So , I get out on the track for the acid test of the six month TT project. The car is pulling well and with the power curve starting at 2,600 there is no nead to go above 6,500 rpm like I did prior to FI. I did get blue smoke in the rvm several times. Thinking the worst I pulled off and found oil collecting in the bottom of the after cooler. A pin hole in the bottom would allow it to squirt on the header under boost. After a leakdown check (4 to 6% and #5 at 9%) I figured I need to re-plumb my crankcase vent system. For $10 and 30 min at Home Dep. I came up with the same thing as the $75 Greddy version except in black plastic. So it seems if you crank up the boost and go on the track, you are going to get more blowby with oil mixed in. How did Mark Basch set up his vent lines? Honda has the OE vent so it sucks the fumes out at idle but I worry about having a check valve sticking and having boost go to the crankcase. Dan
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Got FI, you might need a catch can
- Thread starter tunapie
- Start date
I too am think about adding a "catch can"
to my bbsc car. 75 bucks is a good price,
best I could find was $84. Does anyone
know if the greedy can has some kind of
filter/baffle system? If I put one in my car
where is the best place for it. I don’t want
to move it again when MB does his I/C & 9 psi
kit. The system I am using now is a fuel
filter\w a paper element in the pcv line and it does collect a fair amount of oil vapor\fumes.
But I think the Greddy can is a nice solution IMHO.
Steve
98-T bbsc #28 r\t
to my bbsc car. 75 bucks is a good price,
best I could find was $84. Does anyone
know if the greedy can has some kind of
filter/baffle system? If I put one in my car
where is the best place for it. I don’t want
to move it again when MB does his I/C & 9 psi
kit. The system I am using now is a fuel
filter\w a paper element in the pcv line and it does collect a fair amount of oil vapor\fumes.
But I think the Greddy can is a nice solution IMHO.
Steve
98-T bbsc #28 r\t
Yep, boost will do that. I think the BBSC crowd is still struggling to find the best solution to the same problem. They didn't originally have a catch can and some of those who ran them hard ended up with messy engine compartments.
Romeo in Atl has a Greddy catch can on his BBSC'd car. It looks very nice. I have managed to keep my engine bay clean due to not driving the car but on weekends and not driving hard.
------------------
ALL NSX
92 RED/BLACK 5-SPEED
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ALL NSX
92 RED/BLACK 5-SPEED
On my Turbo NSX I am running 15-16psi and have no blow-by, with a properly designed system you should not get any pressure in the crank case. I have seen some of the FI kits that are for sale and the venting has not been properly designed.
Hey Gerry,
with all due respect, I think all NSX driven hard on the track will have some sort of blow bys. Even my NA had blow by, although not as much as FI guys that I have to worry about.
Maybe you ouught to let me drive your beast on the race track.
Should I send you an exclusive invitation to join our event at Nov 24 at thunderhill
with all due respect, I think all NSX driven hard on the track will have some sort of blow bys. Even my NA had blow by, although not as much as FI guys that I have to worry about.
Maybe you ouught to let me drive your beast on the race track.
I have driven my car on a two day track event at Laguna Seca, I have also been beating the crap out of it for the past 6500 miles in a straight line and on some windy roads testing the limits of the 3.0 NSX motor under heavy boost, I have not yet seen a drip of oil out of the car anywhere. When I was talking about blow-by I was meaning the amount of oil all over the motor, the SC car that I saw had around a quart of oil or more running off the engine.
What is a "Catch can"?
