I've seen several pics of Amazon engines w/o the vented valve cover cap. What are the potential consequences if I switch to a ventless cap? My current vented cap never stays attached to the air filter anyway.

1. The vent relieves pressure in the head from gasses in the combustion chamber. It helps to keep oil from blowing by the valve cover gasket.

2. You also have a PCV (Positive Crankcase Ventillation) system. That is the hose going from the drivers side of the engine over to an inlet on the intake manifold. It is supposed to allow negative pressure (vacuum) in the intake manifold to draw volitile gasses out of the crank case. If gasses are to come out of the crank case, then something must replace it to avoid making a vacuum. Filtered air is supposed to come in via the hose attached to the oil cap.

I had a problem with condensation collecting in the hose fitting below the air filter. I tried taking off the intermediate piece (the plenum between the air filter and carburetor) and just using a little PCV filter directly on top of the valve cover cap. The filter allowed oil to spray out under heavy loads. It was great for saturating the engine compartment and anywhere I parked with a nice coat of hot oil.

Now that the weather is warmer condensation isn't a concern. The factory set up was reinstalled and all is well. Hopefully a solution to the condensation problem will present itself before next winter.

You really should not defeat the purpose of the vented oil filler cap. Please explain about your hose not staying on. Is the hose long enough? Are there hose clamps securing it in place?

Best regards,

Joe M

the hose on the cap end stays attached. However the end at the airfilter clips into the front filter and falls out easily.

So why do I see so many pics of amazons w/o the vented cap?

Old non-PCV system just used a "road tube" that the crankcase vented through.
If you give up on the vented cap you will draw air past the crankcase seals (and rocker cover seal if not very good). This is likely to draw dist with it too (not good!).

Later units had a vented cap that was "all inclusive" meaning it had filter media of some sort inside and metered holes under the "handle" part of the cap (think mushroom).

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Mike!

by road tube you mean a roughly s-shapped metal hose that bolts in place of the flametrap. If, and I'm not saying that I will, used a road tube, I could removed the vented cap and put on a solid one? I happen to have aroad tube, but I'm not sure I want to muck with the system in that way. I just wanted to know why I had to deal with this hose on my oil cap. I hear the tube is a high-performance setup. I'm trying not to kill the car right now just make it looks nicer.

Yes.

Bad for environment and driveway, otherwise no problem. Tube is long enough that dirty air is not generally drawn all the way into the crankcase through it (and indeed usually blow-by has a positive pressure in there).

Drag racers have found that inducing a vaccum in the crankcase helps with power... And that is what the PCV system does (beyond being nice to driveway and environment).

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Mike!

any idea wher I coudl find one of those spiffy caps? (as in what year volvos had them?)