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Induction myths Holden 6 ,Damn triple webers, EFI and Holleys

I am now feeling like the king of rebuilding and sorting out inductions for Holden 6's , I dont know how you guys do it , I really dont. I have a metal fab shop and a few sheds, and even with plasmas and tigs, I still get bogged down on simple jobs on my cars!!!! Anyway, here is a chapter of mine I thought I should share

In my eternal search I have worked out in the real world what is a good/great /amazing set of webers for a semi serious Holden 6 . For what it is worth, here is what I have done and where I am up to.

Car is my second string LJ GTR 82911 , as I also have an early 1973 Xu1 as well.

Engine is as follows. All done in my workshop which just so happens to have a Petersen Mill for head work and a great operator who has done heads for drag cars in the 8's and 9's aspirated, so it is good to have those guys on "wages" not getting a bill from an engine shop!!!

3.3 block
Blue bottom end , blueprinted, clearanced and fully grooved main bearings.
Starfire rods obviously with a set of ARPS fitted
HQ racing series pistons with ultrafine 1/16th rings
Solid Camshaft with all lifter heights revised using Pontiac lifters and cam has 485" lift .
Cylinder head work only minor done to 12 port head, it flowed really well ( amazingly well in stock form which I didnt realize!!!!!) so we fitted slightly increased valve sizes and did some minor short radius work on ports and general clean up and it outflowed my Bathurst xu1 head!!!! SERIOUSLY

Top of bore was releived to shape of combustion chamber and pacemakers were also matched to suit cylinder head.

Valve springs were changed to "serious" double springs and quality retainers and collets etc.

Head was machined to accept 7/16 "bolt on" YT rollers and from factory they had awful gemotery hence pontiac lifters and non std pushrods etc

Recurved electronic ignition and after using every brand of coil ever made, I switched back to a "NEW" standard blue motor coil for best results.

Ignition leads, again, after all super dooper and mega race leads were used I went and bought genuine holden leads and they were absolutely spot on .

I can quote any spring, cam or bore spec, but dont want to bore you guys!!!

I dont want to hear anyone say that their red/blue/black motor revs to 8500 rpms all day and that this engine sucks, I am only just relaying my ACTUAL findings ok...

Set up # 1

Holley 350 on redline manifold. ........awful as I had remembered as a 19 year old , reasonable idle note and fiddling with jets and power valves was worthwhile, but wow, they have no GOOOOOOOOO like even a std carb has .Ordinary to drive , no idea or interest in fuel economy figures

Best Effort
DYNO 122 Rear wheel horsepower at 5350rpm and running oit of puff

Even fitted carb venturi restrictors, Hp IDENTICAL ( 120 at 5200 rpm)


Set up #2 blue engine head, so we fitted VK injection.

Had a set up with modified computer and harness, so it was an easy way out, but still a pain in the ass with return lines and a lot of BAD wiring on my part.

Totally not interested in this set up, lifeless, soul less, and got us 116 Hp on dyno and was just not me........"I like the smell of fuel in the morning...smells like victory"

ORDINARY...but reliable
Set up # 3

Holley 600 Double pumper on custom made manifold with high riser( will not clear standard bonnet with air cleaner fitted on LJ)

(Was actually not as throaty at idle as 350 even after fiddling with dyno guys, and maybe suspect on idle circuit etc)

This rocks and was very good on pick up ( square bore etc) and accelleration and when you dropped those secondaries in this motor loved it, no flat spot or hesitation, but IT HAD TO WARM UP!!!!!)

Massive punch in mid range and really felt like a race motor should even with single 2 1/2" system. Engine will lean out under moderate accelleration and then just drop the secondaries in and it goes up a notch in a big way. Great induction roar.

SIMPLE BUT EFFECTIVE, and you can smell the fuel!!!

Dyno after fiddling for a few hours

197 Hp at 6250 rpm ( HOLY CRAP ) was this a big lift

Dyno guy said this was probably the set up for THIS engine as it really gave that cam some punch up in the rev range. BUT anyway.................

Set up # 4 Triple dcoe 45mm webers on a redline manifold

I didnt own this set up, but a friend did and he said while car was getting a fresh engine to go ahead .

Ummmm, what to say about this.........HOLY #$%K

Totally undriveable in this configuration in terms of being able to control myself from floooring it the whole time, but that sound is just like nothing on earth, it was like I had a completely new engine ................just amazing, I had triple su's 15 years ago and they are not even in the same planet, let alone comparable to these damn 45s

I dropped 40 litres of fuel in a bit over an hour of driving on some bitumen back roads.

SHOCK HORROR DYNO 211 Horsepower in that trim (we couldnt fiddle as I didnt own them) but with that can that be??????????? :( This thing was seriously slaughtering tyres in third gear with a 3.08 diff and was just awesome!!!!!!!!!!!!!!!!!!!!!! I just walked away convinced guy had no idea and was sure this was going to give ma amazing figures that proved that all that money was worth it over the years.

GREAT...But I cant afford the fuel...YET

Set up # 5 40mm trick webers on a three piece manifold warnerford
Dyno guy had an ace up sleeve and pushed me into a trick set of triple dcoe 40mm webers that were in amazing condition and tricked up with additional drillings for air speed compensating and a HUGE set of spares for racing changes etc ( chokes and jets etc)
This is weird...........but these 40mm webers absolutely hauled so hard that I went in after a day of messing around with 2000 bucks in my wallet and hoped for the best not knowing if he wanted to sell them or not.
I asked hime casually if they were for sale and he said he wanted at least 2000, so I now own them. I didnt even dyno this at this stage, it was all about the was like injection on a LS2 v8 , instant, regardless of revs, load or uphill, cornering etc...very hard to describe......but absolutely perfect......dont call me a pussy either, I am trying to give my best description here .