Hi Gerry,
my offer still stand. I don't mind floggin your car at thunderhill
my offer still stand. I don't mind floggin your car at thunderhill
NetViper, they are used for several reason now. The true use for a catch can is to catch oil vapors from the crankcase (blow-by). On a stock Honda/Acura there is an oil breather chamber on the back of the block where vapors collect after combusion. There is a line plumbed in to it and the other side of the line has a PCV valve. (positive crankcrase ventalation) This valve goes to a port on the intake manifold. Basically what happens is that the PCV is a one way check valve that I think has a little ball in it that lets vapors pass through. As the intake sucks..the ball vibrates and allows vapors to come through...limiting the actual oil. The intake manifold acts as a straw and sucks those crankcase vapors (unburned mixture etc..) back into the intake manifold to be burned again. It's a great design for economy because it is efficent reburning the unburnt mixture that was passed on the previous strokes. One problem for high output cars is that adding the oil/fuel vapors/particles to compressed air raises chances of detonation...and generally just polutes the clean, compressod, cool (hopefully coming in from an intercooler
EDIT: My writings on how a catch-can is supposed to work is valid. A lot of this is my theory on how Honda PCV system works....I've talked with other people about it and the helms manual doesn't spell it out. No Honda/Acura technitions have any clue what im talking about when I bring it up. I'm confident, but just a disclaimer before sjs comes and picks it apart.
1.PCV line (connects breather chamber)
2.Removed stock freeze plugs (2) and rethreaded with big hose barbs (super breathing block)
3.valve cover output (working as an overflow)
All 4 of these run to my catchcan which is vented to the atmosphere. About every 6 months of driving it catches about 1 cup of watervapor. pretty nice! I've had it setup like this over a year...seen no problems at all and my cylinder compresion is within spec.
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jack of all trades, master of some.
[This message has been edited by true (edited 22 October 2002).]
My catch can is catching too much oil on the track and overflowing. I do not have FI. Can someone please help me to understand how the catch can SHOULD be plumbed in to the system? If I go back to a stock configuration and remove the catch can, do I risk running all tat oil through the system and mucking something up, or does the issue go away because I don't have FI?
BTW, thanks for the info previously provided - it was an education for me. Now I'm ready for more....
JC
BTW, thanks for the info previously provided - it was an education for me. Now I'm ready for more....
JC
Looks like we have a good topic going here. True, very informative input. You talked about a check valve in the engine that is causing problems for the MBSC. Can you explain. I think all Gerry has a check valve on the PVC line to the manifold to keep from pressuring the engine case under boost. and a small filter on the other end venting to the ap. Why his car does not burp out oil under BIG boost that he runs is a mystery to me. I am just envious. Dan
I got it through summitracing.com.
http://store.summitracing.com/partdetail.asp?part=4509&view=2047&media=2
They call it a breather tank for dry sump, but you can see it is desinged to seperate oil..a LOT of honda guys use it. That picture on summitracing is really bad. I'll try to take some pictures tonight.
This is not what i was trying to say. The PCV acts as a checkvalve under boost. I do not know what oil spewing problems the MSNBSC are having other then loosing oil/vapors from somewhere. I was saying the PCV line is 'basically' a check valve. There is a ball inside the PVC. As vacuum increases it lifts the ball higher sucking more crankcase vapors out from the back of the block (factory oil seperator). If there is NO vacuum, the ball doesn't lift, so it's effectivly a one way valve (check-valve). Now I think the problem is that when you are in BOOST, the PCV doesn't work (closed) because it is a reverse function. If the postive pressure can't be sent down the map line, it blows it out of the valve cover....along with oil. Now this is only part of the problem because don't forget about all the vapors that are still stuck in the crankcase because the PCV is closed. That is why I remove the factory freeze plugs and run them to my catch can as well. Seems to help a lot to have 2 huge holes for breathing.
My assumption was that the oil the bbsc guys were seeing was coming from the port on the valvecover....I don't know if that's really the case.
Hrm, I'm not sure I understand this....If he runs a checkvalve against the port coming off the valvecover...that would defintely stop oil from spewing out, but it would still keep the head pressurized...not sure that makes to much sence.
I'm also wondering exactly how gerry has his setup.
[This message has been edited by true (edited 24 October 2002).]
true,
I saw that one (catch can)
Don't think it will work for me.
