Anyone put a catch can on the hose from the oil cap area to the intake? My car has blown oil into the intake a couple of times now and it seems this comes up from time to time on others? Or is there a PVC valve in the works?
Olddragger

IMO if you're blowing oil into the intake you have other issues that are the cause.

I just know of too many RX-8s including mine that don't have this problem even with overfilled oil sumps.

It's quite normal. Not good, but "normal".

I put a can on the back of the airbox, it currently has about 20mm of oil in it!

The 2007s that are coming in DO have a PCV valve on them, :eek: and in Europe there is a retro-fit kit available, completely updated vent hoses, moved the intake connection etc.

Coming soon to the US......

S

Can you please give me your source of information regarding the 2007s and the European retrofit kit?

why would some cars have the issue and other's not? Apparently there is something more at play :dunno:

I have had that problem. So far they have said it's normal.....but there is a new baffled oil pan, and the 2006's have a reworked breather system that would blow the oil into the vacuum ports on the lower intake manifold and be burnt..

I think there is a retrofit kit for the breather out there for the problem cars.

Like TeamRX8 I think that there is a problem with this....I think that excess blowby is the cause....we will see

One of the threads about it in Europe.....

UK thread... (http://www.rx8ownersclub.co.uk/forum/viewtopic.php?t=10836)

S

Has anyone actually found out the causes of the oil going back into the intake?

So hold on the catch can and wait for the new vent system--any TSB's coming?
Olddragger

:yesnod: don't flame me but the way i understand it a p.c.v. valve is known to be a positive crankcase valve something the rx8 can't use because of the fact it's a oil burner.and if you do that it would cause it to burn even more.i could be wrong but time will tell.

make that a positive crankcase ventalation valve

I have this happen as well. Seems to corrolate w/ oil overfill, but if Teamrx8 and others run it overfilled with no issues, I don't know what to make of it.

I put a catch can on, but not for oil being blown into the intake. Never had that issue, don't know how so many people could have.

Lots of people, from my searching, experienced the sludge on the dipstick issue, though. All this is caused by is condensation. Since there was no PCV system stock, I added a catch can that goes from the oil filler neck nipple to the can, back to the intake. This has effectively stopped the condensation issue and I haven't had any residue on my oil dipstick since then.

I've never had that issue either :dunno:

I've never had that issue either :dunno:
I didn't for a long time either, but after about 6 or 7k I started to notice it more. I thought that was kinda odd, maybe it was the weather change that helped cause it. Either way, the catch can made it dry as a bone.

hi guys,i just my understanding on catch cans, to be honest i dont know much about rotarys but i have some knowledge on doing up nissan gtr engines, which i think is similar when it comes to the p.c.v (positive crankcase ventilation valve). The the oil deposits and gases that come out of the pcv is acutally polluted, and isnt very good for it to re circulate back in the engine, so it is re fed back to the intake so it can be totally combusted in the chambers, burnt and sent out thru the exhaust . Now when it comes to catch cans, the advantage of this is that it catches all the shit and prevents it from entering the intake, which is standard on most cars in my understanding . The downside of not having one installed, is that when the fumes enter the intake it isnt clean oxygen, hence it will lower ur fuel octane when the fumes enter ur engine . Having one installed will actually increase your octane level and will help with pinging to a certain extent, also help with combustion as cleaner air enters the chamber which will increase in slightly higher hp gains , and sorry i dont have dyno figures to prove this but i would highly recomend doing so, especially if u install eg canzoomers unit to retune the car i am sure it will help , sorry for all this write up but my 2cents worth as i dont write up much :-) but i sure read alot !
Hope thats easier reading

Welcome to the forum. Try some sentence structure if you really want someone to read your post.

there is no arguement that some of the renasis engines are having blow back issues. Question is why? Dont know?
New models have new type vent systems --dont know if that will be a tsb for the older ones.
So-----anyone know of a good catch can? reasonable price? best way to hook it up?
olddragger

Could I request some pictures here of what the heck you guys are all talking about?!

What does the ventilation hose look like and where does it attach to the intake.
What does the catch can look like?

I'm a bit lost. I had a PCV valve on my Protege 5 with a ventilation hose back into the intake but I disconnected it , plugged the connector at the intake and terminated the valve cover's vent with something that looks like a small air filter. Am I hot, cold, or warm? Yeah yeah yeah... what's a valve cover...

Thanks for the schooling in advance.

there is no arguement that some of the renasis engines are having blow back issues. Question is why? Dont know?
New models have new type vent systems --dont know if that will be a tsb for the older ones.
So-----anyone know of a good catch can? reasonable price? best way to hook it up?
olddragger
Good catch can? Anything really, you can make your own fairly cheaply from Home Depot parts even. But look on ebay, shiney metal ones are abundant for cheap prices. Don't believe the lie that any of those authentic "Greddy" or "HKS" ones are any better than the 5-10 dollar ones on ebay, because they aren't. A catch can is a catch can... all it is for is to collect condensation, or in your case oil, into and nothing more.

And as far as hooking it up, and for some reference pictures for 416to212, I have some pics. I ran a line from the oil filler neck nipple, which USED to go straight into the intake, to the catch can. From there the catch can runs back to the intake. This will "pull" the condensation/oil vapor out of the neck, through the line, and into the can. The large particles of condensation/residue will stay in the can and lingering vapor will go back into the intake to be burned up in the engine.

