- -
UserInfo

Welcome Anonymous




Membership:
Latest: 996rshmp
New Today: 0
New Yesterday: 0
Overall: 878

People Online:
Members: 0
Visitors: 0
Bots: 13
Total: 13
Who Is Where:
 Bots:
01. Forums
02. Forums
03. Home
04. Forums
05. Forums
06. Forums
07. Forums
08. Forums
09. Forums
10. Forums
11. Forums
12. Forums
13. Forums

Staff Online:

No staff members are online!
We have received
31096529
page views since
July 27, 2010

Hits New Today: 3095
Hits New Yesterday: 26097

Server Time
21 September 2017 03:04:46 AEST (GMT +10)
Q&A > General Tech Advice > Revised catch can setup - thoughts oh wise ones? > Community Forums > Mustang Forum Australia - Mustang Tech

View posts since last visit • View posts last 24 hours • View unanswered posts
Forum Index > General Tech Advice

Revised catch can setup - thoughts oh wise ones? Reply to topic

Go to page 1, 2, 3 Next
Author Message
hybrid
Mustang King

Offline
Joined: Jul 27, 2010
Posts: 8248
Location: Sydney

0 👍 / 0 ğŸ‘Ž


I've been thinking about my setup lately and I must say I'm not really liking it. One of the important jobs of a PCV is to take contaminants out of the crankcase.

I got rid of mine because I was concerned about pressurising the crankcase with the supercharger. I think the reality is though, that with 5-6lbs of boost that just isn't going to happen. Even with a bit more boost it would be fine.

So right now, I'm just venting both rocker covers to the catch can, then have a filter on the catch can.
I'm thinking of using the setup in the image below:



So essentially still vent the crankcase to the catch can, move the breather/filter back to the crankcase and run a new line to the inlet manifold via a PCV/check valve, and also to the intake side of the supercharger with a check valve.

The theory is this:
- At idle and other times the engine is in vacuum, the PCV will open and create a vacuum in the catch can. The check valve in the supercharger line will be closed meaning that the crankcase should be ventilated.
- On boost, or at least non-vacuum periods the supercharger should continue to ventilate the crankcase by pulling air into it's intake, but via the catch can, so hopefully not too much crap will actually go through it.
- Even if the PCV leaks a bit, the supercharger should more than compensate for it to stop the crankcase pressurising.

I can keep an eye on the vent at the rear and if it's filling with oil, I don't have enough ventilation.

Any thoughts on a better way to do this?


- My 66 Coupe build thread
- My Build Gallery by date
- My Projects page

Last edited by hybrid on Fri Jul 07, 2017 10:45 am; edited 1 time in total

View user's profilePhoto Gallery
boofhead
Mustang King

Offline
Joined: Nov 02, 2010
Posts: 4433
Location: Brisbane

0 👍 / 0 ğŸ‘Ž


You get better performance if there is a light vacuum in the crank case. Also better for the seals - less pressure / load on them so less leaks. Allowing the pressure just go out to air via a oil catch can is ok but not ideal.

The question is how do you get a vacuum. Normally from the engine itself via a PCV valve.
No good for a forced induction car. Best way is to have a Vacuum source, e.g., electric vacuum pump, mechanical vacuum pump or exhaust vac system. It looks like you have another approach using the intake tube as a vacuum source. I do not understand what the top line;s purpose is (then again I am tired so not working on all cylinders).


I will someday think of something clever to say.

View user's profile
ozbilt
Site Admin

Offline
Joined: Jul 27, 2010
Posts: 10227
Location: Duggo Ranch

0 👍 / 0 ğŸ‘Ž


boofhead wrote
I do not understand what the top line;s purpose is (then again I am tired so not working on all cylinders).


To create vacuum in the catch tank?


Kerry

I don't try to explain myself to idiots. I am not the dickhead wisperer

View user's profile
hybrid
Mustang King

Offline
Joined: Jul 27, 2010
Posts: 8248
Location: Sydney

0 👍 / 0 ğŸ‘Ž


Yes the top line is hooked to the intake via a PCV like the original setup. It will create a low pressure in the catch can which should pull fumes out of the crank. Crank gets fresh air from breather as normal.

