Rocker Cover Vent

[Paul McGuffin]

I am thinking of venting my rocker cover vent to the balance tube on the intake manifold. It’s a 1098cc engine in a Bugeye. Has anyone had any problems after doing this? The manifold in the photo is not mine, it’s just a photo off the Web.
PM

 

[nomad]

Without a PCV and a restriction I don't believe that will work well. Whats wrong with the stock PCV from the lifter galley and a restricted oil fill cap? That's what the 10CC engine had.....or do you have a 10CG engine with the draft tube? If you have the 10CG engine the valve cover was vented to the air cleaner....that would work as well.

Kurt.

 

[Gerard]

The manifold you show is designed to be used with the Smith's PCV. I think you will have too much vacuum to vent it directly.

 

[Paul McGuffin]

I have a bad oil leak coming from my lifter cover vent line (cam followers). Engine has good compression and oil pressure. Something is causing the crank case to over pressurize, I would surmise. The rocker cover vent now is routed to the charcoal filter. Could the problem be the charcoal filter plugged or maybe an exhaust valve not closing all the way, out of adjustment? There are only a few things that can cause it to over pressurize.....usually bad rings causing blow by. Engine does not burn oil and no smoke. As I stated, the manifold in the photo is not mine, it’s a picture off the web.
PM

 

[nomad]

I think we need pictures....you really have no need for a charcoal filter. Do you have a vent from your lifter cover and where does it go??

Kurt.

 

[Gerard]

The 1098 never had a charcoal canister/filter as part of the system, so I'm unclear as to your connection. Do you mean the oil separator on the form tappet cover, as shown in the epic I attached? In any event, your leaking tappet covers are not related to excess pressure. Excess pressure cause oil to leak from the rear main cap (scroll seal). The tappet covers came in two styles; early ones had a stepped edge, but it is flat and will allow the gasket to migrate away from the cover. The later type has the edge formed as a channel, and are more rigid, keeping the gasket in place better. The later style is the one with the oil separator. However, both types will leak, either from the gasket or a a perished seal around the fixing bolt on the center. Original gaskets were cork, but many new gasket sets have rubber tappet cover gaskets. You probably just need to clean everything well, and replace the gaskets.

Posting pictures would be a big help. You should also add your vehicle to you profile, so people know what you have.

I have a bad oil leak coming from my lifter cover vent line (cam followers). Engine has good compression and oil pressure. Something is causing the crank case to over pressurize, I would surmise. The rocker cover vent now is routed to the charcoal filter. Could the problem be the charcoal filter plugged or maybe an exhaust valve not closing all the way, out of adjustment? There are only a few things that can cause it to over pressurize.....usually bad rings causing blow by. Engine does not burn oil and no smoke. As I stated, the manifold in the photo is not mine, it’s a picture off the web.
PM

 

[Paul McGuffin]

The rocker cover vent hose goes down to can attached to the timing chain cover. I “thought” that was a charcol canister. The oil leak is coming from the pipe (vent line) off the tappet, lifter covers. The gaskets are new. the leak is not coming out there, it drips on the floor from the pipe itself. I’ll get some photos up soon. 1961 Bugeye with a 1098cc engine, early 1098.
PM

 

[Boink]

The rocker cover vent hose goes down to can attached to the timing chain cover. I “thought” that was a charcol canister. PM

I thought the so-called "oil separator" was filled with something equivalent to rough steel wool (like a kind of elongated screen).

 

[Gerard]

That's simple then, the pipe is cracked at the base. I've seen this before. You can probably fix it with solder if you're good with a propane torch. Cleaning the joint area and some good flux will be required to be successful. Alternately, you could try to find a good used one, but they seem to be kind of rare.

The rocker cover vent hose goes down to can attached to the timing chain cover. I “thought” that was a charcol canister. The oil leak is coming from the pipe (vent line) off the tappet, lifter covers. The gaskets are new. the leak is not coming out there, it drips on the floor from the pipe itself. I’ll get some photos up soon. 1961 Bugeye with a 1098cc engine, early 1098.
PM

 

[Gerard]

It usually is... sometimes it's been removed. looks like those coarse pot scrubbers you used to be able to get. I believe it's purpose is not to filter, but rather to have a lot of surface area to condense the oil from the air flow so it can drain back to the engine.

I thought the so-called "oil separator" was filled with something equivalent to rough steel wool (like a kind of elongated screen).

