crankcase evac system vs open breathers

for a bracket car, i'm not real up to speed on how this system works, i know what parts are required and how to plumb them but could use some of the knowledge out there on how it works vs. open breathers vs. pcv set up.


thanks
rick

from what I have understood when under full exceleration the pvc valve is not working because you loose all the vacume going to it and most race engines has limited vacume and not enough to run a pvc valve.I going to run a evac hose from my header to the valve cover on mine and open filter cap on the other valve cover. But that what have understood on the evac from pvc valve on most race engines.

True on the PCV. The evac to the header collectors work great IF installed in the collector CORRECTLY. Until you get up in the big inch engines, then you need a vacumn pump.

from a post on the other forum that charlie had commented on they need to be installed at a 45 where the tubes transistion to the collector and pointing to the aft,

what are considered big inch engines?

rick

^^^ The fact that Monroso sells the kit, the directions are wrong to a point. What Charlie is saying is correct in the post you mentioned..

Big Ci is anything over 1 cubic inch.. Just depends on "How you look at it"

they've actually changed thier directions so that the tube is intalled facing the right direction as charlie mentions but they don't mention on where in the collector to place it.


rick

any engine will make more power with a vac pump,
it doesnt have to be big
ehx vac hoses work ok,and use to be the norm

A pcv valve in a race motor is counterproductive. As the other poster said a race motor won't create enough vacuum for it to work, and think about it; you wouldn't want hot internal engine air thats contaminated with oil and combustion by-products to be injected into the intake stream. It can actually cause detonation. You might ask Chuck on the "chuck-a-thon" part of this forum to take some pics of the collectors I donated to his rebuild; they are factory welded hooker collectors with the evacupan fittings installed. Would make for a good reference for the forum. They are simple and work good. A vacuum pump is superior, but the cost is much more.

Big Ci is anything over 1 cubic inch.. Just depends on "How you look at it"

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I personally like vacuum pumps over the collector style. I like the fact that on a vacuum pump setup you can tune the desired crankcase vacuum very easily. It does not take as much as some people think and too much is bad also.

63boxtop wrote:from a post on the other forum that charlie had commented on they need to be installed at a 45 where the tubes transistion to the collector and pointing to the aft,

what are considered big inch engines?

rick

You mean instead of the 1/2 pipe welded in pointed towards the front of the car there supposed to be welded in pointed towards the rear of the car??

Tore

Tore wrote:

63boxtop wrote:.... installed at a 45 where the tubes transistion to the collector and pointing to the aft,
rick

You mean instead of the 1/2 pipe welded in pointed towards the front of the car there supposed to be welded in pointed towards the rear of the car??

Tore

That's what Rick said.

aft = rear

here is the ones that chuck has https://www.429-460.com/general-discussion-f5/chuckathon-help-chuck-get-back-onto-the-dragstrip-t1598-135.htm?sid=f772ed7058466ad925b256e12889c2ca

the tubes that are welded in the collector are suposed to be pointed toward the engine,THIS MEANS THE NIPPLE ENDaof the valve that is screwed on the welded in pipe, the angle end goes in collector,and its end points toward the rear of car, vlave to engine,this is so air passing by the angle cut end pulls crankcase presser from engine



-rich

So how does the open breather caps work? Or is it just a unjustified little air filter?

Tennessee Bullitt wrote:So how does the open breather caps work? Or is it just a unjustified little air filter?

they dont, unless you connect them via a hose to the valve in the collector

ask 4eyed to post some pics on here,i did his last year



-rich

That is what I thought, I am going to run them to a evac hose to the collector.