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View Full Version : Crankcase Vaccum= 20 lb/ft more torque??



redneck323
02-15-2009, 02:31 PM
A friend of mine said that he and another guy was playing with crankcase vaccum. He said they used an Air reactor pump tied the input to the PCV system and was able to pull 2 inches of vaccum on the crankcase. I asked what the effects were and he tried to explain to me how he had a scrubber hooked up as well to clean the crankcase gases seperating the carbon from actual gasoline vapor and said that the 2 together was able to free up 20 lb ft of torque on the dyno. Which means better fuel economy also!! Does this make sense as i cant get my head all the way around it. I mean theroetically it makes sense to me less air mass in the crankcase = less air resistance to the downward motion on the bottom side of the piston. I would also think less air resistance to the rotating assembly also (rods, crank...) any one else have any thoughts on this???

Painless
02-15-2009, 06:22 PM
I would worry that too much vacuum would have a negative effect on the distribution of oil from the sump.

redneck323
02-15-2009, 08:28 PM
Hmm... I dont know i wonder if it would?? Possible have an adverse effect on the suction into the oil pump itself? Is that what you are thinking? I dont know, thats easy enough to find out pull a vaccum then measure oil pressure obviously with mechanical gauges as far as the returns i dont see a problem gravity will still pull the oil back down from the heads, cam journals and such i would think. Dont know kinda interesting...It was my night off and i was havin a few brewskis so i didnt absorb as much info from him as i wanted to ill quiz him about it again and have him show me and try to bring more to the table.

jericoriver
02-15-2009, 09:19 PM
A friend of mine said that he and another guy was playing with crankcase vaccum. He said they used an Air reactor pump tied the input to the PCV system and was able to pull 2 inches of vaccum on the crankcase. I asked what the effects were and he tried to explain to me how he had a scrubber hooked up as well to clean the crankcase gases seperating the carbon from actual gasoline vapor and said that the 2 together was able to free up 20 lb ft of torque on the dyno. Which means better fuel economy also!! Does this make sense as i cant get my head all the way around it. I mean theroetically it makes sense to me less air mass in the crankcase = less air resistance to the downward motion on the bottom side of the piston. I would also think less air resistance to the rotating assembly also (rods, crank...) any one else have any thoughts on this???
Wouldn't it be a catch 22? The pistons would be fighting the vacume on the way back up. I also wonder how long your crank seals would hold up under a vacume.

Painless
02-15-2009, 09:34 PM
How much vacuum does the standard PCV pull in comparison?

In high load with high rpm situations the engine can have issues pulling oil from the sump up to the cams, my thought is that the vacuum would help pull the oil back down to the sump as well as providing more force for the oil pump to fight in getting the oil back up there again.

redneck323
02-16-2009, 08:31 AM
Yes... all good questions i will throw at him. He was using it for a horsepower application so he may have had a high volume oil pump on this motor i am not sure. The guy seems fairly smart always has. He always blows my mind with all kinds of stuff. I am trying to interest him in going to the Alt energy confrence with me. Unfortunatly i havnt been able to convince him about the benefits of HHO and i have not invested enough run time to disprove his theory that the HHO gains are only from decarbonization because i dont have enough run time on my setup due to lack of money/time to work on it. I personaly believe that it does act as a catlyst but i dont know how scientifically and have heard many theories ranging from HHO releases addtional O2 into the combustion cycle to things about thermal expansion. He is trying to get me to run a water vaporization can first for a bit then run the HHO. Any way the guy throws out more than i can absorb at one time im always tellin hi to slow down but then again i did ruin my brain when i was younger and cant retain as much as i used to LOL. I will let you guys know what he says heck maybe ill see if i can get him to join the forum the guy is deep into pcm programmin also and has lots of experience with it.

Carl