Injectors that point backwards!!!!!

Pilninggas · Post by **Pilninggas** » Thu Jul 27, 2006 8:32 am

Hi,

I'm a newbie presently fitting a ms2 to an FZR1000 motorcycle. I am trying to save myself agro' by using gts1000 tbs ( straignt fit) and Bimota YB11 manifolds with their matched Weber Marelli injectors (308cc/min) - also a straignt fit. Anyway what is bugging me is why the injectors point back toward the tbs. I'm guessing its to aid charge mixing at low loads/rpms, but it still seems a little wierd. Has any one seen this before/does anyone know why the injectors are arranged in this way.

Cheers Merv.

Bow · Post by **Bow** » Thu Jul 27, 2006 11:45 am

According to popular belief by engine tuners, this is the best way to get a good air/fuel mix..

However, since it is not very manufacture-friendly to build that way, most do not do it.

Pilninggas · Post by **Pilninggas** » Thu Jul 27, 2006 11:57 am

Bow wrote:According to popular belief by engine tuners, this is the best way to get a good air/fuel mix..

However, since it is not very manufacture-friendly to build that way, most do not do it.

Well if Bimota did it it must have flow benefits, glad to know that this is a better way and that pointing towards the valves is considered a compromise - cheers Bow

detcollector · Post by **detcollector** » Mon Jul 31, 2006 6:04 am

They increase the time the fuel is in the intake and so allow for better mixing at high speed. The down side is they are not good on cold starts, can cause fuel to come out the manifold (the wrong way) which is dangerous.
Not good on cold starts means:-
Bad for emissions.
LOTS of extra fuel required for priming, cranking etc.
Problems with fuel puddling when cold.

Typically a usefull solution for racing vehicles.

Ferret · Post by **Ferret** » Mon Jul 31, 2006 9:17 am

I heard that injectors pointing that way have a strong tendncy to clog up. It is probably only relevant if the cranckcase breathers are connected to the intake.

Avner.