Crank Case Mod helps Octane burn

Discussion in 'Fuel Economy & Emissions' started by Stormin' Norman, Jul 24, 2008.

  1. Stormin' Norman

    Stormin' Norman Well-Known Member

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    PVC valves have been used like almost forever (mid to late 50's?), and this fellow moved it off of his air-box on his I-4 Dodge Shadow and got a few more HP, because the octane burns cleaner.

    What he calls a K&N Breather Filter is actually a Crankcase Vent Filter with a 5/8" diameter steel tube to attach the hose from the air box (air breather above the carb on mine) to the hose from the PVC valve. The fact that K&N even make this filter tells me that it's used on other engines for the same purpose. K & N's part number is 62-1060 or 62-1340.

    http://www.knfilters.com/search/product.aspx?Prod=62-1060

    http://www.knfilters.com/search/product.aspx?Prod=62-1340

    Crankcase Filter Modification
    http://www.karlsnet.com/mopar/crankcase.shtml

    Cheap way to get more MPG and a pony or two more. Here's the conundrum though. The idea of running the Crankcase fumes into the airbreather is to reduce smoke (back in the fast 50's) and today, to reduce emissions. But if your fuel is burning more efficiently (huge volumes of air mass), then the crankcase smoke generated by friction (hot oil) can't be that much. This guy may be onto something.
     
    Last edited: Jul 24, 2008
  2. Senri

    Senri Well-Known Member

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    I was thinking of doing the same. I think now a days it is mostly done for emmisions, but if you think about it, it won't make such a difference. The sucked up fumes will exit the engine true the exhaust (they pass the cat, but I doubt if that has any influence). The only issue I can think of can be that if you have an old engine and your rings are worn, you will have more blow-by and so more fumes in your crankcase. With only a filter these will end up under your hood and may be sucked into the cabin by the ventilator. I had the same with a very small leak in the exhaust at the connection of the first piece of the exhaustpipe onto the exhaust manifold. Exhaust fumes would end up under the hood and I could smell them when standing still at a trafficlight.

    For warming up the engine. Well, most custom build V8's I have seen have just a filter. A lot of other cars have a vacuum valve sucking air past the exhaust manifold when cold and modern engine don't have a provision for warm air to warm up the engine more quickly at all. Besides that, I can't imagine that the little bit of crankcase fumes help to warm up the engine much quicker and they also will be permanently there.

    I will possibly experiment with that when I am back to see if it makes a difference. A few hp and better fuel economy, certainly makes up for a bit of fumes not going true the engine!!
     
  3. Stormin' Norman

    Stormin' Norman Well-Known Member

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    I remember rebuilding a 1955 Chevy 265 V8 or maybe it was a 1957 Chevy 283 V8. They had a crankcase 'exhaust' tube leading to below the car's cowl floor by about an inch to let the fumes go out the back, but other cars and trucks had them closer to the fenderwell. There's probably some fancy 'Billet' chrome reproductions on the web. :evilsmile:

    Any saving in fuel consumption has to help the environment and slow down that new disease - thinning wallets. :biglaugh:
     
  4. Senri

    Senri Well-Known Member

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    In our pro-mod car we had an connection to one of the tubes of the frame. The fumes went true the frame and collected at the back.

    But I was just searching a bit on the net. I found that a lot of turbo-cars see this as a problem (they have more blow-by because of the higher pressures they work with) as the fumes contain old oil that can settle down in the turbo or block the intercooler and mess with the airflow in the throttlebody and so hurt performance. What they do is use in between the line from the valvecover to the carb, airbox or where ever the fumes are going to, use a fancy can. It just has two connections on top. The liquids are collected in the can and the fumes are still sucked up, but it will also cooldown the fumes. It won't work as good as a full filter, but it could be a nice compromise.

    this is just an example:
    http://www.perrinperformance.com/products/show/56/Oil-Catch-Can-Overflow-Tank?category=4&model=22
     
  5. Stormin' Norman

    Stormin' Norman Well-Known Member

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    Now that makes my day! Throw it out for discussion and BANG! A working solution! Well done and thanks!(y)
     

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