Folks, the gas stream from the headers and even back in the tial pipe is a
series of "putts" as internal combustion engineers like to say. And unless
there is a significant diference in the length of the pipes leading to
either a cross over or an x pipe the puts will never collide. Mechanical
impossibility because of the nature of the internal combustion engine
design. Putts are always in the ordr of the firing order and are spaced
accordingly. In the older Ford motors the firing order had 7 and 8 firing
after each other on the left bank and 4 and 2 on the right bank.. Ths puts
two putts together on each side and lessens the scavange effects of the
cross over, either x or h. The H pipe cross over need to consider the speed
of the putts (engine rpm) in designing it because it takes some amount of
time for the putt to actually cross over and you want it timed so that it
arrives between the next two putt son the opposite side. The x pipe is fully
merged so that the putts can never get out of time because there is no
distinction between the two pipes coming from either right or left engine
bank. However, again the old firing order causes two putts to come from each
side in sequence so the scavenging effect is smaller. The newer firing order
, ie 351 and later 5 liter, is better because it effectively does away with
this situation. Either systems helps, however, unless you are looking for
the last once of power from your configuration, it probably isn't worth the
extra hassle involved in trying to fit all that stuff under the tiger.
Mustang, yeah, all right.. I would be more interested in riggin up some cats
to help clean up the air, and maybe some efi to go along with it...
mayf, out in Pahrump, nice weather , still.
----- Original Message -----
From: "Tom Witt" <wittsend@jps.net>
To: <tigers@Autox.Team.Net>
Sent: Friday, November 05, 2004 6:25 PM
Subject: Re: Dr. Gas - Rationale
> If the X pipe is documented to work I guess that there is no disputing it.
> However, logically it would seem that as the two exhaust flows cross each
> others paths that one would inhibit the flow of the other. Try it with two
> garden hoses to see what I mean.
> Now, with the Dr.Gas design it seems that the two flows would for lack of
a
> better term "slide" along side one another (which I would think promote
> scavaging). I say this because looking at the picture and the radius bend
> the two flows seem to be turning before they merge rather than directly
> crossing each others path like this X vs )( with an opening where
> the )( meet.
> . I guess a lot of what I summize would be predicated on how large the
> opening is at the merge point. So, I guess that is the Dr. Gas advantage.
> Tom
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