SoCal Jet Boats

Tech Talk => Engine Mechanical / Electrical => Topic started by: TCRUSH on March 23, 2009, 01:59:08 PM

Title: Breather question?
Post by: TCRUSH on March 23, 2009, 01:59:08 PM: I just got a 1978 Omega with a 454 BBC. I have a question about the breather on the valve cover. I was cruising around the lake at 3500 rpm. It ran great but the problem is I could see a drip of oil every few seconds coming out of the breather. I looks like a cheap chrome mr gasket breather. They also have a chrome plug in the other valve cover instead of a breather. Shouldnt there be one on both covers? What kind of breather should I use. It probably needs some kind of a baffle. It kind of needs to be low profile to fit under the engine cover. Thanks for the help. TC
Title: Re: Breather question?
Post by: beerjet on March 23, 2009, 02:24:15 PM: First and formemost, your valve covers need some kind of baffle, otherwise the breathers will become overlysaturated with oil and leak anyways.

I bought some cheapy stamped steel chrome ones for $25 at the swapmeet that have baffles in them.
I tried the breathers and BAM !
Problem solved.
For me anyways.

I ended up going with the E-vac system but I had OT headers too.

-beerjet-
Title: Re: Breather question?
Post by: TCRUSH on March 23, 2009, 03:05:00 PM: Thanks beerjet. Shouldn't I have one on both valve covers? Seems like the one little breather I have is not enough.
Title: Re: Breather question?
Post by: speedymopars on March 23, 2009, 03:26:30 PM: The crank case is connected together, so really you only need one. Most run two though. Typically you can put a PCV on one side, and a breather on the other, the breather becomes an inlet at that point. In a boat though, usually not done.

Some auto drag racers put two PVC's and no breathers on both sides to help the rings seal better (a poor man's vaccum pump). Of course you then have oil vapor contaminating the mixture, but some feel the trade off is worth it.
Title: Re: Breather question?
Post by: TCRUSH on March 23, 2009, 03:37:43 PM: Thanks for the advice. I think I will run two and get some with baffles so it doesnt drip oil on the valve covers.
Title: Re: Breather question?
Post by: 2savage4you on March 23, 2009, 04:15:29 PM: Quote from: beerjet on March 23, 2009, 02:24:15 PM
First and formemost, your valve covers need some kind of baffle, otherwise the breathers will become overlysaturated with oil and leak anyways.
-beerjet-

Omar, is this the case with bolt on breathers too ???
Title: Re: Breather question?
Post by: beerjet on March 23, 2009, 07:18:43 PM: You know Steve, I had bolt-ons before and they worked OK.

Baffled V/C worked better though.

-beerjet-
Title: Re: Breather question?
Post by: TCRUSH on March 23, 2009, 07:31:16 PM: Can you guy recommend a specific brand. Is their a suitable type at you local auto parts store? My valve covers look like the typical ones with big rubber grommets.Here is a pic of one of the valve covers.
Title: Re: Breather question?
Post by: gregb on March 23, 2009, 08:25:43 PM: If you take the breather out can you see the valvetrain? If so I would replace the grommets with a set of these

http://store.summitracing.com/partdetail.asp?autofilter=1&part=SUM%2DG3413&N=700+4294925232+4294839018+4294871547+115&autoview=sku

they are a grommet but shield the breather from oil spray.
Title: Re: Breather question?
Post by: GT Jets on March 23, 2009, 09:20:14 PM: Quote from: speedymopars on March 23, 2009, 03:26:30 PM
The crank case is connected together, so really you only need one. Most run two though. Typically you can put a PCV on one side, and a breather on the other, the breather becomes an inlet at that point. In a boat though, usually not done.

Some auto drag racers put two PVC's and no breathers on both sides to help the rings seal better (a poor man's vaccum pump). Of course you then have oil vapor contaminating the mixture, but some feel the trade off is worth it.

Good input IMO, however if the carb is sized even close, there wont be enough vacuum to pull hard enough on the PCV to work very well, and if there is enough oil flow in the heads to slow the return to the pan you will definately need to vent both covers, lets just call it a "been there and done that"...Baffled vents give the best bang for the buck..

