| [ Total Views: 1038 | Total Replies: 13 | Thread Id: 85418 ] |
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 Surfsup
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| posted on August 15th, 2010 at 10:59 PM |
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Breather Box/Catch Can????
Ok, not sure about this, I am just finishing building an 1835 and I am trying to work out if I need a breather box, its basically an new motor but I
have been getting conflicting info on if I should install a breather box/catch can or not. My local VW guy is saying I don't need one and they will
attract dirt in the area around the filter
I was thinking of installing breathers on the rocker covers to a breather box with a return to the oil filler and a couple of filters on the breather
box.
Any info would be appreciated.
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jsheppard64
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| posted on August 15th, 2010 at 11:27 PM |
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I get oil blown out of front pulley
so i put a home made catch can made from left over fence post
inside is stainless steel wool which i stole from my kitchen
no more oil out front... but mine has massive blow by because i didn't get a new pair of heads when i rebuilt it
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Newt
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| posted on August 15th, 2010 at 11:34 PM |
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I give up. How do old heads contribute to blow by?
Aso, how does a catch can reduce front leakage? Is it a pressurisation issue?
Cheers
Newt
It is as it is - If you didnt enjoy today, you've missed the opportunity.
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Carter
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| posted on August 17th, 2010 at 02:37 PM |
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old head might mean the rings don't seal as well, therfore combustion gasses enter the crankcase?? maybe?
and it is definately a pressure issue. if the crankcase isn't vented well enough, oil will leak through seals all over the place.
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SuperOwen
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| posted on August 17th, 2010 at 05:03 PM |
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Heads have nothing to do with crankcase blowby, thats the pistons and rings. He might be referring to combustion leakage between heads and barrels???
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Newt
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| posted on August 17th, 2010 at 08:36 PM |
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Do we vent breather boxes or are they a closed system?
Newt
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71-BEETLE-SEDAN
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| posted on August 17th, 2010 at 08:49 PM |
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Vented i do believe.
Steve and Dave Carters bug has a good and explainable set up, i dont have any pics but im sure someone will have a good factory diagram, 68 autobug
maybe.
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jsheppard64
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| posted on August 17th, 2010 at 09:07 PM |
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I vent it to inlet just above the carb.
I don't know why i said heads when i meant pistons barrels set
I only replace the rings and bearings lol
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vlad01
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| posted on August 17th, 2010 at 09:47 PM |
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what size jugs? on that 1835. if its 92mm theres your problem.
71 notchback,
Past owner of, 70 NB, 73 SB and 72 FB TLE |
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Surfsup
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| posted on August 17th, 2010 at 10:57 PM |
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Yep they are 92mm pistons, I don't have any problem yet as I haven't fired it up yet just trying to find out anyone else experience and if its
something I might need to look at doing,
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waveman1500
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| posted on August 18th, 2010 at 12:23 AM |
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In my opinion a breather box/catch tank is really only a band-aid solution, any streetable VW engine in decent condition shouldn't need one. The
stock hose venting to the inlet is more than adequate unless you have fairly serious blowby issues. Also, bear in mind that venting crankcase gases to
the environment constitutes polluting emissions, and therefore is generally illegal on cars built after 1971. On pre-'71 cars you may be able to get
away with venting a breather box/catch tank to atmosphere.
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hellbugged
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| posted on August 18th, 2010 at 02:46 AM |
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| Quote: | Originally
posted by waveman1500
In my opinion a breather box/catch tank is really only a band-aid solution, any streetable VW engine in decent condition shouldn't need one. The
stock hose venting to the inlet is more than adequate unless you have fairly serious blowby issues.
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the stock hose is great for what it's designed for yes......STOCK applications
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71-BEETLE-SEDAN
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| posted on August 18th, 2010 at 04:43 PM |
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Some vent into the air filter element like stock while other running more hypo motors vent the heads too, no just the oil filler location.
Check this post out .
http://www.shoptalkforums.com/viewtopic.php?t=118958&highlight=
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Carter
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| posted on August 18th, 2010 at 05:24 PM |
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i also don't know why i said heads have anything to do with piston rings.... long night haha
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