Please not another crankcase ventilation thread. - Page 5 - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


Engine Performance This section is for discussion on all engine building related questions.
Sponsored by:
Sponsored by:

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 10-26-2015, 01:30 PM   #81
Senior Member
 
Join Date: Feb 2009
Location: Philadelphia
Posts: 815
Total Cats: 47
Default

I'll chime in here since I've had 2 blackstone analysis done with different results

Can was plumbed to both sides of the valve cover (no PCV) and had a breather on top. The resulting fuel content of the oil was 1.5%, as well as the flashpoints and general life of the oil being low.

Then I changed to a setup with PCV that pulls from PCV side, through a sealed can, back into intake manifold, and have a breather on the exhaust side port of the valve cover. Fuel content of the oil was down to under .5% and overall oil health was improved
Mazdaspeeder is offline   Reply With Quote
Old 10-26-2015, 01:33 PM   #82
SADFab Destructive Testing Engineer
iTrader: (5)
 
aidandj's Avatar
 
Join Date: Apr 2014
Location: Beaverton, USA
Posts: 17,992
Total Cats: 1,457
Default

Quote:
Originally Posted by Mazdaspeeder View Post
I'll chime in here since I've had 2 blackstone analysis done with different results

Can was plumbed to both sides of the valve cover (no PCV) and had a breather on top. The resulting fuel content of the oil was 1.5%, as well as the flashpoints and general life of the oil being low.

Then I changed to a setup with PCV that pulls from PCV side, through a sealed can, back into intake manifold, and have a breather on the exhaust side port of the valve cover. Fuel content of the oil was down to
Down to what!!! The suspense is killing me.
aidandj is offline   Reply With Quote
Old 10-26-2015, 01:34 PM   #83
Senior Member
 
Join Date: Feb 2009
Location: Philadelphia
Posts: 815
Total Cats: 47
Default

Quote:
Originally Posted by aidandj View Post
Down to what!!! The suspense is killing me.
Sorry, I went back and edited, such a
Mazdaspeeder is offline   Reply With Quote
Old 10-26-2015, 01:34 PM   #84
SADFab Destructive Testing Engineer
iTrader: (5)
 
aidandj's Avatar
 
Join Date: Apr 2014
Location: Beaverton, USA
Posts: 17,992
Total Cats: 1,457
Default

ITS STILL NOT THERE. I MUST KNOW.

Btw, you cant use the less than symbol. It freaks out.
aidandj is offline   Reply With Quote
Old 10-26-2015, 01:36 PM   #85
Senior Member
 
Join Date: Feb 2009
Location: Philadelphia
Posts: 815
Total Cats: 47
Default

Quote:
Originally Posted by aidandj View Post
ITS STILL NOT THERE. I MUST KNOW.

Btw, you cant use the less than symbol. It freaks out.
That must be why it never saved my edit. Just changed again
Mazdaspeeder is offline   Reply With Quote
Old 10-26-2015, 01:42 PM   #86
Senior Member
 
Join Date: Feb 2009
Location: Philadelphia
Posts: 815
Total Cats: 47
Default

Here's a snap of the values. Far left is the PCV setup, far right is the non PCV setup, middle are targets.


Attached Thumbnails
Please not another crankcase ventilation thread.-80-ce8d2481_a182_4506_b37a_307a3b966ce8_zpsrqi51vf5_a225bf85caa0ac39daeb6142a0f587ace3212b63.jpg  
Mazdaspeeder is offline   Reply With Quote
Old 10-26-2015, 02:08 PM   #87
Moderator
iTrader: (11)
 
sixshooter's Avatar
 
Join Date: Nov 2008
Location: Tampa, Florida
Posts: 15,662
Total Cats: 1,560
Default

What roughly was the lifespan of each oil being sampled? Is yours a street, track, or mixed application? I like that you have some data here to contemplate.

I don't street my car much except for testing. It gets maybe 400-500 miles between changes because it needs fresh oil for the abuse of the track.
sixshooter is offline   Reply With Quote
Old 10-26-2015, 02:41 PM   #88
Senior Member
 
Join Date: Feb 2009
Location: Philadelphia
Posts: 815
Total Cats: 47
Default

Quote:
Originally Posted by sixshooter View Post
What roughly was the lifespan of each oil being sampled? Is yours a street, track, or mixed application? I like that you have some data here to contemplate.

