so, what is the right way to do this?.I keep hearing different things and its making me wonder.... I am going to run burn down breathers on my valve covers. some suggest hooking up a vaccuum sysyem to them to help evac the g***es. others say that the crankcase will evacuate itself ,and that extra measures arent necessary. the engine is a fuel injected 8-71 big block. hopefully thats enuf info? if not,.....just ask. what all is needed to run this set up and not have issues?
ok, heres more info- hopefully useful. 504 cube ,custom efi, 8-71 , will be a street/ strip deal,.... very minimal street usage ,about 12 lbs boost, fair sized cam will have a burn down on each valve cover and most likely a vented cap on each as well. each burn down will have 1 1/4 in hose going to puke tank.(havent decided if I need to have a vacuum source to the tank or just vented to atmosphere? that enuf info?
For what its worth. You have to pick one way to vent. Either you run breathers or header evac( is that what you mean by burn down). If you run both you can accutualy pull oil out from the header drawing and the vent letting it flow instead of creating va***e. Breathers into a puke tank( at least 3/4 hose from each side) with a big vent in the tank work good if you are pulling alot of rpm I found. Not a big fan of the header vacs on blown motors( just a personal thing). Good luck.
I would run the old style racing valve cover breathers you don't really need a puke tank or any type vacuum setup. We ran alot more boost on the blown fuel motors with just VC breathers , although we did eat some 60w racing oil and our old fire suits needed an oil change about every 5 or 6 runs. My opinion "keep it simple" Hold onto your *** when you punch it and have fun. P
thanks for the input. burn downs are not a header evac system, they are a contained unit that directs the fumes/oil/ect to a tank or into the frame.(lack of better description) (they are used more commonly in high end racing applications) so, if what I'm understanding is- run the burn downs and no other vent. so just put plugs in the holes where the oil fill is? I guess thats the part I was wondering about, to use plugs or vented caps where the oil fil is located ? this is probably one of those things that I'm over thinking and shouldnt be so concerned with ....but thats what I do its "new to me" . gotta sort it all out in my head first. thanks for any and all help everyone
intially I was going to use the old racing style breathers ,..... until I ran across the burn downs, after I saw those they fit the style of the build a little better but yes, I'd like to keep it as simple as possible! <!-- / message -->
Alright, what you call burn downs is what I call a puke tank Plug the oil fill and have the burn down setup to its tank. The tank should have the vent and thats it. Mount the tank higher than the valve covers.Make shure your tank has a drain valve and the valve cover peices are mounted close to the blower and not down by the headers.
Mount the valve covers lines below the tank so the top of the vent on the tank is higher than the valve covers.
Check this out . http://www.azcarsandtrucks.com/2000dragster-19.html http://www.azcarsandtrucks.com/2000dragster-15.html http://www.azcarsandtrucks.com/2000dragster-10.html Hope this helps
you mount the can above v.c. height unless you like wasting (pouring out,instead of running back into cover) a LOT of oil.
Black magic, Thats what I said and no you dont want the lines entering the bottom of the tank if you dont like messes I cant figure out how to post pics here to show my blown bbc. I personally have my tank mounted mid blower.
Was not saying you were wrong we have just alway mounted the lines on the bottom of the tank no mess.
I'd run hose to one or two catch cans with filters on top, you will have a lot of crankcase pressure with that setup and I bet you will mist a lot of oils out of just breathers:
thanks! most on this board would kill me if I mentioned what its going in, (probly not HAMB correct). but its an older ford
so, a can on each side? I was thinking maybe a large central mounted can with a hose coming in from each cover?and maybe a breather on each end of the can? I'm gonna have to mock **** back up before I can see what all is going to fit the bill.I need it to function correctly,as well as work asthetically.