What to do with breather pipe as my new air filters have no connection for one?

[vette]

Trying to post, computer malfunction.

Not sure what you mean here; do you mean the hose was stuck in the air filter to filter the gases from the crankcase exiting to the atmosphere (because that's that all an air filter on the 'T' will do, and why a catch can is a better solution)? The vent in the stock (Cooper?) rear filter of a Big Healey is flattened and opens as a 'slot' right next to the mouth of the carburettor; I believe there is significant suction at this point due to the venturi effect,

- the hose is in the air cleaner to facilitate filtered air being drawn into the crankcase. the venturi effect is not stong enough on this hose end at the filter to suck from the hose down the carb. Yes some of course get down the carb, but it is minor compared to a direct draw on the hose. Stop and think about it, the square area of the filter element is providing air to the carb. How can you believe that the hose is providing much of the air volume going down the carb. Also the nipple of the hose inside the air filter is positioned INSIDE THE PERIMETER OF THE FILTER ELEMENT. If the intent was to pull air out of the crankcase and down the carb don't you think it would be a good idea to have the hose positioned so that the air coming out of the crankcase would be drawn thru the filter element itself to try to stop debris from coming from the crank case and down the carb.
either inside the air filter or directly through a separate port.
On every stock PCV valve arrangement I've seen the gases from the crankcase are vented by the PCV valve directly into the intake manifold,either inside the air filter or directly through a separate port.
- Yes "into the intake manifold". and below the throttle plate. this is a vacuum source. A true PCV system never has its pcv valve stuck into an Air Cleaner. There is no vacuum there, it is above the throttle plates. What ever hose is found in a air cleaner is there as the air entry point to the crankcase. The hose is in the air cleaner so that any air drawn into the crankcase will be filtered. That's why I have been saying that the hose on the Healey from the Tee to the rear carb is acting as a two way street. There is no other opening into the crankcase of a Healey 3000, or a 100/6. Therefore there is no crankcase recirculation, only an opening to the atmosphere. One opening.

Some crankcase atmosphere does get pushed up the hose to the rear carb, that's why the carb gets oily. But this is not a perfect system. it's the only opening in the crankcase. If you take the hose off the rear carb and put your finger over the end of it while the engine is running you will feel some pressure. So some people think , well, that's the air coming out of the crankcase. Well sure it is, but is the carb now pulling it out. the hose is in your hand not in the air filter. Stop and think about all the turbulence that is going on in the crankcase even when the engine is idling. The air has to go somewhere, and your holding it in your hand. It's the only opening, and it's a two way street, allowing some in and some out. The Carb and air filter isn't pulling it. And that one two way street opening is restrictive. It allows pressure to be greater than if there was better venting of the crankcase. Well, just a 2" circular filter on the end of the Tee allows better venting, and my rear main seal stopped leaking. And my rear carb stays as clean as the front one, and the little 2" filter on the end of the Tee doesn't get oil saturated in the whole summer of driving. What makes you think I need a catch can.

either inside the air filter or directly through a separate port. The intake air to supply the PCV circuit was always filtered from inside the air filter or by a separate--usually valve cover-mounted--filter. Unfiltered crankcase gases ported directly to the intake manifold have always been a bit of a problem; my Ranger's throttle would get sticky every 20K miles or so due to the accumulation of gunk from the PCV valve. Newer engines with direct injection can be even more problematic, as you don't get the benefit of the 'miracle' cleaners--Techron, V-Power, etc.--at least partially cleaning the intake ports and the backside of the intake valves (this is why some Toyota DI engines have an additional port injector to help keep the intake valves from gunking up).

 

[Bob_Spidell]

Thanks for the feedback. Your points are taken, and I will be thinking about them, as I have a relevant problem. Our BN2 has excessive pulses of pressure as felt at the oil filler hole. When I had the car up on jack stands for a fluid change I checked and you are correct, there was very little pressure at the road draft tube. The car also has excessive oil dripping even with a rear main seal installed. I'm at a loss to explain all this, and I've asked on the email list and, I think, here, but haven't gotten a definitive explanation. I don't think it's caused by excessive blow-by because, as I mentioned, there is very little pressure at the road draft tube and I've got 160PSI+ compression on all four. I never checked the BJ8 to see if there was excessive pressure at the oil filler cap before I installed the PCV valve (when I check now there is a slight vacuum at the hole). I've been driving the M with the oil filler cap off and just a shop rag tie-wrapped over the hole to limit oil splatter, and the oil loss seems to be less, so I'm considering installing a PCV valve (figure I can weld a bung on the balance tube and distribute the gasses more evenly). Note that the 100s had a relatively small vent hole on the valve cover--which in the case of our M is vented to the cold air box--and I think it's insufficient.

