i found on their website a photo of this breather mounted on the outside of the valve cover . On this nailhead engine I don't see a problem, but if I was to mount this same breather on the outside of a SBC valve cover I am concerned that oil will fill up the breather and a mess will be forthcoming. Does anyone have experience with this kind of setup mounted on the outside of the valve cover on a SBC where the heads are at an angle? Should I be concerned or no problem? Thanks in advance!
I just recalled seeing something similar on a car at GOODGUYS SCOTTSDALE 2010. That looks very similar to what I am talking about......at the time I didn't ask him if there were issues with oil coming out, only where he got them now that I think of it....he said that they were some brand name and that he had that machined off, polished up and chromed..... I guess this is encouraging.....would feel better if a few people said oh yeah....that's how mine looks and I have xx,xxx miles on them with no issue.......anyone?
It says it uses open cell foam for baffling so I'm not really sure. Are you using a high volume oil pump?
I couldnt tell you for sure but they look as if they would be high enoughtthat you wouldnt have a messy leaky oil problem.
I have similar breathers on two of my SBC's and it uses the closed cell foam inside to minimize vapors and blow-by. Works very effectively. Blow-by is minimal on my engine due to it being a rebuilt with only 4,000 miles on it, although it was built by a circle track guy that used race motor clearances and specs. Occasionally I need to wipe off a little mist on the valve covers from the breather areas but I think it's more a rubber grommet fit issue than anything else. I had a pair of Moon breathers on another SBC a few years ago and they were excellent. No weeping whatsoever from them. Gotta keep that shiny chrome and paint clean!
I got a high mileage 327 i run them on, lots of higher rpms and high speed with an open engine bay and no problems other than just a little residue. I did make sure they drain good so oil doesnt pool at the gasket.
- not talking about oil puking - just seeps ever so slowly into breather then over time a fine film will settle on motor, engine bay, etc. with no reverse flow back to heads where it is supposed to be breathing will be affected with foam in filter being partly blocked. plus, if you are running these how do you put oil in motor? if must run, put smaller ones on top or top side of covers.
When I install them, I mark on the valve cover where I want them. Then I drill the holes into the valve cover with one or two of them right at the bottom, so the oil will drain back into the valve cover. I don't cut out the whole section and on Moon breathers they have internal baffles that keep the oil from coming out the top. Edit: The holes as drain backs only work if you mount them above the valve cover. Moon makes their lowboy ones so that they will fit between the valve covers and carb.
In the past I have pulled off the valve covers...I have the expensive valve cover gaskets that I have no problem using with lots of change outs. I think I am ok with a fine film.......
I run those on my SBC and have no problem. Mine are originals with non removable top, not sure if they are the same inside.
I ran them on my T Bucket and the only problem was a small bit of oil vapor after a long drive. And I mean a loooong, all day, non-stop drive.
also if you epoxy a small fine screen it helps catch any larger volumes of oil in the mist just put a curve in the screen and not place it against the valvecover side
The Jalopy Journal
