hose from throttle body to left valve cover
06-21-2006, 10:15 PM
#1
TECH Enthusiast
Thread Starter
Join Date: Jan 2005
Location: wisconsin
Posts: 658
Likes: 0
Received 0 Likes
on
0 Posts
hose from throttle body to left valve cover what does this actually do , its about 6 inches of hose from left side of the
t-b and over to left valve cover. not talking pcv ,,,,,,,,,,,,,,,,,,,,,,,,,,,
t-b and over to left valve cover. not talking pcv ,,,,,,,,,,,,,,,,,,,,,,,,,,,
06-22-2006, 01:12 AM
#3
It's called the "fresh air tube". Notice that it plugs into the throttle body BEFORE the blade, thus it's always at 14.7psi. The other side of the PCV system is AFTER the throttle body, so 90% of the time it's at less than 14.7psi.
This pressure differential promotes air to be "sucked" into the crankcase to help purge the combustion gasses that pass by the rings (blowby).
This pressure differential promotes air to be "sucked" into the crankcase to help purge the combustion gasses that pass by the rings (blowby).
06-22-2006, 05:43 AM
#4
TECH Addict
Just a side note, that 14.7psi is standard atmoospheric pressure or 1 bar and should not be confused with turbo boost as that is always measured above atmospheric pressure.
06-22-2006, 04:21 PM
#6
Originally Posted by zrater
any one else.. ive seen pics of this with a filter on it...........
06-22-2006, 04:24 PM
#7
Moderator
iTrader: (11)
Join Date: Mar 2002
Location: East Central Florida
Posts: 12,604
Likes: 0
Received 6 Likes
on
6 Posts
Yes, it's the fresh air line. I put a filter on mine, a
cheapo plastic fuel one. Purpose for that being, I
suspected at wide open throttle both the fresh
air and the PCV port are below ambient (by the
draw-down across MAF/filter/lid) and the crankcase
is pressurized (blowby) meaning both legs are
drawing into the intake; however the "fresh air"
line is totally unchecked while the PCV enforces
a maximum flow rate.
I saw a serious snail-track on the TB core I
ported, so I know this can happen. However in
a couple of years of driving with said filter, I
have accumulated roughly zero oil in it. So it
may take more engine wear, or more time spent
at WOT, or both, to get that hose to back-
draw.
cheapo plastic fuel one. Purpose for that being, I
suspected at wide open throttle both the fresh
air and the PCV port are below ambient (by the
draw-down across MAF/filter/lid) and the crankcase
is pressurized (blowby) meaning both legs are
drawing into the intake; however the "fresh air"
line is totally unchecked while the PCV enforces
a maximum flow rate.
I saw a serious snail-track on the TB core I
ported, so I know this can happen. However in
a couple of years of driving with said filter, I
have accumulated roughly zero oil in it. So it
may take more engine wear, or more time spent
at WOT, or both, to get that hose to back-
draw.
Trending Topics
06-22-2006, 04:38 PM
#8
Originally Posted by jimmyblue
Yes, it's the fresh air line. I put a filter on mine, a
cheapo plastic fuel one. Purpose for that being, I
suspected at wide open throttle both the fresh
air and the PCV port are below ambient (by the
draw-down across MAF/filter/lid) and the crankcase
is pressurized (blowby) meaning both legs are
drawing into the intake; however the "fresh air"
line is totally unchecked while the PCV enforces
a maximum flow rate.
I saw a serious snail-track on the TB core I
ported, so I know this can happen. However in
a couple of years of driving with said filter, I
have accumulated roughly zero oil in it. So it
may take more engine wear, or more time spent
at WOT, or both, to get that hose to back-
draw.
cheapo plastic fuel one. Purpose for that being, I
suspected at wide open throttle both the fresh
air and the PCV port are below ambient (by the
draw-down across MAF/filter/lid) and the crankcase
is pressurized (blowby) meaning both legs are
drawing into the intake; however the "fresh air"
line is totally unchecked while the PCV enforces
a maximum flow rate.
I saw a serious snail-track on the TB core I
ported, so I know this can happen. However in
a couple of years of driving with said filter, I
have accumulated roughly zero oil in it. So it
may take more engine wear, or more time spent
at WOT, or both, to get that hose to back-
draw.
