Outer Limits 4x4 Board

Have a theory --
If anybody has any thoughts or better still real personel experience --

Im just getting my 350 chev together and it will run full time LPG
Now my theory is for intake the lpg system requires vacum and at the point
of throttle opening there needs to be good vacum ,
On a normal carb setup its best to refrian from large plenum chambers
unless you looking at higher rpm opperation.
This is different in a injected setup where the fuel is placed into the port.
and most inj donks have a fairly large plenum type chamber on top .

Im thinking of trying One of the new Proffesional products intakes,
For those that know they are simaler to the Victor jr in looks -
But arent as large in capacity ( heaps of meat there to port match ect-)
Now the theory i have is with the right cam timing the larger capacity of
the manifold would act as a vacum res at the piont of throttle opening even down at idle and below -
any coments ?

a single plane manifold will be better for high rpm and a dual plane for low to mid range/ i havent played around with diferent plenum sizes on lpg engines so i cant even speculate on your assumptions. i would go a dual plane manifold if you want low down power and torque and put a 1 or 2 inch spacer ontop of that before you put on the throttle plate and play around with it that way.

Jes

What Jessie said about the 2 differant manifolds is true, so the first thing to deciside is what sort of power plant you want .... horsepower or torque ?

The manifold you pictured is good for horsepower especially from LPG, but if your after torque I'd look into a Eddlebrock twin plain manifold and get an LPG injected kit and fit that instead of a mixer setup. Sure its a few extra bucks over a traditional mixer setup but you'll get better power and ecconomy.

A patrol running around here had the injected setup done and he then had it dynoed for both petrol and LPG ..... the LPG put out the higher reading by a suprising amount ...... If I had the bucks spare I'd be fitting an injected setup to mine. I'd get pics for you but there isnt really anything to see, the LPG injectors are very small and well concealed .... but if you need pics then ask away.

Kingy

Thanks for the Input Jes n kingy, Have the setup for the standard manifold ,I'll just whack that on,experiment later ,
Don,t want the lpg inj I have heard it works great -
Just like it to be a simple as possible ,
What mixer and converter you guys using ?

Impco converter and a series 45-70 mixer

ive heard gas runs better with single plane manifolds.
some people get the performer dual plane and knock the divider bit out of the middle. is this just a cheap single plane option maybe?

MaccA