Jump to content
SAU Community

I Don't Think This Is The Correct Way To Install A Catch Can?


jimmytim
 Share

Recommended Posts

  • Replies 41
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Posted Images

Catchcans are just a bandaid for tired engines with a bit of blowby.. kinda like my ol' rb20 :)

Edit: 40th.. I just used a larger radius for the bend or you could try ENZED or something to get some elbows :)

Edited by bubba
Link to comment
Share on other sites

In racing you are required by rules and regs to run a catch can that holds a certain litreage. Also they arent there just to catch oil or bad breath from sad motors, perfectly healthy engines still have oil in the head and during corners or even acceleration oil and oil vapour can escape the rocker covers. Every engine has to breathe. A catch can just lets it breathe without feeding contaminated air into turbo/intake. If you want to run it properly/illegally, dont run it into the intake, and put a breather on your can.

Link to comment
Share on other sites

  • 8 months later...
Okay, how about this?

DSC_5328.jpg

Better?

SO this last picture is the correct way for running an oil catch can, wat type of oil catch can was used. how many inlets etc, i have a Greddy oil catch can i want to fit soon, was just wondering on this thread if it was the correct way for doing it for an rb25det, anlso was a breather used here? have u had any problems or noticed a difference anywhere? hamish :rofl:

Link to comment
Share on other sites

jimmytim man thats a lot of pipe. why dontcha trim it to the correct length? what can are you using btw?

hamish i dont think that a breather is used in this setup. the air is returned into the intake

Link to comment
Share on other sites

the last pic is hte 100% correct way of having it

trim down the hose and it will look a lot more neat

also, if i were you i would try to mount it somewhere near the coolant reservoir in the fornt corner of the engine bay.. where you have it now is too close to the turbo and heat + oil is no fun!

Link to comment
Share on other sites

ok i have a question. from what i have read in other threads, there should also be a return line from the can to through the PCV valve (relocated) and into the plenum to prevent it from sucking oily air from the driver's side cam cover on idle. does this air have to come from the can? i mean can i run a setup like jimmytim and just have the pcv valve pulling external(underbonnet) air?

Link to comment
Share on other sites

ok i have a question. from what i have read in other threads, there should also be a return line from the can to through the PCV valve (relocated) and into the plenum to prevent it from sucking oily air from the driver's side cam cover on idle. does this air have to come from the can? i mean can i run a setup like jimmytim and just have the pcv valve pulling external(underbonnet) air?

It would then be a vacuum leak.

Not sure in the picture of the engine bay - where does the PCV hook in? If the can is venting to atmosphere and the PCV is still attached then its an incorrect installation. Unless you racing the car or there is a reason for excess engine breathing then just leave the factory PCV and rocker cover venting hoses standard as there is no gain on a slightly modified engine, apart from the slight reduction in octane as the oil mixes with the incomming.

Link to comment
Share on other sites

post-30915-1194789818_thumb.jpg

the Positive Crankcase Valve is a one way valve, pulling air from the cam cover on idle when the intake plenum pressure is low and closing when intake pressure is high (on boost). the actual valve is in the cam cover itself so ppl usually move it to the plenum and run a hose from the catchcan to it. similar to the one going to the intake pipe after afm. so you have one hose (or 2) from cam covers to can, one to the intake pipe and another thru pcv into plenum. if the pcv is just gonna be sucking can air anyway, does it matter if it sucks ambient air?

i assume no because the hole is small for one and the valve is only open on idle. anyone care to correct me?

Link to comment
Share on other sites

When installing my catch can I never blocked off the PCV as its only open on idle so not much oily air will be going in. Only install the catch can on the intake side to stop oily air going through the intercooler. – Same way jimmytim has it.

Link to comment
Share on other sites

Like I said if the PCV is drawing in ambient air then it is a vacuum leak. If your still running a AFM then this air is not being accounted for and hence will slighlty lean the mixtures out under vauum condtions. And no the PCV is not only open at idle but all rpm under vacuum.

Link to comment
Share on other sites

Just so some of you guys can see, this is how the mechanic set mine up. I do plan on putting to braided lines to the catch can just been lazy.

We also found I needed a breather on the rocker as it was pushing oil out the exhaust.