 

[Boink]

It usually is... sometimes it's been removed. looks like those coarse pot scrubbers you used to be able to get. I believe it's purpose is not to filter, but rather to have a lot of surface area to condense the oil from the air flow so it can drain back to the engine.

Right. Makes sense. Thought it was largely for stopping oil but allowing ventilation. Stopping condensed oil makes sense too.

 

[Paul McGuffin]

The oil leak is from the lifter cover vent line, “not" the vent from the rocker cover. I figured the crank case is going into a positive pressure and blowing it out that tapped, lifter (cam follower) cover vent line. Here is a photo of the can where the rocker cover vents. the other is the vent line off the tappet cover. As you can see, I have attached a hose, ran it to a small can to catch the oil.

 

[Gerard]

It's been difficult to follow your explanations because you're using the wrong terminology/description for things. I realize you may be new to this, so pictures really help you to post. From the picture, I now understand the problem. You have "mix and match" parts, which is not uncommon after more than 5 decades.

What you have is a 1275 timing cover (the cover at the front of the engine) and 948/early 1098 tappet covers. The "rocker cover" is the cover at the top of the engine that covers the valve train. They are both intended for the same purpose, so what you have is redundant, but not designed to work together. The timing cover is intended to be used on a closed circuit system (later 1098 and all 1275cc engines), while the down pipe from the front tappet cover (called a draught tube) is an open ventilation system. The timing cover oil separator superseded the draught tube design. The draught tube relies on a change in air pressure over the end the the tube when the car is moving forward to create a low pressure area, hence a vacuum, drawing crankcase fumes out. Unfortunately, that also means oil collects in the tube, and will accumulate and drip. There's not much you can do about except maybe to have a removable trio pan underneath it that can be emptied periodically. The other option would be to get a spare rear cover and do away with the tube altogether.

You can plumb a Smith's PCV, as shown in earlier pictures, to the timing cover. It may help some, but I don't know that it will completely eliminate the drip.

The oil leak is from the lifter cover vent line, “not" the vent from the rocker cover. I figured the crank case is going into a positive pressure and blowing it out that tapped, lifter (cam follower) cover vent line. Here is a photo of the can where the rocker cover vents. the other is the vent line off the tappet cover. As you can see, I have attached a hose, ran it to a small can to catch the oil.

View attachment 43097

 

[Paul McGuffin]

I was told my 1098 was an early one. They could have been wrong, thus the newer 1098 or 1275 timing chain gismo/can. I’m starting to think, the best answer is get a 1275cc and rebuild it. I have no idea what’s been done to the 1098cc that is in the car. At least with a new engine, I WILL KNOW what’s been done and how. Thanks for the help. Oh... so is it okay to just vent the rocker cover to the can?

 

[Gerard]

You can, but if you have pressure build up in the valve cover, you're going to further pressurize the crankcase. Remove the oil filler cap and put your hand over the opening with a rubber glove on your hand. If you feel air pushing out, I wouldn't.

The timing chain cover you have was only used on the 1275. That later 1098 had it on the front tappet cover and nothing on the timing cover.

I was told my 1098 was an early one. They could have been wrong, thus the newer 1098 or 1275 timing chain gismo/can. I’m starting to think, the best answer is get a 1275cc and rebuild it. I have no idea what’s been done to the 1098cc that is in the car. At least with a new engine, I WILL KNOW what’s been done and how. Thanks for the help. Oh... so is it okay to just vent the rocker cover to the can?View attachment 43107

 

[Paul McGuffin]

This is a photo of my vent line from the rocker cover. No bend or curve, this creates a problem with the hose. Is this type of rocker cover from a 1275cc?

 

[Gerard]

That's a 1098 rocker cover. The hose connection went to the air cleaner.

This is a photo of my vent line from the rocker cover. No bend or curve, this creates a problem with the hose. Is this type of rocker cover from a 1275cc?View attachment 43120

 

[Paul McGuffin]

That’s a 1098 rocker cover. The hose connection went to the air cleaner.

Then it must have had a special hose...already with a bend in it.

 

[Gerard]

It's the type used on Morris Minors (948 and probably 1098 as well). Does one of the badges on it say "MORRIS"? I believe all Sprite and midget that had a had (some later 1275's did not) were curved.

That’s a 1098 rocker cover. The hose connection went to the air cleaner.

Then it must have had a special hose...already with a bend in it.

 

[Paul McGuffin]

The tag on the rocker cover says Austin.
PM