When there is no vacuum in the manifold, the supercharger should be pulling a vacuum via its intake, so it will take over the ventilation.

A page George sent me suggests using another check valve in the PCV line to stop ANY boost pressure getting to the catch can.


- My 66 Coupe build thread
- My Build Gallery by date
- My Projects page

View user's profilePhoto Gallery
boofhead
Mustang King

Offline
Joined: Nov 02, 2010
Posts: 4433
Location: Brisbane

0 👍 / 0 ğŸ‘Ž


Using the arrows as an air pressure directional flow the lower is the vacuum source line. The short line is the feed to place the crank case in vacuum. The vent provides the air into the crank case so any oily crank case air gets caught in catch can. Now the top feed going into the crank case does not make sense to me especially when you have a vent.


I will someday think of something clever to say.

View user's profile
hybrid
Mustang King

Offline
Joined: Jul 27, 2010
Posts: 8248
Location: Sydney

0 👍 / 0 ğŸ‘Ž


The arrows are PCV/check valves.

Yes, the short line ventilates the crankcase based on the catch can being in vacuum.
Both lines with the arrows will provide vacuum at different times.
The top line does not go to the crankcase. It goes to the manifold below the throttle plates, to the location that the PCV would have been connected to originally.
So instead of the PCV being connected directly to the rocker cover, it connects to the catch can instead.

At idle, the PCV should have more vacuum on it than the supercharger inlet, so no crap will go through the supercharger.
I'm trying to avoid having ALL the crankcase ventilation done by the supercharger, but it can do the work when the PCV has no vacuum.


- My 66 Coupe build thread
- My Build Gallery by date
- My Projects page

View user's profilePhoto Gallery
boofhead
Mustang King

Offline
Joined: Nov 02, 2010
Posts: 4433
Location: Brisbane

0 👍 / 0 ğŸ‘Ž


OK but the top line is relying on only a PCV valve stopping boost - I would think it would not be good enough a one way valve. But you never know. If it is then all good.


I will someday think of something clever to say.

View user's profile
hybrid
Mustang King

Offline
Joined: Jul 27, 2010
Posts: 8248
Location: Sydney

0 👍 / 0 ğŸ‘Ž


I just took apart my aftermarket rocker cover plug/PCV jobby and removed the PCV from it.
It seems very robust to me - all metal.



It seals as it should in one direction. I can't see why it couldn't easily handle 20 PSI - I could even test it with my compressor.
So I think I will configure this somehow to connect to the inlet manifold and I will use the old crankcase breather if I can find it.


- My 66 Coupe build thread
- My Build Gallery by date
- My Projects page

Last edited by hybrid on Fri Jul 07, 2017 10:43 am; edited 1 time in total

View user's profilePhoto Gallery
hybrid
Mustang King

Offline
Joined: Jul 27, 2010
Posts: 8248
Location: Sydney

0 👍 / 0 ğŸ‘Ž


boofhead wrote
OK but the top line is relying on only a PCV valve stopping boost - I would think it would not be good enough a one way valve. But you never know. If it is then all good.


I will test it with the compressor, but really... 5-6lbs boost?
Even if a little bit leaked past on boost, the inlet of the supercharger will be producing a lot of vacuum by then (thanks to air filter restriction), so it should more than compensate and keep the crankcase from being pressurised.


- My 66 Coupe build thread
- My Build Gallery by date
- My Projects page

View user's profilePhoto Gallery
gbx78
Mustang King

Offline
Joined: Jun 29, 2011
Posts: 2832
Location: NSW

0 👍 / 0 ğŸ‘Ž


would be similar for the brake booster check valve. I received mix information that the standard check valve would not be suitable for boosted apps but the brake place suggested it was fine. I guess depends how much psi they are rated at, whether it was a quality one and how much psi you are expecting


'You can never test fire too many times.' - Hybrid

'You can never have too many gauges' -
Boofhead

View user's profilePhoto Gallery
ozbilt
Site Admin

Offline
Joined: Jul 27, 2010
Posts: 10227
Location: Duggo Ranch

0 👍 / 0 ğŸ‘Ž


hybrid wrote

I will use the old crankcase breather if I can find it.