Here are the pics, you can see my ebay catch can in between the coolant overfill and intake.

http://students.washington.edu/dreww/installed1.jpg

http://students.washington.edu/dreww/installed2.jpg

http://students.washington.edu/dreww/installed3.jpg

This is similar to what I have, but it's a different shape/size.

http://cgi.ebay.com/ebaymotors/OIL-CATCH-RESERVOIR-TANK-CAN-ECLIPSE-GSX-GST-3000GT_W0QQitemZ8071221701QQcategoryZ46098QQrdZ1QQ cmdZViewItem

But really all you have to do is find the one that will work for you depending on where you want to mount it, how you want it to look, etc. I had this left over from my rx7 and just made it work, was fairly simple. They come with a couple brackets usually and from there you just have to find a place to mount it. Oh and the tubing they supply usually sucks, wont fit right, or is ugly so just go out and buy some rubber hose that will fit.

dDuB.

Thank you very much for your pictures. It has cleared up a significant amount of my confusion. However, I have one more question... Why can't we just vent into the atmosphere rather than actually catching it and sending vapours back into the intake? Besides the legal implications is there anything wrong with my suggestion. I did this on my Protege5, I can't see it being a problem in this application.

dDuB.

Thank you very much for your pictures. It has cleared up a significant amount of my confusion. However, I have one more question... Why can't we just vent into the atmosphere rather than actually catching it and sending vapours back into the intake? Besides the legal implications is there anything wrong with my suggestion. I did this on my Protege5, I can't see it being a problem in this application.
You could. The reason I even put a catch can on was to get rid of the condensation issue. Cars without a PCV system of some sort can develop condensation in the oil system. This is noticeable by a milky/sludge residue on the oil dipstick. This is what I was experiencing.

By only venting it to the atmosphere will not fix this particular problem. You need a source of vacuum to PULL the condensation OUT of the oil system and deposit it somewhere. That will then pull out all the extra oil vapor/condensation floating around and fix this issue. Venting it won't do anything.

What is the purpose even of venting straight to the atmosphere? I don't understand... If you're going to do that why not just leave it stock? There's no point in venting it straight out when you can just leave it the way it was stock. The only reason, like I said, I changed from stock was because there is NO PCV system present and I wanted a way to get the condensation out of the oil system.

I guess I just don't understand the purpose of venting it rather than leaving it hooked up... Not like it provides any gain.

where exactly on the oil dipstick would the condensed sludge show? i took a look at mine today & it appears to be sludge free... if i'm in the clear for now, would it still be a good idea to do this mod in case of future issues??

where exactly on the oil dipstick would the condensed sludge show? i took a look at mine today & it appears to be sludge free... if i'm in the clear for now, would it still be a good idea to do this mod in case of future issues??
Anywhere on it, maybe more near the bottom?

It is much more common in colder times of the year and in colder areas. Being in Miami you might not have to worry ever. Example is I got my car in the spring and all through spring/summer nothing, hit fall/winter and it started showing up. But the catch can fixed it during the colder months and I haven't seen it come back since.

thanks dDuB!
i might just give it a go if i'm bored one of these weekends to be safe...

just made a custom occ out of PVC pipe. steel wool and 2 inch piece of aluminum and the appropiate fittings--cost $20--stuff from Home depo.
olddragger

eBay: $18 shipped :)

eBay: $18 shipped :)
Yep.

did eveyone that did this mod have an existing problem w/ sludge buildup or did u guys do this to prevent any issues in case condensation ever did occur?

I had oil in my intake, and milky "sludge" on the dipstick.

I don't have those issues anymore.

I wonder if this oil blow-back is what has caused the carbon build-up another forum member had in his intake.

It was costing > $2000 to repair.

it sure does cause carbon build up.

RXeightr-- yep I think it sure could add to that problem. Besides heck its a $20 mod-and it sure will not hurt anything. The fact that the 2006's have a differant vent system also helped convince me.
Could have bought one but heck I like making stuff when I can. Besides since I made my own I have some other features in it than "just a can". Steel wool at the bottom to help catch the oil, separtator plate in the can, AND the fitting that catches the stuff from the engines oil tube is a 90 degrees bend directing the "stuff" to the bottom of the can and the steel wool. I am going to inprint"REDMAN TOBACCO "design on it--or maybe "mountain DEW"
I had blow back into my intake and mushy dipstick stuff.
OD

OK - you guys have convinced me to do this. Especially rxeightr's post about the intake carbon.

since i had my SSV's replaced already i'll check the tube again this weekend... though i believe i checked that once a couple years ago and didn't see a problem

OK - you guys have convinced me to do this. Especially rxeightr's post about the intake carbon.

Another convert here. Where are people placing the can under a basically stock engine bay?

Another convert here. Where are people placing the can under a basically stock engine bay?

I mounted mine to the air pump bracket, fits snugly between it and the windshield washer resivoir.

http://www.thedailygoat.com/catchcan.jpg

http://www.thedailygoat.com/catchcan2.jpg

since i had my SSV's replaced already i'll check the tube again this weekend... though i believe i checked that once a couple years ago and didn't see a problem


ok... so i just checked and found a horrific amount of oil/water/crap in my intake accordian tube :cussing:


does anyone know if the cheap e-bay cans that look like the greddy cans actually have the same baffling/screens inside to get the oil to condense out of the air, or do those things only look alike from the outside???