Thinking in a diff direction...
what about a 12v pump that draws
a vac all the time to a catch can/
filter from the pvc hole in the
v cover. That way even under boost
the system is working???
Steve
I saw that one (catch can)
Don't think it will work for me.
Thinking in a diff direction...
what about a 12v pump that draws
a vac all the time to a catch can/
filter from the pvc hole in the
v cover. That way even under boost
the system is working???
Steve
Steve, you don't want to suck vacuum from the valve cover port..... That port on the valve cover is where the fresh air is SUPPOSED to come in, not be sucked out. The port on the valve cover is NOT the PCV..just a small part of the system. Ideally, you would want to pressurize it. Some of the big racers use vacuum pumps to evacuate the bottom end crankcase vapors, but I've only heard of them being neccessary in 20+psi setups. If you got a vacuum pump, I would put it on the crankcase port, not the valve cover one. I still don't know how the basch supercharger is setup....is there just a filter on the valvecover...where is the oil spewing from!
Ok I just downloaded the nsx service manual and and read the section regarding the PCV. The NSX system works as I suspected...like all other Honda's I'm familar with.
Fresh air comes in through the line on the valve cover that plumbs into the Intake tube. The end in the intake tube has a 'slash' cut tube that almost cups the air...looks like this -> /|. This pressurizes the head cover and pushes the crankcase vapors out through the back of the block. Upon exiting the block, it gets sucked up through the PCV line and routed directly back into the intake manifold. It's a perfect loop...reburning the poluted charge.
Ahh, just found the image I was looking for. Here is a drawing of how a catch can is run inline with the PCV.
Note: In order to keep this setup emmisions friendly he puts the PCV on TOP of the catch can and runs that line back to the intake. MOST people just put a filter on the top and remove the PCV completely venting to the atmosphere. That way NO vapors at all make it into the intake charge. He does not show the valve cover port at all. If it was there, it would be at the front of the engine bringing FRESH air in, helping push the polutants out the rear. I dont know if the NSX has the oil seperator factory. My guess would be that it does. I know the integra LS and CRV motors dont use them anymore...just run a line straight out. All the vtec (typer,gsr,si) motors I've seen to have them.
I really think this catch-can talk is much more then the overflow talk the thread started as. If you simply want to 'catch' the oil that's spurting out the valve cover port you can use any old overflow tank. If you want to install a real fresh air breathing system using a catch-can its more complex. I think if the topic said "Got FI, you might need an overflow tank" I probably woulnd't have posted. Since the catch can was phrased I guess I'm posting my thoughts on what a catch-can really is supposed to be used for. It's great.
[This message has been edited by true (edited 25 October 2002).]
Fresh air comes in through the line on the valve cover that plumbs into the Intake tube. The end in the intake tube has a 'slash' cut tube that almost cups the air...looks like this -> /|. This pressurizes the head cover and pushes the crankcase vapors out through the back of the block. Upon exiting the block, it gets sucked up through the PCV line and routed directly back into the intake manifold. It's a perfect loop...reburning the poluted charge.
Ahh, just found the image I was looking for. Here is a drawing of how a catch can is run inline with the PCV.
Note: In order to keep this setup emmisions friendly he puts the PCV on TOP of the catch can and runs that line back to the intake. MOST people just put a filter on the top and remove the PCV completely venting to the atmosphere. That way NO vapors at all make it into the intake charge. He does not show the valve cover port at all. If it was there, it would be at the front of the engine bringing FRESH air in, helping push the polutants out the rear. I dont know if the NSX has the oil seperator factory. My guess would be that it does. I know the integra LS and CRV motors dont use them anymore...just run a line straight out. All the vtec (typer,gsr,si) motors I've seen to have them.
