The Cal-look Lounge

Talking to my pal Tony (RACEHEAD) this morning about all sorts of stuff....Pete Staat's old blue car, the latest short course To#¤ta motor and intake manifold ideas. We were talking about getting ultimate rpm out of a fairly big cc VW, say 2300cc+.
By running some rough numbers, it looks like to go 10,000rpm, your "typical" 2332 will need about a 49mm venturi. A 1776 capable of going 10K rpm would need about a 43mm venturi.
Obviously, the 1776 could run your standard issue 48IDA Webers, but in the case of the 2332, a guy would need to step up to 58mm or 62mm IDA copy carbs.

Or would he?

Take a look at a super hot VW motor. You've got one venturi per cylinder. What's your typical 48IDA flow.... 380cfm per barrel? So each cylinder, on intake stroke, has one runner and one carb barrel to draw through.

Now imagine if the intake runners (to each cylinder, and let's say this is a Angle Flow or spread port, weleded VW head, like Jeff Denham does [or old Berg] in the manifold were not entirely isolated from valve to carb butterfiles, but instead, each runner extended maybe 4" up from sealing flange @ head, and then gently radiused into a large, tapering plenum chamber under BOTH throttle plates. So, if you were looking down onto (or into) intake manifold, w/o carb bolted on, you'd be looking at a flange in the same pattern as IDA Weber (or IDF!) then below port openings (for butterfiles) a large plenum chamber, joining both intake runners at lower edge (and gently radiused floor into intake runners, not a flat floor with holes poked in it). Why? When one cylinder per bank is on INTAKE stroke, instead of pulling through only one venturi, the cylinder now sees BOTH venturis available. Yes, your intake runner would still be your restriction, but with correct ID and radius on floor and roof of runner, one could see that the port volume could now be perfected to flow air needed to see very high rpm (i.e. like when 62mm Terms are utilized). So instead of increasing existing throat diameter, you'd simply be offering another barrel to each cylinder.
Mind you, I am talking all out, race specs here. If everything were to work in the real world as it is in my head and on paper, you'd definitely be trading the gains of high rpm CFM vs the driveability and throttle response of the conventional I.R. set up we all are familiar with running 48's (or 40's, 44's, 45's...whatever) on conventional manifolds (like Skat traks).
This is really nothing new. Look at a tunnel ram on a V8 running two Dominators. Only "restriction" is the actual intake port/runner and the valve itself.

I am sure running a VW with 2 2bbl Webers in this way would require a whole new way of jetting and selecting venturies. Plus, you'd need a motor stout (and rigid enough in valvtrain department) to gulp this much air and spin this kind of RPM.
Maybe not very Cal Look..... ::)

What do you guys think?

Here is a shot of our race engine

tony you should have Wes or Jeff or one of your buddies fab up some manifolds for me.

is this idea that weird?

It make sense.  Now all you need is one of the many talented people on here help you make it a reality. ;D

Jim get me some old not used manifolds and let me see what can be done - the fart knockers can weld alum. now so it can be done.

Jim, I guess you meant exactly this??

http://www.thesamba.com/vw/classifieds/detail.php?id=913554
 :o  :o

I saw Clyde's ad for those manifolds a while back and remembered them as soon as I read Jim's post.

in one of the old HOTVWs there was a racecar with a plenum that fed all four ports with dual IDFs on top. article said it made more power than IDAs in the traditional setup.

Jim , on your picture is shown what the prostock V8 racer do . It works perfect but on our engines with IDF for example you can not get enough fuel in through the needle and seat's :-(
Ron Lummus tried this with 1 holley carb in the past but did not get more power than we have today with 58' or bigger as far as i know
Udo

Bear is now currently running a pair of cut-in-half Holley Dominators (1050cfm in two), mounted on a pair of plenum manifolds with a cross-over balance tube.

Besides the obvious space factor, although not such a huge issue on a race car, I've often wondered why others racers haven't just used a big stone-age club (ie. a fat 4BBL Holley!  :D) on each side when they run out of IDA sizes. Still IR, 2BBL per pot.