^^Bump^^

And thanks Supergoat for the pics. Looks like a great place. Where did you bolt to?

Yes, any pics? That is the exact same unit I purchased but in polished (bling) finish.

Yes, any pics? That is the exact same unit I purchased but in polished (bling) finish.

can you check to see if anything is going on in the inside of those things? I'm hoping they are not that cheap because its just a hollow can inside :Eyecrazy:

When I get mine - I'll snap some pics.

When I get mine - I'll snap some pics.

thanks...





what size tubing fits the stock fittings? I forgot to measure when i was doing this :wallbash:

takes 3/8 tubing.
nice mount Goat
OD

Thanks! I used 5/16 tubing myself. It fits snug, but is a pain to get onti the bung on the intake tract.

Mine is mouned to the big black bracket that holds the air pump. If you look in that area you'll see. I'll go snap a picture though, brb...

<grabs camera and runs outside>

ok, I'm back, here is the mount. I lost the other bolt, so I only drilled and installed the one. I'm going to go buy another bolt today and finish it, but even with just the one bolt it's not going anywhere.

http://www.thedailygoat.com/catchcanmount.jpg

SWEET! looks like u may have found the best spot...
anybody got that info on wheter or not the hollow ebay models are any good or what? what would be the difference b/w those & a greddy model?

Mine IS a hollow eBay model and it works just fine. :) No more oil in my intake and no more sludge on my dipstick.

Does it have a drain? Or do you need to pull it out to clean it?

The one I got off ebay has a magnetic drain plug on the bottom.

Also, I've had mine for many months now and the sludge problem has since been fixed. And it also has an extra tube on the side of mine to show the oil "level" in case it's getting full, still nothing to show. It's mainly for removing condensation in my setup, I never had actual oil pooling in my intake like some of you have been saying.

Yours looks a little different than supergoat's from the pics - and the one I ordered looks like sg's also. Hope it has a drain.

Yah mine's different than supergoats, I tried finding it on Ebay again and it wasn't coming up (this was last week). Not sure if whoever used to sell it stopped or what.

Yes, mine has a drain, and the little tube on the side to show the oil level.

Took the accordian pipe off the REVi intake today, and confirmed there was a small pool of oil condensation gathered in the accordian.

That's all I needed to see. A Catch Can is in my immediate future.

Thanks all for bringing this issue to the forum's attention.

still like my $20 homemade PVC with the downward deflection tube and the collecto steelwool.
But I think everyone needs this mod--e bay sure has bargins.
olddragger

is your mount higher than the stock intake vacumm thingy on the intake or higher than the oil one? Doesnt the catch can need to be lower than those or does it matter?
OD

It shouldn't matter. The oil gets separated during the sudden change of the flow direction.

ok thanks
OD

still like my $20 homemade PVC with the downward deflection tube and the collecto steelwool.
But I think everyone needs this mod--e bay sure has bargins.
olddraggerHey Olddragger,

Sometimes I just like to build stuff and this looks like something I could do. Does this look like what you put together?

http://www.neonrick.com/oilair_howto.html

yea basically. I made mine with a flat top style cap on 2 inch pvc pipe and placed both my fittings on top with a hose going down to the bottom(where there is steel wool to help collect) on the fitting from the engine oil tube. I then mounted mine on the front part of my revi intake (engine side) using one of the bolts holes on the intake that was suppose to hold the bracket for the engine cover(i dont have one) painted it up black and you can hardy tell it is there. Ran my hoses in descreet manner. Has a drainage valve on bottom and it is easy to reach. Easy to do--good luck man
OD

I knew i should have just made this myself...


I just got my rear Greddy can (the new version). First its gigantic (the can is 7" x 4" plus add almost another 2-3" to mount in on the width dimention) and at first glance will not fit anywhere in a stock engine bay. Also its just a hollow can just like the e-bay knock offs.

Not sure if i'm going to return it, sell it, or chop it up and reweld to make it smaller -shrug-

Hate to hear that -- guess I'll choose a different route.

Been thinking about just adding a small filter at the oil inlet tube & blank off the intake tube like another poster did.

you guys mean like THIS??? (a friend's RX-8)


http://i32.photobucket.com/albums/d37/Jedi54/Picture0172.jpg


http://i32.photobucket.com/albums/d37/Jedi54/Picture0152.jpg

The oil in the K & N filter is the after effects of the oil filler vent tube being routed from the factory to the intake manifold.

The 2nd pic shows an in-line filter, which should help. I also was thinking of using that type of filter, but just letting it vent to the atmosphere instead of back into the intake.

Mine -
http://www.rx8club.com/attachment.php?attachmentid=43592

Mounted from inside the airbox, after a little relocation of some stuff.
http://www.rx8club.com/attachment.php?attachmentid=44014

No drain, has some steel wool inside to function as a demister pad.

Works well, amount collected in the last year is around 5 ounces.

S

thank you jedi for posting that..:)...did I tell you that the rattling stoped....

