QUOTE:{is to pick a proven combo that a know engine > builder has > proven works and use it, if it is in alignment with your intended usage.} Earl is completely right in his statements, the quote above is probably the best engine building advice anyone could heed. unless your racing to put food on the table, and have been at it for years. a good read is don D's "ol reliable" 440 build. and as earl said, for most street builds nowadays, the performer RPM is a great all around intake. Sean Dietz --- Paul Lennemann <pjlenn@xxxxxxxxx> wrote: > > Thanks Earl....................I think???????????? > Earl Helm wrote: > > > > Paul, > > > > Now you have done it. This can be a bottomless pit > involving complex > > engine theory including CFM (computational fluid > dynamics), cam theory, > > all revolving around the physical limits of the > parts you have available > > and > > > > the limit on your Visa. > > > > Remember, things change, and technology advances. > Xram manifolds IMHO > > were quite an advancement by Chrysler, but like a > lot of evolution > > became > > a dead branch in the tree of evolution. This > technology has advanced to > > the level of sheet metal manifolds now used by Pro > Stock motors. That is > > not > > > > to say that the Xram manifold does not work, or is > not cool, but in the > > realm of max performance, it has seen its days. > Here in lies the rub. It > > works > > well with parts of that era, but putting an Xram > on a new set of Indy > > heads > > would not be the best overall application for that > manifold. > > > > My recommendation if you're going to build a > motor, and you do not have > > the engineering back ground or experience of > building thousands of > > motors > > over many year's (like Don) is to pick a proven > combo that a know engine > > builder has > > proven works and use it, if it is in alignment > with your intended usage. > > > > Everyone gets in trouble when they try to out > think the experts based on > > > > a magazine article they just read... > > > > I happen, as you know to love RPM manifold's. > Based on my past usage, > > they > > always have given me the best bang for the buck. > Many recent articles > > have > > backed this opinion I developed up with dyno > facts. Remember, the true > > runner > > length is measured from the butterflies to the > valve. We could get into > > raw > > flow > > vs velocity and burn up a good night of bench > racing. For a street > > motor, I > > will > > take velocity over raw flow every time. This > feed's into what I think > > you > > want to > > know and what is causing you some issues. In > theory you're correct > > regarding > > > > dual plane vs single plane. But technology > advances have narrowed that > > gap. > > The > > RPM works almost as well as a Victor, and better > when you take into > > consideration > > the over all curve for a street motor. Just like > head flow, it is not > > always > > the raw > > flow that matters, but what is the flow rate under > the curve that makes > > the > > great > > combo. Many times less flow on top, but more flow > under the curve makes > > the > > best motor. > > > > Call Don and ask him to build you a motor. I know > he claims to be > > retired, > > but > > he just might be glad to help a guy out. > > > > I have most likely put more mud in the water than > you liked, but my > > point is > > > > don't over think this thing. > > > > Earl > > > > > > > > > > I read the "Crossram Chronicles" article that Gary > added to the website. > > > > It talks about a runner length of 15" being the > magic number to > > scavenge the resonant pressure waves which result > from the intake valve > > opening and closing. And that this length was > tuned to an engine rpm of > > > > 5400. Giving the max wedge crossram manifold a > distinct advantage over > > the earlier long ram manifold which was tuned to > provide more torque > > and power from rpm's in the low 2000's to @ 4800. > > > > In reading general theory about intake manifolds > it is stated that a > > single plane manifold generally works better at > higher rpm than a dual > > plane which will give you more torque at lower rpm > & better idle > > quality. Since a dual plane has longer runners > this would seem to put > > these two theories at odds with each other. > > > > I don't think any of the commonly available street > type intakes have > > runner lengths anywhere near 15". I'm thinking > about The Holley Street > > Dominator and the Edelbrock Performer RPM in > particular. But since the > > Performer is a dual plane it should have the > longer runners, making it a > > > > better intake for low end torque and the Street > Dominator a better top > > end unit. I am in the process of making some > performance modifications > > to my 440 so I'm trying to understand this a > little better. > > > > Can anyone clear this up for me, Earl, Don, > anyone? > > > > Paul L. > > '63 Sport Fury > > 440/727 > > > http://www.1962to1965mopar.ornocar.org/ml-lennemann63.html > > > > > > ---- > > Please address private mail -- mail of interest to > only one person -- > > directly to that person. I.e., send parts/car > transactions and > > negotiations > > as well as other personal messages only to the > intended recipient, not > > to > > the Clubhouse public address. This practice will > protect your privacy, > > reduce the total volume of mail and fine tune the > content signal to > > Mopar > > topic. Thanks! > > > > '62 to '65 Mopar Clubhouse Discussion Guidelines: > > > http://www.1962to1965mopar.ornocar.org/mletiq.html. > > > > > > > > > > > > Paul L. > '63 Sport Fury > 440/727 > http://www.1962to1965mopar.ornocar.org/ml-lennemann63.html > > > ---- > === message truncated === ____________________________________________________________________________________ Looking for last minute shopping deals? Find them fast with Yahoo! Search. http://tools.search.yahoo.com/newsearch/category.php?category=shopping ---- Please address private mail -- mail of interest to only one person -- directly to that person. I.e., send parts/car transactions and negotiations as well as other personal messages only to the intended recipient, not to the Clubhouse public address. This practice will protect your privacy, reduce the total volume of mail and fine tune the content signal to Mopar topic. Thanks! '62 to '65 Mopar Clubhouse Discussion Guidelines: http://www.1962to1965mopar.ornocar.org/mletiq.html.