Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[AndyStobbs]

Just make the holes in the cam covers and tee it into the existing breather system. Lots of vehicles use the cam cover as the vent system anyway.

[omega3000]

Quite a few cars run with these systems and have done for years .


Catch Tank

[dublin.jd]

Where did you get the maf btw?

Maf is original as far as I know. If it has been changed by previous owner/s original GM part was used. I reckon my gaskets failed due to age as I clean breathers regular and are clear at the moment. Inc. Breather box.
I'll have to a spare oil cap from breakers and give it a go. Then wait another 80k til New gaskets get hard to post results. (Joke) I'll just block breathers and see if valve works 

[dublin.jd]

T o use a catch tank, would I need to redirect breathers away from plenum and into catch tank?
Basically bypassing plenum preventing gases going back to the intake?

[Webby the Bear]

Why not use a vacuum gauge to look at manifold pressure with and without breathers connected and then again with the modified cam cover OR filler cap.

Post up results next week 

[Sir Tigger KC]

If I wanted to test this I'd do what Entwood suggested re modifying the oil filler cap and post up results. Then there'll be no argument. 

The oil cap was a good suggestion from Entwood and I reckon all it would take is to drill a hole through it and plug it with a bit of silicone. 

Not very scientific I know.....   

It would be scientific if you took vacuum readings before/after

Ooooo you're getting a bit technical there for me Webby!!     

But in theory any before/after reading should be the same as my take on this is not to introduce another vent but a weaker point than the camcover gaskets that would blow if the breathers got clogged.   

[dublin.jd]

Sir Tigger that was the original point of my post but it seems that got side tracked.
A few good ideas came of it though.
When I get around to doing it I'll post results.
Thanks all

[Webby the Bear]

 
Excellent. As ST says by disconnecting breathers (thus creating the blocked breather scenario) the reading should be the same .  . . This would prove either way I woulda thought ?

I,m sure someone will confirm or deny 

If so Dublin do you have a vac gauge?

[Sir Tigger KC]

Just had another thought!! 

If the breathers get blocked does the pressure build up evenly throughout the engine? 

So I may put my rudimentary pressure relief valve on the filler cap, only to find that the pressure builds up under the camcovers and they still blow....   

[andyc]

If your looking for a one way valve why not get a couple of windscreen one way valves, T Piece and some washer pipe. You can then join each valve the either side of the tie and then run one pipe back to where even you want it

Andy

[Entwood]

Just had another thought!! 

If the breathers get blocked does the pressure build up evenly throughout the engine? 

So I may put my rudimentary pressure relief valve on the filler cap, only to find that the pressure builds up under the camcovers and they still blow....   

The whole crankcase/camcovers is the same "void" .. there is no way one bit can have a different pressure to the rest .. 

[Webby the Bear]

I love science. And testing 

ST, are you taking over the white coat roles from Dublin? 

[dublin.jd]

Unfortunately I domy have vac gauge, but hope to get one soon.
At last the thread is going in the right direction

[AndyStobbs]

Why not use a vacuum gauge to look at manifold pressure with and without breathers connected and then again with the modified cam cover OR filler cap.

Post up results next week 

Too many variables I would say. MAP is a function of thottle position and load principally. Even the difference between having the headlights on or off would be enough to skew the MAP reading.

[Ian_D]

Interesting read.

I get what your saying too, and I think its potentially a good idea - after you've changed your gaskets that is... but you know that anyway! 


Anyway, bear with me as this is all made up in my head, but imagine this possible scenario...

Lets assume that you have just fitted new gaskets and cleaned the breathers etc, and the leak seems to be sorted.... you have left it running on the drive for 20 mins, and all is fine.
You drive a few miles to say Tesco and back... all seems fine...

So, we conclude that the gaskets have stopped the oil leaking? yes? We also assume that the breathers are working fine (as you cleaned them remember), plus its not pressurising the crankcase and peeing oil everywhere - so they MUST be working fine...


NOW, lets say you take your car on a really hard run... flat out up steep hills etc, lots of hard breaking on bends etc... and you get back, and OH DEAR, theres oil everywhere from the rocker gaskets. So we know that either A) the gaskets didnt seal properly, or B) its pressurising again. But hang on, it cant be the gaskets as they are new, and it didnt leak when you went to Tesco, and it cant be the breathers as they are clean... or can it?...

So what do we know about the ventilation system...
All engines will pressurise the crankcase - hence the need for it to be vented (into the intake system these days)
All engines create pressure because of blow-by. Which as the engine wears, increases...
The harder and faster the engine works, the bigger the bang, and there's more of them! hence the greater the blow-by....
The breather system uses tiny pipes + holes, which limit the amount of crankcase ventilation into the intake.

So, could... and this is only a 'COULD' it be that if you add up all of the above... you exceed the amount which the standard breather system 'USED' to cope with when it was a new engine?

Just my thoughts...