Horsepower gain with Webers

[Excaliber]

Just to reiterate were basically all on the same page here...

There is little or no doubt throttle response and torque at the lower mid range and reasonably high rpm range are improved with Webers and so it would seem with the inline autolite carb setup. All though the later could be debated. Take fuel slosh, for instance. Center pivot float is better than side pivot, Weber is better yet, degrees of improvement, just short of perfection (enter fuel injection). Hard to beat Webers for a road racing application or even street use (with the possible down side being poor mpg with Webers). All this ASSUMES of course the Webers in question are PERFECTLY tuned, not something to be taken lightly! Which is perhaps another reason Shelby wanted to stay with a single carb, it could be tuned to near perfection easier, more simply? Given enough TIME and TESTING the Webers may well have done a better job.

The sticky point for me here is, "absolute power". Take drag racing, Webers or Carb? You rarely see Webers in that arena, I wonder why? Serious question actually, not drawing any conclusions here one way or the other. NASCAR,,, I wonder, without limitations like restrictor plates, Webers or Carb?

Then of course the next logical step would be, Webers or dual carbs for an "absolute power" application, like the Bonneville Salt flats.

Tom, isn't Kirkham considering a Salt Flat run(s) in the future? Whats your game plan for induction?

[RICK LAKE]

hamster427 Brain if you are building a motor with webers in mind, you don't want to run a carb camshaft. There will be too much reversion. With the right setup and carbs you can make 10-35 hp over a single carb motor. You didn't say what the max rpm or cubes of the motor would be? A set of 48mm webers will get you to the 8,000 rpm range before falling. A carb will still make more power topend. This is on a small block ONLY. A 427 FE will run out of air in the 6,500 to 6,700 rpms with 48mm. Mid range torque is up about 20-30 ft of torque and hp about 10-35 hp. Another big thing is the exhaust on your car. It can cost you any where from 10-50 HP and torque You need back pressure in the 1-2.5 + pressure reading in your power band between max torque and HP.
Has far as webers on lemans car, Shelby went to single carb for the simple issues of less moving parts to have problems with and the bigger issue GAS MILEAGE. Every time you hit the pedal with Obergs or Webers the accellerator pump dumps gas into the motor, 4 pumps, 4 carbs that alot of fuel wasted. 1 carb, 1 or 2 pumps depending on the carb. Gas maileage did come into play back in the 60's. I beleive the the lemans cars where also limited to 6,500 rpms for the 24 hour race. I think they where allowed a higher rpm on the long straights.
Brain if you are looking for this kind of look, go with FI system and s setof TWM throttle bodies. They look like webers and run the same or better. The fi system also has a 10% adjustment for all different condition on weather. Webers are more for racing than street driving IMO. This is not saying that a setup of 58MM of Webers or Olbergs are not a work of beauty. When running right in a good FE motor, they sound great Rick L. Ps I left out the price on the webers and TWM setup. I hope you have deep pockets.

[RICK LAKE]

Excaliper Ernie Tony S cobra ran weber carbs and set some records. I also have pictures of the 390 liteweight"turd" car running webers.
Application has alot to do with running carbs or webers. Some of it was just plain a money issue. Look at a carb, say Holley because it's a simple carb. The kit we carried was a jet box with 10 jets higher and lower that what was in the car, 4 gaskets for the float bowls, 2 base gaskets, 2 accelerator fuel pumps and arms for switch between 35 and 50cc. It all fit in a tackle box for fishing. Look at webers, you have 4 carbs, multiply that my 4. Jets , jet holders, tubes, bore reducers. You have about $500.00 alone in this box, and the box is alot bigger too. Today we have recorders for every race we run, back then test and tune with luck. Today A/F meters for checking A/F during the run or race. EGT monitors for exhaust temps. internal pressure readings for blowby inside the motor, Back pressure in the exhaust, and the list goes on.
The other thing IMO is that a Weber or Olberg motor is not built the same as a carb motor. Different camshaft, high compression than a carb, less timing needed. Can also run on low octane gas without knocking or pre ignition problems. They are great carbs, the price is also great too. If you have the money and time, DO IT. IMO I stay with the simple, less moving parts way. Rick L.

[sdfletch]

What is the main diff between a carb and weber cam? Is it easily explained? Thanks.