looking for modified bellmouth details

[stocky]

im going to put the bellmouth back into my car soon to stop the rough idle. ive heard people have modified their bellmouths by cutting them to a certain shape to improve the airflow but keep a good idle. does anyone have details of this, or a diagram?

[1991_Vn2nV]

Even with the bellmouth it wont be smooth. VN's do not know the meaning of smooth. Effort for no real return in my opinion.

[PaRaDoX]

mines smooth as!!!!!!!!, get the valve train right and shell idle like shes ment to, well on a cold start she rumbles

[Cobez]

Sorry to revive an old thread, but i just took mine out, same results as paradox had, my VP is now idling and driving like a dream, it's very very smooth indeed. It idled alot more rough with it in.

[Bz Kn33z]

also took the bellmouth out of my dads VR and is alot more responsive he loves it lol only took half an hour.

[Cobez]

I think it's one of things that will either have a negative effect, or a positive. I haven't seen any neutral effects for anyone yet. It's either caused rough idle and a few problems, or it's smoothed things right out.

I have a feeling it has better effects on VN series 2 engines and onwards.....

[AirStrike]

I think it's one of things that will either have a negative effect, or a positive. I haven't seen any neutral effects for anyone yet. It's either caused rough idle and a few problems, or it's smoothed things right out.

I have a feeling it has better effects on VN series 2 engines and onwards.....

Maybe that's because the Series I VN didn't run a bellmouth

[Cobez]

Ahhh i see, maybe i got confused there. The bellmouth was to correct a rough idle problem FROM the VN S1 engine????

[AirStrike]

Ahhh i see, maybe i got confused there. The bellmouth was to correct a rough idle problem FROM the VN S1 engine????

Correct

[Cobez]

But that's one thing that's got me confused, if the bellmouth was put onto series 2 VN engines and onwards to VR, why is it my engine idles alot smoother now i have removed it?

[AirStrike]

But that's one thing that's got me confused, if the bellmouth was put onto series 2 VN engines and onwards to VR, why is it my engine idles alot smoother now i have removed it?

Plecebo.........your brain is telling you it will make an improvement. Removing it leans out the two rear most cylinders slightly.

[Cobez]

Ahhh i see, no power difference thats for sure, bit it just seems to idle a bit smoother. But definantly no power difference.

[markovr]

The cam is the performance difference (better mid range)on s1 vns dont blame the bellmouth

[AirStrike]

The cam is the performance difference (better mid range)on s1 vns dont blame the bellmouth

Yep, the bellmouth was purely to smooth the idle out.

[Cobez]

So can 2 cylinders that are slightly leaned out from the bellmouth removal, be somewhat of a bad thing in the long run?

[stocky]

So can 2 cylinders that are slightly leaned out from the bellmouth removal, be somewhat of a bad thing in the long run?

pretty much why i started this thread years ago. to find a way to improve the airflow while not leaning out the cylinders. probably wont cause any trouble

[AirStrike]

So can 2 cylinders that are slightly leaned out from the bellmouth removal, be somewhat of a bad thing in the long run?

I can't see any issues unless it was heavily moddified (FI or high comp) and tuned to within an inch of it's life.

[Cobez]

Well hopefully it works nicely a the set of rockers i'm putting in soon.

[Cobez]

I can't see any issues unless it was running FI and tuned to within an inch of it's life.

My VP is definantly not tuned wretchedly heavy and most definantly isn't running a FI set up.

[stocky]

I can't see any issues unless it was heavily moddified (FI or high comp) and tuned to within an inch of it's life.

bellmouth with FI = bad. caused a bad restriction on my car. when i took it out, the psi readings dropped by 2

[AirStrike]

bellmouth with FI = bad. caused a bad restriction on my car. when i took it out, the psi readings dropped by 2

That is an issue with it. Hmmm maybe cut the neck off and weld a larger diameter neck on, with a new bellmouth.
Second thought's who could be stuffed

[Cobez]

So i'm guessing that if you have a FI set up on a buick 6, and 2 of your cylinders are running slightly leaner, all the air pressure from the blower would be working 4 cylinders alot harder than the other 2 leaner cylinders, therefore causing a few (or one big) problem, whereas on a car like mine with only basic power mods done, it wouldn't be enough to do any damage..........???

[stocky]

not really. when youre forcing the air in there, and have pressure in the manifold, the cylinders shouldnt lean out really. its only running N/A it would cause a problem

[Just_a_stocker]

I have removed the Bellmouth from mine, dont see the point in puttin it back...

[Cobez]

Mine seems to be running a tiny bit more rich without it. Nothing major though.