Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.
Trending News
350 SB Breather Filter Question?
I'm not all that familiar with breather filters, so bare with me! I bought a 1972 Nova a while back. The engine is a 350 out of a 1993 Chevy truck. When I bought the car, it had a breather tube coming out of the driver side valve cover. This tube was just going out into open air under the hood. A few people told me that it shouldn't really be like that and I should put a filter on it. Here's a photo (tube is circled in red):
http://i1197.photobucket.com/albums/aa436/zeppelin...
Today, I cut down the tube and slipped a breather filter onto it. Does this look legit? Like I said I'm not totally familiar with these. To me, it's basically doing the same job, just now it'll be more difficult for debris/water to get in.
7 Answers
- ?Lv 79 years agoFavorite Answer
You just killed the PCV system and hence any vacuum into the crankcase. Get rid of all open holes in the valve covers. Seal them up. The only holes in valve covers that you need is an oil filler cap that is sealed tight, and then a PCV valve. This will aid ring seal, a slight aid in power(because it aids ring seal), and you will stave off oil leaks... especially from the front/rear main seal.
Source(s): Camshaft design/manufacture, full competition race engine building/development, failure analysis of internal engine components, Carb blueprinting, drivability/MPG/durability expert, chem analysis of fuel, super-tuner. - monkeyboyLv 79 years ago
Edit/correction: Now that I can see the photo, I understand better what you mean. Do you have a PCV valve on the other valve cover? As long as you've got a PCV valve, you are fine. I assumed you did. In your case, it appears you may not.
Normal breather is located in the air cleaner, meaning it's not "sealed" in any way, shape, or form.
Pretty sure most racing engines either use breathers (not plumbed into the air cleaner), or an evacuation system that pulls a vacuum from the exhaust.
- How do you think about the answers? You can sign in to vote the answer.
- slipstreamLv 79 years ago
it's a simple filter that was added after positive crankcase ventilation [ P.C.V.] became standard...as the p.c.v.valve ventilated [ by vacuum] the breather filter would allow clean air in ...in older model,s they would simply vent the crankcase fumes to the atmosphere...as engines wore out they would leave a trail of smoke. the E.P.A. was instrumental in forcing the crankcase vent system. the way it was [ in your first photo] would allow dirt/debris to enter the engine...your filter replacement will work fine....in the Original set up [ from the factory] the filter was located in the main air filter housing next to the main air filter on the outside wall of the housing & connected to the valve cover with a hose/tube.....the way you have it now is fine.
Source(s): 49+ year,s wrenching. - done wrenchingLv 79 years ago
The crankcase NEEDS a vent and should also have the pcv. Try to modify the air cleaner base so you can connect that 93 vent pipe to it.
- ?Lv 69 years ago
its just a breather, the stock one on there was for a TBI 350 and it went to a throttle body, your set up looks fine now and even before it really wouldnt have gave you any problems but it looks alot better now. i always use chrome valve cover and chrome breathers when i build an engine,
