Need a couple of dimensions off an EFI manifold

[stirlsilver]

Hi all,
Just a very quick question, does anyone have the inside and outside dimension of the the 3.9L EFI throttle body? Please see the photo below:


It's a photo I dug up so I wasn't exacly focusing on the area in question, But it show where i'm talking about (left hand side of the photo mid way up).

From memory I think it is 2.5" ID and 2.75" OD but can someone please confirm this? I need the dimesions so I can do some machining to the LPG mixer ring I designed.

[rangieman]

Hi all,
Just a very quick question, does anyone have the inside and outside dimension of the the 3.9L EFI throttle body? Please see the photo below:


It's a photo I dug up so I wasn't exacly focusing on the area in question, But it show where i'm talking about (left hand side of the photo mid way up).

From memory I think it is 2.5" ID and 2.75" OD but can someone please confirm this? I need the dimesions so I can do some machining to the LPG mixer ring I designed.

What you dont own a set of verniers , shame on you boy why did.nt you say that when we did you diff ,I could of measured the manifold for you
Engineers

[stirlsilver]

I can't measure it! It's got a mixer ring attached to it now and it is sealed in with silicone!



Surely someone has a manifold kicking around somewhere that they can measure?

[stirlsilver]

Just bumping this back up...

[rangieman]

Just bumping this back up...

Ok slacker now its not a everyday driver (push bike) unattach it and measure it , how hard is it for some

[Utemad]

I just measured mine.

Inside diameter is 65mm. I think I remember reading that somewhere too.
Outside diameter is approx 73mm. I say appox because my verniers are not deep enough to measure it properly so you should check that measurement.
I could have measured the wall thickness but didn't think of that til I had it together again.

I also have LPG with the ring in the intake hose though. I never realised how much the ring restricted airflow. It would only have an approx 40mm opening

Good news is that my airbox is now fitted properly. Must have come off all its mounts when I broke the engine mounts so now it isn't flopping around

[lokka]

One thing i can say is that that mixer ring pictured must restrict the flow a fair bit whats tha go there ive heard that using a LPG set up like that with the EFI manifold is supose to be tha way to go tho with restriction like that il be sticking with the mixer ring mounted over the holly

[stirlsilver]

Thanks for that justin, That is pretty close to what I had though and it should be good enough for my purposes.

lokka, yes exactly right, massive restriction. Thing is you need a reduced opening to get a venturi effect to get the whole system to work.

Anyway to solve the problem I designed this beast:

[lokka]

Looks the go mate tho if ya that handy id go to the trouble of twin throtle boddies and twin mixers to get the flow back as that would make the sucker go like it should