Please not another crankcase ventilation thread.
10-22-2015, 12:54 PM
#42
I haz :
Vibrant AN-10 Check valve
20+ feet of AN-10 hose
allthefittings.
Just don't have a vac gauge/catch can. Guess I could ghetto rig something with a pvc plug and hook it up to a spare VDO boost gauge, and assume a given loss for catch-can placement.
Sounds like a tomorrow problem.
Vibrant AN-10 Check valve
20+ feet of AN-10 hose
allthefittings.
Just don't have a vac gauge/catch can. Guess I could ghetto rig something with a pvc plug and hook it up to a spare VDO boost gauge, and assume a given loss for catch-can placement.
Sounds like a tomorrow problem.
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10-22-2015, 01:08 PM
#45
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I've got two of the crankcase ventilation extractors in the exhaust system of my old 68 gto. I tested it once by putting the hose in a gallon jug of water and blipping the throttle. It drew all of the water out of the jug with just one blip. It may have taken 2 seconds. I just don't want one on my Miata. It will need to be plugged if you ever use a chassis dyno.
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10-22-2015, 01:13 PM
#46
I've got two of the crankcase ventilation extractors in the exhaust system of my old 68 gto. I tested it once by putting the hose in a gallon jug of water and blipping the throttle. It drew all of the water out of the jug with just one blip. It may have taken 2 seconds. I just don't want one on my Miata. It will need to be plugged if you ever use a chassis dyno.
Also, pics of 68 GTO aren't working.
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10-22-2015, 04:32 PM
#47
Smoke represents blowby, the blowby doesn't completely evacuate till a source of fresh air other than blowby is added, like all stock PCV setups. If there is no fresh air whatever blowby manages to exit the system is immediately replaced with more blowby, nothing more.
If you never add fresh air, never pull the bowl, there is always blowby in the crank volume, pretty simple really, that's the extent of the analogy.
If you still have to argue the efficiency or necessity of fresh air source in PCV setup, I can't do anything for you. Bong rips included.
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10-22-2015, 06:00 PM
#52
Yeah, and your point is?
At all other points of operation, with a PCV system, that outlet hole is an inlet hole. It is the same exact way on a stock miata valve cover, massive gaping hole through a half-asssed catch can. It goes to the intake past the MAF meter because all air goes in/out of there goes to the intake sooner or later, same as a recirc BOV.
The only reason air exits the hole on said 300hp run is because the PCV is closed, there is no vacuum in the crank. If it were a bitchin' big cube motor doing 300hp at 50kpa map, no blowby would exit said hole.
Come at me bro!
At all other points of operation, with a PCV system, that outlet hole is an inlet hole. It is the same exact way on a stock miata valve cover, massive gaping hole through a half-asssed catch can. It goes to the intake past the MAF meter because all air goes in/out of there goes to the intake sooner or later, same as a recirc BOV.
The only reason air exits the hole on said 300hp run is because the PCV is closed, there is no vacuum in the crank. If it were a bitchin' big cube motor doing 300hp at 50kpa map, no blowby would exit said hole.
Come at me bro!
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10-23-2015, 03:24 PM
#53
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You dont need a check valve, nothings flowing up that pipe (unless your neighbour decides to stuff a tennis ball up your rear end). Catchcan may or may not stop the bumper oil smell smokescreen hilarity. Not sure yet.
Wow. Nice. What hp? Exhaust/slashcut hose dia?
In 4 chipotle blowby flowrates
Deezums, open your oil cap at idle and tell me if the blowby comes in or out. Put a sliver of paper on top if you cant tell. You seem very strongly opinionated on this... have another toke.
Aside from the PITA of drilling another hole in my VC, why isnt this a good idea:
Im sick of these PCV threads too
In 4 chipotle blowby flowrates
Deezums, open your oil cap at idle and tell me if the blowby comes in or out. Put a sliver of paper on top if you cant tell. You seem very strongly opinionated on this... have another toke.
Aside from the PITA of drilling another hole in my VC, why isnt this a good idea:
Im sick of these PCV threads too
Last edited by sparkybean; 10-23-2015 at 03:45 PM.
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10-23-2015, 05:31 PM
#55
You dont need a check valve, nothings flowing up that pipe (unless your neighbour decides to stuff a tennis ball up your rear end). Catchcan may or may not stop the bumper oil smell smokescreen hilarity. Not sure yet.
Wow. Nice. What hp? Exhaust/slashcut hose dia?
In 4 chipotle blowby flowrates
Deezums, open your oil cap at idle and tell me if the blowby comes in or out. Put a sliver of paper on top if you cant tell. You seem very strongly opinionated on this... have another toke.
Aside from the PITA of drilling another hole in my VC, why isnt this a good idea:
Im sick of these PCV threads too
Wow. Nice. What hp? Exhaust/slashcut hose dia?
In 4 chipotle blowby flowrates
Deezums, open your oil cap at idle and tell me if the blowby comes in or out. Put a sliver of paper on top if you cant tell. You seem very strongly opinionated on this... have another toke.
Aside from the PITA of drilling another hole in my VC, why isnt this a good idea:
Im sick of these PCV threads too
My argument was that fresh air is required, you drew a fresh air line. I wish I could take a toke, it'd make dealing with you stupid turds easier.
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10-23-2015, 07:00 PM
#57
0KPA is not a thing, the PCV is open and doing things anywhere south of 98.5kpa here.
So, without check valve and in a high overrun condition (hardly any exhaust flow) largest intake manifold vac you'll ever see (16kpa for me) you'll probably pull exhaust into the crank.
The main reason it fails is slashcut. If there is PCV there is no need for slashcut, if there is slashcut, there should be no need for PCV. Running slashcut on the street is ******* stupid, 99.9% of the time you have intake manifold vac, and the pcv works just fine.
Opening the oil cap at idle will be an inlet hole, no blowby will escape. Opening the oil cap is the same thing as running the exhaust side vent to the air cleaner which is all I've been arguing for. If you left the oil cap off and ran up to 20PSI, of course blowby will take the path of least resistance and spatter oil all over your hood.
So, without check valve and in a high overrun condition (hardly any exhaust flow) largest intake manifold vac you'll ever see (16kpa for me) you'll probably pull exhaust into the crank.
The main reason it fails is slashcut. If there is PCV there is no need for slashcut, if there is slashcut, there should be no need for PCV. Running slashcut on the street is ******* stupid, 99.9% of the time you have intake manifold vac, and the pcv works just fine.
Opening the oil cap at idle will be an inlet hole, no blowby will escape. Opening the oil cap is the same thing as running the exhaust side vent to the air cleaner which is all I've been arguing for. If you left the oil cap off and ran up to 20PSI, of course blowby will take the path of least resistance and spatter oil all over your hood.
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10-24-2015, 12:43 PM
#58
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Run a check valve. Cheap and easy insurance. It has been shown here that there can be several lbs of pressure in even a straight pipe or with a straight through muffler.
Mine are on a 455 Pontiac engine with dual 2.5in exhausts and long tube headers. The extractors are in the headers' 3in collectors. It has Flowmasters, for reference.
Mine are on a 455 Pontiac engine with dual 2.5in exhausts and long tube headers. The extractors are in the headers' 3in collectors. It has Flowmasters, for reference.
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10-24-2015, 02:12 PM
#60
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Sixshooter, seeing as youre running a slashcut, and by the sounds of it consider it to be working well, what would you say its biggest downsides are?
Do you end up with a lot of oil on your bumper? Clouds of smoke/smells? Ta.
Do you end up with a lot of oil on your bumper? Clouds of smoke/smells? Ta.
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