Skip to main content

For those of you who don't understand what fuel reversion is on independent runner manifolds is, watch this video of the Mclaren on the track. Notice that when the car is under accelleration there are "puffs of 'smoke'" coming out of the stacks.

Those puffs are raw atomized unburned fuel being pushed back out of the carb throats. That's caused by camshaft timing.

You will also notice that the plume is just over the top of the velocity stacks. Those are stock height stacks and are only about 2-3/4" tall.

IF you do any research on the PanteraGp4 cars, you will find that they all used Weber 48ida's on a Detomaso IR manifold. When you see the actual pictures of those cars you will see that they have doubled the height of the stacks to 5 to 6 inches high. Besides changing the torque curve of the engine a bit, it also keeps that fuel plume in the stacks.

Original Post

Replies sorted oldest to newest

The Pantera is really one of the few cars that can use tall stacks. The GT40 put a plate over them but used short stacks.

That just provides a place for it to accumulate. I'd rather keep it in the carbs. It's nice to know where it is and is a pretty simple solution?


You can also hear how the carbs definitely have a "whistle" to them. That's an idiosyncrasy of IDA's.

Last edited by panteradoug

Add Reply

Link copied to your clipboard.