Rattling stopped?! AWESOME news! Think it's time to upgrade to the Revi Intake! (like mine)

i should be receiving my catch can soon but, i have a question!!
would it be a good idea to add an inline filter in the line that goes out of the catch can back to the intake? that way the oil condensation can be collected in the can & the air leaving the can would be filtered before getting in the throttle body.
or... maybe i'm missing something in thinking that the air exiting the can would not be clean air...

good mount. thats where I mounted mine also.
R man need that suction from the intake
OD

10-4 OD

^^BUMP^^
for a reply to this....

i should be receiving my catch can soon but, i have a question!!
would it be a good idea to add an inline filter in the line that goes out of the catch can back to the intake? that way the oil condensation can be collected in the can & the air leaving the can would be filtered before getting in the throttle body.
or... maybe i'm missing something in thinking that the air exiting the can would not be clean air...

shameless BUMP....

i should be receiving my catch can soon but, i have a question!!
would it be a good idea to add an inline filter in the line that goes out of the catch can back to the intake? that way the oil condensation can be collected in the can & the air leaving the can would be filtered before getting in the throttle body.
or... maybe i'm missing something in thinking that the air exiting the can would not be clean air...

Its up to you but it is not needed. Everything is separated in the catch can during the sudden change of the flow direction.

shameless BUMP....
A little impatient are we? Jeez...

But yah, an inline filter is not needed at all.

thanks guys!
just wanted to clarify everything before i did my install...

UPDATE!!!
i went ahead & got my catch can from ebay, but i decided not to install it...
instead, i attached a breather to the oil exit & capped off the intake entrance...
i figured i'd go this route being that since i live in miami will proabably never experience any condensation issues. i wanted to see what'd happen if there was a cleaner burn...
all i can say is that there is definitely a NOTICABLE THROTTLE IMPROVEMENT!!!
i reset the ECU & have been driving it around for a while now... for all i know, resetting the ECU is what gave the car that added umph... but, nobody will know for sure...
my 2nd Gen K&N sounds a bit louder & the pedal is more responsive...

Where is the oil vapor that naturally occurs from operation supposed to go? One of the points of the oil system being attached to the intake in some way, usually through a PCV system, is to PULL the oil vapor OUT of the system and burn it up. Without a vacuum source to pull the vapor out, it will not exit easily on its own.

You'd be better off leaving it stock than what you've done. And there's no way this mod helped with power or throttle response, it's all in your head.

so, what would be the drawback of not venting as much vapor as possible through the use of the vaccum hose?
forgive my ignorance...

thats the problem dgrx--it will not vent without a vacumn source to "suck" it out. the purpose of the catch can is to clean up the stuff being sucked out. Your throttle response was probaly from your resetting the ecu just as you said. Hook the factory system back up man--:) helps the engine run cleaner and it wont get as much carbon buildup.
olddragger

I have to disagree. I put the breather on the oil stem and capped off the vaccum line. The second I cranked it, the rough idle stopped. The breather is puching air out at a pretty good rate. The can does a good job for what it does. However it does not keep a clean burn. The less vaccum on the intake the better anyway. It is like drinking a drink through a straw. If you poke a hole in the side, it makes it harder to get the drink in. Air rushes through the hole instead of the bottom of the straw. That is your vaccum. Depending on how dirty the filter gets, it could draw harder from the oil system vs. through the filter.

Has anyone out there tried both set ups? That is what we need. Guys with the catch can already set up should try it. Why not. We can put this dog down. Work in progress fellows.

dgrx8 has the same results I do. There is a big difference on the response. No bull. It feels smooth like 2nd generation rx7s ran. Very smooth and more responsive. I should add that I am in a hot climate. Prove us wrong. Try it and see. I will be waiting on results. Thanks guys.

well heck-- i was taught that if two people are telling you the same thing --then you need to listen. I have a catch can on and it will be really easy to place a breather --no actually--- what I can do is to leave the can as is(steel wool in the can anyway) and just detach it from the intake vacumn and plug that off with a cap.The catch can should then act like a breather. Will do tonight.
olddragger

sorry guys
could you explain me what is a breather ??? (perhaps my english is too poor)

do you have a picture

thanks

A breather looks like a mini K & N filter that will mount to the oil stem vaccum line. 9 bucks at Auto Zone. 5 min install. Leave the line hooked to the intake, with a cap on the end. I did this for winter time. Perhaps we will need then. Maybe not. If I have to change it back, I will pull the breather and connect the line back.

Does anyone know what the track cars are doing on this? Are they running cans or breathers?

I like to vent the vapors (basically oil smoke) into the intake.

There is no vacuum - the vapors aren't being "sucked out" at that point in the intake tubing there is no vacuum present. With my Revi intake there is even a possible positive pressure.

Venting the breather tube or catch can to atmosphere is no big deal, the only downside I can see is a possible oily film on stuff and the odor issue.

S

learning a lot here! My bad. I always thought that the airflow pass the fitting would provide a "suction" kind of like the front of the intake. Prehaps I am wrong. Stealth are you saying we have Ram Air affect going on?
I do know this. I tried the guys suggestion--now letting the catch can act as a breather/filter(yes there is an odor present but not bad at all) and I capped the intake fitting--------------------------- and :)-------there is increased throttle response-----noticeable. Dudes---thanks! I am unsure if WOT is any better but partial and anything below 3/4 throttle is much better. I already had a smooth idle so I cant verify that. If there are no negative affects from this --- then this is a good mod!
Now the question is "Why"
olddragger

I tried the guys suggestion--now letting the catch can act as a breather/filter(yes there is an odor present but not bad at all) and I capped the intake fitting--------------------------- and :)-------there is increased throttle response-----noticeable. Dudes---thanks! olddragger

Hi. bought a catch can set-up off of ebay last night. I plan on doing what you said above.

