Gamer Posted December 1, 2006 Author Share Posted December 1, 2006 That looks extremely drag orientated, love the accessory belt -Ian I was thinking the same thing, that car looks like it is a trailer queen suited for the dyno or some track runs. Very nicely done though. Link to comment Share on other sites More sharing options...
JohnA Posted December 1, 2006 Share Posted December 1, 2006 At least the alternator is in the loop, lol Link to comment Share on other sites More sharing options...
JamieP Posted December 1, 2006 Share Posted December 1, 2006 Jamie, I believe Digsy has commented on that setup before and didn't rate it for road use, I think... Hmmm i dont know what to do now... ive gone to the expense of removing the PCV valve and welding in a -12 fitting already... i dont really want to put that back in now. Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 1, 2006 Share Posted December 1, 2006 I'd just run it to atmosphere, don't plumb ANY of the breather back into the plenum. I have done this on all engines for years, and although I know where Digsy is coming from, I have never found it an issue. Venting blow by into the plenum is soley an emissions thing, IMO. On my Skyline engine I drain the catch tank back into the crankcase via a flapper valve, as they keep too much oil in the cam boxes and vent some into the catch tank. It's a complex system, but one I designed and is now copied by a lot of RB engine users. You shouldn't need anything as complex on a 2JZ engine as they have very adequate drain back holes in the head as stock, and blow little oil over unless the engines buggered. I'd take a pic of my set up, but my camera got wet and it's not back from being fixed yet. Link to comment Share on other sites More sharing options...
ajazyasin Posted December 1, 2006 Share Posted December 1, 2006 So what about... connection from plenum to inlet cam cover... exhaust cam cover to catch tank...catch tank to inlet pre-turbo? Would this system illiminate any oil contaminants in blow-by gas? Or is the direction of flow reversed? Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 1, 2006 Share Posted December 1, 2006 No, whay would you want to connect to the intake side at all? Just vent the catch tank to atmo, with both cam covers venting into the catch tank. Link to comment Share on other sites More sharing options...
ajazyasin Posted December 1, 2006 Share Posted December 1, 2006 what about all the -ve pressure talk thats been going on through the thread? If its going to atmoshere then thats all removed from the equation? ps. please excuse any numpty statements... not very up on this stuff! Link to comment Share on other sites More sharing options...
garetheves Posted December 1, 2006 Share Posted December 1, 2006 So Chris what would be your choice between these 2 options: 1. A simple filter straight off the cam. 2. A filter coming of a catch can that comes from the cam. Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 1, 2006 Share Posted December 1, 2006 So Chris what would be your choice between these 2 options: 1. A simple filter straight off the cam. 2. A filter coming of a catch can that comes from the cam. Vent cam boxes to a catch can, with baffles, venting into the can below the baffles, vent top of can to atmo, don't bother with a filter, unless you like something else to buy / clean / lose / break. Link to comment Share on other sites More sharing options...
garetheves Posted December 1, 2006 Share Posted December 1, 2006 Vent cam boxes to a catch can, with baffles, venting into the can below the baffles, vent top of can to atmo, don't bother with a filter, unless you like something else to buy / clean / lose / break. Cheers. looks like i need to keep my eyes open for a catch can. Do yuo have to vent both cams to the can or just the exhaust side? At the moment the inlet side goes into the intake manifold doesnt it?? Link to comment Share on other sites More sharing options...
Digsy Posted December 1, 2006 Share Posted December 1, 2006 I'd just run it to atmosphere, don't plumb ANY of the breather back into the plenum. I have done this on all engines for years, and although I know where Digsy is coming from, I have never found it an issue. Venting blow by into the plenum is soley an emissions thing, IMO. On my Skyline engine I drain the catch tank back into the crankcase via a flapper valve, as they keep too much oil in the cam boxes and vent some into the catch tank. It's a complex system, but one I designed and is now copied by a lot of RB engine users. You shouldn't need anything as complex on a 2JZ engine as they have very adequate drain back holes in the head as stock, and blow little oil over unless the engines buggered. I'd take a pic of my set up, but my camera got wet and it's not back from being fixed yet. The closed breather system is primarily an emissions thing, but certain turbo manufacturers do prefer a crankcase depression to prevent blwing oil through the turbo seals. Its been mentioned on here before and didn't believe it myself until I was personally involved in a Honeywell turbo installation. Link to comment Share on other sites More sharing options...