I don't street my car much except for testing. It gets maybe 400-500 miles between changes because it needs fresh oil for the abuse of the track.
1700 miles on setup 1
2000 miles on setup 2

Setup 1 consisted of street driving, street tuning, dyno tuning. Driving was to work casually commuting, sometimes going out for spirited drives, no track time. I'd say the car got worked pretty hard when we were on it, but otherwise, I drive like a sane human being. When I take it out for a fun drive however, I generally wait for the local windy roads to clear out by midnight or 1am and go out at a fun pace.

Setup 2 consisted of street driving, no tuning, but lots of racing in "mexico", and a bunch of spirited drives. No track time here either as I was still chasing some issues with my tune (phantom knock). I'd say the car still got worked pretty hard when we were on it.

Nothing really compares to track driving though with sustained revs, boost, and general abuse. I will continue to do Blackstones in the name of science, and for the sake of catching things like bearing wear early before they destroy other things.

edit: I have not opened my intake manifold to take a look inside, but when I pulled the spark plugs, they looked normal.

Last edited by Mazdaspeeder; 10-26-2015 at 02:53 PM.
Mazdaspeeder is offline   Reply With Quote
Old 10-26-2015, 02:54 PM   #89
Junior Member
 
Join Date: May 2008
Location: Grants Pass, OR.
Posts: 449
Total Cats: 14
Default

Quote:
Originally Posted by sixshooter View Post
I disagree with the notion that the crankcase needs air to flow through it.
An air inlet path to the crankcase, called the breather and often incorporated into the oil filler cap, meant that when a draft was generated at the tube, fresh air swept through the crankcase to clear out the blow-by gases.


I thought that the discussion was about this, you just posted a paragraph with the above statement in it, so now you agree that an air source is needed to be efficient.

Last edited by jmann; 10-26-2015 at 03:33 PM.
jmann is offline   Reply With Quote
Old 10-26-2015, 03:03 PM   #90
Elite Member
iTrader: (2)
 
fooger03's Avatar
 
Join Date: Jan 2009
Location: Columbus, OH
Posts: 4,132
Total Cats: 187
Default

I initially thought misspelling, but then I considered that perhaps my vocabulary was lacking, so I googled.



Turns out the spelling was right. My vocabulary has been updated.
Attached Thumbnails
Please not another crankcase ventilation thread.-image.cfm-archiveid%3D11173-type%3Dimg-name%3Deffient-10mg-contain-30-t1522.jpg  
fooger03 is offline   Reply With Quote
Old 10-26-2015, 03:56 PM   #91
Elite Member
iTrader: (15)
 
patsmx5's Avatar
 
Join Date: Aug 2007
Location: Houston, TX
Posts: 8,796
Total Cats: 247
Default

Quote:
Originally Posted by sixshooter View Post
Wiki wiki wiki wiki.

Large diesel engines use a draft tube and breather to this day.
So, the PCV valve is an emissions device unless you are fording a river with a tank. And it is implemented because it is federally mandated for the control of hydrocarbon emissions. This is what I stated previously.


Anyone removing an oil filler cap from a typical running engine, even one equipped with a PCV valve, could certainly attest to the fact that blow-by exists in far greater volumes than the PCV valve is allowing the engine to ingest. This blow-by is constantly increasing in volume as the engine is running (just like exhaust because much of it is just exhaust that has made it past the rings) and can be piped to an oil separator catch tank and vented to atmosphere if one is unconcerned with emissions.

I am simply stating, again, that the consumption of crankcase vapors and the introduction of outside air to an engine crankcase while it is running is not a performance benefit but an ecological one. And I choose not to contaminate my combustion chambers unnecessarily with oil and other foul byproducts of the combustion process. I have seen the nasty trail within an intake manifold around the inlet for the PCV hose and do not wish to add those elements to my freshly rebuilt engine.
I posted that PCV was an emissions device a while back and even used Wikipedia as evidence, I didn't get very far with convincing deezums of anything.

