comforting to hear! I guess yours and my pistons seal better than some because I have seen next to no signs of blow by whatsoever. Granted I have not cracked the motor open like you have but I have nothing coating the inside of the charge piping, intercooler couplers and what have you. Some slight residue on the walls of the inside of the catch below the fitting openings but that's all. I do like knowing that my crankcase is being vented and that I don't have to worry about pressure leaking past the pcv and into the CC.

Ok update.

City driving with now and then WOT has nearly no blowby. Highway driving with WOT seems to be a different story.

I've also made the same observation. Both my the PCV and CCV side catch cans fill with ethanol rather quickly after some highway WOT.

Shoot, I didn't see your post. I'm running 11PSI and soon to be 20PSI.