So we dynoed them............196 Hp at 6100rpm, but less is more with this set up, mid range, punch is amazing. Good hex linkages etc and just amazing driveability.


This was a huge task over a few months ok.Every damn change was all about fuel lines , accellerator cables, regulators and enormous amounts of energy and motivation sapping crap to go be warned ok.

What I learned was that driveability is really what I want, to start my car up every week or so and take my 8 yo son out for a drive and get take away and just sit around and go to a few spots with his school mates, who think the LJ GTR is pretty cool.

I want it to start and sound good, not chew through fuel like crazy( 45mm's baby, just hold me back if I do see a cheap set)and have some reliability and good simple linkages etc.

Above all this, If i was going around OZtralia, I would throw that 600 DP in the boot for good measure, typical hollley, just bolt on and it was very very good.

DYNO HP is one thing, mid range and torque is just something totally different hey.


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a good read there, thanks

a good read there, thanks for sharing.

youre damn right you cant beat webers, all the best group n xu-1 and charger racers have them and you just cant beat that induction roar.

the 15 hp you are missing between 40's and 45's is clearly a good trade off for the midrange torque it provides.

all the best!

Dandapalm that was a great

Dandapalm that was a great read and alot of hard work!
Back in the 80's i had a fairly warm 253 in my HJ GTS.
I had a pair of 44 IDF webers on a 3inch adapter plate that were sitting in the shed for about 2 years.
I got bored oneday and fitted them knowing the chokes were too small but what the hell i had to try them.
The sound was amazing and it was addictive to just press the pedal just for the sound.
Apart from not running right(chokes)goddamn like you said...instant power everywhere.
It something that you can never forget.


Good read, I would like to

Good read, I would like to know how Webers would go firsthand, but I think I'll stick to my 150CDs for now. :)

They still go plenty hard enough for me at the moment, sounds and goes a LOT better than the 350 Holley, just floor it and you get this instant surge of torque, good fun outrunning new Commodores up big hills. Bloody dad reckons he dragged off a Landcruiser last night (I was asleep in the car) and easily beat it down the highway, and he tells me not to thrash it. He drives it (a lot) harder than I do! :/

Still, if someone offered me the right money I might sell them and get a set of Webers...


My Shed

Dandapalm. Thanks for the

Dandapalm. Thanks for the read. Its a pity you did not try a Q jet on it. I would have been curious to see what the HP figures would be with one of those on it. I have run one on my 202 HR for a couple of years and have always liked the instant power and the good fuel economy from it. It has the best of both worlds (Well good fuel economy when the right foot is not buried anyway).
My Shed

I still think efi is the go

I still think efi is the go in conjuction with an aftermarket ecu. You can get efi throttle bodys to fit the webber manifold if you wish.

Have you ever played with turbos before?

Great read dandapalm! i'm in

Great read dandapalm! i'm in the market for a new carby for mine at the moment. had SU's but there just to much work for a car that barely gets drivin. got a 350 holley on it now which is a dissapointment. looking at either a 500 2 barrel or a 600 though not sure on bonnet space in the HG. any suggestions?


I'd be happy to recommend a

I'd be happy to recommend a set of triple CD Strombergs. I had no end of trouble with my 350 Holley too, greatest POS ever. I'm still sorting out a few last little problems with them, they aren't even tuned properly yet, and it still goes very quick and I managed to get 10.8L/100km down the highway, 12.5/100km around Sydney and on a squirt down the old Pacific Highway. Mind you, this is with a supra 5 speed (0.78:1 5th) and 3.08:1 diff, but that's still good in my books considering I wasn't taking it real easy.

I've found that the Holley is OK for racing (situations where you are constantly over 3000-3500rpm), but is rubbish for street duties.


My Shed

fuel economy

hey mate, interested in your results,
a few quick questions:
1) fuel economy - when you say it doesen't go through that much fuel, what do you mean? 12L/100km?

2) how much compression are you running?

3) are you running an auto or a manual?

thanks mate

thanks for sharing that mate. i am lookin at building up a 300hp 202 nd you've just got me hooked on triple webers! one there any real gains in going to 48mm webers instead of 45mm with regards to this sort of hp? thanks anyone for your advice

NEW Injection Manifold

If you think webers are tuff. Try Stack fuel Injection (like a hilborn but for a holden 6). I manufacture a Fuel Injection manifold that can be configured with either mechanical or efi. Trumpets or air cleaners, 9 or 12 port. The casting can be machined for 45-50mm throttle blades. All machining is done on the latest CNC machines.
Weber EFI throttle bodies still produce a wet manifold situation that still suffers all the fuel drop out issues the webers do. Our manifold fires the fuel into the head producing a true dry manifold which results in more power. Your 300hp target would be done with ease. If you would like any further info just let me know. This is a brand new product.

Sonic Injection

Got any photo's?

This sounds interesting!

Email Me
My Shed

Sonic Injection



 Big Red Truck Shed

 emergency email
Postcode 4810
K munro, G ute, T wagon, Z

Awesome read!! Do you have

Awesome read!! Do you have the figures for the 40dcoe what size jets venturies etc??

Not very groovy

"and fully grooved main bearings."
REALLY bad idea.
Maybe the upper ones grooved like stock, but not the lowers.
Think tyres on a wet road. Smooth, un-grooved (bald) ones easily don't touch the road but skim along on a thin wedge of water. Grooved tyres easily cut through the water and make contact with the road.

Grooves = contact.
Smooth = separated.

me shed...

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