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  #1 (permalink)  
Old 10-21-2006, 12:58 PM
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Default smoke valvecover question

i swithced to a holley hp 830, and got away from my demon race. it seems to run alot better. the holley does not have a pcv valve vaccume hook up in the rear like the demon.

i now have noticed smoke that comes out of my valve cover breathers. it is pretty noticable and smells like gas, not oil. what is this from???????

thanks gents
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  #2 (permalink)  
Old 10-21-2006, 02:19 PM
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Some of this is actually Blowby that had previously been pulled into the intake through the base of the carb. Some of it is also vapours coming off of the oil. Both will have a fuel smell. An 830 is a Competition carb that is jetted pretty rich, you may want to check the fuel curve.
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Old 10-21-2006, 03:03 PM
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I agree with Rick. He is that cat on to power poll.

He's right, you are probably getting blowby. How is your PCV system setup? The holley usually has a pretty good vent at the base for the PCV valve.

It will not get rid of all of it, but with a high perf engine, it helps a lot.
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Old 10-21-2006, 03:24 PM
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Default

i jetted down to 80 squared. i t was 86 out of the box. i do not see a pcv vent at the bottom.

somthing a little different from my demon, is that the verticle transfer slot in the venturi of the holley is higher up in the venturi than the demon. so none of the transfer slot is exposed at idle. should they be squared?(exposing tiny bit of the transfer slot.) this would open my butterflies a bit more. it idles about 1000 the way it is. there is also holes drilled in the butterflies on the holley out of the box.
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Old 10-21-2006, 04:23 PM
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Typically the holes drilled as OEM or added later are intended to eliminate the need of opening the secondaries and ultimately exposing the slot creating an overly rich mixture in an attempt to gain a good idle. Usually with very high duration and overlap cams. (low manifold vacuum)
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Old 10-22-2006, 01:28 PM
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you can add a breather suction to the air filter base, it will require drilling a hole in the base and installing and breather vent line, ie: the old type GM air intake breather line, the line had a foam filter where it pluged into the air filter base, my K&N filter on my dodge truck has such a setup, however there isn't a filter where the vent line plugs into the air filter base, just an open hole, the other end plugs into the breather
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