Alex Posted December 1, 2006 Share Posted December 1, 2006 It's noticeable aswell that there is testament out there from people like Kev Huntley saying he blew seals (whatever does it for you ) until he fitted a proper breather system. Link to comment Share on other sites More sharing options...
Gamer Posted December 1, 2006 Author Share Posted December 1, 2006 It's noticeable aswell that there is testament out there from people like Kev Huntley saying he blew seals (whatever does it for you ) until he fitted a proper breather system. I think it should also be noted that Kevin is running higher then normal boost pressure and running the car in very stressful conditions (1/4 mile runs). I am undecided on what to do at the moment. Link to comment Share on other sites More sharing options...
Ian C Posted December 1, 2006 Share Posted December 1, 2006 I replumbed my WOT breather back to the pre-turbo intake pipe for three reasons: 1) fed up of oil smear on side of cam cover 2) didn't like the idea of a fire if too much oil cam out for any reason 3) don't like the sound of a blown crank seal and the possible fire/engine lunching that could result from it. It cost like £15 to get done -Ian Link to comment Share on other sites More sharing options...
Digsy Posted December 1, 2006 Share Posted December 1, 2006 I think you'd be very unlucky to blow a front crank seal. As Chris and I have said on here before, the primary culprit has got to be a fooked engine running far too much boost for the state of its piston rings - i.e far too much blowby and a very positive crankcase pressure. I'd be interested to get past the "I vent my 2JZ to atmo because my mate vents his Skyline to atmo because all his mates vent their RX7s to atmo because they know that everyone in the US vents their Civics to atmo because high power drag racers vent to atmo" type of development and drill down to precisely why you would not want to run a closed system? 1) "I took my intake pipes off and there's oil in there. Something must be wrong. I need a catch tank vented to atmo". Wrong. A little oil in the intake system is normal. 2) "I took my intake pipes off and there's shitloads of oil in there. Something must be wrong. I need a catch tank vented to atmo" Correct - something is wrong. Either the stock breather system is fooked or you are running too much blowby because your engine is fooked. 3) "All high power cars run atmo breathers". True. Proper race cars do, but then again proper race cars get rebuilt every so often and durability isn't an issue. The majority of people on here are running daily drivers, or close to. 4) "I keep popping front crank seals. My breather system needs upgrading". No, you need to cure the source of the problem: Too much blowby. 5) "Closed breather systems are for emissions only, anyway". Partly correct, but if you don't care about emissions and are carrying over oil, then why not run a closed breather system? 6) "But I don't want to dillute my intake charge". Well, a proper closed system draws fresh air into the engine on part throttle. Its only on WOT that you are pushing all the blow-by back into the intake. If anyone has powercurves pre- and post-brether rework, then I'd be very interested to see them. I maintain that if you are carrying over so much oil that you think its affecting your combustion then you have more to worry about than your breather system. Link to comment Share on other sites More sharing options...
