Where can I re-route my catch-can ?

[cobrAA]

Hey guys,

My catch-can is going back in my intake, we found some oil in the intake and well thats no good ( lol!) So, what should i do ? vent it ? can I convert my actual setup with a little vent filter ? where else can I re-route it if kept recirculated ?

thanks.

would a thing like this be a better choice than the usual 30$ ebya catch can ? http://www.ebay.com/itm/VMS-ALUMINUM...496cd0&vxp=mtr

[Eat_Sleep_Shift]

Have you looked into a nismo oil seperator? I like them for this issue.
That ebay can looks ok though, has the vent etc so it would work well I would think!

[Skym]

I think the size of catch can, internal design might be incorrect on current catch can if oil is making it into the intake. If still get oil in intake after those corrections of design, size, run 2x catch cans, which if the first catch can doesn't catch the oil, the second catch can will catch the oil.

That catch can in link has 1/2 inch hoses (12.7mm). Good for probably 4 cyl Honda's (from memory that's what the 1/2 inch 12.7mm hose works with). Factory PCV hoses off camcover breathers on RB engines are usually 16mm ID, so 12.7mm is smaller. Also capacity is probably not enough.

If for road use (due to emissions), put catch can inbetween exhaust side cam cover breather, intake infront of turbo (should work on racetrack as well) which is how it's done on GTS engines, should be similar with GTR engines. Usually blowby is externally vented just behind engine on racetrack, but that requires a retune to suit (cylinders don't get filled with dirty blowby gas, so engine gets more clean air in cylinders, hence engine runs leaner, thus ECU tune is needed to correct this).

Avoid the filter on catch can way, as is incorrect. It's a way around the emissions, as the filter filters the blowby gasses before reaching atmosphere. But has it's own set of problems, like having to change filter often because it clogs with oil, etc and causes engine problems (leaking camcover gaskets, etc), catch can filling after a few laps, etc.

Can make your own catch can using sheets of aluminium (or very large diameter piping with 2x caps if space is an issue), 2x female boss fittings, 2x male screw / ribbed nipple or screw / AN fittings. Pay someone with welding equipment to weld it together. Can bend it on some sides or corners (if square type of catch can) to give it that high quality seemless look (or get the aluminium sheet pressed with a press, so welded surface faces the bottom only for a showcar quality look).

Catch can needs a vertical plate inside at the top of catch can, inbetween entry, exit to make sure the blowby turns 90 degrees or more, which makes the heavier oil separate from the blowby gas before the blowby gas exits catch can. Catch can needs to be minimum 2 litres for 2000cc+ engine. 2668cc x 1.7 = 4535.6cc (real capacity of a turbocharged engine).

[cobrAA]

Thanks Skym, Will talk to this issue to my mechanic monday morning. Just found out most catch can are max 15mm while breather thank can be very huge with an14 fitting and such, look better build overall.

[Skym]

You're welcome. Always good to get second opinions.

With catch cans it's best to go custom, as build them to correct specs. Also what you'll find out is there's many ways to separate the oil inside catch can (baffles), some good design's, some not so good. The small size plate inbetween in and out on a catch can is simple, less restrictive, but it has to be mounted high enough and not too tall to take into account catch can filling up.

That's why most use AN fittings, female boss fittings (steel or aluminium, which I think both can be welded onto aluminium) that are welded onto side of a custom catch can.