• Protip: Profile posts are public! Use Conversations to message other members privately. Everyone can see the content of a profile post.

FI catchcan revisited

Joined
22 May 2002
Messages
333
Ok, so I am having the 6,000 calorie dinner last night and friend suggested a fix for my catchcan that is filling up only on the track. Just run a return from the bottom of the can back to the engine and change the name of the thing to a oil separator. Mmmmm, simple, cheap, what is the down side here. The only thing I need help on is how MB has the oil return from the SC set up. A brief discription on how he does it would a big help. Thanks, Dan
 
On my 95, AofB braised a Y into the dipstick tube and I ran a hose from my catch can back to the engine through that tube.
 
I'd agree that it may be a good solution once you have determined (as I think you have) that the oil loss is not indicative of another problem that needs to be fixed such as worn rings. I say may be a good solution because the underlying cause could create other problems under sever conditions.

As Dan and I have discussed recently, I think that his problem is likely not "blow-by" as typically defined. (where the crankcase is pressurized by excessive combustion chamber gasses getting by the rings.) I think I have a pretty good idea of what is happening, but the short answer is that a larger vent tube on the font valve cover (rear for 97+ engines) may reduce the problem significantly. Other changes to the opposite valve cover and the crankcase baffle plate might also be necessary for track driving. Since I have spare valve covers I plan to modify the front one and test the theory. Now if I just had better access to track time…
 
Dan, I have my catchcan draining as you (and Chuck) describe. Mine drains back through a modified freeze plug with a nipple. I have a schematic of my catch can setup at work I'll scan for you on Monday. I really don't have the same setup as you guys since I vent the crankcase through the plugs - but the drain idea is the same....you have several choices for that. Just find any non-pressurized oil opening that's lower then your catch can.....oil pan, freeze plug, dipstick etc.. I would assume the bbsc oil return is into the oil pan.... I'm not sure though. That's standard for a multitude of aftermarket forced induction kits.

Good thought Sjs - a lot of the racers use 2 full 1" vent lines off a modified valve cover. I've been wanting to weld a few -12 AN nipple's or similar on my valve cover for a while. I might beat you to it as I'm doing a rebuild now. (not nsx)

Here are some pics of my custom freeze plug nipples:

nipple1.jpg



[This message has been edited by true (edited 30 November 2002).]
 
True, what engine is that? I'm not aware of any similar plugs on the NSX block and the return passages are not easily tapped. BTW, I think you'll find that the term "freeze plug" refers to a plug pressed into a water passage not an oil return passage. The term comes from the idea that if the coolant should freeze the "ice" will pop out those plugs rather than crack engine parts. (The NSX block does not have any of those either.) However, most are sand exits from casting and may not really be expected to live up to their name, so I guess applying the term to an oil passage plug is no big deal.
wink.gif
 
as I recall on my old drag car the pcv
was plumbed into the exhaust header with a slash cut angel to draw the oil/fumes out of the motor into the exhaust. why couldn't this be done if it was plumbed after the cats & o2's.
 
Originally posted by heretic:
as I recall on my old drag car the pcv
was plumbed into the exhaust header with a slash cut angel to draw the oil/fumes out of the motor into the exhaust. why couldn't this be done if it was plumbed after the cats & o2's.

That's fine once it's just fumes and a little spray, but the problem here is that on the track it passes a significant amount of liquid oil.
 
Originally posted by sjs:
True, what engine is that?

It's not an nsx engine, it's an acura integra/type-r engine, sorry I didn't make that clear.

I'm not aware of any similar plugs on the NSX block and the return passages are not easily tapped.

Hrm, I would be suprised if the NSX doesn't have one of those ports...every 4 cylinder honda block I've seen has them ; however, I've never seen a honda 6 though...it's possible nsx doesn't. I was simply trying to illustrate my catch can drain setup. That's just an example of one of the drain points mentioned in that post. If the nsx engine doesn't have a casting plug to drain, I would just tap the oil pan.


BTW, I think you'll find that the term "freeze plug" refers to a plug pressed into a water passage not an oil return passage.


You are correct. It is not a freeze plug, I don't know why I called it that. My fault, I believe it's a casting plug as you mention previously. That's my mistake calling it freeze plug. Your description of the function of a freeze plug is the same as mine. That casting port is threaded from the factory, I didn't tap it...it's simply plugged with a big hex head. I would be surprised of the nsx engine doesn't have it. Maybe someone has a block sitting around they can take a look at.


------------------
jack of all trades, master of some.
I don't own an NSX.


[This message has been edited by true (edited 01 December 2002).]
 
Originally posted by true:
... That casting port is threaded from the factory, I didn't tap it...it's simply plugged with a big hex head. I would be surprised of the nsx engine doesn't have it. Maybe someone has a block sitting around they can take a look at.

I've got a stripped bare block sitting here next to me and I don't see one, but casting methods for this block are likely different than for one with a closed deck design. Coolant and oil flow passages on these are remarkably simple so it doesn't need all the holes for the sand to escape.

You had mentioned that your car was not an NSX, I just wondered what it was.
 
Originally posted by sjs:
casting methods for this block are likely different than for one with a closed deck design.

My engine is open deck as well. Actually, I think all honda motors are open deck except for the H22 motors. (prelude)


You had mentioned that your car was not an NSX, I just wondered what it was.


The car is a crx..engine is integra.
 
Originally posted by heretic:
as I recall on my old drag car the pcv
was plumbed into the exhaust header with a slash cut angel to draw the oil/fumes out of the motor into the exhaust. why couldn't this be done if it was plumbed after the cats & o2's.

That is called a pan-evac system, it allows
the exhaust gas passing past a pipe put in the header collector (attached to a valve on the valve cover) at the proper angle to help evacuate the crank case preasure and free up the rotating mass to free up HP.
 
Back
Top