GT
Title: Re: Breather question?
Post by: YumaJet on March 23, 2009, 11:07:13 PM: i had the same problem too. i just went with edelbrocks top mount baffled valve covers and havent had a drip of oil since. the covers were only about 50 bucks.
Title: Re: Breather question?
Post by: Luckie Stiff on March 24, 2009, 05:15:15 AM: Quote from: TCRUSH on March 23, 2009, 07:31:16 PM
Can you guy recommend a specific brand. Is their a suitable type at you local auto parts store? My valve covers look like the typical ones with big rubber grommets.Here is a pic of one of the valve covers.

These should suit your needs
http://store.summitracing.com/partdetail.asp?autofilter=1&part=KNN%2D62%2D1490&N=700+115&autoview=sku (http://store.summitracing.com/partdetail.asp?autofilter=1&part=KNN%2D62%2D1490&N=700+115&autoview=sku)
Title: Re: Breather question?
Post by: jet boat performance on March 24, 2009, 08:24:19 AM: Quote from: beerjet on March 23, 2009, 02:24:15 PM
First and formemost, your valve covers need some kind of baffle, otherwise the breathers will become overlysaturated with oil and leak anyways.

I bought some cheapy stamped steel chrome ones for $25 at the swapmeet that have baffles in them.
I tried the breathers and BAM !
Problem solved.
For me anyways.

I ended up going with the E-vac system but I had OT headers too.

-beerjet-
Well siad unbaffled Vcs will simply burp oil period also the bigger the better on breathers , we use alot of KNs (center grommets enlarged) the baffle inside keeps the oil from being slung at the breather base the vapors will filter thru and disapate. We also use /sell "burn down" breathers which work with puke tanks and Pan vac systems (headers only) Tom
(https://www.socaljetboats.com/proxy.php?request=http%3A%2F%2Fi147.photobucket.com%2Falbums%2Fr319%2Fjetboatperformance%2FMiller%25202%2520%2520cust%2FAnthony-Miller-06.jpg&hash=8930cddf41e25c8735df0f403c28b608643c4579)
(https://www.socaljetboats.com/proxy.php?request=http%3A%2F%2Fi147.photobucket.com%2Falbums%2Fr319%2Fjetboatperformance%2FEliminator%2520V-drive%2FResizeofDSC00303.jpg&hash=74669d6d715527cf7a16b6a036e57587cd7f7b82)
Title: Re: Breather question?
Post by: TCRUSH on March 24, 2009, 08:59:03 AM: Thanks guys. Tom your boats are awesome! I guess I will pick up a couple of breathers with baffles. The holes in the valve covers are wide open with no built in baffles. I probably dont want breathers with any kind of filter or foam because they usually will get saturated and then drip right? Thanks for the help guys.
Title: Re: Breather question?
Post by: 2savage4you on March 24, 2009, 10:30:50 AM: Quote from: TCRUSH on March 24, 2009, 08:59:03 AM
Thanks guys. Tom your boats are awesome! I guess I will pick up a couple of breathers with baffles. The holes in the valve covers are wide open with no built in baffles. I probably dont want breathers with any kind of filter or foam because they usually will get saturated and then drip right? Thanks for the help guys.

You can mount baffles in those M/T v/c's

these might even work ;)
http://store.summitracing.com/partdetail.asp?autofilter=1&part=MOR%2D68790&N=700+400105+303660+115&autoview=sku
Title: Re: Breather question?
Post by: TCRUSH on March 24, 2009, 11:33:56 AM: Those look simple. Do you drill two holes in the valve cover and bolt them in? Looks easy.
Title: Re: Breather question?
Post by: 2savage4you on March 24, 2009, 12:09:31 PM: Quote from: TCRUSH on March 24, 2009, 11:33:56 AM
Those look simple. Do you drill two holes in the valve cover and bolt them in? Looks easy.

