79Wusterhausen Posted January 27, 2013 Report Share Posted January 27, 2013 I have a IMCA modified that leaks oil out of the breathers when racing or when I hold the trottle open for a few seconds. I have just the regular circle track valve covers with the two breather tubes on the drivers side, they do have baffles under the holes. Last couple times I ran it I cut sponges and put them in the holes and inside the breather filters. Then zip tied socks over them. This kept the slobbering down but they still leak some. Leaks mostly on the rear tube, but I figured that may be just due to it possibly having the least resistance on that tube from adding the sponges and socks to them both. Is there anything I can do to keep the oil from blowing out? I thought about running a long breather tube maybe 3-4' long of of the valve covers and behind the engine to either 1) give more length to allow the oil to not reach the end or 2) allowing it to blow out under the car rather than in my face and all over the exhaust. I was also told to maybe use an exhaust evacuation tube to suck the crank case pressure out with the exhaust, I have done this with drag cars, but wouldn't that make it smoke like hell if oil was going out the exhaust? Maybe someone has a better idea? Link to comment Share on other sites More sharing options...
rebelracewriter Posted January 27, 2013 Report Share Posted January 27, 2013 latex gloves over the socks?..... Link to comment Share on other sites More sharing options...
railer Posted January 27, 2013 Report Share Posted January 27, 2013 stuff some stainless steel wool inside the tubes .You can get them at HEB in the cleaning supplies Link to comment Share on other sites More sharing options...
Pacecar Posted January 27, 2013 Report Share Posted January 27, 2013 Hope you are able to find a short-term "fix". The steel wool or plastic scouring dishwashing pads are helpful, as well as longer breather plumbing. To fix the "root problem" - next time the engine is rebuilt, make sure that the block's rear oil drainback hole in the back of the lifter valley is enlarged by grinding. In the valley, oil is trying to drain back down to the pan, while the blowby is trying to find its way upward towards the breathers. These two flows can fight each other. It's best that most of the "top-end" oil can drain back at the back of the lifter valley, while the blowby travels through the other, more-forward holes in the lifter valley. Link to comment Share on other sites More sharing options...
79Wusterhausen Posted January 27, 2013 Author Report Share Posted January 27, 2013 Hope you are able to find a short-term "fix". The steel wool or plastic scouring dishwashing pads are helpful, as well as longer breather plumbing. To fix the "root problem" - next time the engine is rebuilt, make sure that the block's rear oil drainback hole in the back of the lifter valley is enlarged by grinding. In the valley, oil is trying to drain back down to the pan, while the blowby is trying to find its way upward towards the breathers. These two flows can fight each other. It's best that most of the "top-end" oil can drain back at the back of the lifter valley, while the blowby travels through the other, more-forward holes in the lifter valley. I was actually thinking of pulling the engine and having it rebuilt because I thought the rings may be bad, I've heard that alcohol makes them wear out faster but don't know how true that may be. But the engine runs great so I thought I would do a blead down test first. As far as the oil not draining down fast enough, I know I have that problem because it was pumping the pan dry the first time I put the car on the track at RPM's of 7500+ on the big track. Since then I got the gearing right and put a oil accumulator on the car to help with the oil pressure drop issue. However, I think I may be pumping the pan dry not only because of the higher RPM's but maybe the engine has a high pressue/volume oil pump because the oil pressure is always 80+ psi. I have also always ran Valvoline racing 50wt or 60wt. I was told to run this mainly because the alcohol delutes the oil and makes it thinner. But this may be a cause of why the oil can't drain down fast enough because it's so thick? This thicker oil may also be the reason for such higher oil psi? Sounds like the root problem may be this thick oil? Link to comment Share on other sites More sharing options...
jwmbishop Posted January 27, 2013 Report Share Posted January 27, 2013 One thing we've done is a gulp valve on an evacuation setup. The gulp is from an older A.I.R. equipped vehicle - it is a one way valve that goes on the exhaust - inserted and welded so that the inside end is 1/3 of the way though the pipe and perpendicular to the pipe. This creates a siphon effect - the valve itself is a check so that a backfire does not ignite the cranckase. A hose then runs from the outside of the gulp to a tee in a hose connecting both valve covers together. Yes you will get some smoke - but it take a LOT of oil to even make a visible smoke at speeds over 30mph. Another option is to run your breather tubes into a catch can - inlet from the engine halfway up the can (and aimed to swirl and thus separate incoming) and vent on top with a regular breather vent. This method does not make for a positive flow though - and must be drained after each race. Link to comment Share on other sites More sharing options...
ks2290 Posted January 27, 2013 Report Share Posted January 27, 2013 Another quick fix is the oil deflectors that go under the valve cover I had the same kind of problem and that fixed it and I haven't had a drop of oil since. Link to comment Share on other sites More sharing options...
SamDuncan Posted January 28, 2013 Report Share Posted January 28, 2013 If you run a evacuation system type set up you will end up being Black flagged for excess smoke or oil being discharged from the exhaust system. Just something to think about Link to comment Share on other sites More sharing options...
79Wusterhausen Posted January 29, 2013 Author Report Share Posted January 29, 2013 I found a set of crossover tube and breathers with the valve covers on speedway motors that look like it might be the way to go. Has anyone used them before? They simply have a tube that connects the 2 valve covers together at the front of the motor and has 2 breathers centered on the top of the tube. Link to comment Share on other sites More sharing options...
SamDuncan Posted January 29, 2013 Report Share Posted January 29, 2013 Those valve covers may help being the breathers are at the front but it sounds like you pump a lot of oil to the top of the motor . Like someone else stated you need better drainage or your going to starve the bottom end . Link to comment Share on other sites More sharing options...
