Fins on back of Valve & Fins pre TB

[vlad01]

Saw a pile of these at the wreckers, first time I got a close look at one.

2 separate small plenums fed by 2 ram tubes from one large TB.



and the lower section, just straight runners with fuel rail in the middle.



The lowest section of this look to be inline with the runners on an ecotec LIM about 1/2 way down.


Cut the top flange section off and weld tubes to a chopped ecotec LIM, Project anyone?

Looks like a quicker way of testing a dual plenum manifold on ecotec rather than fabricating one from scratch.

[Jayme]

on the alloytec 190 (never looked at a 175) there is a flap at the back of the two plenums to join them together at a certain RPM point as well.... presumably to improve airflow for multiple rpm ranges.

it would be verrrry interesting to see what effect a manifold like this had on an ecotec.

[vlad01]

I looked at them and saw they have provisions in the casting but no flap, just solid casting awaiting machining.

There was some junk engines there with different manifold which a separate square cover on top of the manifold. I presume that would be the ones with the flap?

[Jayme]

ill take a pic of my 190 manifold tomorrow so you can see... I cant remember lol.

this motor is also found in other cars like the c(r)aptiva and rodeo, maybe its a different style manifold for those cars too?

[vlad01]

There is also the potential to use the aftermarket CPR6 manifold too.

[Gareth]

The alloytech manifold is a long way off, have both here and would be a huge job, the alloytech runners are heaps bigger too... See on saturday vlad..

This is where my idea for the dual plenum for ecotec came from.

The flap you are talking about Holden call the VIM or variable intake manifold, all VE's except LPG have it, only the 190 VZ im pretty sure had it... Made heaps of difference to the power band of the engines fitted with it.

This is more proof of the potential of an improved manifold for pre alloytec engines

[vlad01]

Thats why i say cut the flange off, the top part its actually small and it virtually doubles in size at the bottom where it goes to 2 valves.

I don't think its a huge job, just welding and bending up tubes really and relocating the alternator most likely.

[HQ355]

My VZ 190 definatly has the dual plenum, had the intake off a couple of months back to change the plugs, what a nice job that is !

[Holden202T]

all 190's have it .... that and all the cams adjustable is the main differences between the 175 and the 190 motors.

by the feel of it the difference in the 190 motor is mostly felt from about 4000rpm ... I am guessing this is either where the flap opens or its a difference in the cams adjusting .....

have driven both 175 and 190 for a lot of kms, and the 190 is totally worth it over the 175 hehehe!

[vlad01]

wonder which way the flap goes, one big plenum at low or high revs?

I 1st seen this flap between twin plenums on Ferrari engines. Seem to be common place on a lot of cars now.