But yes it's an emissions device. And it can help extend oil life in a street car.

I don't run PCV on my car for the same reason you don't run it. I keep my oil changed.
patsmx5 is offline   Reply With Quote
Old 10-26-2015, 04:12 PM   #92
Senior Member
 
Join Date: Feb 2009
Location: Philadelphia
Posts: 815
Total Cats: 47
Default

I wonder how much the vapors you eliminate by eliminating the PCV actually hurt the octane as someone said. And how intense of a blow-by you would have to have for this to make a real difference. Wouldn't an ECU be reading the octane at all times and be compensating for any changes?
Mazdaspeeder is offline   Reply With Quote
Old 10-26-2015, 04:23 PM   #93
Elite Member
iTrader: (15)
 
patsmx5's Avatar
 
Join Date: Aug 2007
Location: Houston, TX
Posts: 8,796
Total Cats: 247
Default

Quote:
Originally Posted by Mazdaspeeder View Post
I wonder how much the vapors you eliminate by eliminating the PCV actually hurt the octane as someone said. And how intense of a blow-by you would have to have for this to make a real difference. Wouldn't an ECU be reading the octane at all times and be compensating for any changes?
My car doesn't have an octane sensor inside the intake manifold, downstream of the PCV system, for every cylinder. So it doesn't read the octane. Or model it. Not aware of any car that does this to compensate for PCV.

Also consider that when you intake manifold is coated with oil from a PCV system, and then you go wide open, the air speed inside the manifold rises to its highest levels. That's when it's going to suck all the oil from the intake into the engine- at full power. Not ideal from a reliability or octane standpoint. But great for emissions.
patsmx5 is offline   Reply With Quote
Old 10-26-2015, 04:44 PM   #94
Senior Member
 
Join Date: Feb 2009
Location: Philadelphia
Posts: 815
Total Cats: 47
Default

Quote:
Originally Posted by patsmx5 View Post
My car doesn't have an octane sensor inside the intake manifold, downstream of the PCV system, for every cylinder. So it doesn't read the octane. Or model it. Not aware of any car that does this to compensate for PCV.

Also consider that when you intake manifold is coated with oil from a PCV system, and then you go wide open, the air speed inside the manifold rises to its highest levels. That's when it's going to suck all the oil from the intake into the engine- at full power. Not ideal from a reliability or octane standpoint. But great for emissions.
Pardon my ignorance in regards to tuning, I had a professional tune my car, so some of the things I "understand" might be false. I played with tuner studio software and saw there is an AFR target table, as well as some required fuel. I thought that the MS constantly compared the target vs actual values and could compensate for things. I may be 200% off base here.

As far as IM cleanliness, I have to say that when we did my Skunk 2 TB, we took off the top of the plenum, and I remember being very happy about the cleanliness of my IM runners. That was after having the setup for about 1000-1500 miles, again, no track, but hard pulls here and there, and I love the sunday night drags (no homo). Perhaps my ring seal is just good and I'm not getting a lot of blow-by. Perhaps my catch-can is doing a good job. I do have a section in there with some steel wool that helps catch the oil on the way in. It is not otherwise baffled inside.

This is the can I have:
https://i486.photobucket.com/albums/...ps71e28f98.jpg
Mazdaspeeder is offline   Reply With Quote
Old 10-26-2015, 05:30 PM   #95
Sadfab Union President
iTrader: (3)
 
Join Date: May 2014
Location: Kansas
Posts: 2,690
Total Cats: 113
Default

Quote:
Originally Posted by sixshooter View Post
Wiki wiki wiki wiki.

Large diesel engines use a draft tube and breather to this day.
So, the PCV valve is an emissions device unless you are fording a river with a tank. And it is implemented because it is federally mandated for the control of hydrocarbon emissions. This is what I stated previously.


Anyone removing an oil filler cap from a typical running engine, even one equipped with a PCV valve, could certainly attest to the fact that blow-by exists in far greater volumes than the PCV valve is allowing the engine to ingest. This blow-by is constantly increasing in volume as the engine is running (just like exhaust because much of it is just exhaust that has made it past the rings) and can be piped to an oil separator catch tank and vented to atmosphere if one is unconcerned with emissions.

