i need to fit a catch tank, im getting lots of blow by gases when cornering on track and now that im pushing more boost i get loads when i turn it up. at 17 psi its fine though.

 

Whos fitted one? i know there has been some talk about re routing the pcv system, im not going this route, maybe when i next have the plenum off i could do, but for now im going to fit a catch tank.

 

Can someone also mention what size and how many take offs it needs

Thanks

 

James.

IMO the best way to do this would be mod the rocker cover to have to top takeoffs as shown then use those as your catch tank feeds - as mentioned that should limit the amount of oil going to the tank. Blank off the PCVs and ALL the other associated pipework including the ones at the front of the rockers which will just be causing an un-metered air leak if you have an atmospheric vented catch tank fitted. Essentially all you are doing is seperating the crankcase from the intake system then venting the crankcase to atmosphere.

Ideally, get a catch tank with 2 decent sized inlets and a large outlet. You really want around a 1/2" hose off each rocker minimal if you're venting to atmosphere. Also, pretty sure some scrutineers insist on tank >2liters for engine >2 litres.

If you pipe the outlet from the tank under the car then the smell shoudln't be an issue.

Personally, I'd relocate the PCV system to the top of the rocker covers and see how that helps before bothering with a catch tank.

 

Yeah i have seen that mod a few times. dont have the time to take the rockers off though :(

 

If it aint broke Jimmy dont mend it,the thrapping your cars had on circuits and its been fine,leave it alone if its ok.its not some performance mod that proves your running more power.It reminds me of people automatically fitting an adjustable fuel pressure regulator just because they are running more power on a higher flow rate injector when most of the time its not needed.

 

Yeah i know this but it burns loads of oil on track as i can see in my rear view mirror, and im pretty sure this is dangerous in terms of detonation.(i also hate the gunk in the ic's) I have never had my boost turned up on the track before i only ran 12psi at caste combe, Anyway i have a plan :)

 

IMO the best way to do this would be mod the rocker cover to have to top takeoffs as shown then use those as your catch tank feeds - as mentioned that should limit the amount of oil going to the tank. Blank off the PCVs and ALL the other associated pipework including the ones at the front of the rockers which will just be causing an un-metered air leak if you have an atmospheric vented catch tank fitted. Essentially all you are doing is seperating the crankcase from the intake system then venting the crankcase to atmosphere.

Ideally, get a catch tank with 2 decent sized inlets and a large outlet. You really want around a 1/2" hose off each rocker minimal if you're venting to atmosphere. Also, pretty sure some scrutineers insist on tank >2liters for engine >2 litres.

If you pipe the outlet from the tank under the car then the smell shoudln't be an issue.

 

Ok heres what im thinking.

 

The tank i have bought has 2 take offs both 12mm 1/2 inch, i can T one side which isnt a problem. the outlet is also quite large fitted with a filter thing, ( can route this to the bottom of the car though).

 

Ok so i block off all the pcv valves etc then If i plum a hose into the exhaust rocker cover in the stock location (as mentioned no time to remove rockers and change the take offs) but have the hose come out at a 90deg angle and guide it vertically upwards till its higher than the catch tank and even rockers then from there into the catch tank. woulndt this prevent the oil from sloshing out as the hose is higher than the rockers as we all know how gravity works, i may also retain some of the stock hose restrictors in the new hose i plum in. Then have the intake take offs Teed into the tank(these are pretty high on the intake rockers in stock location)

i also want it venting to atmosphere dont like the idea of dirty gases in the intake so a sealed catch tank wont work and it will prob over pressurise the crank system anyway.

 

i was thinking of having the vent guided to the bottom of the car to prevent the smell but thats just a luxury i can do without for now.

 

so what are your comments? its not a perfect system but it will work surely?

Edited August 13, 201015 yr by j1mmytt

Yes, what you have described should be fine. DON'T leave the restrictors in place though! The whole purpose of the breather system is the vent the crankcase blowby gasses and prevent the crankcase pressurising up and blowing oil seals etc. There is a surprising amount of flow required to keep the pressure down.

Yes, what you have described should be fine. DON'T leave the restrictors in place though! The whole purpose of the breather system is the vent the crankcase blowby gasses and prevent the crankcase pressurising up and blowing oil seals etc. There is a surprising amount of flow required to keep the pressure down.

 

Cool :) i wont leave the restrictors in then.

 

I was even thinking, you could prob get away with just adding extra length of hose pipe from the take offs and guiding it upwards then back down into the rocker for the same effect without the need for a catch tank, if your looking for a mild mod on your 300zx, anyone could do this it obviously wont have the same benifits as the tank venting to atmosphere but it will help with the oil slosh.

Edited August 13, 201015 yr by j1mmytt

How did this whole catch tank setup work out for you jimmytt, still going good?

Jimmer and John Dixon did mine, gets very little oil in it and was for a mk2 escort if remember right?

Jimmer and John Dixon did mine, gets very little oil in it and was for a mk2 escort if remember right?

