http://twinturbo.net/net/viewmsg.aspx?forum=technical&msg_id=908813

 

Found this link posted by lymon a while back while searching but wondered if anyone had some further thoughts. From reading the thread it seems duffman had a few reservations (and clearly im not clever enough to know whos right..)

 

Just ask as my pcvs need changeing and was wondering about taking this route..

Way I see it-the crankcase pressure alone will get rid of the vapours,vacuum is a bonus!-when I built the Chevy,it simpley ran 2 breathers on the rocker covers,and Boy!-did it breathe!!

But rather that than have all that oily cack going into my nice new engine! LOL! :smash:

You really need a vacuum and a source of clean air though to fully purge the crankcase. Best way would be to feed the intake covers through independant filters and have a vac pump, drawing through a catch can from the exhaust rocker covers. That way, none of the breather air is metered and oil life will be extended....

Group buy on 'leccy vac pumps! :D

so you would fit breather filters at one end and a vac pump sucking though the other..anyone know what pressure the crankcase gets up to as the vac pump would need to be higher to avoid through blow on the filters

Some heavily modded engines do breath quite heavily so would have to be capable of flowing enough air for blow-by PLUS vacuum. Wonder what's available....

Some heavily modded engines do breath quite heavily so would have to be capable of flowing enough air for blow-by PLUS vacuum. Wonder what's available....

Found this one PMSL!!

http://www.drjoelkaplan.com/shop/customer/product.php?productid=16141

Seriously tho'-this looks interesting........

http://www.martelbrothers.com/catalog/Electric-Vacuum-Pump-Kit-p-8787.html

Does look interesting - wonder how long it would last under continuous use though?

hmm its a thought

Does look interesting - wonder how long it would last under continuous use though?

Surely got to be rated for continuous use for brake vac? :duffer:

Yeah I suppose, although isn't it intended for boosted applications? In which case its duty would be pretty low...

So will the same situation apply to an NA Z32 engine as Daz's V8. Just vent the crank cases into the catch tank????

I dont "do " turbos!! In case you hadnt noticed! :cool:

So will the same situation apply to an NA Z32 engine as Daz's V8. Just vent the crank cases into the catch tank????

I dont "do " turbos!! In case you hadnt noticed! :cool:

 

Block off one PCV valve. T remaining pipe into adjacent rocker cover. Put catchcan in other PCV hose...

 

Think that should work....

Some more info which will either clear things up or confuse matters worse :D

http://www.twinturbo.net/net/viewmsg.aspx?forum=general&msg_id=1884979

 

Unfortunately the pic links to this one are dead, but you'll get the idea...

http://www.twinturbo.net/net/viewmsg.aspx?forum=technical&msg_id=801233

 

cheers

smithy

I am running a oil catch can system and done away with the pcv set up completely, i have a breather catch can with 2 inputs (1 from the left back rocker cover and one from the front right rocker cover feeding the oil tank), then the oil catch tank drain goes to the sump, (below oil level or the crank pressure will blow back the dirty oil into the rockers), Have done this on many a turbo car and had no probs. have been running this system for a few weeks now and had no probs so far, i check the tank a couple of time a week to see how dirty it is and i dont think a drop of oil has even been in it ?

so can someone make this simple for me :wack: on this diagram which is a n/a what do i have to block and what does my catchcan plumb into thanks

seems i might just have to conceed and fit new pcv valves and accept the job will need doing again at some point

im gonna just fit 2 catch cans pre pcv valves that way no dirty oil to gum up the pcv valves.

I don't see the problem with the PCVs? They're an absolute piece of piss to replace and absolute minimum mileage before failure would be over 30k miles!!! Its rarely the valves that fail anyway - more usually the front hoses to the intake rocker cover clogg up due to there being flame arrestors in there - look a bit like a pipe cleaner jammed inside it :)

No problem really duffman (for me at least) was just wondering really. Here about so many other bits that can be trimmed off (egr AIVV etc..) just wondered if pcv was one of them...

 

Il try and get my pcvs fitted before the weather gets too bitter!

Sorry to bring this back up but i have an idea to this and will get a diagram up later today but it keeps the pcvs and still allows clean air into the block.

right have done the diagram, have assumed that the pcvs are the in the same position on each side of the block, correct me if I am wrong. This is a development of a system we use on the CA18DET (uses a pcv as well) which allows air to be drawn in through a mini filter, the shit to be pushed out through the pcvs and collected in a catch can.

 

 

As I say I think this right might need a little adjustment.

Check valves are working against the PCV valves :confused: Remove the PCVs and you'll inflate the catch can with boost :D

your right sorry did that wrong, are the pcv actually on the inlet manifolds then? if so ditch them block the hole and then just use the two feed off the block that I have shown as blocked to feed the catch can.

 

Will work well then. going to go check my pals set up again and see where the pcv is on his car.

Nope because there's no positive purge on the crank case. You're relying on positive crank pressure to evacuate the system and not supplying clean air to flush it out... This will cause the oil to deteriorate very quickly...