I am simply stating, again, that the consumption of crankcase vapors and the introduction of outside air to an engine crankcase while it is running is not a performance benefit but an ecological one. And I choose not to contaminate my combustion chambers unnecessarily with oil and other foul byproducts of the combustion process. I have seen the nasty trail within an intake manifold around the inlet for the PCV hose and do not wish to add those elements to my freshly rebuilt engine.
Could you be any more dense!!

The PCV was invented for tanks to ford rivers, it just so happened to be about around the same time we got all environmentally friendly, so it were called an emissions device. Lots of cool **** discovered during WW2 makes our lives better to this day, pcv one of them. The fact that it's so simple and works so well is a feat of modern engineering, all from a slug of lead and two springs...

My argument is this, again, if the blowby is cleaned by blowby, why's it matter if there is a pcv for clearing a river? May as well just send the breather up on a pole, 30 feet up?

Answer, clean oil lasts longer, even if you are fording a river. It lasts exponentially longer, so much so that it's worth all the trouble.

We've now got the Blackstone results (that I mentioned earlier) in this thread showing that in under 2K miles a proper PCV setup kills it, oil lasts longer.
deezums is offline   Reply With Quote
Old 10-26-2015, 05:40 PM   #96
Senior Member
 
Join Date: Feb 2009
Location: Philadelphia
Posts: 815
Total Cats: 47
Default

Quote:
Originally Posted by Mazdaspeeder View Post
1700 miles on setup 1
2000 miles on setup 2

Setup 1 consisted of street driving, street tuning, dyno tuning. Driving was to work casually commuting, sometimes going out for spirited drives, no track time. I'd say the car got worked pretty hard when we were on it, but otherwise, I drive like a sane human being. When I take it out for a fun drive however, I generally wait for the local windy roads to clear out by midnight or 1am and go out at a fun pace.

Setup 2 consisted of street driving, no tuning, but lots of racing in "mexico", and a bunch of spirited drives. No track time here either as I was still chasing some issues with my tune (phantom knock). I'd say the car still got worked pretty hard when we were on it.

Nothing really compares to track driving though with sustained revs, boost, and general abuse. I will continue to do Blackstones in the name of science, and for the sake of catching things like bearing wear early before they destroy other things.

edit: I have not opened my intake manifold to take a look inside, but when I pulled the spark plugs, they looked normal.
Quote:
Originally Posted by Mazdaspeeder View Post
Pardon my ignorance in regards to tuning, I had a professional tune my car, so some of the things I "understand" might be false. I played with tuner studio software and saw there is an AFR target table, as well as some required fuel. I thought that the MS constantly compared the target vs actual values and could compensate for things. I may be 200% off base here.

As far as IM cleanliness, I have to say that when we did my Skunk 2 TB, we took off the top of the plenum, and I remember being very happy about the cleanliness of my IM runners. That was after having the setup for about 1000-1500 miles, again, no track, but hard pulls here and there, and I love the sunday night drags (no homo). Perhaps my ring seal is just good and I'm not getting a lot of blow-by. Perhaps my catch-can is doing a good job. I do have a section in there with some steel wool that helps catch the oil on the way in. It is not otherwise baffled inside.

This is the can I have:
https://i486.photobucket.com/albums/...ps71e28f98.jpg
I know this is a contradiction, but I got called in to work 9am-9pm today instead of being off cause boss got really really sick, so my mind wasn't there. I realized later this afternoon in the second post that we had to take the upper off to bore it out for the new throttle body. I somehow forgot about this procedure in the morning when I was originally posting. Just saying to keep the one idiot at bay who's going to try and call me out for making things up. But yes, the inside of the manifold looked clean, and when we felt around with a finger and rubber glove, both came out with the slightest oil film (literally traces), nothing my mechanic considered out of the norm.
Mazdaspeeder is offline   Reply With Quote
Old 10-26-2015, 06:43 PM   #97
Elite Member
 
Join Date: Apr 2010
Location: Newcastle, Australia
Posts: 2,638
Total Cats: 25
Default

