Real ca18det catch can/ popping dipstick

[Soonboosted240]

Ok I have been searching google for like 2 weeks now and have been talking to other 240 owners with ca18det swaps and have been getting so many different answers and so many do's and donts I'm so sick of it haha help would be so greatly appreciated!!!!!

Here's the scoop ca18det swapped coupe runs good but it has it's days
It has a huge fmic, sr t25, hks 13psi wg, 3" from turbo back, aem wideband, rc 550cc, tuned ecu, and a e60 maf, and turbo xs catch can etc....

I run 13 psi daily driven on it and AFRS are great! It pulls hard and is a blast to slide etc.... Whenever I hit anything like 13psi or bounce rev in
1st or 2nd and so on the dip stick pops and oil sprays
The underside of my hood and gets everywhere..... I have been told I am running my catch can 100% right by everyone I have showed... I have a turbo xs catch can and it has no external breather and only has to hose ports I'll post a pic in a min of my setup! Basically I wanna know why my dipstick keeps popping and if my catch can is routed correctly and if not how is it suppose to be routed?!?!?!? Thanks in advance!

[Soonboosted240]

This is how it was routed when I purchased it, the 1st hose your seeing on the catch can was just to atmosphere but I was getting crazy amounts of blow by, so I got a longer hose and connected it to the pcv valve.... So I am under the impression that my dipstick is popping because I have no breather in my system or because there's a problem with the way it's hooked up thanks again any help would be great pics would be great pics would be even
Better

[themadscientist]

You are blowing the dipstick out because you are getting cylinder pressure in the crankcase. The engine was vented the way it was because he was treating a symptom, not the cause. When you restored the system to it's proper arrangement you ripped off the band-aid and the "problem" returned. It's likely blowing past the rings if you getting such a dramatic pressurization.

Run a compression check and I think you will find low readings. Time for an overhaul.

[Soonboosted240]

Already ran a comp test and a leak down test results came back with flying colors . So its not blow by from the rings I want to say its because my catch can doesn't have a breather in it

[themadscientist]

I was running a T04E with weak rings and the stock catch can and not getting that sort of blowby. If you think it's the lack of a breather then give it a shot. It can't hurt.

[Soonboosted240]

I will try that I have read that Instead of going to the pcv valve I should have. By g welded onto my intake intercooler piping and run it pre turbo?

[themadscientist]

Here's how I ran mine.

[TheMAN]

This is how it was routed when I purchased it, the 1st hose your seeing on the catch can was just to atmosphere but I was getting crazy amounts of blow by, so I got a longer hose and connected it to the pcv valve.... So I am under the impression that my dipstick is popping because I have no breather in my system or because there's a problem with the way it's hooked up thanks again any help would be great pics would be great pics would be even
Better

it's hooked up wrong
people you talked to have no understanding of how the PCV system works, that's why they tell you it's "fine".... it's not!
both hoses SHOULD NOT be tied together... the hose on hooked up to the intake cam cover should be hooked up directly to the PCV valve, otherwise a catch can in between, UNVENTED and NOT spliced in to anything else

the hose on the exhaust cam cover should go to the catch can and from the catch can either vented to the atmosphere via a breather filter or connected back to the suction pipe

the PCV system must have equalized air pressure between the outside and inside the crankcase, or it doesn't work... the system relies on outside air replacing what's in the crankcase while the crankcase vapors/pressures get pulled out via the intake manifold/PCV valve under vacuum (off boost)... on boost, the system should work in reverse, except the PCV valve is closed off and nothing from the intake manifold bleeds through to the engine... any blowby pressures will get pushed out through the breather hose (exhaust cam cover hose)... connecting the hose to the suction hose will help improve blowby scavenging under boost, but at the price of oily residue in the pipes and turbo.. but that is the legal way

[srt4monster]

what Theman said.

[boost_boy]

Unforunately, they are going to spit-up oil regardless under higher boost pressures than your 13 psi. TMS is right about one thing in the fact that you are creating excessive pressure in your crank case which is more than likely from your rings. Though you're getting normal readings in the combustion chamber via a compression tester, the lower tapered portion of your cylinders exposes the mechanical wear within that hardware and allows some blow-by. And some of that excessive boost pressure gets into the crank case and coupled with the operation of the rotating mass, creates enough pressure to push that oil going to the head to feed the camshafts, right through the breather tube on the exhaust side cam cover and that's not so easy to do. But don't worry, it will not affect performance. However, the spitting-up of oil can be annoying, so the best way to run around that is not to over-oil your engine. If you don't have an external oil cooler, there's no need to be putting 5 quarts of oil into your engine as even with a healthy engine, it will spit-up oil. good luck.

[TheMAN]

you can of course install an air/oil separator and plumb the drain back to the oil pan instead... it won't fix the blowby problem, but it most definitely will fix the oil spray problem... most catch cans are just gimmicks... just 2 tubes welded onto a can with nothing special inside... no baffles, no dipped tube, nothing... that's why most catch cans (even mad tyte JDM ones) don't do ****! real catch cans have baffles and they're hard to come by... but oil separator cans are a little easier to find because they are stock on some cars

or you can do this $5 mod:
http://mx5unleashed.com/tech/valve-cover.html

[cbh148]

So running 2 hoses from the valve cover nipples to a catch can with a big breather on it is bad?

