Oil Catch Can
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cammerfe
Dedicated LVC Member
Crankcase pressure, 'blowby', pushes oil out of the engine. On race engines, particularly those with a dry sump, use a catch vessel with a vent on the top, placed as high above the engine as possible to catch the oil that is carried out by the crankcase pressure.
KS
K&N sells a cast aluminium catch can. Very nice and costs about the same as the DIY version in the Turbophile article above. KS
KS
K&N sells a cast aluminium catch can. Very nice and costs about the same as the DIY version in the Turbophile article above. KS
Quik LS
Dedicated LVC Member
yep - installed two in the LS, one in the Lotus
Quik LS
Dedicated LVC Member
Steve - I see you have the driver's side valve cover venting to the air - with a little filter. What do you have on the passenger side? (which does not pass inspection if you have it in your area)
The catch cans are to seperate oil from the air coming out of the valve covers before re-entering the intake - common issue with IF the blow-by increases and more oil is in the intake.
But if you are not connecting the valve covers to the intake with your current setup - you really are not getting any blow-by - right? Or am I missing something?
How do you have your other vacuum lines running? the ones that should only see vacuum and never boost?
The catch cans are to seperate oil from the air coming out of the valve covers before re-entering the intake - common issue with IF the blow-by increases and more oil is in the intake.
But if you are not connecting the valve covers to the intake with your current setup - you really are not getting any blow-by - right? Or am I missing something?
How do you have your other vacuum lines running? the ones that should only see vacuum and never boost?
ILLS
Dedicated LVC Member
The passenger side and drivers side valve covers are connected via the front timing chain cover. If you release pressure from one then the other side is releasing pressure as well.
His vacuum lines are routed the same way as stock. There is nothing, vacuum wise, that really has to be drastically changed with a centrifugal s/c or turbocharger. Now with your PD Roots blower most of your vacuum lines had to be re routed to the upper plenum "above" the s/c, while others like your FRPT and boost gauge vac line had to go to the lower plenum below it.
Quik LS
Dedicated LVC Member
not sure what you mean by 'routed the same way as stock'? you had to move those vacuum lines to infront of the turbo - correct?
can't boost your evap, brake booster, ..etc - right?
does the 03+ not have seperate PCV tubes for each valve cover like to Gen1s do?
and so catch cans - do not make any sense in this setup unless he is planning to get rid of the filter and route back into the intake - before the turbo - right?
can't boost your evap, brake booster, ..etc - right?
does the 03+ not have seperate PCV tubes for each valve cover like to Gen1s do?
and so catch cans - do not make any sense in this setup unless he is planning to get rid of the filter and route back into the intake - before the turbo - right?
ILLS
Dedicated LVC Member
No you don't have to move them. They can stay in the same routing for lower boost on a centri or turbo system. Heck, many people leave them alone even when going for higher boost. Now if you start running higher boost then it is advisable to install one way check valves and/or pressure bypass valves but most do not. You cannot move it pre turbo or centri blower because then they will not see enough vacuum to properly operate when decellerating or cruising. Now with a PD roots or twin screw you can move those pre-blower and still have proper vacuum to them because you are still post TB and will see engine vacuum.
Nope the Gen2 has just the one on the drivers side.
A catch can does make sense in this turbo application if the owner prefers to install one. He will need to get rid of the little filter and instead install the catchcan in place of it though.
1) If you decide to vent the other side of the catchcan to atmosphere then it will function in a similar way to the regular breather filter was doing but will better separate oil/water/air because of its inherent design.
2) If you decide to route the other side of the catchcan back into the intake then you will need to install a one-way check valve so that the crankcase will not get pressurized by boost. However it will not be able to release any held pressure until you are out of boost and the one-way check valve releases. The other way it can release pressure is once the pressure in the crankcase exceeds the boost pressure. On lower boost vehicles the minute crankcase pressurization for the few seconds when you are in boost usually doesn't pose a problem. In higher boost vehicles #3 is recommended because the differential will be so great that on a long pull allot of pressure could build in the crankcase and cause a oil pan, valve cover, timing cover gasket failure.
3) In some cases people will take this one step further and install a one-way check valve in the return line and also a 3 way solenoid valve that is turned on and off by a Hobbs pressure switch. This will function almost like #2 except that not only will it prevent boost from entering the crankcase but it will also allow the crankcase to vent as normal while under boost too.
Quik LS
Dedicated LVC Member
wow - I have never run a low boost turbo before - all mine have been 15psi + ....
I noticed on my SC - foot on the brake on the line - bring rpm and boost up - the braking was letting go... until I moved the brake boost vacuum line to the vacuum side of the intake. Does the turbo not make enough boost without load to cause a 'negative vacuum'?
I would have though that the epav system would be angry pressurized. How does the boost into the evap not mess up the line pressures?
Not questioning your install - just not familiar with boosting the vacuum side of things....
I noticed on my SC - foot on the brake on the line - bring rpm and boost up - the braking was letting go... until I moved the brake boost vacuum line to the vacuum side of the intake. Does the turbo not make enough boost without load to cause a 'negative vacuum'?