79Wusterhausen Posted January 29, 2013 Author Report Share Posted January 29, 2013 Those valve covers may help being the breathers are at the front but it sounds like you pump a lot of oil to the top of the motor . Like someone else stated you need better drainage or your going to starve the bottom end . Is there a way to enlarge the holes without having to rebuild the engine? Link to comment Share on other sites More sharing options...
sm44 Posted January 29, 2013 Report Share Posted January 29, 2013 My 383 was doing that, when I tore it down I had 5 broken rings. I would pull it and freshen it while It's hundreds instead of waiting and it being thousands..just my two cents. Joe Link to comment Share on other sites More sharing options...
4cylfordz Posted February 9, 2013 Report Share Posted February 9, 2013 Most of the oil leaking breathers are caused by a screwdriver.. Because someone will bend the baffles in order to get oil in the engine during a change ( otherwise it takes around two hours to put in 7 qts). Most of the newer design covers (within the last year) have both the modified freeze plug baffle and a deflector under the tube shielding the vent from pushrod spray. Best thing I've found is a moroso oil deflector kit for the older style covers. Though I would do a compression and leak-down test to check out my rings before I pulled the engine. Oil drain holes are usually suffectent being ur talking about a modified which most likely is running a solid lifter cam with oil restrictors. So not much is going up there anyways. Link to comment Share on other sites More sharing options...
DirtRacer9s Posted February 10, 2013 Report Share Posted February 10, 2013 Oil deflectors fixed mine. Didn't have a drop come out all season. Link to comment Share on other sites More sharing options...
koab26 Posted August 16, 2013 Report Share Posted August 16, 2013 HEY GUYS I REALIZE THIS POST IS A LITTLE OLD! HOWEVER CRAZY AS THIS SEEMS A GUY TOLD ME TO USE TAMPOONS INSIDE THOSE TUBES AND IT REALLY WORKED, NOW THIS IS WAAAAY BEFORE I STARTED RUNNING BETTER MOTORS AND WAS NEW TO THE SPORT. WAS RUNNING AN IMCA HOBBY STOCK AND IT WOULD JUST SPIT OIL ALL OVER THE DAMN PLACE! GOT ME A BOX OF THOSE HEAVY DUTY BADD BOYS. OPEN AND PUT IN A CUP OF WATER, THEY WILL EXPAND OF COURSE, REMOVE FROM CUP SQUEEZE OUT EXCESS WATER, LET DRY AND PUT AROUND 2 OF THEM IN EACH BREATHER TUBE. YES IT DOES WORK, DID IT FOR OVER 2 SEASONS OF RACING, CHANGE THEM OUT OFTEN, AND CARRY A FEW SPARE ONES THAT HAVE ALREADY BEEN PREEPED AND KEEP IN A ZIPLOCK BAG IN CASE YOU NEED THEM AT THE TRACK. DID THIS FOR A FEW FRIENDS WHEN IT WAS THAT TIME OF THE MONTH FOR THEIR MOTOR AND THEY LIKED THAT IDEA A LOT! NO MORE SLOBBERING FOR SURE! Link to comment Share on other sites More sharing options...
keith Posted August 18, 2013 Report Share Posted August 18, 2013 HEY GUYS I REALIZE THIS POST IS A LITTLE OLD! HOWEVER CRAZY AS THIS SEEMS A GUY TOLD ME TO USE TAMPOONS INSIDE THOSE TUBES AND IT REALLY WORKED, NOW THIS IS WAAAAY BEFORE I STARTED RUNNING BETTER MOTORS AND WAS NEW TO THE SPORT. WAS RUNNING AN IMCA HOBBY STOCK AND IT WOULD JUST SPIT OIL ALL OVER THE DAMN PLACE! GOT ME A BOX OF THOSE HEAVY DUTY BADD BOYS. OPEN AND PUT IN A CUP OF WATER, THEY WILL EXPAND OF COURSE, REMOVE FROM CUP SQUEEZE OUT EXCESS WATER, LET DRY AND PUT AROUND 2 OF THEM IN EACH BREATHER TUBE. YES IT DOES WORK, DID IT FOR OVER 2 SEASONS OF RACING, CHANGE THEM OUT OFTEN, AND CARRY A FEW SPARE ONES THAT HAVE ALREADY BEEN PREEPED AND KEEP IN A ZIPLOCK BAG IN CASE YOU NEED THEM AT THE TRACK. DID THIS FOR A FEW FRIENDS WHEN IT WAS THAT TIME OF THE MONTH FOR THEIR MOTOR AND THEY LIKED THAT IDEA A LOT! NO MORE SLOBBERING FOR SURE! Koab, that was too entertaining, some times you just have to do what you have to do to go race! Link to comment Share on other sites More sharing options...
koab26 Posted August 29, 2013 Report Share Posted August 29, 2013 Koab, that was too entertaining, some times you just have to do what you have to do to go race! HEY KEITH I KNOW THIS WAS CRAZY SIR BUT IT IS A TRUE FACT LOL! AND YES WE WILL DO WHATEVER IT TAKES TO RACE INCLUDING PUTTING SELF TAPPING SCREWS WITH RUBBER WASHERS AND JB WELD TO FIX A LEAK IN YOUR OIL PAN! NO MORE OF THOSE CHEAP MADE IN CHINA OIL PANS FOR ME! HAD MY ENGINE REPLACE THAT JUNK WITH A MOROSO AND PUT ONE ON MY NEW ENGINE ALSO LOL! Link to comment Share on other sites More sharing options...
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