I think the noticeable difference is due to the car not sucking hot air in from the engine, but sucking cold air in in lieu of it....thus it is noticeable.

there is no arguement that some of the renasis engines are having blow back issues. Question is why? Dont know?
New models have new type vent systems --dont know if that will be a tsb for the older ones.
So-----anyone know of a good catch can? reasonable price? best way to hook it up?
olddragger


Sounds like more of Mazda's not acknowledging a known problem because they would have to spend money to Fit it. I'll have to pull mine to check on it.

i knew we were on to something here turbine...

I still think you're all crazy about the throttle response. But to prove it to myself I took the lines off the can, capped, and drove around for a day. Noticed zero difference in throttle response or idle, so I still think you're all crazy.

Also, the experience I got with just venting it with a filter on my 2nd gen rx7 was that the condensation problems were WAY bad. I got terrible condensation without the vapor being pulled out of the oil system. Added a catch can to it and poof, dry as a bone. So just something to look out for.

Checked oil yesterday. I used almost a quart. No condinsation. Quick question. Can condinsation occur in hell? I may hook it back when it stops pegging 90-105 degrees. Like I said before, the car does not have these problems unless it is hot outside. I am under the hood every other day. I will keep the breather on until I see some condinsation. Another question? How does water vapor find its way into the oil system? If there is water in the oil system, I would think my problems are elsewhere. I think the vaccum line on the oil stem is a part of the LEV equipment. The equipment has a flaw of pulling engine oil in.

So let me get this straight. I want to get the condinsation off my bud lite. The best thing to do is go into the closet and get my vaccum cleaner and stand over it for a couple of hours while it sucks the condinsation off. Please! It is faulty LEV, plain and simple. It may affect some cars, may not.

ok... here's my report after a whole weekend...
i did a few more things i should mention - i cleaned my MAF, K&N intake pipe, & throttle body. i noticed that i had barely sucked in any oil. i also want to mention that i live in Miami & have not experienced any condensation whatsoever.

on to my driving impressions...
what is most noticeable is defenitely the smothness. the impression of better throttle response might just be a result of feeling the car pull so smooth. it really does idle & drive a lot smoother... :icon_tup:

oldragger is defenitely feeling what i'm feeling at about 3/4 throttle. :beerchug:

dDuB, maybe you're not feeling it because you went into this mod so negatively b/c of your past experience w/ the 2nd gen. you have to be able to feel the idle & smoothness difference. you don't notice the slightest difference :icon5: :icon5:

Jaguar MBA & Oldragger, I'm not sure that the catch can will work to seperate the oil if it isn't attached to the vacuum line. simply attaching a breather or leaving the can's exit open will not get the sudden pressure difference needed to get the oil in the can. for those that are experiencing the oil in the intake, i recommend leaving the catch can on. & for those who aren't... i suggest the breather route.

this might be another option for those not experiencing any oil sucking...
3/8" inline filter (http://www.homedepot.com/prel80/HDUS/EN_US/diy_main/pg_diy.jsp?CNTTYPE=PROD_META&CNTKEY=misc%2fsearchResults.jsp&BV_SessionID=@@@@1460569558.1151935462@@@@&BV_EngineID=cceiaddiemellhicgelceffdfgidgin.0&MID=9876)

dDuB, maybe you're not feeling it because you went into this mod so negatively b/c of your past experience w/ the 2nd gen. you have to be able to feel the idle & smoothness difference. you don't notice the slightest difference :icon5: :icon5:

I seriously noticed no difference. The way I could tell was that when idling my shifter would still shake like it did before (slightly), and when I put my hand on it I could feel the vibration that was occuring at idle. So the "roughness" did not go away.

I like to vent the vapors (basically oil smoke) into the intake.

There is no vacuum - the vapors aren't being "sucked out" at that point in the intake tubing there is no vacuum present. With my Revi intake there is even a possible positive pressure.

Venting the breather tube or catch can to atmosphere is no big deal, the only downside I can see is a possible oily film on stuff and the odor issue.

S

Actually, it is a big deal environmentally. Crankcase fumes are an awful mix of partially-burned hydrocarbons, which is one of the reasons that PCV systems were one of the first anti-pollution measures instituted on car engines back in the 1960's.

any thoughts on why you couldn't just use PVC to make a catch can... because i can't think of any and its alot cheaper and easier to work with -shrug-

any thoughts on why you couldn't just use PVC to make a catch can... because i can't think of any and its alot cheaper and easier to work with -shrug-
Yes you could, it's not very hard and I've seen people do it.

made one today from PVC for about $15 and an hour of labor... has a level guage on and I put a nice baffle design inside for extra seperation, we'll see how it works

thats what I did
OD

rOter,

How about some pics? I'd like to see your creation.

rOter,

How about some pics? I'd like to see your creation.

here you go... fairly simple

a straight piece of 2" diameter PVC pipe, 2 caps, 2 3/8" barb fittings, 3 feet of 3/8" tubing, some PVC cement, and a hose clamp ... and for the level guage I found 2 fittings and a hose from the home aquarium section :hahano:

I got about a 10" long piece of pvc and cut it down to about 5", then used the scrap piece and cut a section out of it and drilled it a bunch of times to act like a baffle. If you'd see inside the curved baffle piece seals on the top between the 2 fittings and on the sides about 3/4 of the way down... figured if thats not going to make the oil drop out i don't know what will. Probably not needed as the greddy can i bought and returned was just an empty can - but i thought i'd go the extra step.

