Re: [ihc] anti-backfire valve

["John Stricker" <jstricke@xxxxxxxxx>]

T.R.E.,

You have it exactly right.  The crankcase is vented through the PCV valve to
the intake manifold or carb base.  That sucks the air and pressure out.  The
other hose is to let air in so it needs to be filtered air.  On the IH
engines, they pull that air from inside the air cleaner housing.  Other
engines use a little foam element in the air filter can on the outside of
the element like the old Chevy engines did.

We always called them an anti-backfire valve because their purpose was to
keep a backfire from inside the air cleaner housing from getting to a
potential mixture that could burn.  On the other styles like the Chevy I
mentioned before, they weren't necessary because the air filter was in
between a potential backfire and the element.

All the valves are is either a mesh or series of passages that, supposedly,
a flame can't travel through, like a mini marine carb flame arrester.
Technically, the flame arrester description is probably better than what
I've always called them, so pays your money and makes your choices.  8-)

John Stricker

PS: Mac, you still haven't given me a wish list of prizes yet.  What do you
need for a Scout II?  Just make it reasonably shippable and if I have it,
it's yours.
----- Original Message ----- 
From: "T.R.E.Jr." <T_R_E_Jr@domain.elided>
To: "Mac @ TRIAD" <mac@domain.elided>; "John Stricker" <jstricke@domain.elided>;
"IHC Digest" <ihc-digest@domain.elided>
Sent: Tuesday, October 28, 2003 9:39 PM
Subject: Re: [ihc] anti-backfire valve


> ---FWIU it acts just like the power valve protector for Holley
carburetors.
> What it does AFAIK is allow a vent on the other end of the crankcase, from
> the PCV valve. Basically, it completes a loop through the crankcase so it
> can breathe rather than burp air now and again. If the crankcase does
burp,
> the screens inside the flame arrestor block the flame from making it to
the
> carb... or up through the power valve.
>
> ---Thank you,
> -T.R.E.Jr.
> -`73 Scout II (StoneThrower)
> -`51 Farmall H (Heinz)
> -`49 IH fridge (presently unnamed and in need of a compressor)
> -`49 Plymouth Special Deluxe 4-door Sedan (Papapalooza)
>
>
> ----- Original Message ----- 
> From: "Mac @ TRIAD" <mac@domain.elided>
> To: "John Stricker" <jstricke@domain.elided>; "IHC Digest"
> <ihc-digest@domain.elided>
> Sent: Tuesday, October 28, 2003 8:38 AM
> Subject: RE: [ihc] anti-backfire valve
>
>
> > ## >> As for the "flame arrester", I call that an anti-backfire
> > ## >> valve.  Yes, it
> > ## >> has that hose to the air cleaner.  That's to keep a backfire
> > ## >> from possibly
> > ## >> igniting the air/oil mix in a valve cover.  All of the V8
> > ## >> Scouts I've seen
> > ## >> have that.
> >
> > this raises an interesting question for me.  my BD220 and my first two
> 304s
> > all had the "flame arrestor" or "anti-backfire valve" installed...  it
was
> > on the top of the valve cover for the BD, and in the top of the oil
filler
> > tube for the 304s.  all of them had a hose to the air cleaner.  my
> question
> > is this:  if that's to keep the backfire from igniting the oil/air
mixture
> > inside a valve cover (crankcase in the case of my 304s), then what's to
> keep
> > a backfire from igniting the air cleaner itself?  all three of these
> engines
> > were oil bath air cleaner equipped.  isn't it pretty nearly the same
> air/oil
> > mixture in one of these air cleaners?
> >
> > --Mac
> >
> > ---------------------------------------------------------------
> > Take care and be well, all thee and thine;
> >
> > May the Hamr lend thee Strength and Courage,
> > May the Twin Ravens lend thee Wisdom and Guidance,
> > May the Wolves Guard and Protect thee, and
> > May the Light of Harmony ever shine brightly upon thee and thine,
> > Through all thy Life's Journeys, from this life unto the next!
> >
> > Hail the Gods and Goddesses of our Folk!
> > Wassail!
> >
> > Krystof "Mac" MacBryghde
> > TyrGothi
> >
> > http://master.triad.ath.cx/