BBC valve cover baffles

[CactusJack]

You can always run a braided hose to a stainless catch can breather like this above the tappet cover in the rigging.... then any oil that blows up there will drain back once the engine is cool, like what mam4 said.... these are polished aluminum and less than $50, but you can prolly get stainless as well. This one is on Ebay.

[LoxStroker383]

http://www.summitracing.com/parts/mor-6 ... Aplt8P8HAQ

I used one of these on my 383. I had the same problem as you. I ran the hose from this breather to my air filter. and a pcv valve on the other valve cover. I have no more oil leaking on the valve covers or anything. These breathers have a high quality steel wool in there that trap the oil and let it drip back into the valve cover. They are awesome quality too.

[RJC5778]

joe,

your fine, its hard explain sometimes on these forums, it is in my breather system, I need a better one

its a shane Lejeune race engine, its nothing with the engine itself as I have all the good parts in it, motor is good to 8k rpm and 1200 hp if I wanted to, my issue is the breather system obviously, so any big block guy who wants post some pics of their setup I would greatly appreciate it guys. im trying to find at least 2 solutions to this problem to try that will work and be very simple

[RJC5778]

Look this has been done, I have posted pictures of how to do this. Go to home depo or lowes, purchase some of the clear hose with the string in it, put the hose on your valve cover pipes and run it strait up to the cage. Run the hose along the inside of the cage to the front of the top of the prop. Cut the end of the hose at a 45*, long part / point part up! zip tie the end of the hose about 5" from the end of the hose so the end will hang down a little. it will angle down after it gets warm a few times. As your run your engine the prop will pull air past the hose and suck your crank case pressure out. You will see oil mist climb up the hose but it will only climb about a foot or so, when you shut your engine down the oil mist will go back into your valve covers. If you pull oil all the way out the end of the hose you need to cut about 1/2"-1" off the end of the hose and try again. The end of my hose was a couple inches from the prop.

My valve covers had no baffle in them at all and neither did the boat before that. I did not blow any oil out of any place after I did this and I have done it on 3 different boats.

If your search through my threads you will find pictures.

could you post some pics for reference please?

[RJC5778]

anyone have pictures of a proven set up for this? preferably with standard valve cover

[RJC5778]

I ran a standard pcv system this weekend and not a drop of oil out the engine, shielded breather and pcv valve to carb plate and it worked like a champ, ill see how this runs for an oil change interval

[RJC5778]

has anyone every run a puke tank on their airboat? ive been doin some research on this and it seems the drag boat guys like them, seems easy enough to build and very simple concept, ive heard about the 2 lines run just in front of the prop but don't like look of it. running a pcv setup now and after a small run chasing down some pigs, it had a good amount of oil out the breather but during normal straight running it leaks a few drops. I like the idea of the puke tank, looks like clean straight forward application, what you guys think?

[odcjohn]

you really need 4 breathers tube should be about 5-6 inches long run several engines like that with no issue

[rbjscott]

I would have to ask my self, Why so much crank case pressure. I would close the system and see how much pressure I have.

[RJC5778]

its a newly rebuilt dyno tested motor, I bought a moroso 68800 kit that has 2 baffles per side perpendicular to one another and an oil fill plug, the breathers are shielded, if this doesn't work I will bring it to the engine builder for a leak down test, its not a steady stream of oil out the breathers, its intermittent under certain driving conditions. I have a lot of confidence in these new baffles

[rbjscott]

Does the engine have a "Windage tray or baffle"?

[RJC5778]

no just a 9 quart oil pan for marine use, I got the breathers on and the oil fill installed, the powder coat came out good, iva attached a picture, I will test this next time I run it hard and see how she does

[RJC5778]

finally had time to put the valve covers back on, I sure hope they work

[Rich Andrews]

I'd like to think that i'm 99% sure its a problem a lot of people have even with good ring gap motors. A high volume oil pump will throw a lot of oil on top of the valves, probably more than enough. Now, you create this sucking/vacuum with the prop and start pulling oil up the breathers and it's not necessarily blow by but oil. One solution i've seen on a motor with an EVAC system(blower 502) is simply extend the vent tubes with clear plastic tubing as stated earlier. Start it to the top and see just how far the oil will run up the tube and cut it down. Be sure to drill out a hole in the actual breathers them self,and wire them to the cage.


I played around with the breather shields themselves turning them forward,and rear and saw some diff results. RPM results

I'm building a new motor right now,and will be 100% sure that IF I have the same situation it will not be because ring gap. Nothing worse then oil on a new motor right!

[RJC5778]

I 100% agree, I have over 100 psi oil pressure at the upper rpm band and I know with the prop creating a large vacuum and right conditions it will suck the oil out the breather w/o baffles, im pretty confident in this system as it has 2 baffles perpendicular to each other with will prevent the oil splash IMO, interested to test them and finally cure my problem.

[Rich Andrews]

When I get home i'll upload a pic that fixed the issue

[Joe]

My breathers are on the back of the valve covers,the closer to the prop the better. It'll create more vacuum that way

[Rich Andrews]

and sucks more oil..

[Rich Andrews]

[Joe]

Rich,my boat doesn't suck any oil. The prop won't suck oil up the tube and out unless the oil is already being pushed up the tube the tube. But hey,think what ya want.

[Rich Andrews]

Joe, did you ever run your breathers on the other side of the heads?

[Joe]

There has never been any reason to turn them around and try it. It's worked without issue for 6 years. Buddy of mine had a small block with them in the front and had issues,turned them around and no more issues. Most engine builders send there airboat motors with them in the back so I did it and no issues.

[Rich Andrews]

guess that would have been a KISS fix.. i'll try it if I have the same issue,always ran em in the back