I really think this catch-can talk is much more then the overflow talk the thread started as. If you simply want to 'catch' the oil that's spurting out the valve cover port you can use any old overflow tank. If you want to install a real fresh air breathing system using a catch-can its more complex. I think if the topic said "Got FI, you might need an overflow tank" I probably woulnd't have posted. Since the catch can was phrased I guess I'm posting my thoughts on what a catch-can really is supposed to be used for. It's great.
[This message has been edited by true (edited 25 October 2002).]
true,
I think the 97+(3.2L)
are plumbed backwards.
my rear v cover has the
pvc valve that goes to
the air plenum and is
under vacuum from the engine.
at least the vac gauge says so.
it draws the air out of
the engine except under
boost and then the pvc
is closed like we think.
the front v cover was
going into the air filter
box, it's now is just venting
to the outside air thru
a mini k&n. if the system
was under a vacuum and your
"catch can\filter thing"
was inline with the pvc
hose don't you think most
of the fumes/smoke would
get trapped there leaving
the air in much better shape
when it is drawn back into
the intake? also being
under or at a near vacuum
should relieve the spitting
of the oil from the breather
hose we hear about sometimes
b/c the system has no pressure
(to speak of)
yes no ???
steve
[This message has been edited by heretic (edited 25 October 2002).]
I think the 97+(3.2L)
are plumbed backwards.
my rear v cover has the
pvc valve that goes to
the air plenum and is
under vacuum from the engine.
at least the vac gauge says so.
it draws the air out of
the engine except under
boost and then the pvc
is closed like we think.
the front v cover was
going into the air filter
box, it's now is just venting
to the outside air thru
a mini k&n. if the system
was under a vacuum and your
"catch can\filter thing"
was inline with the pvc
hose don't you think most
of the fumes/smoke would
get trapped there leaving
the air in much better shape
when it is drawn back into
the intake? also being
under or at a near vacuum
should relieve the spitting
of the oil from the breather
hose we hear about sometimes
b/c the system has no pressure
(to speak of)
yes no ???
steve
[This message has been edited by heretic (edited 25 October 2002).]
Steve, I think you are on the right track. Yes, if you run the can inline with the PVC it will filter the air before the intake sucks it back in. On the honda 4 cylinders that line simply comes off the back of the block. I looked again at the NSX picture and it actually does have the PCV in the rear valve cover like you said. So you're first post was correct...It will filter the oil vapors from that crankcase air before they are plumbed back into the intake manifold. That is good. I thought you were talking about putting it inline with the other valve cover port where you currently have the K & N. Doing what you suggest will definetly filter your inhaled air, but I don't think it will have any effect on the oil coming out the filter hole. I don't see how filtering on the PCV line will relief any pressure from the fresh air pcv port. It's simply an inline filter...working just like a fuel filter would. Are you contemplating removing the PCV completely and venting to the atmosphere? Even in that case you are gonna have some coming out of the fresh air hole under boost.
By the way, I don't know if the PCV system on the obd2 is the same as the obd1 nsx's. Also, it looks like you are hitting enter on your posts to space them down. You don't have to, it does a return for you. You're posts are comming out formatted strangly.
true,
When the pcv valve is closed (under boost)the engine builds pressure inside. Wouldn't
you say the only place left is back out the other valve cover were the (in my case) mini k&n is??? I know you said you have the freeze plugs out in your set up, but set that a side for now.
steve
When the pcv valve is closed (under boost)the engine builds pressure inside. Wouldn't
you say the only place left is back out the other valve cover were the (in my case) mini k&n is??? I know you said you have the freeze plugs out in your set up, but set that a side for now.
steve
Yes, exactly, but you won't be doing any filtering in this situation if you simply put the can on the port where the K & N is. (don't need baffles)
If I were you, I would probably:
Get a baffled catch can and run BOTH lines into the can. I would remove the PCV. (might not be legal in some states) You will then be filtering your intake charge AND catching the slop that comes out off the valve cover port.
[This message has been edited by true (edited 25 October 2002).]
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