Visit The Dirt Forum for More Information

Author Topic:   Puking oil out breathers
mod777
Dirt Newbie

Total posts: 3
posted September 18, 2001 09:50 PM
SB Chev 406 w/bowtie heads and high volume oil pump on meth.
Pukes about a cup of oil out the breathers ( on left side) each race. Really makes a mess! Others say theirs does too, but what I've seen, theirs is just a little condensed oil vapor where mine actually runs out and blows all over the covers, the firewall, the distributor and wires and runs downs the side of the block.Almost as if the valve cover is filling up. Any ideas?

------------------
mod777

dirtracer14
Dirt Maniac

Total posts: 133
posted September 18, 2001 10:06 PM UIN: 23443678
What covers do you have?? I have used the stamp steel ones and had to open the baffle up so it didnt take 2 hours to fill the oil, but when i did that it allowed the oil to really come out. I solved this by putting socks over the breathers to keep the oil from running all over the places. They last about 4 or 5 races befor they are totaly soaked. Do you have the restrictors in it???

mod777
Dirt Newbie

Total posts: 3
posted September 18, 2001 10:43 PM
Yeah, I have the baffles in place. I checked to see which way the open end of the baffles was pointed, and they are down. Thought maybe they were pointed up, and oil was spattering into them and building up enough to run out, but they were pointed down. Even so, I guess it would take a lot of oil to fill the filler tubes and bottom of the breather filter. I'll try a sock for the next race ( one invitational left to go this season on Sept 28-29), but I'm guessing it'll be soaked (the sock, not the invitational, although some years we have had SNOW by then!).

------------------
mod777

dirtracer14
Dirt Maniac

Total posts: 133
posted September 18, 2001 11:41 PM UIN: 23443678
one other thing is that you could be getting excesive amount of allky or condesation in the pan that steams out as the motor heats up. Just my 2

c21
Dirt Roller

Total posts: 24
posted September 19, 2001 10:25 AM
The problem with rags or socks wrapped around the outside of the breather is that the condenced oil still tends to drip onto the valve covers (headers, firewall,etc)and if is slowing down oil leaving the motor chances are it is also increasing the crankcase pressure.

The trick is to extract the oil before it gets to the breather filter. I've raced with guys who put steel wool in the breather tubes (kinda seems scary), but I run a rolled up scotch-brite pad in each tube. The scotch-brite does not breakdown or get into the motor, but does stop nearly all of the oil trying to escape.

3x Racing
Dirt Roller

Total posts: 20
posted September 19, 2001 11:54 PM
By adding socks and steel wool??!? to your breathers your just defeating the purpose. They're called BREATHERS right? The problem is that they are already too restrictive (as they almost always are with performance camshafts). The profiles of racing cams don't allow the cylinder pressures and in turn the crankcase pressure to escape out the exhaust. To solve your problem effectively, get a set of baffeled valve cover push-ins from Morosso that allow you to create a vacuum by running a hose into your headders. Morosso sells it as a drag racing part but it is highly effective on oval track cars as well. Your engine will thank you for it.

c21
Dirt Roller

Total posts: 24
posted September 20, 2001 10:53 AM
The idea behind the scotch-brite is to stop the splash allowing you to open up the tabs at the bottom of the tubes a little more. But I will agree it is a band-aid at best. I like the idea of a free source of vacuum using the exhaust. I am going to have to check that out myself, thanks 3x.

bbracer17
Dirt Maniac

Total posts: 172
posted September 21, 2001 07:35 PM
I used to run the craankcase evacuation system on a 4 cylinder years ago. It is amazing how well your oil stays in the motor when using these. There were two times that I had run over something and cracked my oil pan but didn't loose the oil untill I shut the motor off. This was a crack not a hole.

Wheels47
Dirt Newbie

Total posts: 4
posted September 30, 2001 09:47 PM
WE among other racers at our track are running the blue hand towell that you buy a walmart in a roll. We wad them up and stuff them in the brather tubes. Very effective and seems to work well. We change them after every 2 races so as to let them still get there air. Not sure this is right or safe but seems to work for us.

dreamcatcher
Dirt Full Roller

Total posts: 40
posted September 30, 2001 10:08 PM UIN: 14464409
i had this problem, and it was pretty bad on my street stock. this is what i did, take a piece of tin or something simaler and bend it so that it stands about 1/4 of an inch of of a table and it has tabs to put bolts. bolt it over the holes on the inside of the valve cover. i had mine to where it covered from about 2 inches on either side of the holes and against the wall. it solved my problem . i could run about 6 or 7 races before any oil showed up on the breathers.you can check for looseness when you adjust your valves. i hope this made sence b/c im sick and on some medicine.good luck. o- yea, i was able to bend the baffle tabs down on the front vent so oil could go in faster.

Back to the Archives