I picked a pair of finned Cal Custom V/C's up. One has a hole in it already that I plan on using for a PCV. The other is uncut and unmolested. I need to run a breather for air to come in. Late 70's 350 small block. No oil fill tube in the manifold. My question is this. Should I only, or do I only need to run one breather on the drivers side? The p*** side will have the PCV. What type of breather will work best? The kind the sits on top of the cover, or comes out the side? Any pics of similar set ups?
Tommy did a good tech on it... http://www.jalopyjournal.com/forum/showthread.php?t=61376&highlight=PCV+breathers As far as breathers on the side or top, it's up to your tastes. Just remember to baffle any breather you install in the valve cover. Mutt
OK, I got the theory part down. As far as installing a breather on a virgin V/C; I see that i can get an angled breather from Summit and others that would go on the intake side. What is the procedure to install those? Drill holes in addtion to the mounting holes? Do they come with a template, or do you gues at how much to open it up? As far as the one mounted on top of the V/C; I've seen the push in kind that come wit a rubber looking baffle, is that sufficient, or do I need to add a baffle from a stock valve cover? Also if I had to drill the valve cover to use a push in style, do you drill the hole from the back?
The breathers come with a gasket that you use as a template. Always mount them as high as you can to lessen the oil that gets to it. If you get a push-in they will tell you what size hole to drill, but I wouldn't recommend a push-in on finned valve covers. If you insist on using one, drill from the rear in a drill press with a hole saw, or step up the bit size with multiple drilling to get the right size. For the push-in style, you will have to trim the fins to get the grommet to set tight. I don't know what the baffle you refer to looks like, so I can't say how well it will work. Try it and see, and if you need more baffling, you can do it later. You can make a baffle for the side mount breathers out of a small piece of sheet steel, and use the breather screws to mount it. Be sure to mount the breather away from the rocker arms so there's no interference with the baffle. I don't drill one big hole, I prefer to swiss cheese the center hole of the gasket. Mutt
Thanks. I figured you would need to drill small holes inside the area that the side mounted ones would go. Sounds like that will be the plan. What is the purpose of the baffle? Also would the baffle be a flat piece that covers the holes but has a small space behind it to let the air in? sorry for the dumb questions..
The baffle keeps oil from getting into the breather, where it can be pulled out by the suction of wind p***ing it, or pushed out by pressure from the crankcase. You can use wrist sweatbands around the breather to keep misting down, also. The side mount breathers usually have foam inside them. Correct on the discription of the baffle, and they're not dumb questions... Mutt
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