(I wanted black tubing but they only had clear - which i thought might be cool for the first month or so since since i'll be able to see if the can is doing its job by looking at the tube going in and coming out.)


In case you can't tell, its mounted between the air pump and the windshiled washer fluid tank.

good job! I found a good mount on the engine side of the RB intake.
olddragger

thanks

yea, i should have just done that the first time around instead of buying one, finding out it was too big to fit, and then paying for return shipping... that pretty much doubled my investment in the thing -smacks head-

So are our Crankcases constantly running then at approximately -15 inches of Hg? If no "air" is getting into the crankcase to replace what has been pulled out then we should be running a vacuum in the crankcase....?

Great ....another MOD.

anybody else done the breather mod???
i think we need a 'road draft tube' DIY...

road draft tube is a "no brainer". just run a tube from the oil filler neck to beneath the car(choose your own location) shield the tip of the tube with material of choice. Make the shield a little funnel shaped and there you have it. Dont have bends in the tube.
olddragger

here's what i had in mind...
attach a 90degree fitting to the oil stem & run a 3/8" vacuum hose down beneath the car from it...
my question is...
how can i achieve some kind of vacuum?

The funnel shape on the end and the cars momentum will create a small vacumn.
OD

Does this not need to be done to a 06?
I'll do it but if they remade the 06 then it might not do anything anyways.

i've seen some that have a 90-deg bend at the very bottom and have a small hole drilled at the FRONT side of the tube that faces the FRONT of the vehicle... this would get the air through the hole flowing straight out of the REAR eixt... i guess this is what would cause the most amount of gases to exit out of the pipe as the car moves...
is this logic right???

I just added a filter and let it be. Capped off the intake end.

learning a lot here! My bad. I always thought that the airflow pass the fitting would provide a "suction" kind of like the front of the intake. Prehaps I am wrong. Stealth are you saying we have Ram Air affect going on?
I do know this. I tried the guys suggestion--now letting the catch can act as a breather/filter(yes there is an odor present but not bad at all) and I capped the intake fitting--------------------------- and :)-------there is increased throttle response-----noticeable. Dudes---thanks! I am unsure if WOT is any better but partial and anything below 3/4 throttle is much better. I already had a smooth idle so I cant verify that. If there are no negative affects from this --- then this is a good mod!
Now the question is "Why"
olddragger


Because the engine wants pure oxygen and the fuel mixed in from the MAF.

Doesn't like poluted air. Hard to burn or uneven burn in chamber?

I just added a filter and let it be. Capped off the intake end.

well???
how does it feel for ya Razz1?

So are our Crankcases constantly running then at approximately -15 inches of Hg (Vacuum)? If no "air" is getting into the crankcase to replace what has been pulled out, then all of our crankcases are running in a vacuum???

bump

So are our Crankcases constantly running then at approximately -15 inches of Hg (Vacuum)? If no "air" is getting into the crankcase to replace what has been pulled out, then all of our crankcases are running in a vacuum???

Oil resevoirs for all kinds of machinery are usually kept under a slight vacuum. It keeps water out of the oil, burned oil vapors out of the oil, reduces leaks in some cases, and improves oil return flow.

If you turbo your car do you just leave this line unhooked also? Or do they want you to run it down to infront of the turbo?

Ive seen some pictures of the RX8 with the Catch can installed but no return line,just a breather.

Oil resevoirs for all kinds of machinery are usually kept under a slight vacuum. It keeps water out of the oil, burned oil vapors out of the oil, reduces leaks in some cases, and improves oil return flow.

rOtor, what's your take on capping the intake & using the breather at the oil stem on our 8's???

bump
Why do you keep bumping this?!

rOtor, what's your take on capping the intake & using the breather at the oil stem on our 8's???

my general take is realistically its probably not going to harm anything... did i or would i do it? no

I would say it is more responsive.

And anything to make the intake air cooler is good for me.

So far no oil mess from the filter. I believe those are old war stories and instances from old cars that make a mess.

In fact my 65 Ford does make a mess when I disconnect the tube and let it hang.

She has alot of unburned mixture to return to the intake.

New technology has reduce this signifigantly.

Why do you keep bumping this?!

b/c i'm interested in what is being discussed in this thread... :mad:

I would say it is more responsive.

And anything to make the intake air cooler is good for me.

So far no oil mess from the filter. I believe those are old war stories and instances from old cars that make a mess.

In fact my 65 Ford does make a mess when I disconnect the tube and let it hang.

She has alot of unburned mixture to return to the intake.

