PCV system - interesting read

[EVO-00X]

I'd like to know how he did the part in red font below or what he used for that matter? plus what effects its done by causing extra turbulence inside his intake manifold??? :huh:

QUOTE: Shot of the 2 3/8" lines to the intake with a valve each to hopefully keep the fresh air circulating well and not kill the car. The one on the right goes to a tube inside the intake mani that has a hole in each runner to take some vac from all of them. The one on the left is just off of the main section of the intake mani.

 

[MDK87]

Nah it's like that from factory Rob.
One sec, I'll take a pic for you.

 

[MDK87]

Ok the pics are kinda crap but maybe its enough for you to see the tube cast in the manifold that the guy is talking about. The shiny things inside the runners are the ports for cylinder 2 and 3. They each have their own but I couldn't get a good pic of all four.

 

[rob323]

dAMMIT, I'M GOING TO HAVE TO READ THAT ORIGINAL ARTICLE TO UNDERSTAND WHAT YOU GUYS ARE ALL ON ABOUT AREN'T I?

Double dammit, bloody caps lock :fuuuuu:

 

[rob323]

Ok, I just read it. How is what he did any different in idea to how they came from the factory? Just with larger lines and therefore more capacity and one way valves in the lines going to the intake manifold? Surely the engineers at Mitsubishi didn't have a clue as to what they were doing and just fluked it by accident?

 

[brisvr4]

I don't think the engineers at Mitsubishi thought about nutters like me trying to run 30+psi on a stock motor though Rob

 

[rob323]

Maybe not 30, but over 20 was common on the group A cars and almost that much on the Group N ones as well.

 

[MDK87]

Ok, I just read it. How is what he did any different in idea to how they came from the factory? Just with larger lines and therefore more capacity and one way valves in the lines going to the intake manifold? Surely the engineers at Mitsubishi didn't have a clue as to what they were doing and just fluked it by accident?

Yeah that's what I was thinking. He's just kicked the catch can out of the equation.
I don't understand why this method would be better than venting it to atmo, or through a catch can, then intake.
For some reason I really don't like recycling blow-by to the intake.
Tim can be the guinea pig with this one. Besides, he usually knows what he's doing, unlike some of us, like me...:blink:

 

[brisvr4]

Maybe not 30, but over 20 was common on the group A cars and almost that much on the Group N ones as well.

But what age did any of those motors ever get to? I'm thinking of this as something to help older engines, not those that get rebuilt every rally like the works cars....

 

[bazeng]

I don't think the PVC hoses are making most of the difference, I think its the lines that go to his intake pipe.

At the same time, you'd only be getting VAC in your intake pipe IF you had a restriction in the intake pipe.

Really, without restriction, the intake pipe should be at atmo anyway..

A good test for you guys is to not go to the extent of fitting all these lines as yet, but rather, add another breather to your rocker cover and test.

I've thought about doing this by using a stock oil cap, drilling holes to allow it to breath and measure the back pressure. Hopefully not too much oil pisses out. If it does, fab something up to keep the oil in.

A good atmo setup with a breather that is sufficient in size should do the trick. A vac pump would be the best setup though

 

[rob323]

I don't understand why this method would be better than venting it to atmo, or through a catch can, then intake.

I reckon that having the sump of a motor under vacuum would definately be better than having it at atmospheric pressure. For one, vapours condense under a vacuum so therefore, in theory at least, less misting. Most light aircraft motors run with a breather hose attached to the exhaust causing vacuum.

For some reason I really don't like recycling blow-by to the intake.

Recycling blow by to the motor when under load is certainly not good, but when the motor is "off throttle" then there is no problem. This is how the factory pcv system is set up.

But what age did any of those motors ever get to? I'm thinking of this as something to help older engines, not those that get rebuilt every rally like the works cars....

Yep, point conceded. Those with prehistoric motors should just hurry up and blow them up and have them rebuild.

At the same time, you'd only be getting VAC in your intake pipe IF you had a restriction in the intake pipe.

Really, without restriction, the intake pipe should be at atmo anyway..

Don't forget the venturi affect Baz, any airflow past the ends of those hoses will create a venturi effect to a small degree.

I've thought about doing this by using a stock oil cap, drilling holes to allow it to breath and measure the back pressure. Hopefully not too much oil pisses out. If it does, fab something up to keep the oil in.

You would need a splash guard Baz. Just take the oil cap off and start the car and you will see why .

 

[MDK87]

vapours condense under a vacuum so therefore, in theory at least, less misting. Most light aircraft motors run with a breather hose attached to the exhaust causing vacuum.

Well there's the answer to my question

 

[JayRome]

i shall be installing this set up tomorrow..... changing oil at the same time... so i can give you guys feed back.... on average my oil last only 3000km..... goes black pretty quick... if it lasts longer then that.. it works i guess....

 

[bazeng]

Good way to test Jay!
Those 2 + the stock 2... see if you can tap in a boost gauge to see if it is still under pressure

 

[JayRome]

Good way to test Jay!
Those 2 + the stock 2... see if you can tap in a boost gauge to see if it is still under pressure

yer will do when i have time again..

 

[brisvr4]

Only issue I can see with that Jay is the fact that there isn't any baffles under the oil filler cap.
Where the extra fittings are placed in Jacks cover is right above the baffles to minimise oil simply being sucked in. Try it anyway though.

 

[JayRome]

Only issue I can see with that Jay is the fact that there isn't any baffles under the oil filler cap.
Where the extra fittings are placed in Jacks cover is right above the baffles to minimise oil simply being sucked in. Try it anyway though.

thats exatly why the filters are there...... i can clearly monitor the amount of oil that comes out... so far non yet and i have been redlining it alot...