SW SHO
Boss Man
What is the vaccum line from closest to IAB? I'm pretty sure the other is the Crank Vent or esentially the PCV right?
Image courtesy of SHO Phoenix Project site.
What is this vaccum line?
- Thread starter SW SHO
- Start date
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HopefulSHO
SHO Member
Big one is PCV (Goes to your front head). Small one I belive goes to the charcoal canister or related plumbing - sucks in gas fumes from yer tank.
IAC gets it's air from right in front of the throttle plate.
IAC gets it's air from right in front of the throttle plate.
MeSHOYouHow
New Member
how does that help reduce oil in the plug wells?
The V6 SHO motor has a very unusual and IMHO anemic PCV system. Rather than use a PCV valve as 99% of the other motors in the world the Yamaha V6 uses three venturi type ports in the TB to produce draw on the crankcase vapors.
This results in positive pressure in the the crankcase during heavy and WOT usage. This pressure pushes the oil out the plug well seals. By plugging the PCV intake air source you produce a slight vacuum in the crankcase at normal cruising speeds. This will prevent the oil from getting into the plug wells by maintaining the seal during 90% of engine operation time.
Most of the carbon that builds up on your lower intake manifold and valves is from these PCV vapors. Another advantage of plugging the fresh air intake of the PCV system is the near elimination of water vapor into the crankcase. This water vapor will make up more than 50% of the actual crankcase blowby gas reducing the volume of blowby sludge considerably.
On my '97 I use a condensation can that is inserted between the PCV gas/oil separator (located between the heads and under the intake manifold) and the PCV ingestion point. This point on the '97 is an intake manifold port. On the V6 it is the large hose on the back and bottom of the TB. It is amazing the amount of condensate that is expelled from the can when the engine is shut off. It has also kept my intake virtually free of any oil or deposits over a +20k mile period. This is normally a big problem with the V8.
This results in positive pressure in the the crankcase during heavy and WOT usage. This pressure pushes the oil out the plug well seals. By plugging the PCV intake air source you produce a slight vacuum in the crankcase at normal cruising speeds. This will prevent the oil from getting into the plug wells by maintaining the seal during 90% of engine operation time.
Most of the carbon that builds up on your lower intake manifold and valves is from these PCV vapors. Another advantage of plugging the fresh air intake of the PCV system is the near elimination of water vapor into the crankcase. This water vapor will make up more than 50% of the actual crankcase blowby gas reducing the volume of blowby sludge considerably.
On my '97 I use a condensation can that is inserted between the PCV gas/oil separator (located between the heads and under the intake manifold) and the PCV ingestion point. This point on the '97 is an intake manifold port. On the V6 it is the large hose on the back and bottom of the TB. It is amazing the amount of condensate that is expelled from the can when the engine is shut off. It has also kept my intake virtually free of any oil or deposits over a +20k mile period. This is normally a big problem with the V8.
SW SHO
Boss Man
Thanks!
How hard would it be to get a setup like that on any of our engines?
projectSHO89
SHOless In St L
HopefulSHO said:
Correct on all counts.
The small one goes to the CANP (CANister Purge) solenoid.
Steve
Devin said:
It is easy to install. You just take off the large line going to the TB base and splice a longer hose in. Run it to the can the run a hose from the outlet side of the car back to the TB.
On the one I use in the V8, the crankcase vacuum will run about 5 to 7 "Hg of vacuum and the can has a vacuum sealed check valve that will open when crankcase vacuum drops to 0" Hg so it is self draining. I don't think the V6 will pull it shut do to the much lower crankcase vacuum levels achieved (don't really know). You would have to put in a petcock drain valve and manually drain it once a week or so.
jessemachone
No Mo SHO
Where can a person buy one of these condensation cans?
Dr. Tweak
Mad Scientist
Jason, you should show some pics of your PCV setup 
I also expect a pic of that boost guage reading positive in a few months here.
SW SHO, thanks for giving credit where due. I thought that pic looked familiar! :laugh_ti:
I also expect a pic of that boost guage reading positive in a few months here.
SW SHO, thanks for giving credit where due. I thought that pic looked familiar! :laugh_ti:
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