New technology has reduce this signifigantly.

it's only been a week so far... but, my breather filter is as clean as the first day it went on... :ylsuper:

When the car is running can you feel air pushing out where the breather was put on?
I'd check on my car but it just keeps rainning everyday.

guys --you will not feel a positive pressure from the oil filler tube when the engine is running in the driveway--at least I couldnt. Neither could I feel a vacumn from the intake connector being used by the hose from the oil filler neck. matter of fact there was no change in the way my car ran(for a short distance) with that intake connector open. That surprised me. Thought I would have at least a little rough idle.
Now I have had blowback and that is guaranteed positive pressure in our "crankcase". I had a large amount at one time. Small amount on several occasions. Since this mod I have had none. But it has only been on for a little while. No condensation in my oil either since this mod--did have a little before it.
I did do the downdraft tube thing but from my oil catch can- not directly from the oil filler neck. I dont like messes.
No one has answered my question concerning the tube that goes to the oil metering pump and what is its purpose. No one has any idea?
FI --I believe will need some modification to the crankcase vent system--dont know how much but in some recip's they have to add a 2nd and sometimes a 3nd pcv valve to get good seal. Heck some "strong" FI engines actually install a vacumn pump.
I am now finally able to voice what my engines response is to this mod. In cold weather and the engine is warming up the engine response to partial throttle is stronger. it pulls stronger than it does after the engine has warmed. That is how it feels now all the time. Cant really tell a differance in WOT. By the way does our car disconnect the egr at WOT?
olddragger

Well I drove 250 miles or more in 105 degree heat. The next day I drove another 125 miles
and Auto X in 108 degree heat.

Filter is still clean. No oil residue.

Just looked in my intake yesterday and found it to be a oil filled, the air filter had a large patch of oil right in the middle. It is a mess. I ordered a catch last night and will have it in this week end. I'll post pictures of before and after.

Any increase in mileage with a drop tube?

good info in here, I took my car in for the same oil in the intake problem last week, well I actually took it in several times for them to fix it.

On normal driving conditions, the car works great.. but when it is extreamly hot...and driving a bit hard WOT..by the time I get home.. almost a 1/2 Quart of oil. is in my intake..no matter how short the run.

when I was at my dealership for the last time, they told me that madza said they would change my engine the next time I bring my car in again.....do you all think it is worth it? by this I mean I am reading the fix being done here with the can...or my over oil blow off.. is def a problem....thank for your input..

If the new engine has the 06 breather then that might solve the problem, I haven't seen one yet but have read Mazda redesigned it.

don't flaim me for this question.. but does anyone know aprox. how long it takes to do an engine swap? I know everywhere is diferent...I am just wondering how long they will keep my car for..

What's up bro!

I've read on here that someone was getting an engine swap and their car was at the dealership for about 2-3 weeks.

Is the engine swap the greatest solution? hmm, not really sure... BUT... if Mazda is willing to do it since you're leaking so much oil then I think you might as well go that route.

P.S. You're leaking oil all over my intake?! :eek: haha, just kidding bro. You know I don't care...

What's up bro!

I've read on here that someone was getting an engine swap and their car was at the dealership for about 2-3 weeks.

Is the engine swap the greatest solution? hmm, not really sure... BUT... if Mazda is willing to do it since you're leaking so much oil then I think you might as well go that route.

P.S. You're leaking oil all over my intake?! :eek: haha, just kidding bro. You know I don't care...


ha ha don't worry jedi I will wipe it all clean for you, I did not take the car in yet, since I got it back I drove it in the same manner I did to see if the problem would repeat it self. but I have been so busy with work I did not get a chance to open up the intake to see if I can take it back now. The dealership wanted to keep the car, but mazda wanted them to move around the hoses to the intake"big joke" to see it that would help... ha ha....

I will cal you later...

the only thing i can think of think of the pcv valve as a vacuum diaphragm that opens n closes, u might just have a bad diaphragm, that doesnt close or close all the way when its supposed too............take ur 8 to mazda n let them check it out.....or just take out the pcv valve, put a breather filter over it n cap off the valve on the intake.........n f*ck emissions lol

Let them fix it.

With the number of miles you drive everyday to SD, it would be worth starting over with a new engine.

Installed the Greddy catch can today.

I used the area that Supergoat pointed out except mine can sit horizontally ;)

Stealth's place on the stock air box is great too. I know eventually it will be coming out though... for forced induction...

Installed the Greddy catch can today. ...Wow, the Greddy can looks really macho in there. :mdrmed: And what's with the mongo braces? It looks like you're ready to go bash into walls or sumthin. ;)

nice Greddy can . goes well with the blue stainless look you have going on. Now off thread but color the greddy name in blue.
Glad a lot of people are on to this. I really think it does help some cars. Dont forget also to use a long neck funnel when pouring oil down the filler pipe.
olddragger

Wow, the Greddy can looks really macho in there. :mdrmed: And what's with the mongo braces? It looks like you're ready to go bash into walls or sumthin. ;)

:D Thanks Paul!
The brace is real nice but lacks the master cylinder brace :(
We will be working one to add to it.
The brand is Revolution Motoring Communications I believe it is made in Japan.
Couldn't pass it up when I saw it. Matches up looks with the rear Mazdaspeed brace. It is much more rigid too. I noticed a difference in steering when I added it.

That's a good idea olddragger. :)

Ok so I took a few pictures of my 06 Rx8 today.
I dont know how the older models are piped but they are suppose to be differant I hear.

