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304 VN AERO REBUILD (304 stroked to 350ci flat top pistons std 4" bore)

Deuce

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Catch cans on holden 304 efi rocker covers
If we want to keep things reasonable standard for emission, and legal registration purposes how we get on with running catch cans and still making the system legal
Had a look here on parts shelf and have a few stefs catch cans (single- hose), was thinking of utilising this by running the 2 rocker cover vents into the one catch can and then running a hose out to pick existing holden emission hoses

Is there a know fitting which can slip onto the holden rocker cover cent which can be adapted to AN 8-10 fitting
I see there is a fitting made for R26/Barra etc.
This is 22mm OD was thinking could drill out the inside to suit holden aluminium hose connection 16-17mm OD, then epoxy the fitting on
I'm sure I was reading somewhere that stock rocker ports are -10 size.
I've been thinking about this same question (as a future bridge to cross).
I re-did everything to stock style when fitting the COME TTB Mani.
Basically the drivers side cover breathes fresh air from the air box (I fitted a breather filter). And the other side goes through a PCV valve to the throttle body on the engine side of the blade.
Basically the air goes in one cover, through the motor (collecting vapour) and out the other side.

So catch cam should go between the passenger cover and the PCV.

I was thinking with mine though, I might breather both sides, and drill the manifold (-12?) and run the PCV straight out from the valley. I then have the option to go into a catch can and then through PCV back to t/b
 

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I have a few AN10 and AN 12 fitting here, so will take a closer look,
Maybe we can hack off one side of the fitting and leave the thread AN side and just drill out fitting and then epoxy on to rocker cover vent, then at least we have some fitting to start the transition
 

Deuce

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I have a few AN10 and AN 12 fitting here, so will take a closer look,
Maybe we can hack off one side of the fitting and leave the thread AN side and just drill out fitting and then epoxy on to rocker cover vent, then at least we have some fitting to start the transition
You should be able to weld them on (I don't trust glue products on these)
 

gtrboyy

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Pro holden guys all seem to like dash 12 fitting with baffle plate inside rocker opened up etc.

On my junk motorit's got dash 12 fitting back of intake near dissy & dash 10 left on rocker covers so can make it look like factory at first glance.

Other engine will get dash 12 fittings both rocker covers & intake.

Can't see why we cant just stick pcv valve in top of catch can plumb it back to be legal
 

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In theory it doesn't matter where the PCV valve is as long as the system is closed and not breathing to atmosphere.
 
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someguy360

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Catch cans are legal in Australia provided it’s a sealed can running through the pcv system. You can’t run a vented can.

I’ve got one on mine.

Dash 10 fittings in the rocker covers, drivers side rocker cover goes out to the can, and then returns to the PCV valve and the passenger side rocker cover is plumbed to the throttle (in my case the base of the air cleaner) same as the way the factory plumbs it.

Works really well, catches a surprising amount (my engines tired though). I also prefer the sealed can with internal baffles to separate the oil from vapours rather than vented cans, I've run both and the vented cans really stink of oil on a hot summers day in traffic when the breathers are venting to atmosphere.
 
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bjf66

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Pro holden guys all seem to like dash 12 fitting with baffle plate inside rocker opened up etc.

On my junk motorit's got dash 12 fitting back of intake near dissy & dash 10 left on rocker covers so can make it look like factory at first glance.

Other engine will get dash 12 fittings both rocker covers & intake.

Can't see why we cant just stick pcv valve in top of catch can plumb it back to be legal
Anyone happy to throw some pic up
 
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