Intake manifold tuning for Favorit

[RicardoM]

I've found a photo on a tuning site for Favorit engine. Anyone knows what is that modification for? Better breathing? More power? More mileage?

 

[ThomasItis]

Equalize pressure among cylinders?  What do you think?

[RicardoM]

I really have no idea. I could only speculate but I don't know if those bullet-like parts are just hollow or they are 1-way valves (?). Maybe our rally participating members know better.

[ThomasItis]

I'm also curious why they have the pipe pairs (1-3,2-4) like that and not otherwise.

Edited 15 May, 2016 by ThomasItis

[RicardoM]

They look like some kind of nozzles or jets...

 

 

[felicia16v]

I can't see any benefits from doing that unless they are adding nos through the pipes.

[ThomasItis]

Or maybe water-meth?

[KenONeill]

As it stands the blue pipes are probably to keep the (presumed) injectors clean. I can't think what you could inject to a non-turbo engine that would make significant power though. You'd have to over-fuel to get a benefit from NOS, and I don't see the intake being hot enough for water-methanol to be a benefit.

 

The angle's wrong to be a port-injection conversion, since the injectors want to fire fuel along the manifold branches towards the engine rather than at right angles across the manifold in that case.

[RicardoM]

Ken, you missed the main point. This mod is for a Favorit with carburettor.

[RicardoM]

I will ask Lugosy for an opinion.

[KenONeill]

As it stands the blue pipes are probably to keep the (presumed) injectors clean. I can't think what you could inject to a non-turbo engine that would make significant power though. You'd have to over-fuel to get a benefit from NOS, and I don't see the intake being hot enough for water-methanol to be a benefit.

 

The angle's wrong to be a port-injection conversion, since the injectors want to fire fuel along the manifold branches towards the engine rather than at right angles across the manifold in that case.

 

 

Ken, you missed the main point. This mod is for a Favorit with carburettor.

Ricardo, note the words I've now emboldened. This means that I was considering the possibility of replacing the carburettor with a 4-point injection system whilst retaining the original manifold.

[RicardoM]

 I was considering the possibility of replacing the carburettor with a 4-point injection system whilst retaining the original manifold.

If that contraption looks to you a 4-point injection system then perhaps you could explain to us how it works. I am sure all Favorit (with carburettor) owners will die to know how to have on their engine both a carburettor and a multipoint injection system with all the benefits.

Edited 20 May, 2016 by RicardoM

[felicia16v]

Simple. You just use the carburettor as a throttle plate. No fuel to it and blank jets off. Then use a standalone ecu to work fuel injection. But i dont think they are injectors.

[Tamber]

Could it just be that someone's heard about using balance pipes -- like for multiple carbs, or individual throttle bodies -- and perhaps had a (maybe not so) bright idea about it perhaps improving performance on a single-carb system?

[RicardoM]

Could it just be that someone's heard about using balance pipes -- like for multiple carbs, or individual throttle bodies -- and perhaps had a (maybe not so) bright idea about it perhaps improving performance on a single-carb system?

I subscribe to this idea. Balance might be the key word. Scavenge gases might be another one. But I don't understand what are the benefits.

 

The interesting thing is the Slovak tuning company that tuned heavily that Favorit engine consider it is one of their most representative jobs done. They used mechanical parts from Felicia 1.3 MPI (crankshaft, head, pistons, conrods, valves, pushrods)  but no electronics at all.

 

http://www.tuning.sk/dokument-cobra_tuning_skoda_favorit_motor

[RicardoM]

In a very broad translation, they call it "nozzles for regulating pressure to suction"...

 

The engine is a 1992 136L Favorit.

Edited 20 May, 2016 by RicardoM

[daverapid]

I think they are handles to make lifting the manifold easier 

[RicardoM]

I've got the exact translation and explanation from Lugosy. They call it "regulator for smoothing the intake mixture flow". Apparently some mixture is lost due to pressure pulsations and this effect is more noticeable at higher rpm. In other words, that (let's call it) pressure equaliser helps getting more power from the same quantity of fuel.

 

Never heard of that though...

[ThomasItis]

Post #2. I got really close to answer!  :clap:  :clap:   

[RicardoM]

Post #2. I got really close to answer!  :clap:  :clap:   

You have won a trip to Miami :$$$:

 

I've looked briefly on my auto library for more clues and I think I've got the theory behind that 'regulator' or dampener. I have doubts for the moment about how efficient is this particular implementation on a Favorit engine but here is the theory:

 

In an internal combustion engine the flow of air/fuel mixture is not linear but cyclic due to the movement of pistons and opening / closing of valves. During intake stroke, the piston moves down creating a vacuum and the mixture has an accelerated flow to fill the cylinder. After the intake valve closes, the flow is stopped abruptly and a pressure wave is created that hits the intake valve and bounces back to air filter housing. Depending on rpm, that pressure wave could be beneficial resulting in a "supercharge" effect or could hinder the flow resulting in a poor fill of the cylinder. Modern engines use the so called "variable-length intake manifolds" to take full advantage of that supercharging effect.

 

I believe that the Favorit intake dampener tries to smooth the flow so that the engine will breathe more uniform over a wide range of rpm.

[ThomasItis]

You have won a trip to Miami :$$$:

 

I've looked briefly on my auto library for more clues and I think I've got the theory behind that 'regulator' or dampener. I have doubts for the moment about how efficient is this particular implementation on a Favorit engine but here is the theory:

 

In an internal combustion engine the flow of air/fuel mixture is not linear but cyclic due to the movement of pistons and opening / closing of valves. During intake stroke, the piston moves down creating a vacuum and the mixture has an accelerated flow to fill the cylinder. After the intake valve closes, the flow is stopped abruptly and a pressure wave is created that hits the intake valve and bounces back to air filter housing. Depending on rpm, that pressure wave could be beneficial resulting in a "supercharge" effect or could hinder the flow resulting in a poor fill of the cylinder. Modern engines use the so called "variable-length intake manifolds" to take full advantage of that supercharging effect.

 

I believe that the Favorit intake dampener tries to smooth the flow so that the engine will breathe more uniform over a wide range of rpm.

Thank you for the trip! Perhaps you could hook me up with a trip to your country  ! Travel guides say beautiful things (I'm very serious).

 

My answer was only based to the fact that in theory equalizing pressure in to the intake manifold will help mixture. The closer to 11.0 afr (only for racing, not on road) the better the engine will work (produce work: hp-torque)along with an aggressive timing. My thought was that if we use race fuels with high engine compression, high rpms e.t.c. we definitely will need 1 AFR meter instrument to every exhaust pipe (4 in count) in order to see how the cylinders work after the combustion. But since we can't know exactly what happens before the mixture goes in, a pressure equalizer will help a little better.

Edited 21 May, 2016 by ThomasItis