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take that and the one from the center iron and put it to a vented catch can.
The center iron one is the one I'm talking about, and yes, that's how it's arranged now, I just want to know where the center iron nipple goes to see how effective it'll be at venting both sides of the pan.
mainly the issue is running the catch can below your nipple level, it allows gravity carry the oil down into the catch can versus just the vapors.
rotaries in general, especially turbo rotaries generate a fair amount of crankcase vapors.
1) tee both the filler neck and center iron nipples to a single line leading to the catch can
2) have the catch can as high as you can mount it without any dips in the line
3) drain it regularly
oil viscosity also plays a large role in the crankcase vapors, thicker oils will not vaporize as easily as thinner weight oils. 15W-40 and 20W-50 are recommended if you have more than average blowby. you really can't eliminate blowby in turbo cases. some of my bridged turbo engines fill up the cans quickly so i recommended thicker oils and it slowed considerably.
Last edited by RotaryEvolution; Mar 7, 2013 at 12:15 PM.
mainly the issue is running the catch can below your nipple level, it allows gravity carry the oil down into the catch can versus just the vapors.
rotaries in general, especially turbo rotaries generate a fair amount of crankcase vapors.
1) tee both the filler neck and center iron nipples to a single line leading to the catch can
2) have the catch can as high as you can mount it without any dips in the line
3) drain it regularly
oil viscosity also plays a large role in the crankcase vapors, thicker oils will not vaporize as easily as thinner weight oils. 15W-40 and 20W-50 are recommended if you have more than average blowby. you really can't eliminate blowby in turbo cases. some of my bridged turbo engines fill up the cans quickly so i recommended thicker oils and it slowed considerably.
The best advice that I have seen on this condition. Now that I am running high boost I am having a lot of oil in my intake track and will have to get a catch can.
mainly the issue is running the catch can below your nipple level, it allows gravity carry the oil down into the catch can versus just the vapors.
rotaries in general, especially turbo rotaries generate a fair amount of crankcase vapors.
1) tee both the filler neck and center iron nipples to a single line leading to the catch can
2) have the catch can as high as you can mount it without any dips in the line
3) drain it regularly
oil viscosity also plays a large role in the crankcase vapors, thicker oils will not vaporize as easily as thinner weight oils. 15W-40 and 20W-50 are recommended if you have more than average blowby. you really can't eliminate blowby in turbo cases. some of my bridged turbo engines fill up the cans quickly so i recommended thicker oils and it slowed considerably.
The problems with FDs on track is that due to cornering forces oil goes up the oil fill neck and then gets pressurized behind it and forces a lot of oil into the catch can.
single turbo FDs vent the secondary turbo drain because it's on the opposite side of the engine so at least 1 of the vents can always breath.
hopefully the internal vent on FCs will solve this, I'm just worried it's not big enough (FD's use -10AN vents...)
I'll just run as is and see how it works out for now.
if it's really that big of a problem for you then ditch the oil filler cap and install a -10 line to the catch can off a modified cap and cap the unused ports.
if you still have problems then you really have problems(excessive blowby not remedied by venting).
Goopy performance sells the cap i mentioned btw. if you order it at least give me some credit through mention.
you can also consider an oil pan baffle to keep oil from the fill tube. if all of that doesn't fix it you have me baffled(pun intended!).
Last edited by RotaryEvolution; Mar 7, 2013 at 04:09 PM.
Saw this thread with same question. I have a 93 rx7 and currently replacing seals and gaskets. Saw this nipple on the center iron at the top near the filler neck tube blocked off. So this is for for venting the air pressure built up in the oil pan? Do FD's have this nipple or only FC's? Ive been looking through the 93 FSM and cant find what it originally hooked up to it. If 93's and up rx7's dont have this, then looks like someone in the past used an center iron from an older generation rx7?
So looks like I do have a center Iron from a 93 and up as should since I have a 93 rx7. I really dont want to start another thread in the FD section, hoping someone here can answer for me. So as my previous post stated, what does the nipple on the center iron near the filler neck go to on an FD?
Haha answered my own questions. I pulled up the emissions section of the S5 FC car and this is what it showed, goes to charcoal canister. So looks like for an FD that nipple doesnt go to anything and is just blocked off.
Haha answered my own questions. I pulled up the emissions section of the S5 FC car and this is what it showed, goes to charcoal canister. So looks like for an FD that nipple doesnt go to anything and is just blocked off.
that is correct, some FD housings have the nipple and some don't, its kind of odd