Should already have the holes threaded on each side of the hole in the v/c

My M/T did on both sets
Title: Re: Breather question?
Post by: TCRUSH on March 24, 2009, 03:39:17 PM: Sounds good. I will check it out when I get home.
Title: Re: Breather question?
Post by: 2savage4you on March 24, 2009, 05:28:04 PM: Quote from: jet boat performance on March 24, 2009, 08:24:19 AM
We also use /sell "burn down" breathers which work with puke tanks and Pan vac systems (headers only) Tom

Which reminds me , im still waiting for a price qoute ::) ;)
Title: Re: Breather question?
Post by: TCRUSH on April 03, 2009, 11:17:25 AM: Hey fellas, I put a breather in both valve covers and I have clearance issues on the one side. My engine cover hits the top of the breather and wont let the cover close all the way. I put a new breather in the other valve cover and in clears fine. Is it possoble to use a pcv valve on the other one and hook it to the carb? I dont know if its ok to use a pcv valve on a boat. Thanks for the input. TC
Title: Re: Breather question?
Post by: 2savage4you on April 03, 2009, 11:18:49 AM: Quote from: TCRUSH on April 03, 2009, 11:17:25 AM
Hey fellas, I put a breather in both valve covers and I have clearance issues on the one side. My engine cover hits the top of the breather and wont let the cover close all the way. I put a new breather in the other valve cover and in clears fine. Is it possoble to use a pcv valve on the other one and hook it to the carb? I dont know if its ok to use a pcv valve on a boat. Thanks for the input. TC

In short...............Yes ;D
Title: Re: Breather question?
Post by: TCRUSH on April 03, 2009, 11:30:29 AM: I will take your word for it. My valve covers dont have built in baffles so I used a baffled grommet and a new breather on the one side. I could possible use a breather that goes in the oil fill cap. The kind that goes in a goes about a half turn. The problem with that is their is no baffle there and im sure the breather would start to leak again. If I have one breather and a pcv valve will it be ok for the motor? Thanks. TC
Title: Re: Breather question?
Post by: 2savage4you on April 03, 2009, 11:41:11 AM: You will be fine ;) I cant count the boats i have seen with a pcv valve in the V/C.......

just wierd , you think boat but forget its still a engine pushing it... just the same as in your car/truck (kinda)
Title: Re: Breather question?
Post by: crewchief22 on April 03, 2009, 12:53:50 PM: I run a PCV valve with no problems except at the very top of rpm (it starts to push oil out the dipstick).
Title: Re: Breather question?
Post by: TCRUSH on April 07, 2009, 02:37:05 PM: I was given two fancy billet breathers,one for each valve cover. The weird thing is they both have pcv valves in them. Its basically a regular pcv valve inside a fancy billet shell. They are held in through the bottom of the breather with a c-clip. Both breathers have a threaded fitting on them to hook a steel line or braided hose to. Would it work to run two pcv valves and run a hose off of each one to some kind of puke tank? If my engine cover didn't come down so low I wouldn't be having to deal with this. If the one on the right side of the motor was about a 1/4" lower I wouldnt have any problems. Thanks for the help.
Title: Re: Breather question?
Post by: crewchief22 on April 07, 2009, 07:26:11 PM: A PCV valve needs to be plumbed to a vacuum source to function properly. The idea is that the vacuum source pulls through the PCV valve and creates a vacuum through the crankcase, drawing air through the breather on the other side of the engine. If you run a PCV valve in both cylinder heads you will need a large vent for the crankcase to draw through somewhere else.
Title: Re: Breather question?
Post by: jet boat performance on April 07, 2009, 08:35:23 PM: Quote from: crewchief22 on April 07, 2009, 07:26:11 PM
A PCV valve needs to be plumbed to a vacuum source to function properly. The idea is that the vacuum source pulls through the PCV valve and creates a vacuum through the crankcase, drawing air through the breather on the other side of the engine. If you run a PCV valve in both cylinder heads you will need a large vent for the crankcase to draw through somewhere else.

GOOD info here ! x2
Title: Re: Breather question?
Post by: TCRUSH on April 08, 2009, 10:15:21 AM: Thanks for the help guys. I think I will make these two cheap chrome breathers from Checker Auto parts work. I custom bent the one that was to tall with a hammer and a block of wood. It barely touches the engine cover. I also used the baffled grommets on both breathers.The valve covers don't have built in baffles so hopefully this works. I also feel better have a breather on both valve covers.Let this BBC breathe. Thanks for all the help. TC