[TheMAN]

yes... they need to be kept separated
if you want both sides hooked up to a catch can, use TWO catch cans... DO NOT TIE BOTH HOSES TOGETHER

[cbh148]

yes... they need to be kept separated
if you want both sides hooked up to a catch can, use TWO catch cans... DO NOT TIE BOTH HOSES TOGETHER

I don't have the hoses running into each other directly, they both run separately to the same catch can, which has a breather on it.

Like this:


Is this bad?

[TheMAN]

you're still tying both hoses together, so no difference... bad is bad!

[cbh148]

Whereas this is good?

[TheMAN]

no... intake side needs to be hooked up to the PCV valve instead of having a breather filter

[cbh148]

I don't have a PCV valve. That whole plate on the back of my intake manifold has been removed and blocked off. I think I have another one from my parts engine though.

Am I really at risk with my current setup? I get oil residue in my catch can, but it's never been enough to actually pour out.

EDIT: typos lol

[mdb4879]

post6198714.html#p6198714

If you only want one catch can it'd be most beneficial in between the exhaust cam cover and the suction pipe because under boost is when you'll have the most blow-by and since it goes before the turbo it'll put oil and blow-by in your intake plumbing. Whereas the intake side can go directly to the PCV valve then the intake because there aren't as many vapors and such when your cruising (under vacuum) and there'll only be a residual amount of that stuff and only in the manifold, runners, and ports.

Now, I don't really think it'll hurt anything not having a catch can since cars are made without them. They'll just keep the insides of everything cleaner and help prevent smoking issues. A catch can with baffles or some sort of material inside to aid in separation is ideal. I think most of them just have a tube going down to the bottom to allow condensation?

[cbh148]

Some people put those poofy shower lather scrub thingies in their catch cans to give the oil vapors something to adhere to.

I don't want any oil or oil vapor in my intake or piping, so I think I'll just stick with what I've got because there's countless people around here running my setup and no issues that we know of. If anything, I could get the PVC on and hooked up to the intake cam cover, since I'm sure my intake manifold is already dirty.

[TheMAN]

you don't need the stock intake back plate... you already got inventive enough to just use a piece of metal to block it off, what is there to stop you from drilling a hole in the intake and tapping some threads for the PCV valve? or what is there to stop you from using a different kind of PCV valve (meant for a different car/engine) and just plumb it to a vacuum source?

the reason for the PCV valve is so that air exchange and therefore crankcase vapor evacuation can happen... right now yours does nothing and a lot of it can stay in the engine while cruising

I can't emphasize enough that this is a balanced air system... you start screwing around with it without any understanding, you can end up making it worse than leaving it alone!
as far as I'm concerned in regards to cars... ignorance isn't bliss, it's f'ing dangerous!

[cbh148]

you don't need the stock intake back plate... you already got inventive enough to just use a piece of metal to block it off, what is there to stop you from drilling a hole in the intake and tapping some threads for the PCV valve? or what is there to stop you from using a different kind of PCV valve (meant for a different car/engine) and just plumb it to a vacuum source?

the reason for the PCV valve is so that air exchange and therefore crankcase vapor evacuation can happen... right now yours does nothing and a lot of it can stay in the engine while cruising

I can't emphasize enough that this is a balanced air system... you start screwing around with it without any understanding, you can end up making it worse than leaving it alone!
as far as I'm concerned in regards to cars... ignorance isn't bliss, it's f'ing dangerous!

I'm just saying, why go to that trouble when I've got a parts engine with that back plate on it? I didn't block it off on this intake manifold, the previous owner did. Personally, I wouldn't have done it.

And I see where you're coming from, but that still doesn't explain why damn near every 240 in the area is running the exact same oil catch can setup as me (many of them drift/dailydriver cars), and none of them have any issues. Not saying it's right, but I'm just not seeing any consequences.

[TheMAN]

I see what you're saying... maybe those issues takes a long time to come up

[mdb4879]

So I just had an idea. I know that on a lot of drag cars they have a sealed crankcase and a vacuum pump to keep it under vacuum at all times. This is suppose to give a little bit more power because there's less resistance from windage for the crank and pistons to fight. I don't think a belt driven pump would net any power on our motors because most of us aren't making enough power to overcome the loss from driving the pump. But has anyone ever thought to use the vacuum pump from a Volvo (the same one I have heard some use for the butterfly system) to put the crankcase under vacuum and also pull out blow-by and vapors?

I haven't looked into that pump, so without knowing about it my first guess would be that it may be too small for that task, but just some food for thought.

[TheMAN]

you'll end up popping the seals
why vacuum pump? because race car!
I'm serious... those cars don't run for more than a few minutes at a time, whereas we put many many hours on our registered, "legally" street driven vehicles

[louiswun]

http://www.facebook.com/photo.php?fbid= ... =3&theater
This is how I connect my catch can, I have PCV valve but it is blocked off, I don't have any popping dipstick problem.

[cbh148]

http://www.facebook.com/photo.php?fbid= ... =3&theater
This is how I connect my catch can, I have PCV valve but it is blocked off, I don't have any popping dipstick problem.

^^ more shields than the legend of zelda ^^

Yeah, no dipstick launches for me either.

[bentvalves]

there is so much misinformation posted in this thread it makes my head hurt.

[mdb4879]

you'll end up popping the seals

How would a vacuum pump cause seals to pop? To the best of my knowledge every seal in the motor has some sort of backing that keeps it from going in too far and makes the seal even/level when installed. A vacuum would pull the seal against that backing if anything. Even disregarding the vacuum pump, the crankcase is under a vacuum when cruising and idling because of the factory PCV system.

[mdb4879]

why vacuum pump? because race car!