Air Intake 225 V6

Hi all -

Looking for some clarification on the two 'intakes' on the oil bath. What I assume is the main air intake goes into the top of center canister, whereas there is a second metal tube going into the side of the outer reservoir container. Currently, this second side tube is plugged.

Can someone clarify what the second, side intake is for? I am thinking it was for feedback from exhaust/emissions? Currently there is no air pump or emissions on engine although there could have been originally (1970 V6 CJ5)? Should I leave it plugged or should it be opened up?

I'd post a picture but apparently I do not have attachment permissions.

thanks - James

 

yep - looks like that. Thought it might be for emissions. Thanks.

ps - can I ask about why the hose connecting the breather to the intake in your photo?

 

Good point - my bad.

 

I probably am confused - and the pic looks to have been removed - but that didn't look like the PCV hose (at least not the small diameter hose from the PCV valve to the me - which isn't saying much). From what I remember in the photo it was from the driver side valve cover breather opening (much larger than the PCV opening on the rear passenger valve cover). I thought I could see the small PCV opening/valve in the background of the pic.

That being said - that still doesn't mean I am not confused about the function of the breather on the driver side and how it fits into the PCV system (my FSM is in the mail). Would there normally be feedback hose from the larger 'breather' opening on the driver side to the intake (I may even be using 'breather' incorrectly)? The pic may have had an optical illusion in it, but it looked like there was no fresh air intake - maybe the fresh air intake was just blocked in the picture, but it certainly looked it was directly and only connected to the breather opening by the hose. Maybe it was also only a temporary set-up for some reason as the project was in progress.

Thanks for your patience and help - I feel like I am learning a foreign language and it would have been much easier to learn if I were younger and grew up doing it without thinking about it. Trying to learn enough to keeping it driving and potentially learn enough to one day rebuild it nicely with the help of local shops for the real internal guts work.

Without a doubt this forum has been the most useful for helping with my ECJ5 - thanks.

 

Air is sucked into the intake by vacuum thru the back if the carb. The pcv valve is on the back of the passenger side cover. The make up air is sucked into the engine thru the breather tube on drivers side and thru the aircleaner so it is filtered clean air.
The pcv system gets rid of excess pressure in the engine caused by blowby gasses past the piston rings.
If you plugged off the pcv valve pressure would build up and the engine would leak oil from every seal on the engine.

 

Good diagram - I think I got this now. So basically, neither of the tubes on the oil bath are for intake into the oil bath. The top one is to feed additional air into the crankcase if needed. The side one (as originally indicated by PieLut) is for emissions which can be plugged assuming that's all been removed or never was there to begin with.

I guess I always thought the PCV system only released excess pressure through the PCV valve and feed that back into the intake (a 258 I had on a 7 had a lot of blow by oil that would get fedback into the intake at the paper air filter housing and cause problems), but I never understood the additional make-up inflow direct to the crankcase.

Anyway, a PO decided that it would be better for the additional make-up intake to come through a 'plug-in' breather filter that is not connected to the system. Is it worth closing the system and connecting the oil bath to the breather intake? Seems like I would need some sort of device to fit into the breather opening in the valve cover to connect the hose to.

thanks - James

 

Yup - that is the one I have plugged off as well and shown in picture from Pielut. Plugged off right at the tube on the oil bath.

RJ - how does your 90 degree hose connect to the breather hole in the valve cover - that is the one I am missing. I assume there is some sort of 'nipple' that fits into it. Pielut's pic has a sort of black plastic connecter?

I am also still a little confused about air intake - but I think it pulls air in through the circular gap between the inner and outer canisters (oil cup) of the oil bath. There is no actual intake tube or hose, just sucks in the air directly in through the gap. I think....

 

My guess is that the PCV valve won't release unburned combustables back to the intake as the crankcase breathers will release the pressure and not allow the PCV valve to open. Under conditions when the PCV valve would close and direct air flow into the crankcase would result, you should get flow in through the breathers - so I would say it has no function in your situation. But as you can tell from this thread I am still in the learning phase, but I do agree with you.

 

you need the pcv valve. Or at least a hose that allows the excess pressure to get out of the engine. What I used on my dauntless untill I got my parts was just a screw on breather filter. it was basicly a oil fill cap type of thing for the top of the valve cover. It was about 3 inches in diameter and maybe 2 inches tall. Had the steel wool looking stuff in it to filter out the fresh air being drawn into the valve cover.
You don't have to have the breather tube on the oil bath hooked up, but you do need some valve or orfice to let pressure out of the engine so it doesn't build up pressure and push the oil out the seals.