 

[vette]

Bob, I understand what you are saying and i must admit that I have run into situations with different engines that just don't seem to play by the rules. An example being why you would feel pressure pulses at the oil fill hole but not at the road draft tube. I believe pressure in the crankcase only comes from 2 things. Either blowby or turbulence. There are only 2 solutions to TOO MUCH pressure in the crankcase in my opinion, one, an equivalent amount of venting to compensate for the pressure and two, pull a vacuum on it. Which is done via a properly installed PVC valve. One last note I can think of, when venting, it is possible that the venting device would become saturated with oil. Not all engines will do this it is the result of many variables blow-by being one of them or no baffles or misplaced baffles, etc. In the 6-cyl (i am not familiar with the 4-cyl) Healey, just the deepth of insertion of the Tee into the valve cover can make a difference. Dave.

 

[vette]

I add to the above, loose valve guides will also add to pressure. It is the same as blow-by but mostly at the top. This may explain pressure at the oil fill but not at the roaddraft. Allow recognizing that the continuum of the void is near the same. The roaddraft tube is not that far away from the valve cover. But then the road draft tube usually has a somewhat effective wire mesh screening/filter at the top of it.

 

[Bob_Spidell]

Loose valve guides would be a logical cause, though I would expect them to contribute to lower compression. The head was thoroughly worked-over by a reputable racing engine builder--who had to repair some cracks--so I would think he did the guides correctly (he installed bronze guides in the BJ8 over 110K miles ago, and they have never given a problem). The oil loss is really bugging me, as the car is a hoot to drive and more fun than the BJ8 (but the BJ8 is my preferred ride for longer trips).

 

[DerekJ]

I'm still not clear about parts of this discussion. Its been stated that some people have installed a PCV valve because they changed air filters and do not now attach the breather from the T to the filters. If this is the case can someone explain what PCV valve set up they actually installed and what they have done with the breather hoses. i'm confused.

 

[John Turney]

John,

Can you elaborate on when you say 'I installed a PCV because the Denis Welch ITG filter didn't have a connection for a hose from the valve cover T.'

What exactly was your set up?

thanks

Out of touch for a day. I have a 3000 engine with a BJ8 intake manifold and HD8s. I ran a short hose from the valve cover T to a PCV valve then to the port on the manifold where the vacuum for a brake booster would go. I don't have a brake booster. The manifold port is in the leg going to cylinders 5 & 6. I took the manifold off to replace the gasket because I thought I had a leak (I did from the exhaust side). I could see the tops of the valves and there was a buildup on top of the #5 & #6 intakes, but not the other four.

 

[John Turney]

John, just put a filter on the Tee and see what happens to the oil drips. How hard can that be? People think you need a hose stuck in an air filter or into a PCV valve to draw anything from the crankcase. the hose was just stuck into the air filter as a means of filtering any air that did move thru the hose. The velocity moving down the carburator is not pulling anything thru the hose from the tee. The air cleaner is just a filtered vent opening. take a look at any crankcase venting arrangement on an American engine after the years that the downdraft tube was discontinued. There was a suction point either from a side cover in an in-line engine or at a valve cover in the V8 arrangement which drew its suction from some point in intake stream below the throttle blades. The inlet point was always a hose stuck into the air filter. It was in the air filter just to filter any air that moved " INTO" the hose. the Healey arrangement is an ineffective compromise.

I agree that the hose going to the air filter filters the air which may go into the crankcase/valve cover and doesn't really draw air into the engine unless the crankcase is pressurized. I did as you suggested and now drips went from none to "I can no longer tease my friend about the leaks from his Jeep being like the Exxon Valdez II."

 

[vette]

John, it appears that you have proven that a properly installed PVC system is better than an open, vented crankcase. At least on some engines. As I said earlier I have found that some engines don't respond the same. I am surprised that your rear main has leaked that much because mine has not. The opposite has occurred on the new engine I had built for my '70 Vette. With a K&N breather filter mounted on each valve cover, the engine pushes oil out the rear main seal and the front crank seal. with a PVC plumbed from the drivers side valve cover to the bottom carb flange (below the throttle plates) and an open k&N filter on the passengers side valve cover the engine has no leaks. I am sorry that the open filter did not solve your problem. I am curious, did your rear main seal leak before you installed the PCV valve?

 

[John Turney]

.... I am curious, did your rear main seal leak before you installed the PCV valve?

I couldn't really tell; it was all part of a complete overhaul.

 

[jjs64bj8]

I simply used the old window washer bottle, filled it with a cellular foam, put a fitting on the side of it to attach breather hose, attached it to the carb shield, and installed a tranny type vent filter to the top. Looks like it belongs except for the breather filter on the top. Then plugged hole on rear air filter.

jjs64b78

 

[fishyboy]

Thanks jjs64bj8
Great simple idea which I'll look into.
Phil