I would have though that the epav system would be angry pressurized. How does the boost into the evap not mess up the line pressures?
Not questioning your install - just not familiar with boosting the vacuum side of things....
ILLS
Dedicated LVC Member
Even in a high boost turbo you will still need to have the vacuum lines routed in similar manner to how they were when stock. They will still need to route in post TB (which is of course post turbo as well) so that they can see engine vacuum. With the higher boost app's the use of check valves becomes more advised in the lines that do not like back-pressurization.
With your S/C it is imperative to have the brake booster line on the upper plenum and not the lower one. That is because if it is on the lower one then it will see positive pressure almost right away and hurt your ability to brake; which is what you just described. Once you moved it to the upper then you were able to hold the brakes longer because you saw neutral pressure rather than positive even while revving the engine. The turbo's and centri's do not build allot of boost right off the line and push the air pre-TB which is the big difference in why their vac line configurations have to be different.
Evap solenoid is going to be mostly closed anyways so it will remain relatively unaffected by the boost.
With any kind of normal street driven turbo setup that has the turbo placed pre-TB the vacuum lines will have to be routed into the manifold post-TB to get proper vacuum. I won't bother getting into vacuum booster pumps because most do not use those on street vehicles anyways. Almost all turbo setups have the turbo placed pre-TB. In the rare case where the turbo is placed post-TB then you can route your vac lines pre-turbo/post-TB and still retain proper vacuum without pressurizing the lines. I have never seen a post-TB mounted turbo setup but I am sure they are probably out there somewhere in some sort of weird OEM application.
Quik LS
Dedicated LVC Member
cool. So the turbos don't make enough boost at the lower rpm band to worry about those things - got it.
I do run a vacuum pump on my Lotus and added one to the supra after a couple of scary momments on a road course where I was on high boost then quickly on the brakes.... to find no brakes...
do you have a sense on how much PSI our stock fuel regulator will read before we have to go aftermarket?
but back to this thread.... why is steve seeing oil in his intake if it is not blow-by?
I do run a vacuum pump on my Lotus and added one to the supra after a couple of scary momments on a road course where I was on high boost then quickly on the brakes.... to find no brakes...
do you have a sense on how much PSI our stock fuel regulator will read before we have to go aftermarket?
but back to this thread.... why is steve seeing oil in his intake if it is not blow-by?
ILLS
Dedicated LVC Member
The stocker FRPT will most likely be able to sense more pressure differential than anyone will ever encounter in their LS. But when boosting you are actually encountering less pressure diff range. One side is attached to the fuel rail so that it senses rail pressure while the other side is connected via vacuum line to the intake manifold. It then takes the pressure/vac reading on each side and calculates what the pressure differential is (aka fuel pressure drop across injectors...injector delta). This is what the PCM sees that tells it to either give the fuel pump more voltage to raise pressure and flow or drop the voltage to lower pressure. So when boosting the manifold pressure will rise above neutral vacuum thus getting initially getting closer in pressure differential to the rail fuel pressure which will utilize less of the FRPT's range. This is only for a split second because once the PCM see's the pressure differential dropping it will raise voltage to proportionally increase fuel pressure to maintain targeted injector delta.
All engines have a certain amount of blow by which is one of the reasons why they have PCV systems. Steve isn't getting oil in his intake. He is getting a little that is spurting out of the little breather filter on his valve cover while accelerating. My LS didn't do that but then again I believe Steve is running higher boost than I was too. What Steve is encountering is similar to why you opted to install those catchcans on your car. Running a breather filter, catchcan, or other means of separating exiting crankcase air, oil, fumes, and water vapor is not so important when N/A. But as you know when you are boosted your cylinder pressure rises thus increasing the amount of blowby, which in turn increases crankcase pressure which is able to sling more crap out of crankcase ventilation/PCV ports. Sometimes a car will even do this when N/A but it is usually negligible enough to not worry about it.
So...with that all being said; a catch can will help my issue of oil coming out of the breather and onto the valve covers and exhaust manifold...correct? If that's the case; I need to get this done ASAP. The burning oil and fumes are not enjoyable.
Quik LS
Dedicated LVC Member
right - you will have to pull out the little filters - run a hose from the valve cover to the catch can, and then from the catch can to one of the options ILLS listed above - you do not want to put it where is sees boost ....
Quik LS
Dedicated LVC Member
any fumes coming out the little filter you have now will smell - the catch can should fix that.
Have you check for oil in the spark plug wells yet? with enough pressure, oil can sneak pass the little o-rings in the valve cover gasket and sneak into the plug wells - making more oil-burning smell.
Have you check for oil in the spark plug wells yet? with enough pressure, oil can sneak pass the little o-rings in the valve cover gasket and sneak into the plug wells - making more oil-burning smell.
ILLS
Dedicated LVC Member
I never looked on the LS but the fumes could be making it into the cabin via the A/C intake duct. I have no idea where the LS's draw their air from for the climate control so I could be 180 degrees off. Just a thought though.
Quik LS
Dedicated LVC Member
the inlet is by the passenger wiper blade - through the plastic cowl at the base of the windshield (where the cabin air filter is. It is somewhat 'sealed' from the engine bay - not perfect.