multiple carb applications

We spoke about Weber setups including side-drafts. There are a couple of other choices: Edelbrock or Weiand cast up a few dual-quad intakes, which work well with 390 or 450 Holley 4bbls, or with Hall 90 degree Weber adapters for side-drafts. These last don't work as well as a true side-draft setup, but they are an option. But such intakes are hard to find. Even harder are the dual-quad tunnel rams- the EFI guys have snatched them, welded bungs in for injectors and fabricated custom tops for their own brand of fuel injection. Finally, I think a few triple-2bbl intakes were built. Remember, the 351C was a limited production engine- built 70 to '74, right at the start of the gas crunch and the Insurance cartel's crackdown on muscle cars. The aftermarket industry didn't do much with it.

I've got a set of weber 48 IDA's and manifold for 351C setup for Pantera... bought many moons ago and have never been used or installed.

jj_jennings@mindspring.com

- jeff

Only spotted your post now,so thought I would toss this in for what it's worth......I have converted to 4x Weber-downdaught IDA's,Hall intake on 4V closed-chamber 'quench' heads (with only the un-shrouding of the inlet),flat top pistons, mild Hyd.cam with roller rockers, (not roller-cam)finished off with Hall's excellent 180 degree exh. system,-sounds unbeleivable over 4000rpm, not at all loud either.......This combination I can highly recomend. The negative postings i have seen regarding the 180 type of exh.system being very heavy and hot is not a question at all when using the'right stuff'-quality-wise,- in fact the guy at the shop where i had the 180 degree 'bunch of snakes' ceramic-coated thought they were made out of titanim they were that light, and because of this very thinwall, beatifully welded,(wish I couldd afford a set to hang on my wall) they dissapate heat very quickly indeed,in fact you can grasp them,-i have, after a few minutes of shutting the motor down.- and they certainly were considerably lighter than the standard, restrictive set up........(In fact, in stressfull moments I take time to go to my workshop to just sit in the car and start it up, warm it up, get the old adrenalin pump working and listen to the music........(radio and other ribbish was ripped out long ago.....) Incidendly,the exh.,when un ceramic-coated, running on the previous motor,the deck-lid paint was un-marked over severall thousands miles........
Dont listen to the guys that tell you its a pain to set the Webers up etc , etc.....If your carb linkage is in good shape and properly set up,- on a Dyno. etc. they stay set-up for a long time.- they are exquisite, preciscion-made carbs. I have run 4x Webers for years on the street,on various cars and the best sound, other than the 180 exh.system, is the 'accoustic-symphony' that accompanes the wacking-open the throttle of one of these set-ups on a heathy V8..........You can tell I am into the Aural side of things, ......... I said aural. All the best, tai.

True side-draft Weber carb rigs are uncommon on the Pantera, as no one in the U.S. ever cast up an intake that fits.There are 4bbl adapters, and an Australian unit for EFI that reportedly can be adapted at enormous expense, or Ron Wade in Seattle also has a custom sheet-metal EFI intake that likewise can be made to work with carbs. But if you do manage to assemble such a rig, be very careful of the air cleaners you use.
Fact 1- Webers are always used as individual-runner units; one carb-barrel per cylinder. This results in very strong intake pulsations, with airflow actually reversing each time the intake valve closes.
Fact 2- Webers meter fuel into an airstream regardless of which way air is flowing. This results in the infamous 'blow-back' phenomenon where an operating engine with Webers and no air cleaner often has a visible cloud of gasoline hanging a couple of inches above the air horns. This cloud condenses & saturates any air cleaner. With side-drafts, the condensed fuel can drip out the bottom of an air cleaner- and your very hot headers are right there- next to 20 more gallons of high-test in the gas tank. This is NOT a healthy situation IMHO. Many side-draft guys use an air cleaner that has a solid bottom section with a long vent-hose to re-rout such drips. Incidently, with I.R. EFI, the cloud does not appear as fuel is not metered in the reverse airflow direction.

I also suggest NOT using a foam air cleaner of any type with any Weber setup, verticle or side-draft. A second characteristic of any Weber carb set thats tuned to run correctr fuel mixtures is slight backfires especially when cold. The fuel saturation mentioned above combined with a small backfire and a saturated foam cleaner will ignite the air cleaner. This doesn't happen with paper air cleaners. I recommend carrying a Halon fire extinguisher in ANY Weber-equipped auto, just to protect yourself. Halon will not mess up the engine compartment like a powder extinguisher. I ran Webers for years and had two fires in traffic- both with foam cleaners, one serious (eternal thanks to a passing truck driver who had a fire extinguisher! I bought my own that afternoon).

Finally, buy yourself a good book such as Haynes on Weber carbs and memorize it. Tuning and tweeking such a quad-carb setup will be constant, and properly jetting the things to begin with is a true black art, unless you don't much care how the engine runs or want decent fuel mileage. FYI, there are 5 jets and two air-bleeds per barrel (8 barrels), all removeable and all affect each other. The cheapest Weber jet is $5 or so, and its real easy to get lost in tuning. Weber carbs have been out of production since the early '80s, so all carbs including NOS that have been sitting on a shelf for 20 yrs, will likely need rebuilding, at considerable expense as well. I really recommend I.R. EFI which has the same appearance, tunes simply and costs about the same.

Jack -Hi,& thanks very much for the interesting info. on Webers and yes,you are absolutely right about the various problems concerning running them.- EFI IS the way to go. I always have an fire extinquisher firmly attached to my center-consol, easy to get at but NOT lying loose.-very dangerous. Am also planing to fit a Halon fire suppression system in the engine compartment for insurance.
I am running the 4x big chrome K&N fiters on my old, down-draught IDA's. How would you rate these regards safety and effciency compared to the 'slimmer', ally., Hall Pantera have on offer. I am thinking they are easier to see around, but will they flow as good as the bigger K&N's ?
Thanks again Jack for all your un-stinting devotion and help to us all. Cheers,tai

What is I.R. EFI, is that the brand? Who sells it & aprox. how much?

IR EFI is Independent Runner, which means that it looks like Webers since each cylinder has its own plenum, as opposed to a single- or dual-plane manifold, where all cylinders share a common plenum or two.

Supposedly IR gives a little more responsiveness than a common plenum. Looks cool too, but those looks have a price. Probably the best known off-the-shelf IR system is Dennis Quellas, which will set you back some $4500-$5000.

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Charlie McCall
1985 DeTomaso Pantera GT5-S #9375
"Raising Pantera Awareness across Europe"
http://briefcase.yahoo.com/gt5s_1985

As far as aircleaners, first, I'd fabricate an aluminum heat shield around your IDA Webers similar to that used in GT-40s. Airflow in the Pantera rear section is up from under the car, sweeping past the headers.180 degree headers dump an enormous ampount of heat into the airstream, right about where the carbs suck in. Once you have a shield built, then some decent K&Ns or paper cleaner will work fine. Another problem with multiple Webers is, keeping the sheer volume of trying to keep four big hungry fuel bowls full is about all the stock fuel pump can accoplish. All the Weber manuals say to reduce pressure for their carbs, but my experience shows that most regulators on a stock Ford (or Chevy) pump reduces flow, not pressure, so they act as a rev-limiter.