I also still have the PVC valve connected but again I haven't got a plug made for it, with it still connected it cause a little hunting on idle

and a flutter noise in the exhaust note when just cruising on steady idle (ie 60km/hr)

post-35997-1194837323_thumb.jpg

Link to comment
Share on other sites

hey i going to install my catch can as it been sitting on my shelf of parts in the shed for ages, which is a better place to mount the can? i have provided pics. :angry:

Looking at the car from the front, i either going, the left strut tower (drivers side) or the right. howeveer the turbo is on the right in standard position.

so any advice would be good, also should i block the bottom inlet?

post-36645-1194837922_thumb.jpg

post-36645-1194838014_thumb.jpg

post-36645-1194838164_thumb.jpg

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share




  • Similar Content

  • Latest Posts

    • Go to SP mufflers and get the muffler of size you want and make a nice mid muffler. It's about that simple! I have 2x 3.5 Magnaflow straight through Mufflers and while it's pretty loud with the Varex open, it's quiet enough with the Varex closed. You can also buy off the shelf Magnaflow straight through mufflers as well. You also have a turbo to quiet the car down too. Don't overthink it. Buy my extra Magnaflow muffler sitting on a shelf doing nothing (buy it new, ignore this part)
    • Centre-offset muffler under the floor, same as stock. Just....3.5". The change from straight pipe there to centre-offset will mean that you need to remake some of the pipe (add a bend or two).
    • Hey guys. So my R34 GTT has a custom 3.5” exhaust (done by previous owner) with a high flowing cat, and then just a Varex cannon muffler on the back. The car does drone alot and is really loud even on highway driving just cruising, as you can imagine due to the Varex muffler basically being a straight through with the valve open. As much as i love a loud RB, it can be a bit much with no other muffling in line and just driving casually. I wanted to lower the volume output on the exhaust a bit, as well as remove the drone (probably a way to do both at once), and was going to do it all myself as I am a fabricator and have done exhaust work in the past, so the fab work isnt my issue, im just not sure on the right product or type of product to use to get the job done, and i doubt an exhaust shop would be wanting to help me as they wont be making any money from helping me, unless they supplied the product? Anyway any help or guidance in best way to approach this would be awesome   Thanks in advance
    • Meh, whilst the Honda is a "really" good car and has potential if you want to drop coin on, it was uninspiring for me to look at, but, it did serve its purpose and is now in the boys hands, his happy, his girl is happy, as she wasn't to keen on the noisy old Patrol, and most importantly, the Minister for War and Finances is extremely happy that her "little baby boy" (6'2 nugget who is currently training to be a copper, which will make 3 coppers in the immediate "circle of trust") has a well sorted reliable car that doesn't guzzle diesel Me, I'm more than happy with the NC MX5 that I replaced it with, it's a fun little car that I like looking at, like driving, and yes..... I do like the fact that the maintenance and modifications that I have done/will do are plentiful and relatively cheap, well........ while staying naturally aspirated slow that is, and that's all I really need for a fun little daily, I can rev the 5hit out of it rowing through the gears and never really break the speed limit  In saying that wicked word, "modifications", I've already ordered something for some noise and an additional "3 ish" horse powers, or whatever it gives, in the form of a header, and, a new set of "cheapo" BC coilovers that are already sitting in the shed waiting to get put in, I had the same BC's in my old NB and found they were fine for the street, hwy, and the occasional track days I did in it, they have 6kg front and 4kg rear springs which is about 10% stiffer than the stock springs which I found worked well for their price  I've also already been in touch with MX5 Mania in Dural, so once the header is on it will get a ECUTek RaceROM tune there (I cannot rev match for 5hit, and I loved the RaceROM rev match and FFS in my old 86 "RIP") In other, maintenance news, I put some new sparkler plugs in it, and have a new set of DBA Street series pads to put in over the next day or so, I'm running the DBA street series in the SS and Honda and really like them, they work great and are not dusty at all I've also booked in a few days leave over this weekend to give me 4 days weekend do some paint correction and give the leather seats some conditioning and interior some Bissell and steam cleaning OCD lovin', the carpet and interior looks clean, but from my experience with the Bissell IRT carpet, and the steam cleaner IRT trim, looks can be deceiving I've also found that finding a detachable hard top is proving problematic, the main reason why I didn't like the NC initially was the power retractable hard top that I seen them with gave the roof line a weird look, the detachable roof though looks good, and is a same shape as a NA/NB hard top, similar, but unfortunately not the same as it has different fixture point on the front, so fitting a easy to get NA/NB detachable hard top is no bueno New Old cars are fun, cleaning, hunting and playing around brings much joy How are your beasties going? Do you still have the Skyline with the LS???, or Barra??? that you were playing with
×
×
  • Create New...