Quote:
Originally Posted by sixshooter View Post


Anyone removing an oil filler cap from a typical running engine, even one equipped with a PCV valve, could certainly attest to the fact that blow-by exists in far greater volumes than the PCV valve is allowing the engine to ingest.
Hmm, while I want to agree with you and agree with most of your thoughts, most of what you feel when you open the cap is air pulsing in AND out because the cam lobes are moving air in every direction, I actually have a mazda oil cap with a hose barb and a length of hose on it which can be used to check for oil leaks by pumping air pressure into the engine, and also can be used to check crankcase pressure by putting a boost gauge on it, and if you put the hose on that in a bucket of water during idle no air comes out.

Initially you get a bubble then the hose draws a little water and then the water goes up and down the hose a little. So yeah the gases move but they dont travel out of the engine, thats mostly the cams moving air in and out.

Dann
nitrodann is offline   Reply With Quote
Old 10-26-2015, 06:44 PM   #98
Moderator
iTrader: (11)
 
sixshooter's Avatar
 
Join Date: Nov 2008
Location: Tampa, Florida
Posts: 15,662
Total Cats: 1,560
Default

Quote:
Originally Posted by deezums View Post
Could you be any more dense!!

We've now got the Blackstone results (that I mentioned earlier) in this thread showing that in under 2K miles a proper PCV setup kills it, oil lasts longer.
Was the first line a question? It is written as an exclamation but seems like a rhetorical question.

The Blackstone results with a sample size of one and few controls of variables is science in your view? Interesting. Please tell us more about how things are proven. I am truly curious.

And please, again, do watch the name calling. I have stuck to the details of the topic and advise you to be courteous in your objections.
sixshooter is offline   Reply With Quote
Old 10-26-2015, 06:58 PM   #99
Sadfab Union President
iTrader: (3)
 
Join Date: May 2014
Location: Kansas
Posts: 2,690
Total Cats: 113
Default

I'm sorry, I don't know how else to respond to your last post. Tanks don't need to be efficient, but according to Wikipedia they are the first ever use of the valves. Your argument of "PCV valve is for emissions except tank" makes absolutely no sense, as they could just as easily not have a PCV valve...

All of that is meaningless though, as the draft tube was and still is a thing. Instead of deleting the draft tube which is not an emissions device, they thought it beneficial to continue force feeding the crank fresh air. Coincidence?

If you are worried about oil ingestion, install a draft tube. I guarantee better oil life with airflow through the crank, and would gladly pay for Blackstone results to prove my claims. I still think a PCV valve would outperform a draft tube, by a wide margin...

I'm done, though, no mas from me. I believe I've made my point.
deezums is offline   Reply With Quote
Old 10-26-2015, 07:10 PM   #100
Senior Member
 
Join Date: Feb 2009
Location: Philadelphia
Posts: 815
Total Cats: 47
Default

Well this got serious lol....The only "controls" I have over the test are when the oil is collected. In both instances, I drove to the same mechanic the same distance from my home. We waited the same amount of time (10 minutes) to drain the oil. Pull the plug, count to 3, then fill the jar.

I can't think of anything I changed on the vehicle that would have affected the fuel content of the oil at all, let alone that much, besides that catch-can. My mechanic was telling me for a while that if I cared about my oil, I should change the setup from the vented can I had. Seeing my Blackstone results confirmed that decision. I was dually happy when the latest results proved his argument.

Last edited by Mazdaspeeder; 10-26-2015 at 07:24 PM.
Mazdaspeeder is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Engine swap, now billowing smoke, do I need an oil restrictor? 6strngs DIY Turbo Discussion 15 10-27-2015 02:16 AM
Turbo stuff for sale at [email protected] this weekend gesso Miata parts for sale/trade 18 10-23-2015 10:26 PM
Engineering project ideas MartinezA92 Insert BS here 21 10-08-2015 11:38 PM
Turbo manifold and dowpipe T25 LucaCarMods WTB 0 10-03-2015 06:58 AM
starting issue Johnny Tater Engine Performance 3 09-23-2015 07:10 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 03:37 AM.