Miata Turbo Forum - Boost cars, acquire cats.

Miata Turbo Forum - Boost cars, acquire cats. (https://www.miataturbo.net/)
-   Engine Performance (https://www.miataturbo.net/engine-performance-56/)
-   -   The definitive "How do I catch can?" thread. (https://www.miataturbo.net/engine-performance-56/definitive-how-do-i-catch-can-thread-78293/)

mj1176 08-07-2018 05:30 PM

ok I barely made it out this end of the thread with my head still on straight, but if I'm not retarded it seems like the best option for a turbo street car is to route both crank case ports into a catch can which vents to atmosphere and plug the port on the intake manifold? Or am I definitely retarded?

AlwaysBroken 08-07-2018 05:35 PM

Intake side vent goes to catch can, can goes to pcv valve on intake manifold

Exhaust side vent goes to atmosphere with a filter.

I wanted to put a check valve on the exhaust side but the wise men in this thread said that running the crank case under constant vacuum would be bad

sixshooter 08-07-2018 05:56 PM


Originally Posted by AlwaysBroken (Post 1495267)
Intake side vent goes to catch can, can goes to pcv valve on intake manifold

Exhaust side vent goes to atmosphere with a filter.

I wanted to put a check valve on the exhaust side but the wise men in this thread said that running the crank case under constant vacuum would be bad

No. Try not to be a retard as he mentions above.

Originally Posted by mj1176 (Post 1495265)
ok I barely made it out this end of the thread with my head still on straight, but if I'm not retarded it seems like the best option for a turbo street car is to route both crank case ports into a catch can which vents to atmosphere and plug the port on the intake manifold? Or am I definitely retarded?

Yes.

ChrisLol 09-12-2018 05:53 PM

Turbo 1.6 w/ ~8psi boost.

Based on a collection of advice (from both MT.net and local friends) I plugged the PCV grommet (cold side vent) with a PEX plug and ran the hot side vent to a VTA catch can via AN8 lines.
Internal holes leading into and through the hot side baffles are opened up to 1/2" (AN8 size)
Intake manifold PCV "in" port was removed/welded/is no longer there.
So, very simply, I have the one port out of the "hot side" into a catch can and VTA.

My issue is that I'm getting a full catch can after only ~15 - 20 minute session
If the drained oil is left to sit it never separates and therefore appears to be almost 100% oil.

I have experienced this issue on clockwise rotation tracks which have an abundance of sustained high-G right hand corners.
My hypothesis is that this is simply oil pooling in the VC baffles and being forced into the hose during these high-G corners.

My proposed short-term solution is to remove the valve cover and drill a few more holes into the bottom baffle plate to allow this oil that is pooling to drain. There is already 2 small 1/8" holes but I can always add more...
Long term solution (off-season) is to weld up the hot-side port and add an AN-8 or AN-10 bung facing directly upwards to hopefully keep the oil from being able to run into the hose in the longer corners.

Thoughts?

sixshooter 09-12-2018 06:06 PM

You have half the opening area I have. Mine doesn't do that anymore.

Two 5/8 hoses to a catch can and both sides of the valve cover breathing with internal passages enlarged to slow the air. It is necessary to slow the airflow to allow the oil droplets to fall out of suspension and settle out. Increasing the size of all points in the breather system will allow the slowing needed.

aidandj 09-17-2018 12:22 PM

Chris. Are your baffles fully sealed? Ed took his baffles apart one time, and wasn't careful enough when resealing. They puked oil out like crazy. Resealed the baffles and it was good to go.

ChrisLol 09-17-2018 01:00 PM


Originally Posted by sixshooter (Post 1501417)
You have half the opening area I have. Mine doesn't do that anymore.

Two 5/8 hoses to a catch can and both sides of the valve cover breathing with internal passages enlarged to slow the air. It is necessary to slow the airflow to allow the oil droplets to fall out of suspension and settle out. Increasing the size of all points in the breather system will allow the slowing needed.

I agree, the air must be slow enough for the oil to collect out of it. If I clean everything up and empty the can It collects the vapor as it should and does not start blowing out until the catch can is overfull. You're saying the holes in the valve cover and the hose itself is too small so the oil is not slowling enough inside the VC, before the catch can.... Once the oil vapor reaches the can it finally slows down enough to condense and then it falls out of suspension in the catch can instead of the VC baffles where it should be happening. I could see that. So what I need to do is open up the cold side baffles then add back the cold side port hose and run that to the catch can as well.


Originally Posted by aidandj (Post 1502042)
Chris. Are your baffles fully sealed? Ed took his baffles apart one time, and wasn't careful enough when resealing. They puked oil out like crazy. Resealed the baffles and it was good to go.