So this is what I'm GUESSING is differant.

http://i25.photobucket.com/albums/c58/tablets_/IMGA0009.jpg

The line goes down the past the SSV .

http://i25.photobucket.com/albums/c58/tablets_/IMGA0010.jpg

Breaks off into a T

http://i25.photobucket.com/albums/c58/tablets_/IMGA0014.jpg

and plugs into the intake runners below the SSV.
I couldn't get a good picture where it plugs in at cause its to dark and cramped plus I used my camcorder to take the pictures :P

http://i25.photobucket.com/albums/c58/tablets_/renesis13.jpg

The red circles show right about where they plug in.
Is it differant on the older models?

So they now decide to burn up the gases in the exhaust instad of recycling into intake.

So they now decide to burn up the gases in the exhaust instad of recycling into intake.

That is the intake.
It just looks like the are piped to the very bottom of the manifold to avoid it running down into the filter

so the new system goes to a 'direct" type. There sure is a lot more vacumn there than where it is on the older models. looks like mazda recognized potential problems in this area. Maybe all that we have been speaking off! That is a much better system.
OD

i was having a problem with my 8 prior to the engine being warmed up. if i accelerated to anywhere above 4k it was like my rev limiter was kicking in and the car would buck me until the engine would just start to warm. As long as the engine was warm i never had a problem. i know you guys may flame me saying... you need to warm your car. blah. anyway i removed the line from the oil fill neck and replaced it with an Autozone stainless steel filter and put a bypass cap and tyrap on the Intake nipple. this may sound crazy but now i can rev it to the beeps even when the engine is cold, and no more embarrasing cutback for me. if you guys experience the same cold engine hesitation probs id be interested to see if this works for you as well. The Autozone filter cost me 14.99 and the bypass assortment caps cost me 2.00. well worth it in my opinion

i know you guys may flame me saying... you need to warm your car. blah. anyway i removed the line from the oil fill neck and replaced it with an Autozone stainless steel filter and put a bypass cap and tyrap on the Intake nipple. this may sound crazy but now i can rev it to the beeps even when the engine is cold, and no more embarrasing cutback for me. if you guys experience the same cold engine hesitation probs id be interested to see if this works for you as well. The Autozone filter cost me 14.99 and the bypass assortment caps cost me 2.00. well worth it in my opinion

I doubt the change effected your cold reving...

I'm not going to chide you for reving the engine while it's cold. You'll know if you made a mistake when your engine starts leaking coolant. I'd prefer it if you had to pocket the expense instead of mazda though.

The ECU is programmed to cutout when a person revs and the car is still cold. To protect from accidentally revving the car and causing damage.

I don't drive my 8 till the idle drops to 1500 rpms. It doesn't take long and then I don't go above 4k till it has been up to temp for 5 minutes. This is especially important in the severe cold.

I would think that the top of the oil filler gets most of the water condensed when outside is cold. As the engine warms-up, that water evaporates and gets sucked into the air intake, causing bucking. The shock sensor would kick in and cut power - not the rev limiter. The mod above moves that water into the filter, hence engine is drier until is fully warmed-up.
However, high RPMs when engine is cold is a very, very bad idea. As 4ytsp mentioned, that is the way to do it properly. Sitting in the parking lot until the engine is fully warmed-up is safe but overkill, plus it wastes a lot of gas.

Heres some on Trade me in New Zealand (hope these links work)

http://www.trademe.co.nz/Browse/Listing.aspx?id=104787191

The above tank I'm think about getting or

http://www.trademe.co.nz/Trade-Me-Motors/Car-parts-accessories/Performance/Carburation-induction/auction-104628217.htm?p=1

For the GREDDY style tank.

The above tank I'm think about getting or

http://www.trademe.co.nz/Trade-Me-Motors/Car-parts-accessories/Performance/Carburation-induction/auction-104628217.htm?p=1

For the GREDDY style tank.

I bought one exactly like the one pictured in that link from a guy on ebay. Even the hose is the same. Problem is that the lid doesn't seal, and it had all kinds of goo on the inside. It really really stinks. I tried to seal the lid on but I made a bigger mess and some of the lid bolts didn't fit back on. I ended up tossing it and getting a real greddy catch can (they're only about $80...)

I bought one exactly like the one pictured in that link from a guy on ebay. Even the hose is the same. Problem is that the lid doesn't seal, and it had all kinds of goo on the inside. It really really stinks. I tried to seal the lid on but I made a bigger mess and some of the lid bolts didn't fit back on. I ended up tossing it and getting a real greddy catch can (they're only about $80...)


:worship: Thanks for that info. saves me having the same prob's. Theres aways some type of tank on Trade me, will keep looking :) cheers

still not even a drop of oil in my intake after 2 years :dunno:

still not even a drop of oil in my intake after 2 years :dunno:

Same here as is the case w/99% of the 8's through the shop. 1 % were overfilled at oil change joints.

My deal with this is which is better? Is the customized breather mod better or is the Mazda re-route to the lower intake manifold better?

Any thoughts on this?

I never used to have this problem (oil in intake) but just had it for the first time at track day this week . Ambient temp was around 12-15 degC which is colder than previous track days so this could be a factor .
Just ordered my catch can .