JohnA Posted December 1, 2006 Share Posted December 1, 2006 Why don't you guys temporarily replace the dipstick with a boost/vacuum hose and stick it on the dash for a while? If you see slight vacuum all the time, then your system is fine If you see pressurisation, then you know. It's not a permanent mod, fully reversible and dead easy to fit. turbo oil feeds hate anything over 1 psi in the crankcase, and ideally wouldn't want anything over a few tenths of a psi. [email protected] Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 1, 2006 Share Posted December 1, 2006 Why don't you guys temporarily replace the dipstick with a boost/vacuum hose and stick it on the dash for a while? If you see slight vacuum all the time, then your system is fine If you see pressurisation, then you know. It's not a permanent mod, fully reversible and dead easy to fit. turbo oil feeds hate anything over 1 psi in the crankcase, and ideally wouldn't want anything over a few tenths of a psi. [email protected] Good idea, the only way you'll see a negative pessure in the crankcase, under boost, is on an engine with a proper dry sump system running big scavenge pumps, usually done on mega high revvers, that need all the help they can get to stop ring flutter. For example, all F1 and serious sports car race engines have run scavenges that pul a partial vac in the sump, for years and years. It costs power to drive such big scsvenge sections, but for sure they more than make this back up with better ring control. All academic for road cars, but my take is why dilute the intake charge at all when you don't have to? I think Digsy and I will shake hands and agree to differ on this one I agree with him on 99% of things, it's boring to be too much in harmony! Link to comment Share on other sites More sharing options...
Gamer Posted December 1, 2006 Author Share Posted December 1, 2006 Hmm, where do I go on this one. Do I follow the advice of the bird man of the north or follow the advice of a man with an avatar depicting a scene that I would do better not to explain in print. I think I will go with the squirter on this one. I will run a line to my intake and continue to use the PVC to my plenum. Link to comment Share on other sites More sharing options...
JohnA Posted December 1, 2006 Share Posted December 1, 2006 can't go wrong with a DIY-jetpacked flying monkey Link to comment Share on other sites More sharing options...
JohnA Posted December 1, 2006 Share Posted December 1, 2006 Good idea, the only way you'll see a negative pessure in the crankcase, under boost, is on an engine with a proper dry sump system running big scavenge pumps... Well if you see a few psi under boost then you also know that the crank seal ain't happy. I also stuck boost gauges Teed off the actuators, the only way IMO to see the sequential show live. Boost/vac gauges are cheap, so is a length of vac hose and access to the inside of the cabin is a piece of cake (at least for the auto;) ) No need for electrical wirings either, I wouldn't recommend watching the action in the dark anyway. It's plenty dangerous taking your eyes off the road under boost in the day. Link to comment Share on other sites More sharing options...
ajazyasin Posted December 1, 2006 Share Posted December 1, 2006 Basically, if your engine has be built recently, go with the closed breather system as you prolly have a good tight engine. If your cars a slag then get a catch tank! Right? Thats on the asumption that rebuilt engines dont produce so much oil vapour in blow-by. Link to comment Share on other sites More sharing options...
JohnA Posted December 1, 2006 Share Posted December 1, 2006 A good tip is to use stainless kitchen scourer in the catch tank: It helps liquify the oily mist and keep it in the tank rather than go back in the intake (doing the octane rating no favours) Otherwise you just rely on the cooling down effect and rapid pressure drop to separate the oily bits. Every little helps Poundland, the choice of the discerning tuner. Link to comment Share on other sites More sharing options...
Digsy Posted December 1, 2006 Share Posted December 1, 2006 Good idea, the only way you'll see a negative pessure in the crankcase, under boost, is on an engine with a proper dry sump system running big scavenge pumps... I think Digsy and I will shake hands and agree to differ on this one I agree with him on 99% of things, it's boring to be too much in harmony! Not quite yet I've got dyno logs showing a healthy depressurisation (30mBar) in turbo and supercharged engines at full load in the mid / upper rev range. OEM road car engines never run anything above atmospheric pressure. Of course, to get a depressurisation through the WOT breather you need to have an air filter with an appreciable pressure drop accross it. Maybe another reason why proper race engines run to atmo. Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 1, 2006 Share Posted December 1, 2006 You can sometimes achive negative crankcase pressure by venting into the exhaust headers *ON N/A ENGINES* Volvo used this for years, witha flapper valve in the exhaust, so as to achieve exhaust pulse extraction at the right time. Link to comment Share on other sites More sharing options...
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