Fully re-sealed with hondabond before re-installing the valve cover.

brainzata 09-17-2018 05:28 PM

I'm running the Radium Dual Catch Can. One can per crankcase vent. Closed system operation. One can plopped into the middle of each hose, hoses configured as OEM. Exhaust side baffle chamber drainage hole enlarged, and some mesh installed into both breather chambers, then sealed. GTX pcv used. Hasn't run yet so who knows!

sixshooter 09-17-2018 05:36 PM


Originally Posted by ChrisLol (Post 1502050)
I agree, the air must be slow enough for the oil to collect out of it. If I clean everything up and empty the can It collects the vapor as it should and does not start blowing out until the catch can is overfull. You're saying the holes in the valve cover and the hose itself is too small so the oil is not slowling enough inside the VC, before the catch can.... Once the oil vapor reaches the can it finally slows down enough to condense and then it falls out of suspension in the catch can instead of the VC baffles where it should be happening. I could see that. So what I need to do is open up the cold side baffles then add back the cold side port hose and run that to the catch can as well.

Yes, two big hoses and enlarged ports on both sides will let it breathe more gently.

Most people don't consider at twice the horsepower of stock you might have twice the crankcase gasses trying to escape. Three times at three times. Needs big passages to slow down and drop the oil or you end up with a mister fan at an outdoor bar...


ChrisLol 09-26-2018 10:42 AM


Originally Posted by sixshooter (Post 1502087)
Yes, two big hoses and enlarged ports on both sides will let it breathe more gently.

Most people don't consider at twice the horsepower of stock you might have twice the crankcase gasses trying to escape. Three times at three times. Needs big passages to slow down and drop the oil or you end up with a mister fan at an outdoor bar...

Thanks for the advice. It all makes sense. I'm going to band aid it for the last event of the year then take off the valve cover and add the AN ports sticking straight up. It will be easier to run hoses that way as well.

Eunos91 09-27-2018 01:28 PM

Mind hood clearance.

Gee Emm 10-09-2018 12:11 AM

I have the VC off, the hotside internal passage drilled out, and a 10-AN fitting replacing the external elbow. The covers are off the baffles (hotside only, for now), and I have some ebay copper scrubber ready to go.

Issue: when I cut the scrubber, I am getting lots of fine 'wool' particles as debris. Even after shaking, banging and blowing, there are a few appearing in the inverted VC.

Questions: did I get the wrong scrubber? What are the chances of any residual loose strands finding their way back into the VC, and thereby into the oil (only planning on two pieces, before and just after the divider in the final chamber)? I am not worried about them making it to the catchcan as that is not drained to the sump. If I did get the wrong scrubber, any tips on getting the right one next time?

Pending advice here, my default is to remove it as that way I can be sure of no ill affects.

Thanks for sharing your wisdom!

https://cimg7.ibsrv.net/gimg/www.mia...8e8ba4a9cc.jpg


Leafy 10-09-2018 06:43 AM

You're not supposed to cut the scrubber

sixshooter 10-09-2018 09:00 AM

This

Gee Emm 10-09-2018 04:10 PM

Thanks, that makes sense. However mine came in a long length (maybe half a metre/18inches), I am concerned that packed down to fit in the air passages they would be highly constricted, if it fits at all. I'll experiment with the spare length (I have a second roll).

Tran 10-13-2018 05:55 PM

If not copper scrubbers, what is the next best recommended scrubber material? "Chore Boy" scrubbers aren't available in the UK and I have reservations about putting unknown materials into a hot environment that would have bad consequences if they decomposed.

Gee Emm 10-14-2018 02:29 AM

This morning I bought a three-pack of SS scrubbers, for 90c at the local supermarket. I'm going to put one or two of them in the VC hot side in place of the planned copper. I think I just bought the wrong copper scrubber.

EDIT: HarryB, that is what I should've bought, but nothing like that showed up on my search for some reason. When I clicked on your link, it showed 'out of stock', but it is a good base for further searching.

HarryB 10-14-2018 07:57 AM

Tran, I literally just bought copper scrubbers from eBay UK.

https://www.ebay.co.uk/itm/Redecker-...72.m2749.l2649

Leafy 10-14-2018 08:58 PM

Just scrape the wire, copper will cut through the copper plated will scrape the copper off and show the steel.

m2cupcar 10-16-2018 12:32 PM

Scrubber alternative:
I'm using it in my catch can. It is for real copper.


All times are GMT -4. The time now is 02:51 AM.


© 2024 MH Sub I, LLC dba Internet Brands