So I’ve been having some breathing problems since I’ve had my car tuned & been running e85. My original catch can setup was 2 hoses from the rocker cover going to my catch can (silver catch can bottom right of my engine bay) and then a breather filter coming of that catch can.

When driving normally the catch can would fill up with e85 Vapor, which is normal, I’d empty it as usual and it would be fine. But when I’m at the track and the car is running hotter etc.. I noticed oily residue coming through the breather filter but not filling up the catch can.

So I went back home and added a second catch can, basically instead of using a breather filter on the 1st catch can, I replaced that with a hose which went to a 2nd catch can and then put a breather on that (black catch can with silver filter above my battery). And I’ve noticed after going on track again that neither catch cans are filling up by the oily vapour is coming from the breather filter again.

Is there any reason why the oily Vapor is going past both catch cans and straight out the breather filter? I’ve done a compression test which gave me strong consistent readings on all 4 cylinders but I’m not sure what else to check?

My next plan is to put a small pump on the bottom of my main catch can with a return hose going to the balance shaft inspection hole, that will return any oil back to the engine, also any e85 residue will vaporise when it hits the oil.

What does everyone think?

Benny

 

sounds like you have a healthy engine, and dont need an oil return yet.
at operating temps there shouldnt be any water/fuel in liquid form within the engine. those gases can be handled with a working PCV. any moisture that forms in the spaces within the hoses/canisters when the engine is cold is collected also but it didnt come from blowby.
i have 3 small oil-drain back canisters and remote breathers. one catches all the moisture even with a breather, another catches some but it dries up quickly since Its 'soaking' paper towels

 

What do you recon I should do? I did notice that before I went on track my catch van was about 1/5 full, as I have a sight glass on the side, and then after there was nothing on the sight glass, probably because it came all out of the breather filter.

Maybe I should try re baffling my catch bananas there properly baffled? I just don’t want the stuff to keep coming out of the breather filter and covering my engine bay in crap.

 

I really think you're fine. water and fuel evaporates
on mine, the intake side breather has about 18" hose away from the catch-return can and is upside down into a clear container (with paper towels). btw this side has a working PCV and a vacuum close valve, so it works like stock during idle/cruising and sucking moisture from the engine and the hoses/canisters
on the exhaust side, the breather is on top of a catch can. i put the cap of a spray paint can around the breather so it looks like a cup. here I put a paper towel... its practically the same as wrapping the breather with a paper towel. the idea is to control the spray IF it ever happens. I can also monitor the condition of the towels to see whats going on

I use 10 m-fold towels now

 

you can see here I'm using 3 drainback catch cans in the tight space behind the strut tower bar. I also have 2 remote breathers. it looks messy but its not in the way even when removing the transmission