Look in the box on the shelf above the front fender ...... Poke

Just trying to be helpful (as I had nothing to add to the discussion) ...... 😄


Kerry

I don't try to explain myself to idiots. I am not the dickhead wisperer

View user's profile
hybrid
Mustang King

Offline
Joined: Jul 27, 2010
Posts: 8248
Location: Sydney

0 👍 / 0 ğŸ‘Ž


ozbilt wrote
hybrid wrote

I will use the old crankcase breather if I can find it.


Look in the box on the shelf above the front fender ...... Poke

Just trying to be helpful (as I had nothing to add to the discussion) ...... 😄


Thank you kind sir Snigger


Yeah this is the thing. Factory turbo cars still have boosters... they still have PCV.
So there's got to be some way it works. My diesel challenger runs 20lbs boost from the factory. Pretty sure it's still running a vac booster.

I would be happy to just go back to PCV only to be honest, but reality is it's really only ventilating during periods of vacuum which even on a naturally aspirated engine is not when it's under high load. So now that I've got this catch can, why not try best of both worlds?


- My 66 Coupe build thread
- My Build Gallery by date
- My Projects page

Last edited by hybrid on Wed Feb 08, 2017 10:51 pm; edited 1 time in total

View user's profilePhoto Gallery
hybrid
Mustang King

Offline
Joined: Jul 27, 2010
Posts: 8248
Location: Sydney

0 👍 / 0 ğŸ‘Ž


By the way - can't believe nobody commented on my elite mspaint skills.


- My 66 Coupe build thread
- My Build Gallery by date
- My Projects page

View user's profilePhoto Gallery
gbx78
Mustang King

Offline
Joined: Jun 29, 2011
Posts: 2832
Location: NSW

0 👍 / 0 ğŸ‘Ž


hybrid wrote
By the way - can't believe nobody commented on my elite mspaint skills.


Omg I was going to say your ms paint skills are outstanding cause it looks like Visio!!


'You can never test fire too many times.' - Hybrid

'You can never have too many gauges' -
Boofhead

View user's profilePhoto Gallery
nassi
Mustang King

Offline
Joined: Aug 01, 2010
Posts: 6318
Location: Perth

0 👍 / 0 ğŸ‘Ž


hybrid wrote
By the way - can't believe nobody commented on my elite mspaint skills.


Some things are beyond description.


View user's profilePhoto Gallery
All times are Australia/Sydney
Go to page 1, 2, 3 Next


Jump to:

SocialMedia

Like this page? Google +1 it!

ComingEvents
LatestForumPosts
Last 10 Forum Messages

hybrids 1966 Coupe Project
Last post by hybrid in Mustang Projects on Sep 20, 2017 22:33:40

69 Mach 1 351W 5 speed
Last post by ozbilt in Mustangs for Sale on Sep 19, 2017 21:16:54

Ronin187 - pics as promised
Last post by Husky65 in Mustang Projects on Sep 18, 2017 21:17:52

Jacko's Project
Last post by Ausjacko in Other Projects on Sep 18, 2017 15:48:34

diff gears
Last post by ozbilt in Pre 1973 on Sep 17, 2017 21:15:58

Megasquirt - a story of injection
Last post by hybrid in General Tech Advice on Sep 16, 2017 17:21:27

Sidchrome Project Car - Mustang Edition
Last post by StephenSLR in Pre 1973 on Sep 15, 2017 09:59:57

Hello, I don't have one.
Last post by cage in 2015 onward on Sep 15, 2017 08:51:26

Brake,indicator lights
Last post by 66STNG in General Tech Advice on Sep 15, 2017 08:04:39

tech article -exhaust drone
Last post by Keegan in General Tech Advice on Sep 13, 2017 20:47:25

TopPostersToday
   hybrid 
 Posts: 
 4 

   Shaunp 
 Posts: 
 4 

   ants 
 Posts: 
 1 

   cage 
 Posts: 
 1 

   Ausjacko 
 Posts: 
 1 

   Astro 
 Posts: 
 1