 

but its a fresh engine init bud....should have almost zero blowback should'nt it

Thought ide dig this thread back up and tell you guys that getting rid of the PCV valves on my engine build was so far the best mod ive carried out for a few reasons....The main being that due to the design and routing of this system that iff the valve which in tecnical terms is a 2 way valve blocks and sticks then it can cause positive pressure into the sump of your engine which is not good for a lot of reasons. Ive blocked the threaded holes up on the plenum where they used to live and took 15mm internal size rubber hose from the single drivers side camcover breather and run it down to plumb into the front pipe by the throttle body and down next to the resirc valve...on the pass side ive come off the 2 rear breathers and along the bottom of cam cover to plumb into the throttle body there and down to the pass side recirc valve. Motor is running like a dream with a steady idle and not a whisper of oil mist or smoke from pipes..induction side is now just recieving fuel and air and not dirty hot gasses from the sump which is good..Sump is now not getting positive excessive pressure which is going to be kind to oil seals and no threat of dipsticks popping out (1st sign of a blocked PCV) so all in all all good. Ile try and do a vid of the freshly started engine and show how ive deleted my PCV,s and still retrained an OEM look....I must stress that this is a zero time engine and any engine with worn rings/bore/pistons would suffer from the need to fit catch cans as an oil mist on a hot motor could be the result of what ive stated so bear that in mind if you dont oil stains on the exit side of the breather pipes.

 

PLEASE NOTE...ime not an experienced zed mechanic its just what ive done to my car with only good results so take this post as my experience with my engine and dont bombard me with if ,buts,and why,s:laugh:

Looking forward to the pictures mate, doing a build as we speak, so anything I can do to make it stronger is all hunky dory :thumbsup1:

 

- - - Updated - - -

 

:thumbup1:

glad this has been brought up as i am doing it to my engine too

Looking forward to the pictures mate, doing a build as we speak, so anything I can do to make it stronger is all hunky dory :thumbsup1:

 

- - - Updated - - -

 

:thumbup1:

 

will do pics tomorrow for you mate:thumbup1:

Hi there mate, have you managed to take a few pics yet? I'm going to do this on my car and a visual guide would help no end. Cheers.

Still haven't tested this setup on the track yet amount other things.

I deleted the PCVs the other night as I decided to go with a pre-turbo balance tube as I'm running dual intakes (no Selin) and it was easiest to use the breather inlets on the 'accordions'.

 

1/4" NPT plugs in both inlet manifolds to replace the valves.

Both inlet cam cover breathers at the front routed to the battery area separately (14mm breather pipe, not tee'd).

Blocked the pipe that goes round the back of the head to the offside PCV (easier than removing and blocking at the rear of the engine). This runs from the rear of the nearside exhaust cam cover.

Blocked the outlet on the nearside exhaust cam cover that ran to the PCV.

Edited December 31, 201212 yr by Noz
Clarification

what was the reason to pipe both inlets together ?

as i dont think they share the same breathing system when there connected to cam covers

what was the reason to pipe both inlets together ?

as i dont think they share the same breathing system when there connected to cam covers

 

I haven't, I used one pipe for each intake cam breather routed to the battery area.

 

Like this pic (shamelessly stolen), but without a tee and going to the battery area instead of the front of the car:

ok .. just thinking about it the both heads to share a common breather its located in the head its self the both are linked with the middle inlet section

so the way u have done it will eliminate quit alot of pipe work anyways

are you using a breather catch tank ?

ok .. just thinking about it the both heads to share a common breather its located in the head its self the both are linked with the middle inlet section

so the way u have done it will eliminate quit alot of pipe work anyways

are you using a breather catch tank ?

 

Yeah, I'll probably route the lines into something nice and shiny in the new year. Until the shops open, I'll just use an empty 2l bottle of some beverage :D

so what about the pipe u got connected to both turbo inlet pipes as a balancer is it needed ?

so what about the pipe u got connected to both turbo inlet pipes as a balancer is it needed ?

 

Only because I'm running dual short intakes with a single MAF. It's not completely finished, and I might not need it at all. Alternatively, I may need to tee the IACV pipe into the centre of the balancer when I get time. Whatever gives me the best idle control along with the mapping. Saying that, it was idling perfectly last night when I was checking things over.

Ive tee,d the front pass breather into the hose,s running from the rear cam cover vents and done the same on the drivers side..this just leaves me 2 pipes running to the front underneath the rec valves. ive run the car for about 5 hours now and not one whisper of oil mist coming out the pipes.Getting shut of them PCV valves and letting the sump breath properly plus not putting stale crankcase air into the intake as the engine gods intended ime sure will result in a happier running motor and no positive pressure in the valve covers and bottom end.

Ive tee,d the front pass breather into the hose,s running from the rear cam cover vents and done the same on the drivers side..this just leaves me 2 pipes running to the front underneath the rec valves. ive run the car for about 5 hours now and not one whisper of oil mist coming out the pipes.Getting shut of them PCV valves and letting the sump breath properly plus not putting stale crankcase air into the intake as the engine gods intended ime sure will result in a happier running motor and no positive pressure in the valve covers and bottom end.

 

The one on the driver's side being the pipe that sits at the rear of the engine?

 

I don't get any oil mist either. There was oil residue around the PCV valves and the breather ports on the turbo inlet pipes, so a delete was past due!

The one on the driver's side being the pipe that sits at the rear of the engine?

 

I don't get any oil mist either. There was oil residue around the PCV valves and the breather ports on the turbo inlet pipes, so a delete was past due!

 

Yes Noel...